Anesthesiology最新文献

Background: Both dexamethasone and dexmedetomidine increase the duration of analgesia of peripheral nerve blocks. The authors hypothesized that combined intravenous dexamethasone and intravenous dexmedetomidine would result in a greater duration of analgesia when compared with intravenous dexamethasone alone and placebo.

Methods: The authors randomly allocated participants undergoing surgery of the foot or ankle under general anesthesia and with a combined popliteal (sciatic) and saphenous nerve block to a combination of 12 mg dexamethasone and 1 µg/kg dexmedetomidine, 12 mg dexamethasone, or placebo (saline). The primary outcome was the duration of analgesia measured as the time from block performance until the first sensation of pain in the surgical area as reported by the participant. The authors predefined a 33% difference in the duration of analgesia as clinically relevant.

Results: A total of 120 participants from two centers were randomized and 119 analyzed for the primary outcome. The median [interquartile range] duration of analgesia was 1,572 min [1,259 to 1,715] with combined dexamethasone and dexmedetomidine, 1,400 min [1,133 to 1,750] with dexamethasone alone, and 870 min [748 to 1,138] with placebo. Compared with placebo, the duration was greater with combined dexamethasone and dexmedetomidine (difference, 564 min; 98.33% CI, 301 to 794; P < 0.001) and with dexamethasone (difference, 489 min; 98.33% CI, 265 to 706; P < 0.001). The prolongations exceeded the authors' predefined clinically relevant difference. The duration was similar when combined dexamethasone and dexmedetomidine was compared with dexamethasone alone (difference, 61 min; 98.33% CI, -222 to 331; P = 0.614).

Conclusions: Dexamethasone with or without dexmedetomidine increased the duration of analgesia in patients undergoing surgery of the foot or ankle with a popliteal (sciatic) and saphenous nerve block. Combined dexamethasone and dexmedetomidine did not increase the duration of analgesia when compared with dexamethasone.

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Background: The use of anesthetics may result in depression of the hypoxic ventilatory response. Since there are no receptor-specific antagonists for most anesthetics, there is the need for agnostic respiratory stimulants that increase respiratory drive irrespective of its cause. The authors tested whether ENA-001, an agnostic respiratory stimulant that blocks carotid body BK-channels, could restore the hypoxic ventilatory response during propofol infusion. They hypothesize that ENA-001 is able to fully restore the hypoxic ventilatory response.

Methods: In this randomized, double-blind crossover trial, 14 male and female healthy volunteers were randomized to receive placebo and low- and high-dose ENA-001 on three separate occasions. On each occasion, isohypercapnic hypoxic ventilatory responses were measured during a fixed sequence of placebo, followed by low- and high-dose propofol infusion. The authors conducted a population pharmacokinetic/pharmacodynamic analysis that included oxygen and carbon dioxide kinetics.

Results: Twelve subjects completed the three sessions; no serious adverse events occurred. The propofol concentrations were 0.6 and 2.0 µg/ml at low and high dose, respectively. The ENA-001 concentrations were 0.6 and 1.0 µg/ml at low and high dose, respectively. The propofol concentration that reduced the hypoxic ventilatory response by 50% was 1.47 ± 0.20 µg/ml. The steady state ENA-001 concentration to increase the depressed ventilatory response by 50% was 0.51 ± 0.04 µg/ml. A concentration of 1 µg/ml ENA-001 was required for full reversal of the propofol effect at the propofol concentration that reduced the hypoxic ventilatory response by 50%.

Conclusions: In this pilot study, the authors demonstrated that ENA-001 restored the hypoxic ventilatory response impaired by propofol. This finding is not only of clinical importance but also provides mechanistic insights into the peripheral stimulation of breathing with ENA-001 overcoming central depression by propofol.

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Background: Day-of-surgery cancellations impede healthcare access and contribute to inequities in pediatric healthcare. Socially disadvantaged families have many risk factors for surgical cancellation, including low health literacy, transportation barriers, and childcare constraints. These social determinants of health are captured by the Childhood Opportunity Index (COI) 2.0, a national quantification of neighborhood-level characteristics that contribute to a child's vulnerability to adversity. We studied the association of neighborhood opportunity with pediatric day-of-surgery cancellations.

Methods: We conducted a retrospective cohort study of children younger than 18 years of age scheduled for ambulatory surgery at a tertiary pediatric hospital between 2017 and 2022. We geocoded the primary address to determine COI 2.0 neighborhood opportunity. We used log-binomial regression to estimate the relative risk of day-of-surgery cancellation comparing different levels of neighborhood opportunity. We also estimated the relative risk of cancellations associated with race and ethnicity, by neighborhood opportunity.

Results: Overall, the incidence of day-of-surgery cancellation was 3.8%. The incidence of cancellation was lowest in children residing in very high opportunity neighborhoods and highest in children residing in very low opportunity neighborhoods (2.4% vs 5.7%, p<0.001). The adjusted relative risk of day-of-surgery cancellation in very low opportunity neighborhoods compared to very high opportunity neighborhoods was 2.24 (95%CI: 2.05-2.44, p<0.001). We found statistical evidence of an interaction of COI with race and ethnicity. In very low opportunity neighborhoods, Black children had 1.48 times greater risk of day-of-surgery cancellation than White children (95%CI: 1.35-1.63, p<0.001). Likewise, in very high opportunity neighborhoods, Black children had 2.17 times greater risk of cancellation (95%CI: 1.75-2.69, p<0.001).

Conclusion: We found a strong relationship between pediatric day-of-surgery cancellation and neighborhood opportunity. Black children at every level of opportunity had the highest risk of cancellation, suggesting that there are additional factors that render them more vulnerable to neighborhood disadvantage.

While effects of general anesthesia on neuronal activity in the human neonatal brain are incompletely understood, electroencephalography (EEG) provides some insight and may identify age-dependent differences. A systematic search (MEDLINE, Embase, PUBMED, Cochrane Library to November 2023) retrieved English language publications reporting EEG during general anesthesia for cardiac or non-cardiac surgery in term neonates (37 to 44 weeks post-menstrual age). Data were extracted and risk of bias (ROBINS-I Cochrane tool) and quality of evidence (GRADE checklist) assessed. From 1155 abstracts, nine publications (157 neonates; 55.7% male) fulfilled eligibility criteria. Data were limited and study quality was very low. The occurrence of discontinuity, a characteristic pattern of alternating higher and lower amplitude EEG segments, was reported with general anesthesia (94 of 119 neonates, six publications) and with hypothermia (23 of 23 neonates, two publications). Decreased power in the delta (0.5-4Hz) frequency range was also reported with increasing anesthetic dose (39 neonates; three publications). While evidence gaps were identified, both increasing sevoflurane concentration and decreasing temperature are associated with increasing discontinuity.

Background: Postoperative pulmonary complications (PPCs) can increase hospital length of stay, postoperative morbidity and mortality. Despite many factors can increase the risk of PPCs, it is not known whether intraoperative ventilation/perfusion (V/Q) mismatch can be associated with an increased risk of PPCs after major non-cardiac surgery.

Methods: We enrolled patients undergoing general anesthesia for non-cardiac surgery and evaluated intraoperative V/Q distribution using the Automatic Lung Parameter Estimator technique. The assessment was done after anesthesia induction (T1), after 1 hour from surgery start (T2) and at the end of surgery (T3). We collected demographic and procedural information and measured intraoperative ventilatory and hemodynamic parameters at each time-point. Patients were followed up for 7 days after surgery and assessed daily for PPCs occurrence.

Results: We enrolled 101 patients with a median age of 71 [62-77] years, a BMI of 25 [22.4-27.9] kg/m 2 and a preoperative ARISCAT score of 41 [34-47]. Of them, 29 (29%) developed PPCs, mainly acute respiratory failure (23%) and pleural effusion (11%). Patients with and without PPCs did not differ in levels of shunt at T1 (PPCs:22.4[10.4-35.9] % vs No PPCs:19.3[9.4-24.1] %, p=0.18) or during the protocol, while significantly different levels of high V/Q were found during surgery (PPCs:13[11-15] mmHg vs No PPCs:10[8-13.5] mmHg, p=0.007) and before extubation (PPCs:13[11-14]mmHg vs No PPCs:10[8-12] mmHg, p=0.006). After adjusting for age, ARISCAT, BMI, smoking, fluid balance, anesthesia type, laparoscopic procedure and surgery duration, high V/Q before extubation was independently associated with the development of PPCs (OR 1.147, CI 95% [1.021-1.289], p=0.02). The sensitivity analysis showed an E-value of 1.35 (CI=1.11).

Conclusions: In patients with intermediate/high risk of PPCs undergoing major non-cardiac surgery, intraoperative V/Q mismatch is associated with the development of PPCs. Increased high V/Q before extubation is independently associated with the occurrence of PPCs in the first 7 days after surgery.

Background: The analgesic effect of adding liposomal bupivacaine to standard bupivacaine in supraclavicular brachial plexus block is not known. We hypothesized that addition of liposomal bupivacaine would reduce acute postoperative pain compared to standard bupivacaine alone.

Methods: A randomized controlled trial was conducted. Patients and outcome assessors were blinded. Eighty patients undergoing distal radial fracture fixation under regional anesthesia with supraclavicular brachial plexus block were randomized into two groups. The liposomal bupivacaine (LB-BPB) group received 10ml of 0.5% plain bupivacaine immediately followed by 10ml of 1.33% liposomal bupivacaine (n=40). The standard bupivacaine (S-BPB) group received 20ml of 0.5% plain bupivacaine (n=40). The primary outcome was weighted area under curve (AUC) numerical rating scale (NRS) pain score at rest over the first 48 hours after surgery. Secondary outcomes included AUC scores for pain with movement, overall benefit with analgesia score (OBAS) and other functional scores.

Results: For the primary outcome, LB-BPB group was associated with statistically significantly lower AUC pain score at rest (0.6 vs 1.4, p-value < 0.001) in the first 48 hours. Of the secondary outcomes, no difference between treatment groups reached statistical significance with the exception of AUC score for pain with movement (2.3 vs 3.7, adjusted p-value < 0.001) and OBAS (1.1 vs 1.7, adjusted p-value = 0.020) in the first 48 hours, as well as NRS pain score at rest (0.5 vs 1.9, adjusted p-value < 0.001) and with movement (2.7 vs 4.9, adjusted p-value < 0.001) on postoperative day (POD) 1. Differences in NRS pain scores on POD2, POD3 and POD4 did not reach the level of statistical significance. There were no statistically significant differences in sensory function.

Conclusion: Liposomal bupivacaine given via supraclavicular brachial plexus block reduced pain at rest in the early postoperative period.