Approach
• ABCs: Always address airway/breathing prior to circulation
• Differentiate hypotension from shock
Definition
• Hypotension: BP below pt’s baseline, often defined as SBP <90 mmHg
• Shock: Insufficient perfusion pressures for organs’ metabolic needs
History
• AMS, CP, SOB
Findings
• ↓ BP, ↑ HR, hypoxia, ↑ RR, UOP <1 mL/kg/h
Evaluation
• CBC, Chem 7, PT/PTT, cardiac markers, LFTs, blood gas, lactate, T/S, stool guaiac, ECG e/o ischemia
• POC ultrasonography: RUSH (Rapid Ultrasound in Shock, Emerg Med Clin N Am 2010;28:29) protocol incorporates a 3-part bedside physiologic assessment simplified as:
• the pump (POC cardiac US to assess for pericardial effusion, global LV contractility, relative size of LV to RV)
• the tank (POC IVC US to asses respiratory dynamics of IVC & volume status, as well as lung, pl & abdominal US to assess for pathology that could alter vascular volume; ie, PTX, pl effusion, free intra-abdominal fluid)
• the pipes (POC thoracic & abdominal aortic US to assess for AD/AAA & LE compression US to assess for DVT)
Treatment
• Priority should be to obtain adequate IV access. If peripheral large-bore IVs cannot be placed in timely manner, consider IO (humeral/tibial/sternal) or stat central venous access w/ large internal diameter catheters (ie, cordis).
• Priority should be to restore hemodynamics before time-consuming diagnostic w/u:
• 1–2 L of isotonic crystalloid infusion as rapid as possible (ie, on pressure bag if indicated)
• Consider stat uncrossmatched blood in life-threatening hemorrhage; consider using rapid infuser device; consider permissive hypotension in hemorrhagic shock
• Consider peripheral vasoactive agents if persistently hypotensive after IVF bolus as bridge to obtaining central venous access
• Use MS, UOP, & MAP as early e/o adequate end-organ perfusion
Pearls
• Not all hypotension is clinically significant. Use clinical context, pt’s baseline BP, & check the BP cuff.
• Pulses provide a marker of baseline SBP, but may overestimate the absolute value (BMJ 2000;321:673)
Approach
• Dehydration is a Dx of exclusion; consider other etiologies (hemorrhage, ectopic pregnancy, etc.)
Definition
• Intravascular volume depletion → ↓ perfusion, most commonly 2° blood loss
History
• Trauma, melena, hematochezia, hematemesis, ↓ PO intake
Findings
• E/o trauma, guaiac + stool, pelvic exam
Evaluation
• As above +UA/HCG, FAST (blood in abdomen or chest); consider CT chest/abd/pelvis, pelvic US, type/screen
Treatment
• Identify/treat cause, IV fluid bolus; consider PRBCs; consult immediately for life-threatening disorders requiring definitive tx (surgery, GI, OB/Gyn)
Disposition
• Admit vs. OR
Approach
• Consider intubation early, look for & treat underlying cause
Definition
• ↓ CO + nl intravascular volume → ↓ systolic contractility + ↑ diastolic filling
Findings
• ↑ HR, ↓ BP, ↑ RR, hypoxia, pulmonary rales, S3, S4
Evaluation
• CBC, Chem 7, Ca, Mg, PO4, ECG, CXR, stat echo (systolic/diastolic dysfxn, papillary muscle rupture, ventricular wall rupture, VSD, pericardial effusion, R heart strain)
Treatment
• Treat underlying dz, IV fluids (if ↓ intravascular volume)
• Dopamine: ↑ myocardial contractility & BP, but ↑ O2 demand
• Dobutamine: ↑ HR & inotropy, less O2 demand, but causes vasodilation (best if not tachycardic or severely hypotensive)
• Central venous catheter: Consider for CVP monitoring, administration of pressors
• Cardiology consult
• Revascularization: Early revascularization → ↓ mortality (NEJM 1999;341:625; JAMA 2001;285:190)
• Other: Thrombolytics, IABP, ventricular assist device
Disposition
• Admit to ICU
(NEJM 2006;355:1699)
Approach
• Identify & treat early → best outcomes when treated w/i 6 h
• Look for source of infection
Definition
• Sepsis = SIRS (severe inflammatory response syndrome) + source infection
• SIRS: ≥2 of the following: Temp ≥38°C or ≤36°C, HR ≥ 90, RR ≥ 20, WBC (≥12000, ≤4000, or >10% bands)
• Severe sepsis: Sepsis + sepsis-induced hypoperfusion (hypotension persisting after initial fluid challenge or blood lactate >4 mmol/L) or organ dysfxn (see organ dysfxn variables below)
• Septic shock: Severe sepsis + ↓ BP despite adequate fluid resuscitation
Evaluation
• CBC w/ diff, Chem 10, LFTs, lactate, blood (×2)/urine/sputum culture, PT/PTT, cardiac markers, VBG, CXR; consider CT brain/LP, CT chest &/or abdomen, RUQ US based on pt
• Consider 1,3 beta-D-glucan assay & galactomannan assay if available & invasive candidiasis is in the DDx as cause of infection
Treatment
• EGDT (NEJM 2001;345:1368); ↓ mortality/hospital stay in 1 study, though no prospective validation study
• Protocolized quantitative resuscitation of pts w/ sepsis-induced hypoperfusion. Goals during the 1st 6 h:
• CVP 8–12 mmHg → crystalloid (NS or LR) is the initial fluid of choice; initial fluid challenge 30 cc/kg; consider albumin when pts require substantial IVFs
• Central venous access should be obtained as soon as practical
• MAP ≥65 mmHg → use of vasopressors, whereby:
• Norepinephrine is 1st choice
• Epinephrine (added to or substituting NE) when additional agent needed
• Vasopressin 0.03 U/min can be added to NE to raise MAP or decrease NE dose
• Dopamine as alternative to NE only in highly selected pts (low-risk arrhythmia)
• Phenylephrine not recommended except special circumstances
• Arterial catheter should be placed as soon as practical
• UOP ≥0.5 mL/kg/h
• Foley catheter should be placed as soon as practical for I/O monitoring
• ScvO2 or mixed venous O2 saturation 70% or 65%, respectively
• Trial of dobutamine up to 20 mcg/kg/min should be given or added to vasoactive agent in the presence of myocardial dysfxn (elevated filling pressure/low CO) or ongoing signs of hypoperfusion, despite CVP & MAP goals (ScvO2 <70%)
• Abx: Broad spectrum, given prior to drawing cultures (cover gram+, gram–, anaerobes; consider double coverage for pseudomonas)
• Start abx w/i 1 h of recognition, regardless of whether source is known
• Source control
• ?Hydrocortisone: Consider hydrocortisone use in pts w/ severe sepsis refractory to IV fluids & pressors; corticotropin test + routine steroid use → no benefit & possibly harm (NEJM 2008;358:111); when given, use continuous flow
• Blood products: PRBCs to target Hgb 7–9 g/dL; Platelets if <10000 μLμ−μ1 w/o bleed, <20000 μLμ−μ1 w/ risk of bleeding, <50000 μLμ−μ1 for active bleeding, surgery, procedure
• Oxygenation/ventilation: Supplemental O2; consider need for intubation early; if intubated use VTs of 6 cc/kg predicted BW (NEJM 2000;342:1301) use of sedation/paralytics → ↓ O2 consumption
• Glucose control: q1–2h measurements; initiate protocolized blood glucose management when 2 consecutive measurements >180 mg/dL to a target <180 mg/dL
• Renal replacement therapy: Use continuous therapies (ie, CVVH) to facilitate managing fluid balance in HD unstable pts
• Activated protein C: Use is controversial; ↓ mortality in severe sepsis based on 1 phase 3 trial (NEJM 2001;344:699; Crit Care Med 2003;31:12), but ↑ bleeding, ↑ cost, & no benefit in less sick (APACHE II <25) populations (NEJM 2005;353:1332); recently taken off market
Disposition
• Admit
Guideline: Dellinger RP, Levy MM, Rhodes A, et al. Surviving sepsis campaign: International guidelines for management of severe sepsis and septic shock: 2012. Crit Care Med. 2013;41(2):580–637.
Approach
• Cervical spine injury → risk of apnea, may require intubation; evaluate according to ATLS (19c)
Definition
• Transection of the spinal cord → disruption of sympathetic pathways → loss of vascular sympathetic tone → vasodilation (typically cervical or high thoracic lesions)
History
• Trauma w/ severe injury to the spinal cord
Findings
• ↓ HR, ↓ BP, anesthesia, paralysis below a sp dermatome; saddle anesthesia, ↓ rectal tone, areflexia, Horner syndrome, absent bulbocavernosus reflex, priapism (unopposed PNS stimulation)
Evaluation
• CT spine (esp cervical, thoracic); consider CT head, chest, abd/pelvis if h/o trauma
Treatment
• C-spine immobilization: Aspen or Philadelphia collar for prolonged immobilization
• Strict log-roll precautions
• IV fluids: Prior to starting pressors
• Vasopressors: Dopamine, norepinephrine, phenylephrine
• Consult neurosurgery immediately
Disposition
• Admit
Pearl
• Any trauma pt w/ hypotension should be suspected of having hemorrhagic shock until proven o/w, thus neurogenic shock should be treated if suspected but should not be the primary DDx in the hypotensive trauma pt.