Anesthesia and analgesia最新文献

Background: Xylazine is an alpha-2 adrenergic agonist approved for veterinary use as a sedative and analgesic for animals. Unfortunately, xylazine has recently become a common adulterant of street drugs in the United States with xylazine-related overdoses and deaths increasing each year. Although the alpha-2 adrenergic antagonist, atipamezole, is an efficacious reversal agent for xylazine that is approved for use in animals, it is not approved for humans. In this study, we aimed to test alternative reversal agents for xylazine, and compare them with atipamezole in a rat model of xylazine-induced unconsciousness.

Methods: In adult Sprague-Dawley rats, we induced loss of righting reflex (LORR, a surrogate end point for loss of consciousness) with xylazine (5 mg/kg, intravenous [IV]) and attempted to restore consciousness by administering agents with distinct molecular mechanisms of action: atipamezole (alpha-2 adrenergic antagonist, 200 µg/kg IV); d-amphetamine (norepinephrine and dopamine reuptake inhibitor and releasing agent, 1 mg/kg); chloro-APB (dopamine D1 receptor agonist, 3 mg/kg IV); and atomoxetine (norepinephrine reuptake inhibitor, 3 mg/kg IV). Pulse oximetry and heart rate were monitored continuously. After administration of the reversal agents, time to return of righting reflex (RORR) was recorded (n = 12) and animals were assessed with a novel object recognition test (n = 17). One subset of animals underwent surgery to have electroencephalogram (EEG) leads implanted (n = 4). EEG data were recorded after xylazine injection and ensuing administration of a reversal agent and spectral analysis was performed.

Results: After xylazine-induced unconsciousness, the median time to RORR in atipamezole-, d-amphetamine-, and chloro-APB-treated rats was 1.5 minutes (Interquartile Range [1.0-2.0]), 2 minutes (interquartile range [IQR] [1.0-3.0]), and 2 minutes (IQR [1.0-2.0]) post drug injection, respectively, compared to 56 minutes (IQR [39.5-70.5]) after saline control ( F [4,40] = 41.62, P < .0001). Atomoxetine did not significantly accelerate time to RORR. During the novel object recognition test, all animals spent the same amount of time with the familiar and novel object (range 0-143.5 sec), indicating that no reversal agents restored recognition memory. Xylazine induced an EEG pattern dominated by slow-delta oscillations. Atipamezole, d-amphetamine, and chloro-APB restored EEG oscillations similar to the awake state.

Conclusions: Atipamezole, d-amphetamine, and chloro-APB accelerate emergence from xylazine-induced unconsciousness and restore EEG oscillation patterns consistent with wakefulness. However, none of these reversal agents restore recognition memory.

Background: The PROMIS-29 questionnaire assesses general aspects of physical and mental health that may be relevant to surgical recovery. Although this tool has been endorsed by expert consensus for use in perioperative care, evidence regarding its psychometric performance in this context is limited. This study aimed to assess the content validity, internal consistency, construct validity, and responsiveness of PROMIS-29 as a measure of recovery after colorectal surgery.

Methods: This study was conducted according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines. A cohort of adult patients undergoing elective colorectal resection at two academic hospitals in Canada completed the PROMIS-29 questionnaire preoperatively and weekly until postoperative week (POW) 4. Physical Health Summary (PHS) and Mental Health Summary (MHS) scores were derived from PROMIS-29 t-scores (higher = better health status). Content validity was assessed by comparing PROMIS-29 items against a previously reported conceptual framework of recovery after abdominal surgery. Internal consistency was assessed using Cronbach α. Construct validity was assessed by testing a priori hypotheses that PROMIS-29 scores would be better in patients: (1) with shorter length of stay (≤4 days); (2) without 30-day complications; (3) undergoing minimally invasive surgery; and (4) without a new stoma. Responsiveness was examined by hypothesizing that PROMIS-29 scores would follow the expected recovery trajectory-showing an initial postoperative decline followed by gradual improvement toward preoperative levels. Consistent with PROMIS guidelines, a minimal important difference of 3 points was used as the criterion for confirming hypotheses.

Results: A total of 282 patients were included (mean±SD age 59±16 years; 48% female; 78% minimally invasive; 19% with stoma; median [IQR] hospital stay 3 [1-6] days). PROMIS-29 items covered 36% of health domains considered important by patients in the conceptual framework, indicating limited content validity. Internal consistency across PROMIS domains was acceptable, with Cronbach α ranging from 0.81 to 0.98. Construct validity of PHS and MHS was limited, with 0 of 4 predefined hypotheses supported on POW1 and only 1 to 2 hypotheses supported in subsequent weeks (mean difference between groups ≥3). Responsiveness was supported until POW2 (mean difference between timepoints ≥3), but not after.

Conclusion: Despite demonstrating adequate internal consistency, PROMIS-29 has limited content validity, construct validity, and responsiveness within the first 4 weeks after colorectal surgery. These findings suggest that PROMIS-29 may not fully capture patients' recovery experiences, underscoring the need for psychometrically sound PROMs tailored to the context of perioperative care.

Background: Although the transitional pain service (TPS) has been proposed to manage patients at risk for persistent postsurgical opioid use, no standard criteria exist to identify high-risk patients for TPS management. Specifically, the 2 to 3 months after surgery are critical for the transition from short-term to persistent opioid use, yet little is known about opioid refills during this period.

Methods: This retrospective cohort study included 11,087 adult patients, regardless of opioid-naïve status, who underwent inpatient spine surgery at an academic medical center and were discharged between January 2017 and December 2023. The cohort was identified, and data were obtained from electronic medical records. Data were analyzed using multiple logistic and linear regression and Fisher's exact test.

Results: Of the patients, 25.4% and 14.8% received opioid refills at 31 to 60 and 61 to 90 days postdischarge, respectively. Among the independent risk factors, a refill at 31 to 60 days was the strongest predictor of a refill at 61 to 90 days (aOR 6.71, 95% CI, 5.90-7.65), regardless of preoperative opioid use, cervical or lumbar procedures, or surgical service. Refill rates at 31 to 60 and 61 to 90 days were linearly correlated (P < .0001, slope = 0.73). A refill at 31 to 60 days predicted a refill at 61 to 90 days with a negative predictive value (NPV) of 94.3% and a positive predictive value (PPV) of 41.5%, with consistently high NPVs across subgroups defined by preoperative opioid use, surgical procedure, or surgeon. A refill at 1 to 30 days; preoperative use of opioids, marijuana, and benzodiazepine; the first postoperative pain score recorded on the hospital floor; and depression were all associated with increased odds of refills at both 31 to 60 and 61 to 90 days. In contrast, the total dose of discharge opioid prescriptions had minimal impact on refills.

Conclusions: A refill at 31 to 60 days after discharge may serve as a predictor of high-risk patients who could benefit from TPS management to mitigate further opioid use. Moreover, each refill prescription should be carefully managed to prevent subsequent refills.

Background: Obesity is linked to altered lung function and increased perioperative respiratory adverse events (PRAEs). We examined the effects of obesity, respiratory symptoms, and posture on PRAEs, lung mechanics, and ventilation distribution in children undergoing general anesthesia.

Methods: A total of 110 children (6-16 years) undergoing elective surgery were stratified into normal-weight and overweight/obese groups. Preoperative respiratory symptoms were documented. Respiratory mechanics and end-expiratory lung volume were assessed by forced oscillation technique (FOT) and multiple-breath nitrogen washout (MBW), respectively, in sitting and supine positions before anesthesia induction; FOT was repeated after induction. All PRAEs were recorded.

Results: Severe PRAEs were uncommon (5/110, 4.5%, (95% confidence interval [CI], 1.5%-10.4%) laryngospasm; no bronchospasm). Minor PRAE occurred more frequently in obese children compared with normal-weight children (19/55, 34.5% (95% CI, 22.2%-48.6%) vs 9/55, 16.4% (95% CI, 7.9%-28.3%)), regardless of respiratory symptoms. Obesity was associated with increased peripheral airway resistance, most evident in the supine and anesthetized states. Respiratory symptoms primarily affected tissue mechanics, and additive impairments were observed when children were overweight/obese and had respiratory symptoms. MBW outcomes showed minimal group differences, though supine positioning consistently reduced functional residual capacity and increased lung clearance index. Anesthesia induction led to reduced resistance and improved elasticity, likely reflecting anesthesia-induced bronchodilation, but this effect was attenuated in obese children and those with respiratory symptoms.

Conclusions: Obesity increased susceptibility to minor PRAE and elevated peripheral airway resistance, whereas respiratory symptoms impaired tissue mechanics. Postural change exerted a dominant influence on lung function. Anesthesia-induced bronchodilatation was blunted in obese children and those with respiratory symptoms, highlighting the need for targeted perioperative strategies.