EMLA® cream coated on endotracheal tube with or without epidural lidocaine reduces isoflurane requirement during general anesthesia

Electrospun composite-coated endotracheal tubes with controlled siRNA and drug delivery to lubricate and minimize upper airway injury

Endotracheal Tubes (ETTs) maintain and secure a patent airway; however, prolonged intubation often results in unintended injury to the mucosal epithelium and inflammatory sequelae which complicate recovery. ETT design and materials used have yet to adapt to address intubation associated complications. In this study, a composite coating of electrospun polycaprolactone (PCL) fibers embedded in a four-arm polyethylene glycol acrylate matrix (4APEGA) is developed to transform the ETT from a mechanical device to a dual-purpose device capable of delivering multiple therapeutics while preserving coating integrity. Further, the composite coating system (PCL-4APEGA) is capable of sustained delivery of dexamethasone from the PCL phase and small interfering RNA (siRNA) containing polyplexes from the 4APEGA phase. The siRNA is released rapidly and targets smad3 for immediate reduction in pro-fibrotic transforming growth factor-beta 1 (TGFϐ1) signaling in the upper airway mucosa as well as suppressing long-term sequelae in inflammation from prolonged intubation. A bioreactor was used to study mucosal adhesion to the composite PCL-4APEGA coated ETTs and investigate continued mucus secretory function in ex vivo epithelial samples. The addition of the 4APEGA coating and siRNA delivery to the dexamethasone delivery was then evaluated in a swine model of intubation injury and observed to restore mechanical function of the vocal folds and maintain epithelial thickness when observed over 14 days of intubation. This study demonstrated that increase in surface lubrication paired with surface stiffness reduction significantly decreased fibrotic behavior while reducing epithelial adhesion and abrasion.

Effect of 5% EMLA Cream on Postoperative Sore Throat in Adults Following General Endotracheal Anesthesia: A Randomized Placebo-Controlled Study

BACKGROUND

Postoperative sore throat (POST) is a distressing complaint in adults after endotracheal intubation. This study aimed to evaluate the effect of topical application of a eutectic mixture of local anesthetics (EMLA) cream over the endotracheal tube (ETT) cuff on the incidence and severity of POST, cough, and hoarseness of voice in adults after surgery.

METHODS

In this randomized, placebo-controlled study, adult patients 18 to 65 years old, in American Society of Anesthesiologists (ASA) physical status I and II, and of either sex were scheduled to receive 5% EMLA cream (intervention arm) or lubricant gel (placebo-controlled arm) applied over the ETT cuff. POST was graded as none (0), mild (1), moderate (2), or severe (3). A score of ≥2 was considered as significant POST. The incidence of POST at the sixth postoperative hour was the primary outcome. Secondary outcomes included the incidence of POST at 0, second, and 24 hours, and the incidence of significant POST (score ≥2). The incidence and severity of postoperative cough and hoarseness of voice were recorded simultaneously.

RESULTS

Two hundred and four patients completed the study. The incidence of POST was significantly lower in the EMLA group versus placebo at the sixth postoperative hour (4.9% vs 40.1%; relative risk [RR], 0.12; 95% confidence interval [CI], 0.05-0.29; P < .001); and at 0 hour (74.5% vs 93.1%; RR, 0.8; 95% CI, 0.7-0.9; P < .001) and second hour (51.9% vs 84.3%; RR, 0.61; 95% CI, 0.5-0.75; P < .001) but comparable at 24 hours (1.9% vs 3.9%; RR, 0.5; 95% CI, 0.09-2.67; P = .4). The number needed to treat to prevent POST with EMLA cream application was 5 at 0 hour and 3 at the second and sixth hour. The proportion of patients with significant POST over 24 hours were less in the EMLA group (9.8% vs 43.1%; P < .001). The incidence of postoperative cough and hoarseness of voice was significantly less at the 0, second, and sixth hours in the EMLA group, but comparable at 24 hours. The incidence of severe cough (8.8% vs 31.4%; P < .001) and hoarseness of voice (2% vs 7.4%; P < .001) over 24 hours was less in the EMLA group.

CONCLUSIONS

The application of EMLA cream over ETT cuff reduces the incidence and severity of POST, cough, and hoarseness of voice in adults after general anesthesia in the early postoperative period compared to lubricant gel.

The efficacy of lidocaine to prevent laryngospasm in children: a systematic review and meta-analysis

The purpose of this meta-analysis was to determine the efficacy of lidocaine in preventing laryngospasm during general anaesthesia in children. An electronic search of six databases was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were adhered to. We included randomised controlled trials reporting the effects of intravenous and/or topical lidocaine on the incidence of laryngospasm during general anaesthesia. Nine studies including 787 patients were analysed. The combined results demonstrated that lidocaine is effective in preventing laryngospasm (risk ratio (RR) 0.39, 95% CI 0.24-0.66; I(2)  = 0). Subgroup analysis revealed that both intravenous lidocaine (RR 0.34, 95% CI 0.14-0.82) and topical lidocaine (RR 0.42, 95% CI 0.22-0.80) lidocaine are effective in preventing laryngospasm. The results were not affected by studies with a high risk of bias. We conclude that, both topical and intravenous lidocaine are effective for preventing laryngospasm in children.