Category: Pharmacology & Therapeutics
Keywords: ketamine, shock index, hemodynamic, prehospital, RSI (PubMed Search)
Ketamine is often thought to be the induction agent least associated with hypotension in the peri-intubation period. However, reports of hypotension following ketamine do exist, including 2 cases of cardiac arrest.  There are limited objective means to predict which patients may have an adverse hemodynamic response.
A new prospective observational study followed 112 patients in the prehospital setting who received ketamine for rapid sequence intubation. 81 had a low shock index [< 0.9], 31 had a high shock index. 
Shock index = HR / SBP
What They Found
Patients with a high shock index were more likely to experience hypotension (SBP < 90 mm Hg) in the peri-intubation period compared to those with a low shock index (26% vs 2%).
Application to Clinical Practice
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