💊 Adrenocortical Insufficiency
The Addisonian Crisis in surgical patients — why long-term steroid users need perioperative cover, and how to manage a crisis when it hits.
The Core Concept
An Addisonian crisis is acute adrenal insufficiency — a life-threatening failure of the adrenal cortex to produce adequate cortisol and aldosterone in response to physiological stress. In a surgical context, the most common cause is long-term exogenous steroid use suppressing the HPA axis, such that the patient cannot mount the normal cortisol surge needed to survive the operative stress.
The Single Most Important Concept
Surgical stress normally triggers a 5–10× increase in cortisol output from the adrenal cortex. In a patient on long-term steroids, the HPA axis is suppressed — the hypothalamus, pituitary, and adrenal cortex have all down-regulated. When the stress of surgery hits, the adrenal glands simply cannot respond. If exogenous cover is not provided, the patient crashes into a vasodilatory, hypoglycaemic crisis that is difficult to reverse.
The Mechanism
Long-term steroids → HPA axis suppression → adrenal atrophy → insufficient cortisol and aldosterone at time of surgical stress → crisis.
Aldosterone Loss
Hyponatraemia (sodium follows water out), profound hypotension (loss of vascular tone), and hyperkalaemia (K⁺ retention).
Cortisol Loss
Hypoglycaemia — cortisol is the key counter-regulatory hormone for gluconeogenesis; without it, glucose plummets under the fasting/starvation of the perioperative period.
Management Principle
Aggressive IV saline to restore sodium and circulating volume, plus IV hydrocortisone to replace both cortisol and (at high doses) mineralocorticoid activity.