Transient neurological symptoms (TNS) following spinal anaesthesia with lidocaine versus other local anaesthetics in adult surgical patients: a network meta-analysis.

BACKGROUND: Spinal anaesthesia has been implicated as one of the possible causes of neurological complications following surgical procedures. This painful condition, occurring during the immediate postoperative period, is termed transient neurological symptoms (TNS) and is typically observed after the use of spinal lidocaine. Alternatives to lidocaine that can provide high-quality anaesthesia without TNS development are needed. This review was originally published in 2005, and last updated in 2009. OBJECTIVES: To determine the frequency of TNS after spinal anaesthesia with lidocaine and compare it with other types of local anaesthetics by performing a meta-analysis for all pair-wise comparisons, and conducting network meta-analysis (NMA) to rank interventions. SEARCH METHODS: We searched CENTRAL, MEDLINE, Elsevier Embase, and LILACS on 25 November 2018. We searched clinical trial registries and handsearched the reference lists of trials and review articles. SELECTION CRITERIA: We included randomized and quasi-randomized controlled trials comparing the frequency of TNS after spinal anaesthesia with lidocaine to other local anaesthetics. Studies had to have two or more arms that used distinct local anaesthetics (irrespective of the concentration and baricity of the solution) for spinal anaesthesia in preparation for surgery. We included adults who received spinal anaesthesia and considered all pregnant participants as a subgroup. The follow-up period for TNS was at least 24 hours. DATA COLLECTION AND ANALYSIS: Four review authors independently assessed studies for inclusion. Three review authors independently evaluated the quality of the relevant studies and extracted the data from the included studies. We performed meta-analysis for all pair-wise comparisons of local anaesthetics, as well as NMA. We used an inverse variance weighting for summary statistics and a random-effects model as we expected methodological and clinical heterogeneity across the included studies resulting in varying effect sizes between studies of pair-wise comparisons. The NMA used all included studies based on a graph theoretical approach within a frequentist framework. Finally, we ranked the competing treatments by P scores. MAIN RESULTS: The analysis included 24 trials reporting on 2226 participants of whom 239 developed TNS. Two studies are awaiting classification and one is ongoing. Included studies mostly had unclear to high risk of bias. The NMA included 24 studies and eight different local anaesthetics; the number of pair-wise comparisons was 32 and the number of different pair-wise comparisons was 11. This analysis showed that, compared to lidocaine, the risk ratio (RR) of TNS was lower for bupivacaine, levobupivacaine, prilocaine, procaine, and ropivacaine with RRs in the range of 0.10 to 0.23 while 2-chloroprocaine and mepivacaine did not differ in terms of RR of TNS development compared to lidocaine. Pair-wise meta-analysis showed that compared with lidocaine, most local anaesthetics were associated with a reduced risk of TNS development (except 2-chloroprocaine and mepivacaine) (bupivacaine: RR 0.16, 95% confidence interval (CI) 0.09 to 0.28; 12 studies; moderate-quality evidence; 2-chloroprocaine: RR 0.09, 95% CI 0.01 to 1.51; 2 studies; low-quality evidence; levobupivacaine: RR 0.13, 95% CI 0.02 to 0.69; 2 studies; low-quality evidence; mepivacaine: RR 1.01, 95% CI 0.18 to 5.82; 4 studies; very low-quality evidence; prilocaine: RR 0.18, 95% CI 0.07 to 0.49; 4 studies; moderate-quality evidence; procaine: RR 0.14, 95% CI 0.04 to 0.52; 2 studies; moderate-quality evidence; ropivacaine: RR 0.10, 95% CI 0.01 to 0.78; 2 studies; low-quality evidence). We were unable to perform any of our planned subgroup analyses due to the low number of TNS events. AUTHORS' CONCLUSIONS: Results from both NMA and pair-wise meta-analysis indicate that the risk of developing TNS after spinal anaesthesia is lower when bupivacaine, levobupivacaine, prilocaine, procaine, and ropivacaine are used compared to lidocaine. The use of 2-chloroprocaine and mepivacaine had a similar risk to lidocaine in terms of TNS development after spinal anaesthesia. Patients should be informed of TNS as a possible adverse effect of local anaesthesia with lidocaine and the choice of anaesthetic agent should be based on the specific clinical context and parameters such as the expected duration of the procedure and the quality of anaesthesia. Due to the very low- to moderate-quality evidence (GRADE), future research efforts in this field are required to assess alternatives to lidocaine that would be able to provide high-quality anaesthesia without TNS development. The two studies awaiting classification and one ongoing study may alter the conclusions of the review once assessed.

Airway rescue during sedation: a proposed airway rescue pathway for nonanesthesiologists.

PURPOSE OF REVIEW: This review summarizes key features of adverse airway and respiratory events for which sedation providers must be prepared to diagnose and treat in a timely manner. Key features include elements of the presedation patient evaluation that predict adverse airway and respiratory events; patient profiles, target sedation levels, and procedure types that should prompt a consult with an anesthesiologist; necessary clinical skills, essential equipment, and reversal drugs necessary to manage adverse airway and respiratory events; and a proposed airway rescue pathway that describes a sequence of interventions and prompts to call for help when encountering an adverse airway or respiratory event. RECENT FINDINGS: Several studies have reported adverse events from sedation. Although the overall rate can approach 4.5%, the incidence of events associated with severe harm is low (e.g., <0.5%). Some that are most harmful are prolonged ventilatory compromise leading to hypoxic brain injury or death. Inadequate clinical skills that contribute to these poor outcomes include undetected or delayed detection of hypopnea, apnea, and partial or complete airway obstruction, inadequate rescue skills to manage drug-induced ventilatory depression or airway obstruction, and/or a delay or no attempt to call for expert help followed by a timely response and intervention from that expert help. SUMMARY: To improve outcomes in detecting and managing adverse airway and respiratory events, nonanesthesiologists sedation practitioners must be trained in patient selection, monitoring, pharmacology, physiology, and airway management. One gap in sedation training curriculum is a roadmap to use when managing an adverse airway or respiratory events. This review puts forth a suggested airway rescue pathway for nonanesthesiologist sedation practitioners to use as a decision aid during an adverse airway or respiratory event associated with procedural sedation.

Diaphragm function after interscalene brachial plexus block: a double-blind, randomized comparison of 0.25% and 0.125% bupivacaine.

BACKGROUND: Interscalene brachial plexus block (ISBPB) provides excellent analgesia after rotator cuff surgery but is associated with diaphragm dysfunction. In this study, ISBPB with 20 mL of 0.125% or 0.25% bupivacaine were compared to assess the effect on diaphragm function, oxygen saturation, pain control, opioid requirements, and patient satisfaction. MATERIALS AND METHODS: In this prospective, randomized, double-blind study, 30 adults undergoing outpatient arthroscopic rotator cuff repair were enrolled to receive ultrasound-guided interscalene brachial plexus catheter placement with 20 mL of 0.125% (n = 15) or 0.25% bupivacaine (n = 15). Diaphragm function and oxygen saturation were assessed before ISBPB placement and on discharge from the postanesthesia care unit. Postoperative pain scores, opioid requirements, and patient satisfaction were compared. RESULTS: Diaphragm function and oxygen saturation were superior in the low concentration group. Absent or paradoxic motion of the diaphragm was present in 78% of the 0.25% group compared with 21% of patients in the 0.125% group (P = .008). Oxygen saturation decreased 4.3% in the 0.25% group compared with a decrease of 2.6% in the 0.125% group (P = .04). Pain scores averaged 1 of 10 in the 0.25% group and 0 of 10 in the 0.125% group (P = .02). Opioid requirements and patient satisfaction were not different between the two groups. CONCLUSIONS: In this randomized, double-blind comparison of ISBPB performed with 20 mL of 0.125% or 0.25% bupivacaine, diaphragm function and oxygen saturation were superior in patients treated with more dilute bupivacaine. Furthermore, there were no clinically significant differences in pain scores, and no statistically significant differences in opioid requirements and patient satisfaction.

Posterior reversible encephalopathy syndrome in a patient with severe preeclampsia.

Focal neurologic deficits in the parturient must be rapidly assessed and treated to minimize damage to both mother and child. The following case report features a patient presenting with visual loss, mental status changes, and severe preeclampsia, diagnosed as posterior reversible encephalopathy syndrome. This syndrome manifests radiographically as symmetric hypodensities of the posterior gray and white matter, and is usually reversible with prompt treatment.