Oral midodrine for prophylaxis against post-spinal anesthesia hypotension during hip arthroplasty in elderly population: a randomized controlled trial.

BACKGROUND: We aimed to evaluate the efficacy of midodrine as a prophylaxis against post-spinal hypotension in elderly patients undergoing hip arthroplasty. METHODS: This randomized controlled trial included elderly patients undergoing hip arthroplasty under spinal anesthesia. Ninety minutes before the procedure, patients were randomized to receive either 5-mg midodrine or placebo (metoclopramide). After spinal anesthesia, mean arterial pressure (MAP) and heart rate were monitored every 2 min for 20 min then every 5 min until the end of the procedure. Post-spinal hypotension (MAP < 80% baseline) was treated with 10 mg ephedrine. The primary outcome was intraoperative ephedrine consumption. Secondary outcomes were the incidence of post-spinal hypotension, bradycardia, and hypertension (MAP increased by > 20% of the baseline reading). RESULTS: We analyzed 29 patients in the midodrine group and 27 in the control group. The intraoperative ephedrine consumption was lower in the midodrine group than in the control group (median [quartiles]: 10 [0, 30] mg versus 30 [20, 43] mg, respectively, P-value: 0.002); and the incidence of intraoperative hypotension was lower in the midodrine group than that in the control group. The incidence of hypertension and bradycardia were comparable between the two groups. CONCLUSION: The use of 5 mg oral midodrine decreased the vasopressor requirements and incidence of hypotension after spinal anesthesia for hip surgery in elderly patients. CLINICAL TRIAL REGISTRATION: This study was registered on September 22, 2022 at clinicaltrials.gov registry, NCT05548985, URL: https://classic. CLINICALTRIALS: gov/ct2/show/NCT05548985 .

Perfusion index-derived parameters as predictors of hypotension after induction of general anaesthesia: a prospective cohort study.

BACKGROUND: Induction of general anaesthesia is commonly associated with hypotension. This exposes patients to perioperative organ hypoperfusion and eventually damage. This study was designed to assess the ability of preoperative perfusion index (PI), plethysmographic variability index (PVI), and dicrotic plethysmography (Dicpleth) to predict hypotension after induction of general anaesthesia. METHODS: In this cohort study, 95 ASA I and II adult patients who were scheduled for elective surgery under general anaesthesia were enrolled. The correlation between preoperative PI, PVI, Dicpleth and percentage decrease in mean arterial blood pressure after anaesthesia induction was investigated. Ability of PI, PVI, Dicpleth to detect post-induction hypotension was also analysed. RESULTS: The percent decrease in MAP after anaesthesia correlated with baseline PI (r = -0.45, P < 0.001), PVI (r = 0.45, P = 0.001) and Dicpleth (r = 0.16, P = 0.12). The PI cut-off value was ≤ 3.03 for a patient at risk for post-induction hypotension with 77.8% sensitivity, 75% specificity, positive and negative predictive values of 74.5% and 78.3%, respectively. Similarly, the ROC analysis revealed that baseline PVI (AUC = 0.73, 95% CI = 0.622-0.812) was suitable for detecting post-induction hypotension. Moreover, baseline Dicpleth (AUC = 0.63) showed significant predictive ability. CONCLUSIONS: The pre-anaesthetic PI and PVI 17, respectively, have a good ability to predict those at risk of developing post-induction hypotension in adult patients undergoing elective surgery under general anaesthesia. Future studies are needed in order to investigate the usefulness of Dicpleth in different circumstances during anaesthesia. Clinical trial registration ID: The study was registered at clinicaltrials.gov (NCT04217226).