We assessed the effects of neurokinin (tachykinin) depletion by capsaicin (CAP) treatment on airway inflammation induced by repeated ovalbumin (OA) aerosol exposures (twice a week for 4 wk) in guinea pigs. The animals were then anesthetized, tracheostomized, mechanically ventilated and challenged with ovalbumin aerosol. Maximal values of respiratory system resistance and elastance after antigen challenge were significantly lower in capsaicin-treated guinea pigs than in intact animals (p < 0.001). Morphometric analysis of noncartilaginous airways revealed less intense bronchoconstriction (p < 0.001) and peribronchiolar edema (p < 0.001) in capsaicin-treated guinea pigs. Chronic antigen exposure resulted in a significant increase in lymphocytes and eosinophils both in bronchoalveolar lavage (BAL) fluid and airway wall. Immunohistochemistry with monoclonal antibodies revealed that most of the lymphocytes present in airway wall were CD4+ T cells. Capsaicin treatment resulted in values of CD4+ T cells in airway wall significantly lower than non-capsaicin-treated guinea pigs (p < 0.005). This difference was not observed in eosinophil recruitment. Our results suggest that neurokinin release by sensory nerve terminals results in an amplification of the pulmonary inflammatory changes induced by chronic antigen exposure. In addition, neurokinins play a role in T-cell recruitment induced by chronic allergen exposure.

Consent to participate: Written informed consent was obtained from all subjects or their legally authorised representatives. Consent for publication: Not applicableAvailability of data and material: De-identified data collected during the trial will be made available upon reasonable request to researchers who provide a methodologically sound proposal, after approval by the study authors, and with a signed data access agreement. Questions about data are handled by the corresponding author.

Background: Neuromuscular blocking agents (NMBAs) with a non-depolarising mechanism of action carry the risk of postoperative residual paralysis and are associated with postoperative pulmonary complications (POPC). Owing to the shorter duration of action, the depolarising NMBA succinylcholine may be associated with less postoperative residual paralysis, and hence fewer POPC. We tested the association of succinylcholine administration during anaesthesia and POPC. Methods: In a retrospective cohort study of registry data from two large US academic medical centres, 244 850 adult noncardiac surgical patients undergoing general anaesthesia were included. The primary outcome was POPC, defined as post-extubation haemoglobin oxygen de-saturation to <90%, or re-intubation requiring intensive care unit admission within 7 days after surgery. The association between succinylcholine and POPC and its dose-dependency were tested in a hierarchical fashion using a multivariable logistic regression model. Results: A total of 13 206 patients (5.4%) experienced POPC. Use of succinylcholine was associated with increased risk of POPC (adjusted odds ratio [OR Adj ]¼1.11; 95% confidence interval [CI], 1.06e1.16; P<0.001; adjusted risk¼5.18%; 95% CI, 5.06e5.30 without and 5.69%; 95% CI, 5.53e5.85 with succinylcholine), with a dose-dependent relationship (OR Adj ¼1.08; 95% CI, 1.05e1.11 per mg kg À1 ; P<0.001). In patients receiving non-depolarising NMBAs, succinylcholine further increased the risk of POPC (ORAdj¼1.08; 95% CI, 1.03e1.14; P¼0.001). The association between succinylcholine and POPC was modified (P¼0.03 for interaction) by the duration of surgery with higher odds of POPC in patients undergoing surgeries of <2 vs !2 h (OR Adj ¼1.24; 95% CI, 1.15e1.33 and 1.05; 95% CI, 1.00e1.10, respectively). Conclusions: In contrast to our prediction, succinylcholine administration was associated with an increased risk of POPC. This association was dose-dependent and magnified in surgeries of shorter duration.

We studied the effects of selective depletion of neurokinins in sensory nerve fibers by capsaicin treatment on the airway and pulmonary tissue responses to methacholine. Dose-response curves to aerosolized methacholine were performed on anesthetized and mechanically ventilated Wistar rats. Capsaicin (50 mg/kg sc) was administered to 2-day-old rats, and the animals were studied after 12 wk. The response to each dose of methacholine was determined by measuring changes in airway resistance (R(aw)), dynamic pulmonary elastance (Edyn), and pulmonary tissue resistance (Rtis). We calculated sensitivity (Kx) as the concentration of methacholine required for a one-half maximal response and reactivity as the relationship between the maximum response and Kx. Capsaicin treatment resulted in significantly greater values of Kx and lower values of reactivity for R(aw), Edyn, and Rtis compared with control rats. Morphometric analysis of airways showed similar values of the area occupied by smooth muscle but a significantly lower (P < 0.02) area of airway epithelium in capsaicin-treated rats. Our results suggest that methacholine requires capsaicin-sensitive nerves for part of its airway and lung tissue effects.

BACKGROUND: Residual neuromuscular blockade is associated with an increased incidence of postoperative respiratory complications. The REsidual neuromuscular block Prediction Score (REPS) identifies patients at high risk for residual neuromuscular blockade after surgery. METHODS: A total of 101,510 adults undergoing noncardiac surgery under general anesthesia from October 2005 to December 2018 at a tertiary care center in Massachusetts were analyzed for the primary outcome of postoperative respiratory complications (invasive mechanical ventilation requirement within 7 postoperative days or immediate postextubation desaturation [oxygen saturation {Spo 2} <90%] within 10 minutes). The primary objective was to assess the association between the REPS and respiratory complications. The secondary objective was to compare REPS and train-of-four (TOF) ratio <0.90 on the strength of their association with respiratory complications. RESULTS: A high REPS (≥4) was associated with an increase in odds of respiratory complications (adjusted odds ratio [OR], 1.13 [95% confidence interval {CI}, 1.06-1.21]; P < .001). In 6224 cases with available TOF ratio measurements, a low TOF ratio (<0.9) was associated with respiratory complications (adjusted OR, 1.43 [95% CI, 1.11-1.85]; P = .006), whereas a high REPS was not (adjusted OR, 0.96 [95% CI, 0.74-1.23]; P = .73) (P = .018 for comparison between ORs). CONCLUSIONS: The REPS may be implemented as a screening tool to encourage clinicians to use quantitative neuromuscular monitoring in patients at risk of residual neuromuscular blockade. A positive REPS should be followed by a quantitative assessment of the TOF ratio.

BackgroundThis study evaluated the association between neuromuscular blocking agent dose and post‐operative respiratory complications in infants and children.MethodsData from 6507 general anaesthetics provided to children aged 0‐10 years undergoing surgery were analysed to examine the effects of neuromuscular blocking agent dose on post‐operative respiratory complications (primary endpoint) and secondary endpoints. Confounder‐adjusted analyses addressed age, surgical duration, and comorbidity burden.ResultsIn confounder‐adjusted analyses, high doses of neuromuscular blocking agents were associated with higher risk of post‐operative respiratory complications (OR 2.27; 95% CI 1.12‐4.59; P = .022). The effect was modified by age (P‐for‐interaction = .016) towards a more substantial risk in infants ≤1 year (OR 3.84; 95% CI 1.35‐10.94; P = .012), by duration of surgery (P‐for‐interaction = .006) towards a higher difference in odds for surgeries <90 minutes (OR 4.25; 95% CI 1.19‐15.18; P = .026), and by ASA physical status (P‐for‐interaction = .015) with a greater effect among patients with higher operative risk (ASA >1: OR 3.17; 95% CI 1.43‐7.04; P = .005). Neostigmine reversal did not modify the association between neuromuscular blocking agents and post‐operative respiratory complications (P‐for‐interaction = .38). Instrumental variable analysis confirmed that high doses of neuromuscular blocking agents were associated with post‐operative respiratory complications (probit coefficient 0.25; 95% CI 0.04‐0.46; P = .022), demonstrating robust results regarding concerns of unobserved confounding.ConclusionsHigh dose of neuromuscular blocking agents is associated with post‐operative respiratory complications. We have identified subcohorts of paediatric patients who are particularly vulnerable to the respiratory side‐effects of neuromuscular blocking agents: infants, paediatric patients undergoing surgeries of short duration, and those with a high ASA risk score.

CPT Code Procedure Description Cystourethroscopy for treatment of the female urethral syndrome with any or all of the following: urethral meatotomy, urethral dilation, internal urethrotomy, lysis of urethrovaginal septal fibrosis, lateral incisions of the bladder neck, and fulguration of polyp(s) of urethra, bladder neck, and/or trigone Cystourethroscopy, with injection(s) for chemodenervation of the bladder Cystourethroscopy; with ureteral meatotomy, unilateral or bilateral Cystourethroscopy; with resection or fulguration of orthotopic ureterocele(s), unilateral or bilateral Cystourethroscopy; with resection or fulguration of ectopic ureterocele(s), unilateral or bilateral Cystourethroscopy; with incision or resection of orifice of bladder diverticulum, single or multiple Cystourethroscopy, with removal of foreign body, calculus, or ureteral stent from urethra or bladder (separate procedure); simple Cystourethroscopy, with removal of foreign body, calculus, or ureteral stent from urethra or bladder (separate procedure); complicated litholapaxy: crushing or fragmentation of calculus by any means in bladder and removal of fragments; simple or small (less than 2.5 cm) Litholapaxy: crushing or fragmentation of calculus by any means in bladder and removal of fragments; complicated or large (over 2.5 cm) Cystourethroscopy (including ureteral catheterization); with removal of ureteral calculus Cystourethroscopy (including ureteral catheterization); with fragmentation of ureteral calculus (eg, ultrasonic or electro-hydraulic technique) Cystourethroscopy (including ureteral catheterization); with subureteric injection of implant material Cystourethroscopy (including ureteral catheterization); with manipulation, without removal of ureteral calculus Cystourethroscopy, with insertion of indwelling ureteral stent (eg, gibbons or double-j type) Cystourethroscopy with insertion of ureteral guide wire through kidney to establish a percutaneous nephrostomy, retrograde Cystourethroscopy; with treatment of ureteral stricture (eg, balloon dilation, laser, electrocautery, and incision) Cystourethroscopy; with treatment of ureteropelvic junction stricture (eg, balloon dilation, laser, electrocautery, and incision) Cystourethroscopy; with treatment of intra-renal stricture (eg, balloon dilation, laser, electrocautery, and incision) Cystourethroscopy with ureteroscopy; with treatment of ureteral stricture (eg, balloon dilation, laser, electrocautery, and incision) Cystourethroscopy with ureteroscopy; with treatment of ureteropelvic junction stricture (eg, balloon dilation, laser, electrocautery, and incision) Cystourethroscopy with ureteroscopy; with treatment of intra-renal stricture (eg, balloon dilation, laser, electrocautery, and incision) Acute ICD-9 codes within Diagnosis CCS 149: Biliary tract disease 5740 Calculus of gallbladder with acute cholecystitis Calculus of gallbladder with acute cholecystitis without mention of obstruction Calculus of gallbladder with acute cholecystitis with obstruction 5743 Calculus of bile duct with...

ObjectiveTo assess variability in the intraoperative use of non-depolarising neuromuscular blocking agents (NMBAs) across individual anaesthesia providers, surgeons and hospitals.DesignRetrospective observational cohort study.SettingTwo major tertiary referral centres, Boston, Massachusetts, USA.Participants265 537 adult participants undergoing non-cardiac surgery between October 2005 and September 2017.Main outcome measuresWe analysed the variances in NMBA use across 958 anaesthesia and 623 surgical providers, across anaesthesia provider types (anaesthesia residents, certified registered nurse anaesthetists, attendings) and across hospitals using multivariable-adjusted mixed effects logistic regression. Intraclass correlations (ICC) were calculated to further quantify the variability in NMBA use that was unexplained by other covariates. Procedure-specific subgroup analyses were performed.ResultsNMBAs were used in 183 242 (69%) surgical cases. Variances in NMBA use were significantly higher among individual surgeons than among anaesthesia providers (variance 1.32 (95% CI 1.06 to 1.60) vs 0.24 (95% CI 0.19 to 0.28), p<0.001). Procedure-specific subgroup analysis of hernia repairs, spine surgeries and mastectomies confirmed our findings: the total variance in NMBA use that was unexplained by the covariate model was higher for surgeons versus anaesthesia providers (ICC 37.0% vs 13.0%, 69.7% vs 25.5%, 69.8% vs 19.5%, respectively; p<0.001). Variances in NMBA use were also partially explained by the anaesthesia provider’s hospital network (Massachusetts General Hospital: variance 0.35 (95% CI 0.27 to 0.43) vs Beth Israel Deaconess Medical Center: 0.15 (95% CI 0.12 to 0.19); p<0.001). Across provider types, surgeons showed the highest variance, and anaesthesia residents showed the lowest variance in NMBA use.ConclusionsThere is wide variability across individual surgeons and anaesthesia providers and institutions in the use of NMBAs, which could not sufficiently be explained by a large number of patient-related and procedure-related characteristics, but may instead be driven by preference. Surgeons may have a stronger influence on a key aspect of anaesthesia management than anticipated.