Cardiac rescue with intra-aortic balloon counterpulsation in refractory shock due to acute meningococcemia

Meningococcemia Presenting as a Myocardial Infarction

Neisseria meningitidis is an encapsulated gram negative diplococcus that colonizes the nasopharynx and is transmitted by aerosol or secretions with the majority of cases occurring in infants and adolescents. Meningococcemia carries a high mortality which is in part due to myocarditis. Early recognition and prompt use of antibiotics improve morbidity and mortality. We report a 55-year-old male presenting to the emergency department with chest pain, shortness of breath, and electrocardiogram changes suggestive of ST elevation MI who developed cardiogenic shock and multisystem organ failure from N. meningitidis. We present this case to highlight the unique presentation of meningococcemia, the association with myocardial dysfunction, and the importance of early recognition and prompt use of antibiotics.

Effects of intra-aortic balloon counterpulsation in a model of septic shock

BACKGROUND

Fluid refractory septic shock can develop into a hypodynamic cardiovascular state in both children and adults. Despite management of these patients with empirical inotropic therapy (with or without a vasodilator), mortality remains high.

OBJECTIVES

The effect of cardiovascular support using intra-aortic balloon counterpulsation was investigated in a hypodynamic, mechanically ventilated canine sepsis model in which cardiovascular and pulmonary support were titrated based on treatment protocols.

METHODS

Each week, three animals (n = 33, 10-12 kg) were administered intrabronchial Staphylococcus aureus challenge and then randomized to receive intra-aortic balloon counterpulsation for 68 hrs or no intra-aortic balloon counterpulsation (control). Bacterial doses were increased over the study (4-8 x 10(9) cfu/kg) to assess the effects of intra-aortic balloon counterpulsation during sepsis with increasing risk of death.

MAIN RESULTS

Compared with lower bacterial doses (4-7 x 10(9) colony-forming units/kg), control animals challenged with the highest dose (8 x 10(9) colony-forming units/kg) had a greater risk of death (mortality rate 86% vs. 17%), with worse lung injury ([A - a]O2), and renal dysfunction (creatinine). These sicker animals required higher norepinephrine infusion rates to maintain blood pressure (and higher FIO2) and positive end-expiratory pressure levels to maintain oxygenation (p < or = 0.04 for all). In animals receiving the highest bacterial dose, intra-aortic balloon counterpulsation improved survival time (23.4 +/- 10 hrs longer; p = 0.003) and lowered norepinephrine requirements (0.43 +/- 0.17 microg/kg/min; p = 0.002) and systemic vascular resistance index (1.44 +/- 0.57 dynes/s/cm5/kg; p = 0.0001) compared with controls. Despite these beneficial effects, intra-aortic balloon counterpulsation was associated with an increase in blood urea nitrogen (p = 0.002) and creatinine (p = 0.12). In animals receiving lower doses of bacteria, intra-aortic balloon counterpulsation had no significant effects on survival or renal function.

CONCLUSIONS

In a canine model of severe septic shock with a low cardiac index, intra-aortic balloon counterpulsation prolongs survival time and lowers vasopressor requirements.