A Cochrane review [withdrawn from publication] included 2 studies with a total of 37 subjects. In the first study patients were taking a minimum daily dose of 5 mg prednisolone for at least 2 months, and they had cortisol level below 20 µg/dL (550 nmol/L) in the ACTH stimulation test as an indication of adrenal insufficiency. Patients underwent invasive surgery. All patients continued to receive their usual dose of prednisolone throughout the study, and received either intravenous cortisol or matching saline. In the other study patients took a dose ranging from 5 mg to 15 mg prednisolone daily for at least 6 months as well as various immunosuppressive regimes following organ transplant. Patients undervent standardized gingivectomy procedure under local anaesthetic, and received a single dose immediately preoperatively of either intravenous hydrocortisone or matching placebo. ´
Both included studies used the mean change in blood pressure between treatment groups as their primary outcome measure. In the first study, the mean difference (MD) in systolic blood pressure was 5.52 mm Hg (95% CI -18.29 to 29.33) and for diastolic blood pressure the MD was -4.15 mm Hg (95% CI -16.57 to 8.27). For the other study, the MD in systolic blood pressure was 0.77 mm Hg (95% CI -4.01 to 5.55) and in diastolic blood pressure the MD was 1.98 mm Hg (95% CI -1.65 to 5.61). Neither study reported any adverse effects or complications in the intervention and control groups.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment), by indirectness (minor surgery e.g. gingivectomy under local anaesthetic in the other study may not cause significant physiologic stress of surgery), and by imprecise results (few patients and wide confidence intervals).