Transient corticotropin deficiency in critical illness.

We describe three critically ill patients who displayed indirect evidence of transient corticotropin deficiency. All these patients were elderly, were poorly nourished, and had unexplained hypotension intraoperatively or immediately postoperatively. During the hypotensive episodes, they had inappropriately low plasma cortisol levels (10, 12, and 6 micrograms/dl) and responded dramatically to the administration of glucocorticoids. A normal response to infusion of synthetic corticotropin excluded primary adrenal insufficiency. Two patients tested had low thyroxine levels without increased thyrotropin concentrations and depressed levels of gonadotropins. In all three patients, the dose of glucocorticoids was successfully tapered and then discontinued. After recovery, serum thyroxine levels increased, gonadotropins reverted to normal concentrations, and the administration of metyrapone to two patients demonstrated normal hypothalamic-pituitary-adrenal function. Cortisol levels of less than 15 micrograms/dl in critically ill patients suggest the presence of adrenal insufficiency. The infusion of synthetic corticotropin may not exclude adrenal insufficiency attributable to corticotropin deficiency. If direct tests of corticotropin reserve are impractical, treatment with glucocorticoids is warranted.

Comparison of 26- and 27-G needles for spinal anesthesia for ambulatory surgery patients.

Seven hundred thirty ambulatory surgery patients, randomly assigned to receive spinal anesthesia with a 26- or 27-G needle, were studied for the incidence of post-dural puncture headache (PDPH), postoperative back pain, and patient acceptance. The incidence of PDPH following the use of 26- and 27-G needles was 9.6% and 1.5%, respectively (P less than 0.05). The incidence of PDPH was 5.7% among men and 13.4% among women following the use of 26-G needles (P less than 0.05), whereas no difference between men and women was noted after the use of 27-G needles. Of the patients who were 40 yr of age or younger, the overall incidence of PDPH was 11.9%, with a 7.5% incidence among men and a 16.4% among women following the use of 26-G needles (P less than 0.05) and a 1.8% incidence of PDPH following the use of 27-G needles, with no statistical difference between genders. Postoperative back pain was experienced in 18.3% of the patients in the 26-G group and 20.2% in the 27-G group (difference not significant). Favorable acceptance of spinal anesthesia was reported in 89.4% of patients in the 26-G group and 98.2% in the 27-G group (P less than 0.01). Results from this study demonstrate that, in patients who received spinal anesthesia for ambulatory surgery, the use of 27-G needles resulted in a significantly lower incidence of PDPH and greater patient acceptance compared with the use of 26-G needles. The incidence of postoperative back pain was not significantly different between the two groups.