Anesthesiology最新文献

Background: Enhanced Recovery After Surgery pathways recommend transversus abdominis plane (TAP) blocks, but their efficacy is controversial and limited by the duration of local anesthetics. Liposomal bupivacaine is commonly used in single-injection TAP blocks to extend analgesia, although its effectiveness remains unclear. Therefore, two coprimary hypotheses were tested: first, that opioid consumption during the initial 24 postoperative hours is higher with saline than plain bupivacaine or liposomal bupivacaine; and second, that opioid consumption between 24 to 48 h after surgery is comparable or greater with saline or plain bupivacaine than with liposomal bupivacaine.

Methods: Patients having major abdominal surgery ( e.g. , colorectal, gynecological, hernia repairs) were enrolled and randomly assigned 1:1:1 to bilateral four-quadrant TAP blocks with liposomal bupivacaine (40 ml plain bupivacaine 0.25% with 20 ml liposomal bupivacaine and 20 ml saline), plain bupivacaine (50 ml plain bupivacaine 0.5% with 30 ml normal saline), and placebo (80 ml normal saline). Patient-controlled intravenous opioids were used as needed. Patients, clinicians who adjusted opioid analgesia, ward nurses who evaluated pain scores, and study investigators who evaluated local anesthetic effects were blinded to treatment groups.

Results: In the modified intention-to-treat cohort of 261 patients, opioid requirements during the first 24 h were median [interquartile range] 26 [18, 48] milligram morphine equivalents (MME) for liposomal bupivacaine (n = 89), 33 [13, 75] MME for plain bupivacaine (n = 84), and 31 [17, 53] MME for placebo (n = 88). The estimated ratio of geometric means was 0.86 (97.7% CI, 0.60 to 1.24; P = 0.355) between liposomal bupivacaine and placebo groups, and 0.91 (97.7% CI, 0.63 to 1.32; P = 0.578) between plain bupivacaine and placebo groups. Opioid requirements between 24 and 48 h were also comparable across groups. Secondary outcomes, including time to sensation return, pain scores, and opioid requirements from 48 to 72 h, were similar across all groups, with no significant differences observed.

Conclusions: Single-shot, four-quadrant TAP blocks performed with liposomal bupivacaine, plain bupivacaine, or normal saline before incision for various open and laparoscopic abdominal procedures resulted in similar postoperative opioid consumption and pain scores at 24, 48, and 72 h. Absence of early benefit suggests that routine preincision, single-shot TAP blocks in this mixed surgical population provide little analgesia.

Background: Patients undergoing on-pump cardiac surgery are at high risk for perioperative lung injury and a hyperinflammatory state associated with postoperative complications. The authors investigated the hypothesis that flow-controlled ventilation (FCV) reduces the inflammatory stimulus compared to conventional pressure-controlled ventilation (PCV) in this patient cohort. FCV has the unique feature of controlling airway flows during inspiration and expiration and the potential to reduce mechanical power of invasive ventilation.

Methods: In this single-center randomized controlled trial, 140 adult patients undergoing cardiac surgery with cardiopulmonary bypass were allocated 1:1 to FCV or PCV from August 10, 2020, to November 16, 2022. Participants received perioperatively either individualized FCV with a compliance-guided positive end-expiratory pressure (PEEP) and a compliance-guided driving pressure (ΔP) or PCV with a compliance-guided PEEP and ΔP for tidal volumes of 6 to 8 ml/kg predicted body weight. Postoperative plasmatic interleukin 8 (IL-8) levels 6 h after cardiopulmonary bypass were defined as the primary endpoint. Explorative secondary outcomes included incidences of postoperative pulmonary and extrapulmonary complications and hospital length of stay.

Results: Median postoperative IL-8 levels did not differ significantly between FCV and PCV (FCV, 3.08 vs . PCV, 3.60; β, 0.08 pg/ml; 95% CI, -0.17 to 0.33; P = 0.573). ΔP values and tidal volumes were higher in the FCV group but FCV yielded lower respiratory rates and minute volumes required for normocapnia. As a result, the FCV approach reduced the perioperatively applied mechanical power by 55%. After FCV, incidences of single postoperative pulmonary complications ( e.g. , confirmed pneumonia, moderate and severe hypoxemia) and any postoperative extrapulmonary complication were lower and the hospital stay shorter.

Conclusions: FCV did not reduce plasmatic IL-8 levels at the predefined timepoint 6 h after cardiopulmonary bypass. However, the reduction of mechanical power during individualized FCV application and the findings of the explorative secondary study outcomes justify future trials.