Chest x-ray (CXR)

Overview: A preop CXR should be used to assess the presence of acute, progressive, or chronic changes in cardiac/pulmonary disease. The decision to obtain a preop CXR should be individualized and based on clinical indications (seeTable A-1). CXRs should not be part of a routine preop screening protocol.
Clinical indications: Pneumonia; pulmonary edema; atelectasis; aortic aneurysm; mediastinal or pulmonary masses; tracheal deviation; pulmonary HTN; cardiomegaly; advanced COPD and blebs; dextrocardia; pulmonary embolism.

Electrocardiogram (ECG)

Overview: ECGs evaluate cardiac rhythm/conduction disturbances, ischemia, myocardial infarction, hypertrophy, and metabolic and electrolyte disorders.
Clinical indications: Patients with suspected or known Hx of CAD; patient age > 50; HTN; hx of dysrhythmias, chest pain; CHF; diabetes; OSA, cerebral vascular disease and PVD; syncope or presyncope; dizziness; SOB; DOE; PND; palpitations; leg/ankle edema; abnormal valvular murmurs.

Liver function test (LFT)

Overview: LFTs establish the absence or presence of hepatic injury and the degree of hepatic reserve in disease states. LFTs consist of: AST(SGOT), ALT(SGPT), GGTP, alkaline phosphatase, serum albumin, and bilirubin.
Clinical indications: Patients with suspected or known Hx of hepatitis (viral, alcohol, drugs); infiltration (tumor, immunologic); cirrhosis; portal HTN; gallbladder or biliary tract disease; jaundice; intravascular hemolysis.

Renal function testing

Overview: Renal function testing measures glomerular filtration and the magnitude of renal tubular dysfunction. These tests include: serum creatinine and BUN.
Clinical indications: Renal function testing is indicated for patients with HTN; increased fluid overload (CHF/peripheral edema/ascites) associated with cardiac, hepatic, or renal impairment; dehydration; diabetes; nausea, emesis, or anorexia; polyuria; nocturia; oliguria; anuria; high-risk surgery in patients with low CO syndrome; hematuria; costovertebral angle pain: renal transplant Hx; renal disease; dialysis.

Hemoglobin (Hb), Hematocrit (Hct), CBC

Overview: The decision to obtain a preop Hgb, Hct, or CBC should be individualized and based on clinical indications, medical Hx, and the proposed surgical procedure. Hgb/Hct or CBC should not be part of a routine preop screening protocol.
Clinical indications: Hematological disorder; bleeding/coagulopathy Hx; malignancy; chemotherapy; radiation therapy (CBC); renal disease; anticoagulant and steroid therapy; surgical procedures with high blood loss (> 1500 mL); highly invasive or trauma surgery; malabsorption/poor nutrition status; CNS disease.

Pregnancy testing

Overview: The decision to obtain a preop pregnancy test should be based on clinical Hx and examination. Several assays are available (serum hCG, urine hCG); β-hCG detectable in maternal urine and blood 8–9 d postconception.
Clinical indications: Sexually active; time of last menstrual period; presence or absence of birth control method; patient intuition

Coagulation testing

Overview: Coagulation testing, or clotting function studies, should be obtained in patients with known or suspected coagulopathies as indicated from H&P and drug therapies. Tests include: prothrombin time (PT), partial prothrombin time (PTT). INR, platelet (Plt) count.
Clinical indications: Bleeding disorder Hx; anticoagulants or other drugs affecting coagulation; critical-risk surgeries with significant blood loss expected; hepatic disease: malabsorption/poor nutrition

Urine analysis

Overview: Assessment of renal function, infection, intravascular volume status, metabolic disorders
Clinical indications: There are no routine anesthesia preop requirements for a urine analysis.

Table A-1. Diagnosis-Based Preop Testing

Table A-2. Recommendations for Perioperative Beta-Blocker Therapy (Adapted from the AHA/ACC Recommendations for Perioperative Beta-Blocker Therapy Based on Published Randomized Clinical Trials (1))

Blood pressure (BP)

Usually noninvasive (oscillometric) technique. Match cuff width to arm size to avoid inaccurate BP.

Capnometry/capnography

Measurement of ETCO₂/display of wave form

Gas analyzer (e.g., IR, mass spectometry)

Measurement of respired gases and anesthetics

Electrocardiogram (ECG)

5-lead preferred. Usual display: lead II and V_{4 or 5}

Esophageal or precordial stethoscope

Breath and heart sounds monitored; dysrhythmias and DBP may be detected. Seldom used today, because sound competes with more useful pulse oximetry sound

Nerve stimulator

Monitor status of neuromuscular blockade

Oxygen analyzer

Measurement of FiO₂

Pulse oximetry

Measurement of O₂ saturation of hemoglobin; also gives a pulse sound that indicates heart rate, rhythm, and change in saturation

Temperature

Nasal, esophageal, bladder, rectal, tympanic, or skin

Visual observation of patient

Skin color, pupils, temperature, edema, sweating, movement

Ventilator function monitors

PIP, TV, disconnect alarm, pressure-volume/flow-volume loops, etc.

Light

Midazolam 1–2 mg iv
Lorazepam 1–2 mg
Hydroxyzine 25–100 mg

po 1 h preop
po 1 h preop

Moderate

Midazolam 2–3 mg iv
± Fentanyl 25–100 mcg iv

Prior to induction (in patient holding area or OR)
Monitor for respiratory depression or apnea.

Heavy

Diazepam 10 mg
+ Morphine 0.1 mg/kg
with Scopolamine 0.2–0.4 mg

po 1–2 h preop
im 30–60 min preop

Preinduction

1. [check mark] anesthesia machine, suction, airway equipment, drugs.

2. Attach monitors and verify function.

3. Administer 100% O₂ by mask × 1–3 min.

4. Administer supplemental sedation/analgesia (as appropriate).

e.g.: fentanyl
± midazolam

1–3 mcg/kg iv
0.03–0.1 mg/kg iv

Induction agents

Propofol

1.5–2.5 mg/kg iv (in increments) NB: Pain on injection may be lessened by prior administration of lidocaine 1% 5–10 mL.

Thiopental

3–5 mg/kg iv

Etomidate

0.2–0.4 mg/kg iv NB: Pain on injection; myoclonus

Muscle relaxants for intubation

Drugs

Doses

Onset

Duration

Vecuronium

Rocuronium
Pancuronium
Mivacurium
Cisatracurium
Succinylcholine:
If given after defasciculating dose of NMR
Infusion

0.1 mg/kg
0.2 mg/kg (rapid onset)
0.6–1.2 mg/kg
0.1 mg/kg
0.1–0.2 mg/kg
0.2 mg/kg
1.0 mg/kg
1.5 mg/kg


1 g/250–500 NS (titrated to effect)

2–3 min
< 2 min
45–90 sec
3–4 min
1–2 min
2 min
30–60 sec
30–60 sec


+60 sec

24–30 min
45–90 min
30–120 min
40–65 min
6–10 min
40–80 min
4–8 min
4–8 min


While infusing (phase II block possible)

Inhalational anesthesia

30–100% O₂
+ 0–70% N₂O
+ Isoflurane (MAC in 100% O2 = 1.17%) or Sevoflurane (MAC = 1.8%) titrated to effect
Alternatively for short procedures, consider desflurane (MAC = 6.6%)

Balanced anesthesia

30–100% O₂
+ 0–70% N₂O
+ Meperidine 0.5–1.5 mg/kg/3–4 h (intermittent bolus)
or morphine 0.05–0.15 mg/kg/3–4 h (intermittent bolus)
or fentanyl 1–10 mcg/kg prn response to surgical stimulation
or remifentanil 0.05–2 mcg/kg/min prn response to surgical stimulation (no residual analgesia)
+ Isoflurane or sevoflurane titrated to effect
or propofol 50–200 mcg/kg/min (titrated to effect)
Alternatively, for short procedures consider desflurane (MAC = 6.6%).

Total intravenous anesthesia (TIVA)¹

Oxygen 30% in N₂O (continue 70% N²O until end of procedure)

+ Remifentanil infusion*
(infusion off 2–5 min before end of surgery)
+ Propofol bolus + infusion
(infusion off 2–5 min before end of surgery)

Induction infusion
Maintenance infusion
Induction bolus
Maintenance infusion

@ 0.5–1 mcg/kg/min × 1–2 min
@ 0.05–0.2 mcg/kg/min
1–1.5 mg/kg
@ 40–80 mcg/kg/min

Oxygen 100%; Can add air 50%, but it seldom offers any advantage

+ Remifentanil infusion*

Induction infusion

@ 0.5–1 mcg/kg/min × 1–2 min

(infusion off 5 min before end of surgery)

Maintenance 10 min before end surgery

@ 0.1–0.35 mcg/kg/min
@ 0.05–0.1 mcg/kg/min

+ Propofol bolus + infusion

Induction bolus

1–1.5 mg/kg

(infusion off 2–3 min before end of surgery)

Maintenance 10 min before end surgery

@ 60–90 mcg/kg/min
@ 20–40 mcg/kg/min

*No residual analgesia: postop pain management depends on type of surgery, and analgesic requirements may be substantial. Recommend having fentanyl or meperidine for quick pain relief followed by morphine or dihydromorphone for prolonged pain relief.
¹Steven Shafer, MD
Source:

Short-acting

Mivacurium

0.1 mg/kg/10–20 min or 1–15 mcg/kg/min

Intermediate

Vecuronium
Rocuronium
Cisatracurium

0.025 mg/kg/30 min
0.6 mg/kg/30 min
0.2 mg/kg/40 min

Long-acting

Pancuronium

0.02 mg/kg/60–90 min

1. Reversal of muscle relaxant

As surgical conditions permit, reverse residual muscle relaxant (when at least 1 twitch is present in train-of-four) with one of the following:
Neostigmine 0.05–0.07 (maximum dose) mg/kg iv + glycopyrrolate 0.01 mg/kg iv, or Edrophonium 0.5–1.0 (maximum dose) mg/kg iv + atropine 0.015 mg/kg iv.

2. Analgesia

If remifentanil was used during surgery, supplemental analgesics will be necessary and should be given promptly after emergence.

3. Nausea prophylaxis

Ondansetron (4 mg iv) (or dolasetron (12.5 mg iv), or granisetron (100 mcg iv). Also, consider adding dexamethasone 4–8 mg and/or metoclopramide (10–20 mg iv). The use of droperidol (0.625 mg iv) is unfortunately controversial because of effects on cardiac conduction at higher doses. Consider OG tube placement and suction to empty stomach. See Prevention of PONV (below).

4. O₂

D/C N²O/volatile agents and administer 100% O².

5. Suction

Suction oropharynx thoroughly.

6. Extubation

Extubate after protective airway reflexes have returned, the patient is breathing spontaneously, and is able to follow commands.

Advantages:

Disadvantages:

A.

Midazolam (0.5–2 mg) ± Ketamine (10–20 mg) ± alfentanil 3–7 mcg/kg
or

Profound amnesia and analgesia.
Usually no apnea and airway reflexes maintained.

Patient not “asleep.”
Timing is important.
Possible ↑BP and HR

remifentanil 0.5 mcg/kg all injected 2–3 min before pain:
or

Patient usually able to cooperate.

B.

STP (1–2 mg/kg) or propofol (0.5–1 mg/kg)

Patient “asleep” ± fentanyl (25–50 mcg/kg)

Possible apnea with loss of airway
↓ BP
Patient unresponsive.

1. ↓gastric volume/acidity

Ranitidine 50 mg iv at least 30–60 min before induction
Metoclopramide 10 mg iv 30–60 min before induction
0.3 M sodium citrate 30 mL po immediately before induction

2. Induction

Preoxygenation = 3 min. Suction must be readily available. Stylet ETT.
± Defasciculate: e.g., vecuronium 1 mg iv 3–5 min before using succinylcholine.
Cricoid pressure (Sellick maneuver) by assistant (8–10 lb pressure; beware of force transfer to C6 vertebra). Effective cricoid pressure makes laryngoscopy, mask ventilation, and LMA insertion difficult. Consider Trendelenburg position with graded release of cricoid pressure during laryngoscopy.
Choice of induction agent depends on patient condition including hemodynamic stability. Options include:
Etomidate 0.1–0.4 mg/kg
Or

Ketamine 1 mg/kg
or for patients better able to tolerate ↓ BP:
STP 2–5 mg/kg
Or
Propofol 1–2.5 mg/kg
+ Succinylcholine 1.5 mg/kg or rocuronium 1.2 mg/kg (slightly slower onset) for intubation
Lungs may be ventilated while waiting for NMB—avoid airway pressure > 20 cm H²O

3. Intubation

Intubate only when the patient is fully relaxed.
Watch chest movement and auscultate for equal BBS.
[check mark] expired CO² on monitor.
Listen over stomach.
Secure ETT and release cricoid pressure.
Pass NG/OG tube and suction stomach contents.

4. Failed intubation protocol

[See Anesthetic Considerations for Cesarean Section, Obstetric Surgery, 823.]

5. Maintenance

As indicated by patient's condition and type of surgery.

6. Extubation

Repeat NG/OG suction is often useful before emergence and extubation. Extubate when patient is awake and has active laryngeal protective reflexes. Remember, some may require postop ICU care until safe extubation can be assured.

Premedication

If not contraindicated, patients should receive mild-to-moderate sedation with meperidine 0.5 mg/kg or fentanyl 0.3–0.5 mcg/kg and midazolam 2–4 mg iv.

Topical anesthesia

When premedication has been established, for awake FOI the oropharynx is sprayed vigorously ~ 6 times over a span of 10 min with lidocaine 4% solution using a disposable EZ spray unit powered with oxygen. Initially, the spray is directed at the front of the tongue; gradually, it is directed further back in the throat, until the entire oropharynx is numb. Having the patient inhale deeply while spraying enhances the topical effect. In reality, the lateral recesses of the oropharynx need not be anesthetized topically because both fiberoptic laryngoscope (FOL) and ETT are confined to the midline of the mouth.

Tracheal anesthesia

With patient breathing oxygen from anesthesia circuit or transport mask, transtracheal injection of cocaine or lidocaine 4% (4 mL) is made through the cricothyroid membrane, using a 5-mL syringe and a 23-ga, 3/4-inch needle. So that this injection can be made as rapidly as possible, it is important to use a small syringe, making certain that the connection between syringe and needle is tight. It is important that the operator's hand be fixed firmly against the patient's upper chest to assure that needle movement is minimized should the patient start to cough, and that the full injection is made into the trachea. When the injection is complete, the patient is urged to cough vigorously.

Laryngoscopy

After the mouth and trachea are anesthetized with local anesthetic, an oral airway with a central orifice (e.g., Tudor-Williams, Patel, Ovassapian airway) is placed in the midline of the mouth. A 7-mm orotracheal tube, without connector attached, is placed over a FOL. With the operator at the patient's side near the waist, the FOL is introduced through the hole in the airway and advanced to end of airway. At this point, the epiglottis should be visible. The tip of the fiber optic scope is flexed toward the operator about 15–20°, which should bring arytenoid cartilages and laryngeal opening into view. The scope is advanced into the larynx so that tracheal rings can be visualized. Often, the carina also can be visualized. The laryngoscopist also can place the scope in the airway by darkening the room and using the scope as a light wand, directing the light externally to the sternal notch and advancing it down the trachea. If a wire-reinforced tube is desired, use a Patel or Ovassapian airway instead of the Tudor-Williams airway for guidance, because these airways can be removed with the tube connector in place.

Intubation

The scope is placed on the patient's chest and, holding it so that it not advanced further, the orotracheal tube is advanced gently into the trachea. To facilitate passage of the orotracheal tube past the arytenoid cartilages and into the larynx, it is necessary to rotate the tube counterclockwise 90°—or even as much as 180°—several times as it is being advanced.
Using this rotational movement, the operator should never need to push hard on the tube to position it in the larynx. After the tube is in place, the FOL and oral airway are removed, and the 15-mm connector is reattached to the tube. ETCO₂ confirms proper placement. The orotracheal tube is then firmly taped in place at one side of the mouth.
If manual ventilation of the lungs is possible, it is often beneficial for both patient and anesthesiologist to perform FOI with the patient anesthetized. This is particularly true for patients with cervical spine injuries where manipulation of the head during direct laryngoscopy or coughing during topicalization of the airway or insertion of the tube during awake FOI may aggravate the spinal cord injury. Asleep FOI involves inducing GA, inserting an LMA, and placing the patient on controlled ventilation. Then proceed with Plan C (see ref 4). In brief, a 6.0 uncuffed tube is mounted on the FOI, the FOI is inserted into the trachea using the LMA as a guide, and the 6.0 tube is lubricated and inserted into the laryngeal opening. The FOI is removed and the lungs ventilated via the 6.0 tube. A medium sized airway exchange catheter (AEC) is lubricated on one end and inserted into the trachea via the 6.0 tube. The AEC usually meets resistance at the distal end of the 6.0 tube. If this occurs, rotate the 6.0 tube while pushing on the AEC. Once the AEC is a few cm beyond the tip of the 6.0 tube, the tube and LMA are removed en-block leaving the AEC in the airway. With the AEC in the far right corner of the mouth, thread the final endotracheal tube on the AEC and gently advance it through the mouth into the larynx, rotating it counterclockwise to avoid obstruction from the right arytenoid cartilage. Then remove the AEC and connect the ETT to the anesthetic circuit.

PONV risk factors

Patient-related

Female gender
Nonsmoking status
H/o PONV/motion sickness

Simple Risk Score for PONV in Adults: assign 1 point for each of the following risk factors: female gender, nonsmoker, hx of PONV, postop opioids. Risk of PONV: point sum 0 = 10%; 1 = 20%; 2 = 40%; 3 =6 0%, and 4 = 80%.

Anesthetic-related

Volatile anesthetics
Nitrous oxide
Intra/postop opioids
High dose neostigmine

Surgical-related

Duration of surgery
Type of surgery

Each 30 min → in duration → PONV risk by 60%
Laparoscopy, laparotomy, breast, strabismus, plastic, maxillofacial, gynecologic, abdominal, neurologic, ophthalmologic, urologic

Antiemetics

Pharmacologic Agents

Timing of administration

Serotonin blockers

End of surgery

Ondansetron 4 mg iv, Granisetron 0.35–1.5 mg iv, Dolasetron 12.5 mg iv

Dexamethasone 4–8 mg iv

At induction

Adverse effects not seen with single bolus dose.

Droperidol 0.625–1.25 mg iv

30 min before end of surgery

Consider risk of Q-T prolongation and cardiac dysrhythmias especially at higher doses. Risk low at dose range of 0.625–1.25 mg iv.

Promethazine 6.25–25 mg iv

30 min before end of surgery

Sedating and may cause local tissue damage if iv catheter infiltration occurs.

Metoclopramide 10–20 mg iv

30 min before end of surgery

Can cause anxiety, confusion, or visual changes.

Prochlorperazine 5–10 mg iv

30 min before end of surgery

Scopolamine transdermal patch

2–4 h before surgery

May cause sedation, dry mouth, visual changes, and confusion, especially in the elderly

Ephedrine 0.5 mg/kg IM

End of surgery or as rescue rx in PACU

Nonpharmacologic

Acupuncture, acupressure

Before or after surgery

PONV prevention strategies

↓ anesthesia-related RF's

Consider regional anesthesia where appropriate
Propofol for induction/maintenance where appropriate
Avoid/minimize N²0 and volatile agents
Avoid/minimize postop opioids
Avoid high-dose neostigmine
Adequate hydration

PONV risk stratification and management

Low risk

No prophylaxis→treat PONV when it occurs.

Intermediate risk

Choose 1–2 interventions

High risk

Choose 2 interventions

Weak

Moderate

Strong

Varicose veins

Cancer or myeloproliferative disorders

Surgery (e.g., hip/leg fx)

Immobility

Central venous catheterization

Major trauma

↑Age

Hypercoagulable state

Spinal cord injury

Acute medical illness

Pregnancy postpartum

Smoking

Estrogen therapy

Inflammatory bowel disease

Heart or respiratory failure

Obesity

Oral contraceptives

Pregnancy

Previous VTE

Malignancy

Level of risk

Successful prevention strategies

Risk profiles/examples

Low risk

No specific prophylaxis, early and “aggressive” mobilization

Minor surgery in patients < 40 yr with no additional risk factors.

Moderate risk

LDUH (q 12 h), LMWH (= 3400 U daily), GCS, or IPC

Minor surgery in patients with additional RFs or surgery in patients 40–60 yr with no additional RFs.

High risk

LDUH (q 8 h), LMWH (> 3400 U daily), or IPC

Surgery in patients > 60 yr or age 40–60 with additional RFs (prior VTE, cancer, hypercoagulable, etc.)

Highest risk

LMWH (> 3400 U daily), fondaparinux, oral VKAs (INR, 2–3), or IPC/GCS + LDUH/LMWH

Surgery in patients with multiple RFs (age > 40 yr, cancer, prior VTE), or hip or knee arthroplasty, HFS major trauma; SCI

Analgesics

Morphine
Meperidine
Hydromorphone
Fentanyl
Ketorolac^{see note 2 below}

2 mg/10 min, up to 10 mg iv
10 mg/10 min, up to 150 mg iv; not to exceed (NTE) 600 mg/d
0.5–1 mg/10–20 min, up to 6 mg
12.5–35 µg/5 min, up to 200 mcg iv
30 mg iv slowly; then 15 mg q 6 h × 3 d max

Lumbar Epidural

Thoracic Epidural

Loading dose

Morphine

Hydromorphone

Morphine

Hydromorphone

Lower extremities

2–3 mg

0.4–0.6 mg

—

—

Pelvis

3–4 mg

0.5–0.8 mg

1–3 mg

0.15–0.4 mg

Abdomen

5–7 mg

0.5–1 mg

2–3.5 mg

0.2–0.6 mg

Thorax

7–8 mg

0.5–1 mg

2–3.5 mg

0.4–0.8 mg

Infusion

Morphine

Hydromorphone

Morphine

Hydromorphone

Lower extremities

0.3–0.5 mg/h

0.1–0.2 mg/h

—

—

Pelvis

0.3–0.5 mg/h

0.1–0.2 mg/h

0.1–0.3 mg/h

0.1–0.15 mg/h

Abdomen

0.4–0.7 mg/h

0.2–0.3 mg/h

0.2–0.5 mg/h

0.1–0.2 mg/h

Thorax

0.5–1.0 mg/h

0.2–0.3 mg/h

0.2–0.6 mg/h

0.15–0.2 mg/h

Surgical Site

Epidural Catheter Location

Initial Bolus of 0.5% Bupivacaine

Infusion Rate of 0.125% Bupivacaine

Thoracic or upper abdomen

T6-T8

4–6 mL

5–10 mL/h

Lower abdomen

T10

10 mL

15 mL/h

Hip or knee

L2-3

8 mL

10 mL/h

Loading dose

Morphine
Hydromorphone
Fentanyl

Titrate to comfort
Titrate to comfort
Titrate to comfort

Basal rate

Morphine
Hydromorphone
Fentanyl

0.5–1 mg/h
0.1–0.2 mg/h
5–10 mcg/h

PCA lock-out dose and time

Morphine
Hydromorphone
Fentanyl

1–2 mg q 10–15 min
0.1–0.2 mg q 10–15 min
5–10 mcg q 10–15 min

Loading dose

Morphine
Hydromorphone
Fentanyl

2–3 mg
0.5–1.0 mg
50–75 mcg

Basal rate

Morphine
Hydromorphone
Fentanyl

0.2–0.5 mg/h
0.08–0.12 mg/h
5–10 mcg/h

PCA lock-out dose and time

Morphine
Hydromorphone
Fentanyl

0.1–0.2 mg q 10–15 min
0.02–0.06 mg q 10–15 min
5–10 mcg q 10–15 min

o Morphine

0.15 mg/mL

o Hydromorphone

0.05 mg/mL

o Fentanyl

10 µg/mL

STANDARD PEDIATRIC MONITORS (NONINVASIVE)

Blood pressure (BP)

Capnometry/capnography

Measurement of ETCO₂ display of wave form

Gas analyzer (e.g., Raman, IR, or mass spectroscopy)

Measurement of respired gases and anesthetics

Electrocardiogram (ECG)

5-lead preferred

Esophageal or precordial stethoscope

Breath and heart sounds monitored; dysrhythmias and ↓BP detected

Nerve stimulator

Monitor status of neuromuscular blockade

Oxygen analyzer

Measurement of FiO₂

Pulse oximetry

Measurement of O₂ saturation; 2 pulse oximeters in neonates–1 preductal; 1 postductal

Temperature

Nasal, esophageal, rectal, or skin

Visual observation of patient

Skin color, pupils, temperature, edema, sweating, movement

Ventilator function monitors

PIP, TV, disconnect alarm, etc.

STANDARD PREOP FASTING (NPO) GUIDELINES

· All solid foods and nonclear liquids (e.g., milk, infant formula, orange juice) should be withheld after midnight before scheduled surgery.

· All clear liquids (and breast milk) should be given up to 3 h before scheduled surgery. Because breast milk has a relatively short transit time through the stomach, and to simplify—therefore, to increase compliance with—these guidelines, breast milk is considered a clear liquid.

· In practice, nonemergency cases may proceed 6 h after solids and nonclear liquids and 2 h after clear liquids and breast milk have been ingested.

Preinduction

1. [check mark] anesthesia machine, suction, airway equipment, drugs.

2. Attach monitors and verify function.

3. Premedication: < 6–9 mo—consider atropine 0.01–0.02 mg/kg iv before laryngoscopy to prevent vagally mediated bradycardia.

Induction

Routes of administration:

1. im: ketamine hydrochloride 3–5 mg/kg (with atropine 0.02 mg/kg)

2. iv: Propofol 2–3 mg/kg
STP 4–7 mg/kg

3. Inhalational: sevoflurane (MAC = 3.3% for neonates and younger infants, 2.5% for older infants and children) and halothane (MAC = 0.87% for neonates, 1–2% for infants), in N₂O (up to 70%)/O₂. Increase inspired concentration of sevoflurane incrementally every 3 breaths (up to 8%) and halothane (up to 4%). Monitor BP and HR closely, especially if using halothane.

Muscle relaxation

1. Rocuronium: 0.6–1 mg/kg iv; 1 mg/kg recommended for rapid sequence induction. If airway concerns exist, consider awake intubation, use of succinylcholine.

2. Succinylcholine: 1–2 mg/kg iv or 2–4 mg/kg im (controversial*). May be useful for rapid-sequence intubations, especially if airway concerns exist.

3. Vecuronium or pancuronium: 0.1 mg/kg iv

4. Cisatracurium 0.1 mg/kg iv

5. Deep sevoflurane or halothane anesthesia

Laryngoscope

*Succinylcholine may trigger MH in susceptible patients or cause cardiac arrest in myopathic patients; therefore, many pediatric anesthesiologists avoid the use of succinylcholine.

Age

Wt

Uncuffed ETT size

Cuffed ETT size

Premature
Newborn

1–3 kg
3–4 kg

2.5 or 3.0
3.5

n/a
3.0

≥ 6–8 mo

6–8 kg

3.5 or 4.0

3.0 or 3.5

≥ 8–16 mo

10–12 kg

4.0 or 4.5

3.5 or 4.0

2–3 yr

13–15 kg

4.5

4.0 or 4.5

6 yr

20

Formula (uncuffed tubes): 4+ (age/4) = ETT size (to allow for a slight leak when positive pressure is applied). For cuffed tubes, use 0.5 size smaller and inflate as necessary to attain leak of 20–30 cm H₂O.

9 yr

30 kg

12 yr

40 kg

Inhalational anesthesia only

30–100% O₂
+ 0–70% N₂O. In preemies and for cases where N₂O is contraindicated, air may be used to lower FiO₂.
+ Isoflurane, sevoflurane or halothane, titrated to effect.
Consider warming and humidifying all gases for long cases. Warm room to 75–80°F for infants; 70–75°F for children.

Balanced anesthesia

30–100% O₂
+ 0–70% N₂O
+ ~0.5% isoflurane
or propofol (50–200 mcg/kg/min)
TIVA - propofol 100–200 mcg/kg/min, + remifentanil 0.1–0.2 mcg/kg/min +/- N₂O if procedure allows. Consider including amnestic agents: midazolam, low-dose inhalational agents (e.g., sevoflurane, isoflurane).
+ morphine (0.05 mg/kg/h) or fentanyl (1–3 mcg/kg/h) + Dilaudid 2 mcg/kg/h
+ consider acetaminophen pr 30–40 mg/kg for pain control.
Temperature monitoring; forced air warming; fluid warming if volume/blood/resuscitation expected.
Fluid requirements LR/NS at maintenance:
0–10 kg = 4 mL/kg/h
+11–20 kg = 2 mL/kg/h
+>20 kg = 1 mL/kg/h (e.g., 25 kg = 65 mL/h)
If continued muscle relaxation is required during the above maintenance techniques, several options are available. Always use a nerve stimulator to assess block before redosing.

Short-acting

Mivacurium 0.1 mg/kg → 6–10 min

Intermediate

Vecuronium 0.1 mg/kg → 25–30 min
Rocuronium 0.6 mg/kg → 30 min
Cisatracurium 0.1 mg/kg → 30 min

Long-acting

Pancuronium 0.1 mg/kg → 40–65 min

1. Reverse muscle relaxant

As surgical conditions permit, reverse residual muscle relaxant (when at least 1 twitch is present in train-of-four) with one of the following:

· Neostigmine 0.05–0.07 (maximum dose) mg/kg iv + glycopyrrolate 0.01 mg/kg iv, or

· Edrophonium 0.5–1.0 (maximum dose) mg/kg iv + atropine 0.01 mg/kg iv.

Enlon Plus - 0.05–0.1 mL/kg is equal to edrophonium 0.5–1 mg/kg (max: 10 mg), atropine 0.007–0.014 mg/kg (max: 4 mg).

2. Nausea prophylaxis

Ondansetron 0.1 mg/kg iv or Metoclopramide 0.1 mg/kg iv (~1 h before emergence).
Dexamethasone 0.1 mg/kg can be considered (avoid in oncology patients due to special protocols).

3. O₂

D/C N₂O/volatile agents and administer 100% O₂.

4. Suction

Suction oropharynx thoroughly.

5. Extubation

Laryngeal spasm is common in children; therefore, it is usual to extubate them when they are awake, moving all limbs, and breathing adequately. Infants and children with full stomachs or difficult airways must be extubated when they are fully awake. The pharynx and stomach should be suctioned thoroughly prior to extubation. If laryngeal spasm occurs, Rx with 100% O₂ and CPAP or PPV. If spasm fails to resolve and hypoxemia occurs, give succinylcholine 0.1–0.5 mg/kg and administer PPV. Consider reintubation if hypoxemia fails to resolve quickly. Consider atropine 0.01–0.02 mg/kg iv before succinylcholine, to preempt bradycardia.

Pain assessment

Unlike most adults, infants and children < 7 yr have difficulty understanding and using a Visual Analog Scale (VAS). A frequently used tool for assessing pain in children 3–7 yr old is the Wong-Baker Faces Scale (Fig. E-1). For infants and nonverbal children, observational scales that rely on behavioral and/or physiologic parameters are often used (e.g., the FLACC Pain Scale, Fig. E-2, PIPP, NIPS, CHEOPS, CRIES as well as appropriate translations). The “gold-standard” of pain measurement is to solicit a direct subjective report from the child whenever possible.

Oral medications

For simple outpatient procedures, such as tonsillectomy, hernia repair, circumcision, or closed reduction of a fracture, a weak oral opiate, in combination with acetaminophen, is appropriate (see chart for dosing examples, p. E-4).

Intravenous medications

Patient Controlled Analgesia (PCA) can be considered in patients > 5 yr who are expected to remain hospitalized overnight, especially in those who are unlikely to tolerate oral intake in the initial hours after surgery (see initial dosing chart, p. E-4). For younger children, a Nurse Controlled Analgesia (NCA) can be employed. When the patient begins oral medications, D/C the basal rate but continue to provide the lockout dose for several more hours to be sure that the child is tolerating the oral medication. For opioid-related side effects such as nausea and vomiting, ondansetron can be added (0.1 mg/kg q 6 h to maximum of 4 mg q 6 h), and for pruritus, diphenhydramine (0.5 mg/kg q 6 h max 50 mg), or nalbuphine (0.05 mg/kg q 6 h max 20 mg), especially effective for epidural opioid-related pruritus. For respiratory depression, naloxone can be carefully titrated beginning at 0.001 mg/kg q 1–2 min as needed to restore adequate respiratory effort and wakefulness. Care must be taken, as the naloxone will have a short half-life (10–15 minutes), and respiratory depression may recur. Reversal of analgesia may also occur if naloxone is administered for treatment of pruritus or respiratory depression.

Adjuvant medications

In addition to opiates, several adjuvant medications are useful in the periop period. Lorazepam (Ativan) 0.025 mg/kg iv q 6 h is useful in preventing spasms and lessening fear in an unfamiliar environment. It is important to remember that lorazepam has a half-life of up to 16 h and doses can be additive.
Another useful adjuvant is ketorolac (Toradol) 0.5 mg/kg, up to a maximum of 30 mg loading dose, followed by 15 mg iv q 6 h, up to 72 h. Ketorolac is not recommended in patients with poor renal function or following surgeries where there is a large bleeding surface or complex bone repair. Ketorolac has been shown to cause delay in bony fusion in animal models, but conflicting information has been presented in humans. It also has been reported to cause acute renal failure with prolonged use, and is not recommended for use in bariatric patients due to its potential adverse impact on renal function. Given these concerns, it is helpful to observe hydration status, Plt count, and Cr, and discuss the use of this medication with the surgical team.
Other adjuvants to consider include acetaminophen po (10–15 mg/kg/dose q 6 h) or pr (20 mg/kg/dose q 6). An initial loading dose of 30–40 mg/kg pr administration for post-op pain may be helpful. Ibuprofen 10 mg/kg po dose also may be used. Medications to manage side effects, such as pruritus, N/V, constipation, and respiratory depression are presented in detail on the PCA order form, p. E-5.

Figure E-1. Wong-Baker Faces Scale used in pain assessment in children (and other patients developmentally from 3–7 years-old). The higher the score, the greater the child's pain. (After Wong DL, Bakr CM: Pain in children: comparison of assessment scales. Pediatr Nurs 1988; 14:9.)

Epidural pain management

In children, it is generally considered safer to place epidurals after induction of GA to avoid movement during placement. For children 0–12 mo, a caudal technique can be used. The patient is placed in the lateral decubitus position, the caudal anatomy is identified, and an 18-ga iv catheter is used to enter the caudal space. The catheter is advanced and aspirated. The space is then dilated with 5–8 ml of preservative-free NS. A 20-ga epidural catheter is then advanced to the desired location, or until obstruction is felt (~10–15 cm). The catheter tip may be visualized using ultrasound or nerve stimulation, if available. The catheter is taped secured with a moisture-resistant dressing, as it can easily become dislodged with regular activity. A test dose is given (lidocaine 1.5% with 1:200,000 epinephrine 0.1 ml/kg + 0.8 ml for the dead space of the catheter). Lumbar and thoracic epidurals can be placed in children > 10–12 mo. or earlier in experienced hands. Contraindications for epidural catheters include infection at the local site, coagulopathy, low Plt, sepsis, progressive neurologic deficit, and refusal of patient or parent.
Epidural placement should be checked by syringe aspiration before starting the infusion. Return of any bloody fluid or > 0.5 ml clear aspirant necessitates further evaluation before use of the catheter for pain control. Patients with indwelling epidural catheters may receive postop analgesia with either continuous infusion alone of continuous infusion with intermittent bolus dosing (patient-controlled epidural analgesia [PCEA]). Similar to PCA, PCEA can be used in ages ≥ 5–7 yr. Typical starting infusions are discussed in the table below. Medication dosage will depend on patient's age, location of surgical pain, catheter insertion level, and catheter tip location.
A bolus dose equivalent to the hourly volume of infusion may be given when a patient is uncomfortable. Increase the infusion by 10% to maintain the new level of analgesia. Infusion should not exceed 0.3 ml/kg/h in children ≥ 6 mo or 0.5 ml/kg/h in older patients. If inadequate analgesia persists after two dosing increases, it may be appropriate to abandon this form of treatment in favor of systemic analgesia. Do not leave a patient in pain for an extended period of time trying to “fix” an epidural catheter. If in doubt, check catheter placement then bolus catheter with 2% lidocaine w/ 1:200,000 epi 0.1 ml/kg to determine if a level is able to be obtained.

Peripheral Nerve Catheters

Increasingly, peripheral nerve catheters are being employed for peri-operative pain control. Local anesthetic infusions (bupivacaine 0.1% or ropivacaine 0.2%) are continued for 3–5 days postop.

Figure E-2. FLACC Pain Scale for pain assessment in non-verbal patients. By Merkel S, Voepel-Lewis T, Shayevitz JR, Malviya S. et al. Am J Nursing 2002; 102:55–8.

Common PCA Medications

Medication

Loading dose

Basal Rate

Patient-controlled bolus

Morphine (1 or 5 mg/ml)

0.03 mg/kg

0.01 mg/kg/h

0.02–0.03 mg/kg

Hydromorphone (100 mcg/ml)

5 mcg/kg

1 mcg/kg/h

2 mcg/kg

Fentanyl (50 mcg/ml)

0.3 mcg/kg

0.1 mcg/kg/h

0.2–0.3 mcg/kg

Age

Starting dose

0–6 mo

hydromorphone 3 mcg/ml + 0.1% bupivacaine @ 0.1–0.15 ml/kg/h (max bupiv 0.3 mg/kg/h); for neonates, consider 0.1% bupivacaine infusion only

6 mo–3 yr

hydromorphone 3 mcg/ml + 0.1% bupivacaine @ 0.1–0.15 ml/kg/h (max bupiv 0.5 mg/kg/h)

3–7 yr

hydromorphone 3–5 mcg/ml + 0.1% bupivacaine @ 0.1–0.15 ml/kg/h (max bupiv 0.5 mg/kg/h)

≥ 7 yr

hydromorphone 5–10 mcg/ml + 0.1% bupivacaine @ 0.1–0.15 ml/kg/h + 0.05 ml/kg/h PCEA dose q 30 min lockout (max bupiv 0.5 mg/kg/h)

Notes:
In general, use a lower concentration of opiate infusion for neonates. When spread is desired (for surgeries with incisions that cross multiple dermatomes or when catheter placement is below the level of anticipated pain), a lower concentration and higher volume infusion may be desired.

Preop Drug or Drug Class

Anesthetic Drug or Drug Class

Interaction

Clinical Management

Adrenergic agonists (Sympathomimetics)

Inhalation anesthetics

↑ risk of dysrhythmia

Monitor rhythm.

Alteplase

Nitroglycerin

Impaired thrombolytic effect

Avoid combination.

Alfentanil

Propofol

Opisthotonus, seizure

Avoid combination.

Aminoglycosides

Fluorinated inhalation agents

↑ potential for nephrotoxicity 2° to fluoride

Monitor renal function postop.

NMR (nondepolarizing muscle relaxants)

↑ blockade, possible prolonged respiratory depression

Support respiration.

Succinylcholine

↑ depolarizing blockade

Delay administration of aminoglycoside for as long as possible after recovery. Support respiration.

Amiodarone

Inhalation anesthetics

Enhanced myocardial depression and conduction defects

Monitor HR and rhythm.

Phenylpiperidone derivative opiate agonists (alfentanil, fentanyl, sufentanil)

↓ HR, ↓ BP, sinus arrest

Monitor hemodynamic function. Administer inotropic, chronotropic, and pressor agents as indicated. Large doses of vasopressors may be required. Bradycardia usually not responsive to atropine.

Amphetamines

Opiate agonists

↑ analgesia

Titrate dose of opiate.

Antacids

Oral medications

Delayed drug absorption 2° to delayed gastric emptying

Avoid administration within 2 h of each other.

Anthracyclines including doxorubicin, daunorubicin, idarubicin, epirubicin

Isoflurane

Prolonged QT interval

Monitor HR & rhythm.

Antibiotics, polypeptide (bacitracin, capreomycin, colistimethate, polymyxin B)

NMR, Succinylcholine

↑ blockade, possible prolonged respiratory depression Colistimethate and polymyxin B may have independent NMB activity.

Support respiration. Consider calcium gluconate to reverse blockade prolonged by colistimethate.

Anticholinergics, including drugs with an anticholinergic adverse effect profile

Opiate agonists

Potential for central or peripheral anticholinergic syndrome

Monitor for effects.

Anticholinesterase inhibitors, including donepezil, galantamine, rivastigmine, tacrine + opthalmics

Succinylcholine
Mivacurium

Blockade may be prolonged or antagonized.

Titrate to therapeutic effect. Monitor and support respiration.

NMR

↓ blockade

Titrate to therapeutic effect

Antifungal agents, azole systemic (fluconazole, itraconazole, ketoconazole, voriconazole)

Alfentanil

Inhibition of alfentanil metabolism

Monitor for respiratory depression. Consider lower dosage.

Midazolam

Prolonged CNS depression

Titrate midazolam to effect. Consider lower dosage

Aprotinin

NMR

Prolonged or recurring apnea

Monitor respiratory status.

Aprepitant

Phenylpiperidone derivative opiate agonists

↑ opiate effect

A lower dose may provide appropriate analgesia.

Aprepitant

Midazolam

↑ midazolam effect

A lower dosage may provide appropriate sedation.

Arsenic Trioxide

Inhalation Anesthetics

Prelong QT Interval

Monitor HR & Rhythm

Atorvastatin

Midazolam

↑ midazolam effect

A lower dosage may provide appropriate sedation.

Barbiturates

Inhalation anesthetics

↑ respiratory depression

Monitor and support respiration.

Ketamine

↑ respiratory depression

Monitor and support respiration.

Meperidine

Possible increase in normeperidine formation

↓ analgesic duration ↑ potential for seizure

Midazolam

Synergy

Monitor for CNS depression.

Opiate agonists

↑ respiratory depression

Monitor and support respiration.

Benzodiazepines

Barbiturates

Synergy

Titrate doses.

Bupivacaine

Sz threshold raised masking signs of toxicity

Monitor for symptoms of bupivacaine toxicity.

NMR

May prolong or antagonize blockade

Monitor and support respiration.

Opiate agonists

May decrease respiration and BP

Monitor and support respiration and BP.

Beta Blockers

NMR

May potentiate, delay or antagonize blockade

Titrate to effect. Monitor and support respiration.

Bosentan

Propofol

Propofol is a CYP3A4 strong inhibitor

Monitor ↓ BP

Botulinum toxins

NMR

↑ blockade

Titrate NMR to therapeutic effect.

Bupivacaine

Chloroprocaine

Enhanced bupivacaine toxicity

Avoid combination!

Calcium channel blockers

NMR

↑ blockade

Titrate NMR to therapeutic effect.

Propofol

↓ BP

Monitor BP

Calcium channel blockers-nondihydropyridine (diltiazem, verapamil)

Phenylpiperidone derivative opiate agonists

Enhanced bradycardia and ↓ BP

Monitor HR & BP

Midazolam

Enhanced midazolam effect

Consider dose reduction of midazolam

Carbamazepine

Diltiazem, Verapamil

Potential for CNS toxicity

Monitor for symptoms of CNS toxicity.

Midazolam

↓ effect of midazolam due to enzyme induction

Titrate midazolam to effect.

NMR

↓ blockade

Titrate NMR to therapeutic effect.

Cimetidine

Opiate

↑ CNS depression due to possible CYP 3A4 interaction

Titrate opiate to effect. If needed use naloxone.

Clindamycin

NMR

↑ blockade

Avoid combination if possible. Monitor and support respiration. Anticholinesterases or Ca⁺⁺ may be beneficial.

Clonidine

Esmolol

Attenuation or reversal of antihypertensive effect

Monitor BP.

Clonidine, epidural

Local anesthetics

Prolonged sensory and motor blockade

Titrate dose of local anesthetics.

Conivaptan

Midazolam

Enhanced midazolam effect due to conivaptan strong CYP3A4 inhibition

Titrate to effect

Phenylpiperidone derivative opiate agonists

Enhanced opiate effect due to conivaptan strong CYP3A4 inhibition

Titrate to effect

Propofol

Enhanced propofol effect due to conivaptan strong CYP3A4 inhibition

Titrate to effect

Corticosteroids

Anticholinesterases

Possible antagonism of reversal agents

Monitor and support respiration.

NMR

Altered effectiveness of blockade

Titrate NMR to therapeutic effect.

Cyclophosphamide

Succinylcholine, Mivacurium

↑ blockade, even if patient received cyclophosphamide in past few weeks

Titrate to therapeutic effect. Monitor and support respiration.

Cyclosporine

NMR

↑ blockade

Titrate to therapeutic effect. Monitor and support respiration.

Dantrolene

Propofol

↑ muscle weakness due to inhibition of dantrolene metabolism

Monitor for hypotension.

Delavirdine

Phenylpiperidone derivative opiate agonists

↑ opiate effect

Consider dose reduction. Titrate to therapeutic effect.

Digoxin

Esmolol

↑ digoxin toxicity

Monitor for symptoms of toxicity.

NMR

Precipitate new dysrhythmias or potentiate existing dysrhythmias

Monitor rhythm.

Succinylcholine

Precipitate new dysrhythmias or potentiate existing dysrhythmias

Monitor rhythm.

Disulfiram

Inhalation anesthetics

Reduction in gas metabolism

Monitor for increased effect of inhalation agent.

Dobutamine

Inhalation anesthetics

Ventricular arrhythmias

Monitor HR and rhythm.

Dofetilide

Sevoflurane

Prolonged QT intervals

Monitor HR & rhythm

Echothiophate iodide (ophthalmic)

Succinylcholine

Prolonged blockade

Consider dose reduction or alternative NMB

Erythromycin (also see macrolide)

Midazolam

↑ CNS depression

Titrate dose of midazolam.

Esmolol

Alpha/Beta adrenergic agonists

↑ pressor effects

Infiltrating larger volumes of local anesthetics may have clinical relevance.

Estrogens

Succinylcholine

↑ blockade

Titrate NMR to therapeutic effect.

Ethanol

Barbiturates

Acute ingestion →CNS depression; chronic ingestion → tolerance

Avoid combination as tolerance is unpredictable.

Benzodiazepines

Acute ingestion →CNS depression; chronic ingestion →tolerance

Titrate dose of benzodiazepines.

Phenylpiperidone derivative opiate agonists

Chronic alcohol consumption→ pharmacodynamic tolerance

Titrate dose of opiate.

Fluvoxamine

Ropivacaine

Inhibition of CYP1A2 metabolism

Monitor for ropivacaine toxicity.

Furazolidone

Adrenergic agonists

↑ pressor sensitivity due to MAOI activity of furazolidone

Avoid combination! In hypertensive crisis, consider phentolamine.

Meperidine

Risk of MAOI/meperidine interaction

Avoid combination!

Gabapentin

General anesthetic agents

Case report of myotonia & dystonia

Monitor for potential adverse reactions.

Imatinib (tyrosine kinase inhibitor)

Midazolam

↑ midazolam effect

Consider dose reduction. Titrate to effect.

Propofol

↑ effect of propofol

Consider dose reduction. Titrate to effect.

Inhalation anesthetics, halogenated

Epinephrine

Increased cardiac irritability

Limit or reduce dosage of epinephrine with local anesthetics.

NMR

↑ blockade

Titrate dose of both agents.

Isoniazid (INH)

Enflurane

Fast acetylators of INH facilitate defluorination of enflurane →high output renal failure

Monitor renal function postop.

Halothane

↑ hepatotoxicity

Avoid giving rifampin-INH after halothane anesthesia.

Phenylpiperidone derivative opiate agonists

↑ opiate effect

Monitor for respiratory depression.

Ketamine

Halothane

↓ BP, ↓ CO

Monitor BP.

NMR

↑ blockade

Monitor and support respiration.

Labetalol

Beta-2 agonists

↓ bronchodilatation

Monitor for bronchospasm.

Inhalation anesthetics, halogenated

↓ BP

Monitor BP. Titrate anesthetic to effect.

Lidocaine

Cocaine

Possible ↓ in metabolic clearance of lidocaine

Monitor for lidocaine toxicity.

Meperidine

Risk of MAOI/ meperidine interaction

Avoid combination!

Linezolid

Adrenergic agonists

↑ pressor sensitivity due to MAOI activity of linezolid

Avoid combination! In hypertensive crisis, consider phentolamine.

Lithium

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Local anesthetics (large doses)

NMR

↑ blockade

Titrate NMR to effect. Monitor and support respiration.

Loop diuretics (including bumetanide, ethacrynic acid, furosemide, torsemide)

NMR

Blockade may be prolonged or antagonized; possibly dose-dependent, ↓ K⁺ → ↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Macrolide antibiotics including azithromycin, clarithromycin, erythromycin

Alfentanil

↑ effect of alfentanil

Titrate dose of alfentanil. Monitor and support respiration.

Macrolide antibiotics, including erythromycin, clarithromycin. But NOT azithromycin

Midazolam

↑ effect of midazolam

Titrate dose of midazolam. Monitor and support respiration.

NMR

Case reports of potentiation of blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Magnesium, parenteral

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Mercaptopurine

NMR

May ↓ or reverse blockade

Titrate NMR to therapeutic effect.

Methotrexate

Nitrous oxide

Potentiation of cytotoxic effects

Avoid before or during methotrexate treatment

Methyldopa

Ephedrine

↓ ephedrine effect

Consider alternative pressor agent.

Naloxone

Naloxone may precipitate a mild ↑ BP

Monitor BP.

Metoclopramide

Succinylcholine, NMR

↑ blockade

Titrate succinylcholine to therapeutic effect. Monitor and support respiration.

Monoamine oxidase inhibitor (MAOI); selective MAO Type B may have a lower risk.
Antidepressants MAOI: Isocarboxazid, phenelzine, tranylcypromine.
Anti-Parkinson agents MAO
Type B: rasagiline, selegiline

Meperidine

Agitation, Sz, diaphoresis, hyperpyrexia, coma, apnea

Avoid combination! Although other opiate agonists may not have these associated problems, monitoring is prudent.

Succinylcholine, mivacurium

↑ blockade

Titrate succinylcholine to therapeutic effect. Monitor and support respiration.

Sympathomimetics (including local anesthetic/epinephrine combinations, and cocaine)

Indirect- or mixed-acting sympathomimetic may cause severe HA, hyperpyrexia, or hypertensive crisis. (Direct-acting sympathomimetics appear to interact minimally.)

Avoid combination! Treat ↑ BP with phentolamine.

Muscle relaxants, skeletal

Anticholinesterase inhibitors

Possible severe muscle weakness

Monitor neuromuscular blockade. Titrate dose of anticholinesterase.

Nefazodone

Midazolam

↑ effect of midazolam due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Phenylpiperidone derivative opiate agonists

↑ effect of opiate due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Propofol

↑ effect of propofol due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Nicardipine

Midazolam

↑ effect of midazolam due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Phenylpiperidone derivative opiate agonists

↑ effect of opiate due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Propofol

↑ effect of propofol due to strong inhibition of CYP3A4

Monitor and titrate to effect.

Nitrates, including NTG

Pancuronium

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Omeprazole

Midazolam

Possible enhanced ataxia or sedation due to ↓ clearance of midazolam

Monitor for prolonged effect of midazolam.

Opiate agonists

NMBs

↑ potential for opiate toxicity

Titrate dose of opiate.

Propofol

↓ BP

Titrate dose of each agent.

Succinylcholine

↓ HR

Monitor HR, heart block

Oxytocic drugs (including oxytocin, ergotamine, methylergonovine)

Adrenergic agonists

↑ BP 2° to synergistic vasoconstrictive effects

Titrate dosage. Monitor BP.

Pegvisomant

Opioids

Influences therapeutic efficacy of pegvisomant

May need dosage adjustment of pegvisomant.

Phenothiazines

Alpha/Beta adrenergic agonists

↓ alpha-adrenergic effects

Potential for dysrhythmias.

Barbiturate anesthetics

↑ neuromuscular excitation ↓ BP

Monitor BP.

Opiate agonists

↓ analgesic effect

Titrate opiate to effect.

Phenoxybenzamine

Local anesthetics

↑ absorption of local anesthetic

Titrate dose; possibly add epinephrine to local anesthetic.

Phenytoin (including fosphenytoin)

Midazolam

Enzyme induction

Titrate midazolam to effect. May need to ↑ dosage.

NMR

Reduced duration of blockade

Consider cisatracurium. Titrate NMR to therapeutic effect.

Phosphodiesterase 5 inhibitors (sildenafil, tadalafil, vardenafil)

Nitroglycerin

Enhanced vasodilation

Separate dose by at least 24 h (timing depends on specific agent) Half life may be prolonged by drug interactions, renal, hepatic impairment.

Piperacillin (including piperacillin/ tazobactam sodium)

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Probenecid

Thiopental

↑ CNS depression

Titrate dose of thiopental.

Procaine, procainamide

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Succinylcholine

↑ blockade 2° to competition for pseudocholinesterases

Titrate NMR to therapeutic effect. Monitor and support respiration.

Propofol

Alfentanil

Alfentanil may enhance the adverse effects of propofol

Monitor for opisthotonos and/or Sz.

Atracurium

Bronchospasm

Anaphylactoid-type reaction

Succinylcholine

↓ HR

Monitor HR. Consider atropine premed when propofol precedes succinylcholine.

Vecuronium

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Protease inhibitors except tipranavir

Phenylpiperidine derivative opiate agonists

↑ fentanyl levels due to CYP3A4 enzyme inhibition

Monitor respiration.

Midazolam

↑ midazolam levels

Titrate midazolam to effect. Contraindicated with amprenavir and ritonavir.

QTc Prolonging Agents
Public website for listing:
http://www.qtdrugs.org, International Registry Drug-Induced Arrhythmias; University of Arizona Health Sciences Center, Tucson, AR

Inhalation anesthetics

Effects can be additive with enhanced/advertise/toxic profile

Conduct a risk assessment Monitor rate and rhythm

Quinine, quinidine

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Succinylcholine

↑ blockade

Use this combination with caution.

Ranitidine

NMR

Possible resistance to NMR

Titrate dosage. Consider another NMR.

Rasagiline

Meperidine

Risk of MAOI/meperidine interaction

Avoid combination!

Reserpine

Sympathomimetics

↑ direct-acting agents; ↓ indirect-acting agents

Monitor BP.

Rifamycin derivatives including rifampin, rifabutin, rifapentine

Alfentanil

↑ clearance of alfentanil

Titrate alfentanil to effect. Increased dosage may be needed.

Halothane

↑ risk of hepatotoxicity

Avoid administration of rifampin-INH after halothane anesthesia.

Midazolam

Enzyme induction

Titrate midazolam to effect. May need to ↑ dosage.

Selective serotonin reuptake inhibitors (SSRIs)

Opiate agonists

Unknown mechanism

Monitor for serotonin syndrome.

Adrenergic agonist agents

Potential for serotonin syndrome

Monitor for serotonin syndrome.

Selegiline

Meperidine

Risk of MAOI/meperidine interaction

Avoid combination!

Sevoflurane

Drugs that prolong the QT interval

Synergy

Monitor heart rate and rhythm.

Sibutramine

Phenylpiperidine derivative opiate agonists

Package insert caution

Monitor for serotonin syndrome.

Sotalol

Sevoflurane

Prolonged QT intervals

Monitor rhythm.

Succinylcholine

Anticholinesterase inhibitors

↑ blockade

Use combination with caution. Titrate NMR to therapeutic effect. Monitor and support respiration.

Succinylcholine

Opioids

↓ HR

Monitor for bradycardia/heart block.

Tetracycline

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Theophylline

Halothane

↑ catecholamine-induced dysrhythmias

Use alternative inhalation agent.

Ketamine

Sz

Use combination with caution.

NMR

Resistance to blockade

Titrate NMR to effect.

Midazolam

↓ midazolam effectiveness

Titrate midazolam to effect.

Propofol

Possibly antagonized sedation

Titrate propofol to effect.

Thiazide diuretics

NMR

↑ blockade may be 2° to hypokalemia

Correct hypokalemia. Titrate NMR to effect.

Thiopental

Succinylcholine

Possible disseminated intravascular coagulation

Use large veins. Flush tubing with saline. Wait 2–3 min between administration.

Thiotepa

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Tricyclic antidepressants

Adrenergic agonist agents

↑ direct-acting agents;↓ indirect-acting agents

Monitor BP and rhythm. Effect unlikely in dose administered as infiltration with local anesthetics.

Fentanyl

Potentiation of fentanyl

Titrate opiate agonist to effect.

Trimethaphan

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Succinylcholine

↑ blockade

Avoid combination! Use nitroprusside instead.

Vancomycin

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Succinylcholine

↑ blockade

Avoid administering vancomycin in the postanesthesia period.

Verapamil

Etomidate

↑ respiratory depression, apnea

Monitor and support respiration.

Midazolam

Deep and prolonged sedation

Monitor CNS and respiratory status.

NMR

↑ blockade

Titrate NMR to therapeutic effect. Monitor and support respiration.

Plant

Precautions for Anesthesia and Surgery

Aloe vera

May impair hemostasis.

Bilberry (Vaccinium myrtillus)

May impair hemostasis.

Black cohosh (Cimicifuga racemosa)

Potential for hypotension.

Bladderwrack (Fucus vesiculosus)

May impair hemostasis.

Cat's Claw (Uncaria tomentosa)

May impair hemostasis.

Cayenne (Capsicum annum)

Has biological effect of ↑ catecholamine secretion.

Chamomile. German (Matricaria chamomilla)

May enhance CNS depression.

Coleus (Coleus forskohlii)

May impair hemostasis. Has potential for hypotension.

Devil's claw (Harpagophytum procumbens)

May have chronotropic and inotropic effects. May impair hemostasis.

Dong quai (Angelica sinensis)

May impair hemostasis. May cause vasodilation.

Echinacea

May increase the sedative effect of midazolam.

Ephedra ma huang (Ephedra sinica)

Potent sympathomimetic may cause cardiac arrhythmias.

Evening primrose (Oenothera biennis)

May impair hemostasis.

Fenugreek (Trigonella foenum-graecum)

May impair hemostasis. Contains coumarin.

Feverfew (Tanacetum parthenium)

May impair hemostasis.

Fish oils

May impair hemostasis.

Garlic (Allium sativum)

May inhibit Plt aggregation; potential for enhanced ↓ BP.

Ginger (Zingiber officinale)

May → prolonged bleeding time; possible ↑ catecholamine secretion; cardioactive in large and prolonged doses.

Ginkgo (Ginkgo biloba)

Selective antagonist of Plt aggregation; may cause vasodilation.

Ginseng, American (Panax quinquefolius)

May impair hemostasis.

Ginseng, Panax (Panax ginseng) root

Dose-dependent effects on BP. May cause tachycardia. May impair hemostasis.

Ginseng, Siberian (Eleutherococcus senticosus)

May impair hemostasis. Use barbiturates with caution. May affect BP.

Golden Seal (Hydrastis Canadensis)

May impair hemostasis. Potential for hypotension and bradycardia. May alter liver enzymes.

Grapefruit

Cytochrome P450 (CYP3A4) inhibition. Onset of midazolam may be delayed and action increased.

Grape seed (Vitis vinifera)

May impair hemostasis.

Green tea (camellia sinensis)

May impair hemostasis.

Guggul (Commiphora mukul)

May impair hemostasis.

Hawthorn (Crataegus oxyacantha)

High doses may cause hypotension + CNS depression.

Horse chestnut (Aesculus hippocastanum)

May impair hemostasis. Has cholinergic properties.

Kava kava (Piper methysticum)

Synergy with midazolam.

Licorice (Glycyrrhiza glabra)

May impair hemostasis. Mineralocorticoid effect

Melatonin

May enhance CNS depressants.

Passion flower (Passiflora spp)

Synergy with CNS depressants.

Red clover (Trifolium pratense)

May impair hemostasis. Contains coumarins.

Reishi (Ganoderma lucidum)

May impair hemostasis.

Schisandra (Schizandra chinensis)

Inducer of Cytochrome P450 enzyme system.

St. John's wort (Hypericum perforatum)

May have some MAOI activity. May reduce midazolam levels due to enzyme induction. Delayed emergence from anesthesia with propofol.

Tumeric (Curcuma longa)

May impair hemostasis.

Valerian (Valeriana officinalis)

Potentially synergistic with opiates & CNS depressants, including thiopental.

White willow (Salix alba)

Salicylate, may impair hemostasis.

Yohimbe (Corynanthe yohimbe) (Pausinystalia yohimbe)

May cause CNS stimulation. May have cardiovascular effects.

Figure H-1. P6 Acupoint. P6 is located three fingerbreadths proximal to the wrist crease directly over the median nerve and between the tendons of palmaris longus and flexor carpi radialis. For PONV prophylaxis, the two nerve stimulator electrodes can be placed over the median nerve at (1) a point proximal to the wrist crease (marked with an x) 2 cm proximal to P6, and (2) on P6 or 1 cm distal to the P6 point. Stimulus parameters: 1Hz, 0.2ms, 50 mA during anesthesia.