Anesthesiology最新文献

Background: Recent evidence indicates that general anesthesia and sleep-wake behavior share some overlapping neural substrates. γ-Aminobutyric acid-mediated (GABAergic) neurons in the central amygdala have a high firing rate during wakefulness and play a role in regulating arousal-related behaviors. The objective of this study was to investigate whether central amygdala GABAergic neurons participate in the regulation of isoflurane general anesthesia and uncover the underlying neural circuitry.

Methods: Fiber photometry recording was used to determine the changes in calcium signals of central amygdala GABAergic neurons during isoflurane anesthesia in Vgat-Cre mice. Chemogenetic and optogenetic approaches were used to manipulate the activity of central amygdala GABAergic neurons, and a righting reflex test was used to determine the induction and emergence from isoflurane anesthesia. Cortical electroencephalogram (EEG) recording was used to assess the changes in EEG spectral power and burst-suppression ratio during 0.8% and 1.4% isoflurane anesthesia, respectively. Both male and female mice were used in this study.

Results: The calcium signals of central amygdala GABAergic neurons decreased during the induction of isoflurane anesthesia and were restored during the emergence. Chemogenetic activation of central amygdala GABAergic neurons delayed induction time (mean ± SD, vehicle vs . clozapine-N-oxide: 58.75 ± 5.42 s vs . 67.63 ± 5.01 s; n = 8; P = 0.0017) and shortened emergence time (385.50 ± 66.26 s vs . 214.60 ± 40.21 s; n = 8; P = 0.0017) from isoflurane anesthesia. Optogenetic activation of central amygdala GABAergic neurons produced a similar effect. Furthermore, optogenetic activation decreased EEG delta power (prestimulation vs . stimulation: 46.63 ± 4.40% vs . 34.16 ± 6.47%; n = 8; P = 0.0195) and burst-suppression ratio (83.39 ± 5.15% vs . 52.60 ± 12.98%; n = 8; P = 0.0003). Moreover, optogenetic stimulation of terminals of central amygdala GABAergic neurons in the basal forebrain also promoted cortical activation and accelerated behavioral emergence from isoflurane anesthesia.

Conclusions: The results suggest that central amygdala GABAergic neurons play a role in general anesthesia regulation, which facilitates behavioral and cortical emergence from isoflurane anesthesia through the GABAergic central amygdala-basal forebrain pathway.

Background: Prescription rates for buprenorphine in opioid use disorder are increasing, and recent guidelines recommend its continuation during and after surgery; however, evidence from clinical outcome studies is limited. The authors tested the hypotheses (1) that perioperative continuation of buprenorphine does not result in higher pain scores and (2) that this approach does not result in higher supplemental postoperative opioid requirements.

Methods: The Veterans Affairs Corporate Data Warehouse was queried for patients who underwent surgery while being prescribed buprenorphine/naloxone for opioid use disorder between 2010 and 2020. Analysis of the prescription record was used to infer buprenorphine management, and a 3:1 matched control set of patients without buprenorphine prescriptions was generated. The authors examined patients who continued buprenorphine, patients who had buprenorphine interrupted, and control patients. The primary outcome was time-weighted average postoperative pain scores from inpatient and outpatient sources within 72 h of surgery. The secondary outcome was postoperative average daily morphine equivalent opioid requirements within 2 weeks of surgery.

Results: A total of 1,881 surgical procedures in 1,673 patients taking buprenorphine for opioid use disorder were included; these procedures were matched to 5,748 control patients (5,775 procedures) without a buprenorphine prescription. Among the 1,881 procedures, 1,186 (63%) continued buprenorphine through the perioperative period, while 695 (37%) interrupted buprenorphine. Pain scores (± SD) were clinically similar for all three groups (4.1 ± 1.9 control [n = 3,284], 4.9 ± 2.0 continued buprenorphine [n = 662], and 5.5 ± 1.7 interrupted buprenorphine [n = 419]; P < 0.001). Patients who continued buprenorphine did not require significantly more supplemental opioids as compared to controls (39.7 ± 1.9 mg morphine equivalents/day vs. 36.5 ± 0.7; P = 0.23), and patients who interrupted buprenorphine received more supplemental opioids than those who continued it (74.2 ± 4.5 mg morphine equivalents/day vs. 39.7 ± 1.9, respectively; P < 0.001).

Conclusions: Continuation of buprenorphine is not associated with higher average pain scores or postoperative opioid requirements, supporting recently published guidelines.

Background: The incidence of central venous catheter-related thrombosis and the long-term effects of thrombosis on catheterized veins in neonates are unknown. The authors therefore determined the incidence of central venous thrombosis, identified associated risk factors, and evaluated outcomes at 6 months.

Methods: The study enrolled neonates aged less than 28 days scheduled for major intestinal or cardiac surgery who were expected to require central venous catheters for at least 48 h. Catheter size, insertion method, and puncture site were determined by the attending anesthesiologist. The duration of catheterization was also determined by clinical need. Central venous thrombi were diagnosed by color Doppler ultrasound imaging within 48 h after catheter removal; results were not shared with clinicians. Ultrasound examinations were repeated 1, 3, and 6 months after discharge.

Results: The study enrolled 188 neonates during a period of 2 yr. The median duration of catheter insertion was 12 days. A total of 128 (68%) of the neonates had central venous thrombi at the catheter site, all of which were asymptomatic. Among patients with thrombi, 29 (23%) had complete vessel occlusion and 5 (4%) had venous stenosis at 6 months after discharge. Thrombi therefore spontaneously resolved by 6 months in 73% of the neonates. Central venous catheter to vein diameter ratio, duration of catheterization, and catheter dysfunction were independent risk factors for vessel thrombus. Complete vessel occlusion was most common in patients whose thrombus occupied more than 58% of the vessel at the initial assessment.

Conclusions: Covert central venous thrombosis is frequent in neonates who have central venous catheters, and complications are most common in patients who have large intravascular thrombi. Neonates with large intravascular thrombi should be followed and considered for anticoagulation.