The patient receives fluid resuscitation, broad-spectrum antibiotics, and is started on norepinephrine infusion. An intra-arterial catheter is placed for blood pressure monitoring. His central venous pressure is 14 mmHg, blood pressure is 85/45 mmHg, and heart rate is 115/min. His oxygen saturation is 93% on two liters of nasal canula oxygen. His urine output is 15 ml/hr. Which of the following best explains the hypotension in this patient?
- A. Catecholamine-driven vasodilation [26%]
- B. Pulmonary hypertension [3%]
- C. Renal failure due to acute tubular necrosis [8%]
- D. Stress-induced cardiomyopathy [6%] .,
- E. Suppression of the pituitary-adrenal axis [56%]
This patient likely has suppression of the pituitary-adrenal axis from long term prednisone use for his rheumatoid arthritis. The use of exogenous corticosteroids results in negative feedback upon the pituitary and decreased ACTH secretion. Cortisol is a stress-related hormone that is critical to survival from septic shock. Even among patients who are not on chronic corticosteroids, many are unable to mount a sufficient cortisol response to counteract the stress of sepsis and may have a “relative” cortisol deficiency. Exogenous corticosteroids should be considered for those not previously on steroids who have a systolic blood pressure below 90 mmHg for at least one hour despite adequate fluid resuscitation and use of vasopressors. Steroids in these patients are typically given as a tapered dose over 5 to 7 days with treatment begun during the first 8 hours of presentation. Since this patient was previously on steroids and has suppression of the pituitary-adrenal axis, corticosteroids should be started upon admission regardless of whether the above criteria are met.
(Choice A) This patient has elevated catecholamine levels secondary to stress and the exogenous norepinephrine, both of which should result in vasoconstriction to counteract the vasodilatory effects of the underlying sepsis.
(Choice B) There is no evidence to suggest the presence of pulmonary hypertension in this patient.
(Choice C) Renal failure from acute tubular necrosis may be an effect of prolonged hypotension rather than its cause.
(Choice D) Stress-induced cardiomyopathy, also known as Takotsubo cardiomyopathy, can occur in critical illness but is much less likely here than suppression of the pituitary-adrenal axis.
Educational objective: Patients on longstanding corticosteroids often have suppression of the pituitary-adrenal axis secondary to negative feedback. Hypotension may be exacerbated in these patients should they develop septic shock unless stress dose steroids are given during the acute illness. Corticosteroids may even be necessary in patients who did not previously take corticosteroids due to a “relative” adrenal insufficiency.