Use of a lighted flexible catheter as a detector for accidental oesophageal intubation through the intubating laryngeal mask: a preliminary study

We have evaluated the use of a prototype lighted flexible catheter using the transillumination of the light through the soft tissues of the neck, as a detector of the accidental oesophageal intubation during the tracheal intubation through the intubating laryngeal mask. Two hundred patients undergoing general anaesthesia were studied. Accidental oesophageal intubation occurred in 12 patients (6%) during the first intubating attempt and was diagnosed by noting absence of glow on the neck during the tracheal tube advancement and was confirmed by capnography. However, 11/12 (92%) of the above patients were finally intubated successfully, using the lighted flexible catheter. In one patient persistent accidental oesophageal intubation occurred and was classified as failure.     

Comparison between two different propofol dosage regimens for insertion of cuffed oro-pharyngeal airway

Conditions for insertion of the cuffed oropharyngeal airway (COPA) were assessed following two different dosage regimens of propofol: group I (n = 40): 1.5 mg.kg-1; group II (n = 40): 2.5 mg.kg-1. The insertion conditions were evaluated by using a scoring system (-, + and +2) of gag and cough reflexes. The necessary use of additional dosage of propofol and the duration of post-induction apnea were also recorded. There were no significant differences between the two groups in the incidence of coughing, gagging and the additional usage of induction agent. The mean (+/- SD) duration of apnea was significantly longer in the high dose group: 9 +/- 6 min vs 5 +/- 7 min (p = 0.007). Low dose of propofol combines efficient insertion conditions with decreased length of post-induction apnea.     

Plasma arginine levels and the response to inhaled nitric oxide in neonates

Inhaled nitric oxide (iNO) can be an effective vasodilator in pulmonary hypertension of the newborn (PHN). The aim of this study was to determine whether differences in arginine levels, from which endogenous NO is produced, explain the variability in response to NO and whether the arginine levels were lower in term and preterm infants with PHN than in infants without PHN (controls). We prospectively studied 30 infants (17 born preterm) with clinically diagnosed PHN and treated with iNO and 22 controls (14 born preterm). Three NO levels (10, 20, 40 ppm) were administered to the PHN infants to identify that associated with maximum oxygenation. Twenty-seven infants with PHN improved following iNO and had lower arginine levels than those infants who did not respond to iNO (p < 0. 05). No significant relationship, however, was noted between the arginine levels and either the magnitude of change in the oxygenation index in response to iNO or the NO level associated with maximum oxygenation. The median plasma arginine level prior to iNO of the PHN infants was 12.5 (range 2-53) mu mol/l, but not significantly lower than that of the controls (median 24, range 3-82 mu mol/l). We conclude that differences in plasma arginine levels are unlikely to explain the variation in response to iNO and that, although arginine levels tended to be lower in infants with PHN, this is not a consistent finding in either the term or preterm infants.     

Effect of maturity on maximal transdiaphragmatic pressure in infants during crying

The aim of this study was to determine the effect of maturation on diaphragmatic function. In addition, we investigated whether noninvasive assessment yielded similar results to invasive measurement. Twenty-eight infants, median gestational age (GA) 35.5 wk (range, 25 to 42 wk) and postconceptional age (PCA), 37.6 wk (range, 32 to 44 wk), were examined. Diaphragmatic function was assessed by measuring the maximal transdiaphragmatic pressure during crying (cPdi) using balloon catheters in the midesophagus (Pes) and the stomach (Pgas). In 14 of the infants, a noninvasive measurement of inspiratory muscle strength, maximal inspiratory pressure (PImax), was also made. cPdi and PImax were recorded during a crying effort with the airway occluded at end-expiration. The median cPdi and Pes during crying (cPes), but not Pgas during crying (cPgas), were significantly lower in those studied at a PCA of less than term compared with those studied at an older age (p < 0.05). cPdi and cPes, but not cPgas, correlated significantly with PCA (r = 0.44, p < 0.02; r = 0.43, p < 0.03; respectively) and gestational age (r = 0.46, p < 0.02 and r = 0.56, p < 0.01; respectively). In the 14 infants, the median PImax was lower, but it correlated significantly with cPdi (r = 0.79, p < 0.01). We conclude maturation does affect diaphragm function, and PImax may provide a noninvasive index of diaphragm strength.     

In vivo kinematic evaluation of total hip arthroplasty during stair climbing

Stair climbing is a physically demanding task and a painful limitation for patients suffering from severe hip osteoarthritis. Although total hip arthroplasty (THA) is the definitive treatment for end‐stage osteoarthritis, it is not well understood whether THA restores hip kinematics during strenuous activities. The purpose of this study was to compare the 3D kinematics of THA and native hip during physically demanding tasks and correlate potential differences with THA components orientations/positions in patients with unilateral THA. In vivo hip kinematics were determined during step‐up and leg stance activities using a validated combination of 3D CT‐based computer modeling and dual fluoroscopic imaging system (DFIS). The THA side demonstrated an average 3.4° (±6.5°, range: ?5.9° to 15.2°) greater internal rotation than the contralateral native hip, during the step‐up activity but not during leg stance. The difference in internal rotation was highly correlated to the difference in femoral anteversion and anterior translation of hip joint center between implanted and native hip (R² = 0.71, p < 0.01). The results suggest the importance of accurate THA component placement in restoring normal hip kinematics during functional activities. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1087–1093, 2015.

     

Caffeine increases strength and power performance in resistance-trained females during early follicular phase

The effects of 4 mg·kg⁻¹caffeine ingestion on strength and power were investigated for the first time, in resistance-trained females during the early follicular phase utilizing a randomized, double-blind, placebo-controlled, crossover design. Fifteen females (29.8 ± 4.0 years, 63.8 ± 5.5 kg [mean ± SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One-repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, was assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee extensions, while utilizing interpolated twitch technique to measure voluntary muscle activation. Maximal power and jump height were assessed during countermovement jumps (CMJ). Caffeine metabolites were measured in plasma. Adverse effects were registered after each trial. Caffeine significantly improved squat (4.5 ± 1.9%, effect size [ES]: 0.25) and bench press 1RM (3.3 ± 1.4%, ES: 0.20), and squat (15.9 ± 17.9%, ES: 0.31) and bench press RTF (9.8 ± 13.6%, ES: 0.31), compared to placebo. MVC torque (4.6 ± 7.3%, ES: 0.26), CMJ height (7.6 ± 4.0%, ES: 0.50), and power (3.8 ± 2.2%, ES: 0.24) were also significantly increased with caffeine. There were no differences in RFD or muscle activation. Plasma [caffeine] was significantly increased throughout the protocol, and mild side effects of caffeine were experienced by only 3 participants. This study demonstrated that 4 mg·kg⁻¹ caffeine ingestion enhanced maximal strength, power, and muscular endurance in resistance-trained and caffeine-habituated females during the early follicular phase, with few adverse effects. Female strength and power athletes may consider using this dose pre-competition and -training as an effective ergogenic aid.     

Early prediction of chronic oxygen dependency by lung function test results

Chronic oxygen dependency (COD) is a common sequela to very premature birth. Steroid therapy may reduce COD if given within the first 2 weeks, but has important side effects. It is, therefore, crucial to identify an accurate predictor of COD and hence only expose high-risk infants to intervention therapy. The aim of this study was to determine if, within 48 hr of birth, abnormal lung function predicted COD and whether such results performed better than readily available clinical data. Results from 100 consecutive, very low birth-weight infants, median gestation age 28 weeks (range, 24-33), who were ventilated within 6 hr of birth and survived beyond 36 weeks postconceptional age (PCA), were analyzed. Lung volume was assessed by measurement of functional residual capacity (FRC) using a helium gas dilution technique, and compliance was measured using either a passive inflation or an occlusion technique. The maximum peak inflating pressure and inspired oxygen concentration within the first 48 hr were recorded. The infants who remained oxygen-dependent beyond 28 days (n = 58) and 36 weeks PCA (n = 24) differed from the rest in being more immature (P < 0.001), more had a patent ductus arteriosus, and they had both a lower median lung volume (P < 0.001) and lower compliance (P < 0.01) on day 2. An FRC <19 mL/kg and a low gestational age were the most accurate predictors of COD at 28 days. An FRC <19 mL/kg on day 2 remained the best predictor of COD beyond 28 days if only the 50 infants whose gestational age was < or = 28 weeks were considered. We conclude that demonstration of a low lung volume in the first 48 hr helps to identify infants who might benefit from therapy aimed at preventing COD.     

Concomitant Mitral Regurgitation in Patients Undergoing Surgical Aortic Valve Replacement for Aortic Stenosis: A Systematic Review

Background: Concomitant mitral regurgitation (MR) is frequently seen in patients undergoing surgical aortic valve replacement (AVR) for severe aortic stenosis (AS). When the severity of MR is moderate or less, the decision to undertake simultaneous mitral valve intervention can be challenging.Methods: A systematic search of Medline, PubMed (NCBI), Embase and Cochrane Library was conducted to qualitatively assess the current evidence for concomitant mitral valve intervention for MR in patients with AS undergoing AVR. The primary outcome for this systematic review was the postoperative change in the severity of MR and other outcomes of interest included factors that predict improvement or persistence of MR and long-term impacts of residual MR.Results: A total of 17 studies were included. The percentage of patients demonstrating improvement in MR severity following AVR ranged from 17.2% to 72%; the studies that exclusively included patients with moderate functional MR and reported longer term echocardiographic follow-up of greater than 12 months demonstrated an improvement in MR severity of 45% to 72%.Conclusion: This systematic review demonstrates that a proportion of patients can exhibit an improvement in MR following isolated surgical AVR, but whether this confers any long-term morbidity and mortality benefit remains unclear.