Epidural nalbuphine versus dexmedetomidine as adjuvants to bupivacaine in lower limb orthopedic surgeries for postoperative analgesia: a randomized controlled trial.

BACKGROUND: Administration of adjuvant drugs epidurally in combination with local anesthetics offers new dimensions in the management of postoperative pain. This study aimed to compare the addition of either nalbuphine or dexmedetomidine to epidural bupivacaine for postoperative analgesia in lower limb orthopedic surgeries under combined spinal-epidural anesthesia. METHODS: This prospective randomized double-blind study included 69 patients scheduled for lower limb orthopedic surgeries. Anesthesia was started with 15 mg hyperbaric bupivacaine 0.5% intrathecally, and then an epidural bolus dose of 12 ml (10 ml 0.25% bupivacaine with 2 ml normal saline in group C, 2 ml (10 mg) nalbuphine in group N or dexmedetomidine 2 ml (100 µg) in group D was administered when sensory regression to T10. Postoperatively, when visual analogue scale (VAS) was ≥ 3, an epidural top-up dose of 8 ml (6 ml 0.25% bupivacaine plus 2 ml normal saline in group C, 2 ml (2 mg) nalbuphine in group N or 20 µg dexmedetomidine (2 ml) in group D was given. The primary outcome was to evaluate the duration of postoperative analgesia and secondary outcomes were any side effects and patient satisfaction. RESULTS: The onset of epidural analgesia was 17.83 ± 2.53 versus 13.39 ± 1.27 versus 12.17 ± 1.27 min in groups C, N and D, respectively (p value < 0.001). The mean duration of analgesia was 241.3 ± 14.24 versus 318.38 ± 22.54 versus 365.87 ± 18.01 min in groups C, N and D, respectively (p value < 0.001). The mean sedation score was less in group C than group N and D (P < 0.001). The patient satisfaction score showed the lowest degree of satisfaction in group C (p value < 0.001). Top-up doses consumed and total analgesic requirements were lower in groups N and D than in group C. There was a statistically significant difference between the studied groups regarding VAS over time (p value < 0.001), intraoperative bradycardia (p value 0.029), and shivering (p value 0.029). CONCLUSION: The addition of either nalbuphine or dexmedetomidine to epidural bupivacaine was effective for postoperative analgesia in terms of onset, duration, and patient satisfaction with the superiority of dexmedetomidine over nalbuphine. TRIAL REGISTRATION: Approval from the research ethics committee of the Faculty of Medicine, Zagazig University was obtained with the reference number (ZU-IRB#:7045-15-8-2021) and it was registered under clinicaltrials.gov (NCT05041270) on registration date 13/09/2021.

Inferior vena cava collapsibility index as a predictor of hypotension after induction of general anesthesia in hypertensive patients.

BACKGROUND: Hypertensive patients are more susceptible to develop hypotension after the induction of general anesthesia (GA), most likely due to hypovolemia. An inferior vena cava collapsibility index (IVCCI) > 40-50% can predict hypotension after the induction of GA in the general population by variable accuracies. The current study aimed to investigate IVCCI% as a predictor of postinduction hypotension in hypertensive patients undergoing noncardiac surgery. METHODS: Ultrasound IVCCI % was assessed for all controlled hypertensive patients immediately before induction of GA. After induction of GA, patients were diagnosed with postinduction hypotension if their systolic arterial pressure (SAP) dropped by ≥ 30% of the baseline value and/or mean arterial pressure (MAP) dropped to < 65 mmHg up to 15 min after intubation. The receiver operating characteristic (ROC) curve of IVCCI% was compared to patients' classification either developing hypotension after induction of GA or not as a gold standard. RESULTS: Of the 153 patients who completed the study, 62 (40.5%) developed hypotension after the induction of GA, and 91 (59.5%) did not. An IVCCI > 39% predicted the occurrence of postinduction hypotension with high accuracy (84%) (AUC 0.908, P < 0.001). The area of uncertainty (by gray zone analysis) of IVCCI lies at values from 39 to 45%. This gray zone included 21 patients (13.7% of all patients). CONCLUSION: An inferior vena cava collapsibility index > 39% before anesthetic induction can be a simple noninvasive reliable predictor of hypotension after the induction of GA for hypertensive patients not treated with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) and undergoing noncardiac surgery. TRIAL REGISTRATION: This clinical trial was approved by the Institutional Review Board (IRB) at Zagazig University (ZUIRB #9424 dated 03/04/2022), and patients' informed consent for participation in the study was obtained during the period from May 2022 to May 2023. All study procedures were carried out in accordance with the ethical standards of the Helsinki Declaration of 2013.