Shock Flashcards
What is shock?
Broad term that describes a physiologic state where oxygen delivery to the tissues is inadequate to meet metabolic requirements, causing global hypoperfusion. It may also be thought of as an imbalance between tissue oxygen supply and demand.
What is the difference b/w compensated and uncompensated shock?
- Compensated: normal BP with inadequate perfusion
- Uncompensated: hypotension and inability to maintain normal perfusion
What are some types of distributive shock?
Sepsis, anaphylaxis, neurogenic
What are some types of obstructive shock?
(non-cardiac obstruction)
PE, tension PTX, tamponade
*How is the shock index calculated?
What’s a nl range?
HR / sBP
0.5-0.7
Repeated shock index values >___ indicate decreased left ventricular function and are associated with higher mortality.
1.0
How do the following change in cardiogenic shock?
- HR
- CVP
- Contractility
- SVR
- HR: ^
- CVP: ^
- *Contractility: vv
- SVR: ^
How do the following change in hypovolemic shock?
- HR
- CVP
- Contractility
- SVR
- HR: ^
- *CVP: vv
- Contractility: +/- ^
- SVR: ^
How do the following change in distributive shock?
- HR
- CVP
- Contractility
- SVR
- HR: ^
- CVP: vv
- Contractility: +/-
- SVR: v
How do the following change in obstructive shock?
- HR
- CVP
- Contractility
- SVR
- HR: ^
- CVP: +/- ^
- Contractility: +/-
- SVR: ^ (tamponade, PE) or v (tension PTX)
Besides elevated lactate, what other lab suggests a shift to anaerobic metabolism and tissue hypoperfusion?
Decreased serum bicarbonate
What are some lab/radiology signs of end-organ damage in shock?
- elevated creatinine
- abnormal liver function tests
- ARDS/edema on chest x-ray
- arrhythmia/ischemia on EKG
- abnormal cardiac enzymes
- ischemic neurologic changes on CT/MRI
Proper oxygenation is critical in shock tx. Target central venous oxygenation levels above ___%.
70%
*Why might you start a central venous catheter in shock tx?
Can help for rapid fluid and medication delivery, as well as provide invasive monitoring
*In the cardiogenic shock pt with pulmonary edema, in initial resuscitation, what must you be careful about? (1)
Giving fluids
In the shock pt, if volume resuscitation does not improve the patient’s hemodynamic status, what types of medications can you resort to?
Vasoactive medications:
- epinephrine
- norepinephrine
- dopamine
- vasopressin
What are invasive ways to monitor fluid status during shock besides a central venous catheter?
- Urinary catheter
- Intra-arterial BP measurements
How does an intra-aortic balloon pump work?
- Inflate in diastole, improved venous return to the cardiac muscle
- Deflates in systole, decreasing afterload
- Combined, v myocardial O2 demand and ^ O2 supply
Resuscitation of a shock state is thought to be successful when the following occurs: (5)
- *lactate decreases by ______ in the first couple of hours
- normalization of hemodynamic state (BP, HR, and urine output)
- *lactate decreases by half in the first couple of hours
- normal volume status restored
- maximal tissue oxygenation
- resolution of acidosis and return to normal metabolic parameters
What is the usual dispo of the shock pt?
ICU
Despite proper treatment, the mortality rates from shock can exceed ___%.
50%
True or false: SIRS criteria have poor sensitivity and specificity for sepsis.
True
*Define SIRS criteria
- Temp > 38°C (100.4°F) or < 36°C (96.8°F)
- HR > 90
- RR > 20 or PaCO2 < 32 mmHg
- Abnormal WBC: >12,000/µL or < 4,000/µL or >10 bands
*Define sepsis crteria
2/4 SIRS + signs of infection
*Define severe sepsis
Sepsis-induced tissue hypoperfusion
- Elevated lactate (>4) or new organ dysfunction
*Define septic shock
Sepsis-induced hypotension persisting even with fluid resuscitation (*SBP < 90, MAP < 65, or SBP < 40 from baseline)
- Would also therefore meet criterial for severe sepsis
Review some end-organ signs of severe sepsis.
- (SBP)<90 mm Hg or mean arterial pressure <70 mm Hg or a SBP decrease >40 mm Hg or <2 SD below normal for age or known baseline
- Creatinine > 2.0 mg/dl (176.8 mmol/L) or Urine Output < 0.5 ml/kg/hour for > 2 hours,
- Bilirubin > 2 mg/dl
- Platelet count < 100,000,
- Coagulopathy (INR >1.5 or aPTT >60 secs),
- Lactate > 2 mmol/L (18.0 mg/dl)
- Urine output < 0.5 ml/kg/hour
*What is the agreed upon adequate amount of fluid resuscitation before diagnosing septic shock?
30 mL/kg
____________ is the primary method of risk stratification for patients presenting with sepsis.
Lactate
- Correlates with mortality
In sepsis, should abx be initiated before testing at all times?
Not necessarily (studies show it might not matter up to 5 hrs later, so can get studies first to find source often)
*What is involved in early goal directed therapy (EGDT) for sepsis tx?
This involved:
- placement of an arterial line and central venous catheter (CVC),
- titration of IV fluids to achieve a central venous pressure between 8-12 mm Hg,
- titration of vasopressors to achieve a MAP greater than 65 (monitor w/A-line), and
- measurements of central venous oxygen saturation. When low, blood transfusions and dobutamine were administered to raise this level.
What parts of the early goal directed therapy for sepsis protocol might not be needed?
CVC and Scvo2 monitoring for most patients.
**In the sepsis SEP-1 criteria, what is in the 3-hour bundle?
*In the sepsis SEP-1 criteria, what is in the 6-hour bundle?
- Lactate
- BCx before abx administration
- Abx
- 30 ml/kg IV crystalloid for hypotension or lactate ≥ 4 mmol/L. (use caution in patients with ESRD, CHF, and ESLiverD)
- Vasopressors for hypotension -> MAP ≥ 65 mmHg
- Reassess and document volume status after fluids for patients with hypotension that does not respond to fluids or lactate ≥ 4 mmol/L
- Repeat lactate if initial was ≥ 4 mmol/L
In sepsis, must reassess patients frequently because often patients may become hypotensive __-__ minutes after antibiotic administration.
30-60 min
