The Poison Review

High-dose insulin: A consecutive case series in toxin-induced cardiogenic shock. Holger JS et al. Clin Toxicol 2011;49:653-658.

Abstract  

This observational case series, from Regions Hospital in St. Paul MN, retrospectively reviewed charts of patients seen by the toxicology service and treated for toxin-induced cardiogenic shock over an approximately 3 year period (February 2007 – March 2010). Cardiogenic shock was diagnosed if a patient exhibited signs or symptoms of organ hypoperfusion. Treatment of these patients was guided by a protocol that used high-dose insulin as the primary intervention and attempted to  avoid vasopressors.

The authors identified 12 cases. Cardiovascular toxins included:

• beta-blockers (BB, 5 patients)
• calcium-channel blockers (CCB, 2 patients)
• combined BB and CCB overdose (2 patients)
• tricyclic antidepressant (1 patient)
• polydrug overdose (2 patients)

Although the number of cases was so small — and baseline clinical characteristics and supplementary therapeutic interventions so heterogeneous — that no solid conclusions can be drawn from the data, the authors make the following important points

1. Experimental data suggest that vasopressors are not beneficial and possibly harmful in toxin-induced cardiogenic shock.
2. Insulin is not a vasopressor but rather a positive inotrope and a vasodilator.
3. When monitoring treatment of these patients, following mean arterial pressure (MAP) as a primary indicator can be misleading, since cardiac output can decrease even as MAP increases, especially when vasopressors are used.
4. A more important goal is to follow signs indicating adequate tissue perfusion: improved mental status, increased skin warmth and color, good urine output).

The one patient who failed high-dose insulin therapy had known hypertrophic cardiomyopathy. The authors point out that in this condition positive inotropes may increase obstruction of aortic outflow.  When this patient’s mental status deteriorated when the rate of insulin infusion was increased, intravenous fat emulsion was administered with good response.

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