The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients

Coronary Artery Occlusion with Sharp Blood Pressure Drop during General Anesthesia Induction: A Case Report

Most anesthetics reduce cardiac functions and lower blood pressure (BP), potentially causing excessive BP reduction in dehydrated patients or those with heart conditions, such as coronary artery disease (CAD). Considering the increased prevalence of cardiovascular disease with age, anesthesiologists must be cautious about BP reduction during general anesthesia in older adults. In the present case, a 76-year-old male patient with undiagnosed CAD in a hypovolemic state experienced a significant drop in systolic BP to the fifties during propofol and sevoflurane anesthesia. Despite the use of vasopressors, excessive hypotension persisted, leading to anesthesia suspension. Subsequent cardiac examinations, including computed tomography heart angio and calcium score, and coronary angiogram, revealed a near total occlusion of the proximal left anterior descending coronary artery (pLAD) and the formation of collateral circulation. After 5 days of hydration and anticoagulation medications and confirmation of normovolemic state, general anesthesia was attempted again and successfully induced; a normal BP was maintained throughout the surgery. Thus, it is important to conduct a thorough cardiac evaluation and maintain normovolemia for general anesthesia in older adults.

A Review of Novel Anesthetic Technique for Vitreoretinal Surgery

BACKGROUND AND OBJECTIVE

Currently, there is no standardized formulation of intravenous anesthetic that exists for vitreoretinal surgery. We describe a novel anesthetic protocol for vitreoretinal surgery that is safe and effective for patients and surgeons alike.

STUDY DESIGN

Review the current challenges to vitreoretinal anesthetic technique and descriptive overview outlining the proposed anesthetic protocol and associated experience with technique.

RESULTS

The proposed anesthetic technique utilizes a sub-tenon peribulbar block with a continuous propofol infusion. A low dosage continuous propofol infusion provides patients with profound anxiolysis and relaxation while maintaining wakefulness. Fentanyl can be additionally titrated for patients that report symptoms of pain or increased respiratory rate.

CONCLUSION

A low dose propofol infusion in combination with sub-tenon peribulbar block and judicious use of fentanyl provide an ideal operative condition for ambulatory vitreoretinal surgery. [Ophthalmic Surg Lasers Imaging Retina 2023;54:xx-xx.].

Effective dose of propofol combined with a low-dose esketamine for gastroscopy in elderly patients: A dose finding study using dixon’s up-and-down method

Objective: This study aimed to determine the optimal dose of propofol combined with esketamine to inhibit the response to gastroscope insertion in elderly patients.

Methods: This is a prospective, non-controlled, non-randomized, single-center study. Elderly patients aged 65–80 years were enrolled in the study with the American society of anesthesiologists (ASA) physical status I or II undergoing elective gastroscopy. All patients were administered propofol after an intravenous esketamine at the dosage of 0.3 mg/kg 30 s, the subsequent dose of propofol was determined by the response of the previous patient to gastroscope insertion (choking, body movement, etc.) using Dixon’s up-and-down method. The initial dose of propofol administered to the first elderly patient was 3.0 mg/kg, and the standard ratio of propofol dose in adjacent patients was 0.9. At least six crossover points were obtained before the conclusion of the study. By using Probit analysis the median effective dose (ED₅₀), 95% effective dose (ED₉₅), and the corresponding 95% confidence interval (CI) for propofol were determined.

Results: The study continued until we obtained seven crossover points and 32 elderly patients (17 males and 15 females) were collected. The ED₅₀ of propofol combined with esketamine inhibiting response to gastroscope insertion in elderly patients were found to be 1.479 mg/kg (95% CI 1.331–1.592 mg/kg), and ED₉₅ was found to be 1.738 mg/kg (95% CI 1.614–2.487 mg/kg).

Conclusion: According to the present study, propofol combined with 0.3 mg/kg esketamine is safe and effective for elderly patients undergoing gastroscopy. The ED₅₀ and ED₉₅ doses of propofol inhibiting response to gastroscope insertion in elderly patients when combined with 0.3 mg/kg esketamine were 1.479 and 1.738 mg/kg, respectively, without apparent adverse effects.