Anesthesia and analgesia最新文献

Achondroplasia accounts for approximately 70% of all forms of dwarfism. Cesarean delivery is often required in parturients with achondroplasia due to cephalopelvic disproportion. There is no consensus on the optimal management for cesarean delivery considering the difficulties in both general and regional anesthesia in patients with achondroplasia. The aim of this study was to explore the literature for prior case reports and series to determine the optimum anesthetic management for cesarean delivery in achondroplastic patients. We conducted a review of the literature using Embase, Medline, Scopus, and Web of Science database searches for case series and case reports on achondroplasia and pregnancy through January 2024. Conference abstracts >3 years old were excluded, as well as data on forms of dwarfism other than achondroplasia, patients taller than 147 cm, and non-English language papers. Extracted data included demographic information, anesthetic management, and reported complications. The literature review resulted in 57 manuscripts with a total of 80 anesthetics. Anesthetic management consisted of planned general anesthesia (n = 16), single injection spinal (n = 28), epidural (n = 17), combined spinal-epidural (n = 12), and intrathecal catheter (n = 1). Six patients required conversion from neuraxial anesthesia to general anesthesia due to failed neuraxial placement (n = 3), inadequate blockade (n = 2), and high neuraxial block (n = 1). Reduced dose of intrathecal bupivacaine was common in this population. Complications such as hypotension (4 in 64), inadvertent dural puncture (1 in 64), and transient paresthesia (3 in 64) during neuraxial technique were reported but were infrequent. Neuraxial anesthesia is more common and a viable option in carefully selected parturients with achondroplasia. We recommend reduction of intrathecal local anesthetic as part of a titratable neuraxial technique (ie, combined spinal-epidural) that minimizes the risk of hypotension, high spinal, and emergent intubation.

Background: Despite the widespread use of pulse oximetry for intraoperative estimation of arterial oxygen saturation, there is growing evidence that certain patient populations may be vulnerable to inaccurate pulse oximetry measurements and that unrecognized hypoxemia is associated with end-organ damage and adverse outcomes. In this single-center retrospective cohort study, we sought to better elucidate the relationship between intraoperative occult hypoxemia and postoperative mortality among patients undergoing anesthesia and surgery.

Methods: Data were collected from our departmental data warehouse for adult patients (≥18 years) undergoing anesthesia between 2008 and 2019 with at least 1 intraoperative arterial blood gas recorded. The number of occult hypoxemic events, defined as arterial oxygen saturation (Sao2) of <88% despite oxygen saturation measured by pulse oximetry (Spo2) >92%, were determined. Mortality data were obtained from the Social Security Death Master File and used to determine 30-day and 1-year postoperative mortality. Propensity score overlap-weighted Firth logistic regression and Cox proportional-hazard modeling were performed to analyze whether at least 1 occult hypoxemic event was predictive of 30-day and 1-year mortality.

Results: There were 25,234 patients and 62,707 paired readings included in the final analysis. There were 351 patients (1.4%) with at least 1 occult hypoxemic reading. The overall 30-day mortality rate was 3.3% and 1-year mortality rate was 10.2%. In the overlap-weighted models, patients who experienced at least 1 occult hypoxemic event had significantly higher odds of both 30-day mortality (odds ratio [OR] = 2.89, 95% confidence interval [CI], 1.46-5.72, P = .002) and 1-year mortality (hazard ratio [HR] = 1.90, CI, 1.48-2.43, P < .001). There was no significant interaction between occult hypoxemia and self-reported race/ethnicity for predicting mortality.

Conclusions: Intraoperative occult hypoxemic events are associated with significantly higher odds of 30-day and 1-year mortality, independent of self-reported race/ethnicity.

Background: Increasing the temperature of intrathecal local anesthetics has been shown to increase the speed of onset and block height of spinal anesthesia. However, how this influences dose requirement has not been fully quantified. The aim of this study was to determine and compare the effective dose for anesthesia for cesarean delivery in 50% of patients (ED 50 ) of intrathecal bupivacaine given at temperatures of 37 °C (body temperature) or 24 °C (room temperature).

Methods: Eighty healthy parturients having elective cesarean delivery under combined spinal-epidural anesthesia were randomly assigned to receive intrathecal hyperbaric bupivacaine stored at 37 °C (body temperature group) or 24 °C (room temperature group). The first subject in each group received a bupivacaine dose of 10 mg. The dose for each subsequent subject in each group was varied with an increment or decrement of 1 mg based on the response (effective or noneffective) of the previous subject. Patients for whom the dose was noneffective received epidural supplementation after data collection with lidocaine 2% as required until anesthesia was sufficient for surgery. Values for ED 50 were calculated using modified up-down sequential analysis with probit analysis applied as a backup sensitivity analysis. These values were compared and the relative mean potency was calculated.

Results: The ED 50 (mean [95% confidence interval, CI]) of intrathecal hyperbaric bupivacaine was lower in the body temperature group (6.7 [5.7-7.6] mg) compared with the room temperature group (8.1 [7.7-8.6] mg) ( P < .05). The relative potency ratio for intrathecal bupivacaine for the room temperature group versus the body temperature group was 0.84 (95% CI, 0.77-0.93).

Conclusions: Warming hyperbaric bupivacaine to body temperature reduced the dose requirement for spinal anesthesia for cesarean delivery by approximately 16% (95% CI, 7%-23%).