Daily Anesthesiology Research Analysis

BACKGROUND: Whether an adductor canal block (ACB) is more effective when administered before or after total knee arthroplasty (TKA) is unclear. This study compared pain, stress, and functional outcomes between patients who received the block before surgery and those who received the block after surgery. METHODS: In this double-blinded trial, 100 patients at our hospital were randomized to receive an ACB at either 30 minutes before general anesthesia or postoperatively in the post-anesthesia care unit (PACU). All patients received periarticular local infiltration analgesia during surgery. The 2 groups were compared with respect to the primary outcome, the postoperative consumption of morphine as rescue analgesia, and in terms of the secondary outcomes, including the time from the end of surgery to the first rescue analgesia or discharge, intraoperative and postoperative stress, postoperative pain, functional recovery, the incidence of chronic pain, and complications. RESULTS: All included patients were Asian (Chinese) in race/ethnicity. The 2 groups had similar demographic information. Compared with the postoperative ACB, the preoperative ACB was associated with significantly lower morphine consumption within the first 24 hours postoperatively and lower total morphine consumption. It was also associated with a longer time until the first rescue analgesia, lower intraoperative consumption of opioids and inhaled anesthetic, fewer episodes of hypertension during surgery, a lower rate of rescue analgesia in the PACU, lower levels of cortisol and adrenocorticotropic hormone in serum on the morning of postoperative day 1, lower pain on a visual analog scale while at rest or during motion within 12 hours postoperatively, better range of knee motion on postoperative day 1, and a lower incidence of chronic pain at 3 months postoperatively. The 2 groups did not differ significantly with respect to postoperative ambulation distance, time until discharge, or complication rates. CONCLUSIONS: Administering an ACB before rather than after TKA may lead to lower opioid consumption during hospitalization, lower intraoperative and postoperative stress responses, better pain relief during hospitalization, and a lower incidence of chronic pain at 3 months postoperatively. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND AND PURPOSE: Phentolamine is a non-selective α-adrenoreceptor antagonist used to reverse local anaesthesia, for example, during dental procedures when a vasoconstrictor is co-applied. Phentolamine-mediated vasodilation leads to faster clearance of injected drugs. Previous electrophysiological studies hypothesized that phentolamine acts as a modulator of voltage-gated sodium channels, which could conflict with its indication as local anaesthetic reversal agent. EXPERIMENTAL APPROACH: We performed manual and high throughput patch-clamp recordings on HEK and CHO cells expressing Na KEY RESULTS: Phentolamine inhibits Na CONCLUSIONS AND IMPLICATIONS: Phentolamine blocks voltage-gated sodium channels via the local anaesthetic receptor site. This may conflict with its current indication as an antidote for local anaesthetics. We propose alternative α-adrenoreceptor antagonists as possible candidates for local anaesthetic reversal because these are less potent inhibitors of both cardiac and neuronal voltage-gated sodium channels.

IMPORTANCE: While national guidelines recommend avoidance of hypoxia, hypotension, and hypocarbia in the prehospital care of traumatic brain injury (TBI), limited data validate the association of these adverse physiologic events with TBI outcomes. OBJECTIVE: To validate the associations of prehospital hypoxia, hypotension, and hypocarbia with TBI outcomes in a US national trauma network. DESIGN, SETTING, AND PARTICIPANTS: This cohort study examined data from 8 level I trauma centers and their affiliated ground and air emergency medical services (EMS) agencies in the Linking Investigations in Trauma and Emergency Services (LITES) Network from January 1, 2017, to June 30, 2021. Adult patients (aged ≥18 years) with confirmed TBI (head Abbreviated Injury Score [AIS] of 1-6) and Injury Severity Score (ISS) of at least 9 were included. Interfacility transfers and patients who underwent prehospital cardiopulmonary resuscitation were excluded. Data were analyzed between April 20, 2022, and November 27, 2023. EXPOSURES: Adverse prehospital TBI events, including hypoxia, hypotension, or hypocarbia. MAIN OUTCOMES AND MEASURES: The primary outcomes were death in the emergency department (ED), hospital death, and unfavorable discharge disposition. Log-binomial regression models were used to estimate the association between adverse TBI events and outcomes, adjusting for sex, race and ethnicity, age, study site, transport mode, initial Glasgow Coma Scale, ISS, head AIS score, injury mechanism, and multiple trauma. RESULTS: The analytic cohort included 14 994 patients (median [IQR] age, 47 [31-64] years; 71% male; median [IQR] head AIS, 3 [2-4]). Patients with adverse TBI events included 12% (1577 of 13 604) with hypoxia, 10% (1426 of 14 842) with hypotension, and 61% (650 of 1068) with hypocarbia among those with advanced airway management. Patient outcomes included 2% (259 of 14 939) who died in the ED, 12% (1764 of 14 623) who died in the hospital, and 25% (3705 of 14 623) with an unfavorable discharge disposition. Hypoxia (adjusted relative risk [ARR], 2.24; 95% CI, 1.69-2.97), hypotension (ARR, 2.05; 95% CI, 1.54-2.72), and hypocarbia (ARR, 7.99; 95% CI, 2.47-25.85) were associated with increased risks of ED death. Each adverse TBI event exposure was also associated with higher risks of hospital death and unfavorable discharge disposition. CONCLUSIONS AND RELEVANCE: In this multicenter cohort study, prehospital hypoxia, hypotension, and hypocarbia were associated with poorer TBI outcomes. These results underscore the importance of optimal oxygenation, ventilation, and perfusion in prehospital TBI care.