Effect of Interscalene Brachial Plexus Block on the Pulmonary Function of Obese Patients: A Prospective, Observational Cohort Study.

BACKGROUND: The effect of interscalene block (ISB) on pulmonary function of obese participants has not been investigated. The goal of this study is to assess the association of obesity (body mass index [BMI] >29 kg/m vs BMI <25 kg/m) and change in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) after ISB in participants undergoing outpatient shoulder surgery. METHODS: This prospective, observational cohort study compared obese (BMI >29 kg/m) and normal-weight (BMI <25 kg/m) groups undergoing ISB for ambulatory shoulder surgery, on preblock and postblock FVC and FEV1, at 30 minutes postblock and in the postanesthesia care unit (PACU). The primary outcome in this study was FVC% change (percentage change from preblock to postblock values of FVC) at 30 minutes postblock in the supine position. Secondary outcomes included FVC% change at PACU and in the sitting position, FEV1% change (percentage change from preblock to postblock values of FEV1), FVC, FEV1, incidence of diaphragmatic paresis, modified Borg scale for perceived dyspnea, Richmond Agitation-Sedation Scale scores for sedation, and intraoperative airway events. RESULTS: Fourteen participants were recruited to each group. The mean (standard deviation) BMI in the normal-weight and obese groups was 23 (1.7) and 33 (3.1) kg/m, respectively. ISB success rate was 100%. All participants demonstrated hemidiaphragmatic paresis after ISB. Compared to the normal-weight group, in the sitting position, the obese group had a significant decrease in FVC% change at 30 minutes (-30 [10.5] vs -23 [7.2], P = .046) and an FEV1% change in the PACU (-40 [12.6] vs -27 [13.9], P = .02). No difference was found for measurements taken in the supine position. A repeated-measures analysis demonstrated that, adjusted for position, there is no significant group effect on FVC% change or FEV1% change from 30 minutes to PACU. The 2 groups were not different in terms of breathlessness and sedation at 30 minutes (P = .67, P = .48, respectively) and in the PACU (P = .69, P > .99, respectively) nor in the occurrence of intraoperative airway events (P > .99). CONCLUSIONS: ISB is associated with greater FVC and FEV1 reductions in obese participants undergoing shoulder surgery compared to normal-weight participants. Neither time (30 minutes versus PACU) nor position (sitting versus supine) affected this relationship. Despite these changes, obesity was not associated with increased clinical respiratory symptoms or events.

The effects of an acute dose of Rhodiola rosea on endurance exercise performance.

The purpose of this study was to determine the effects of an acute oral dose of 3 mg·kg(-1) of Rhodiola rosea on endurance exercise performance, perceived exertion, mood, and cognitive function. Subjects (n = 18) ingested either R. rosea or a carbohydrate placebo 1 hour before testing in a double-blind, random crossover manner. Exercise testing consisted of a standardized 10-minute warm-up followed by a 6-mile time trial (TT) on a bicycle ergometer. Rating of perceived exertion (RPE) was measured every 5 minutes during the TT using a 10-point Borg scale. Blood lactate concentration, salivary cortisol, and salivary alpha amylase were measured before warm-up, 2 minutes after warm-up, and 2 minutes after TT (n = 15). A Profile of Mood States questionnaire and a Stroop Color Test were completed before warm-up and after TT. Testing was repeated 2-7 days later with the other condition. Rhodiola rosea ingestion significantly decreased heart rate during the standardized warm-up (R. rosea = 136 ± 17 b·min(-1); placebo = 140 ± 17 b·min(-1); mean ± SD; p = 0.001). Subjects completed the TT significantly faster after R. rosea ingestion (R. rosea = 25.4 ± 2.7 minutes; placebo = 25.8 ± 3.0 minutes; p = 0.037). The mean RPE was lower in the R. rosea trial (R. rosea = 6.0 ± 0.9; placebo = 6.6 ± 1.0; p = 0.04). This difference was even more pronounced when a ratio of the RPE relative to the workload was calculated (R. rosea = 0.048 ± 0.01; placebo = 0.057 ± 0.02; p = 0.007). No other statistically significant differences were observed. Acute R. rosea ingestion decreases heart rate response to submaximal exercise and appears to improve endurance exercise performance by decreasing the perception of effort.

Teaching the use of respiratory inhalers to hospitalized patients with asthma or COPD: a randomized trial.

BACKGROUND: Hospitalized patients frequently misuse their respiratory inhalers, yet it is unclear what the most effective hospital-based educational intervention is for this population. OBJECTIVE: To compare two strategies for teaching inhaler use to hospitalized patients with asthma or chronic obstructive pulmonary disease (COPD). DESIGN: A Phase-II randomized controlled clinical trial enrolled hospitalized adults with physician diagnosed asthma or COPD. PARTICIPANTS: Hospitalized adults (age 18 years or older) with asthma or COPD. INTERVENTIONS: Participants were randomized to brief intervention [BI]: single-set of verbal and written step-by-step instructions, or, teach-to-goal [TTG]: BI plus repeated demonstrations of inhaler use and participant comprehension assessments (teach-back). MAIN MEASURES: The primary outcome was metered-dose inhaler (MDI) misuse post-intervention (<75% steps correct). Secondary outcomes included Diskus® misuse, self-reported inhaler technique confidence and prevalence of 30-day health-related events. KEY RESULTS: Of 80 eligible participants, fifty (63%) were enrolled (BI n=26, TTG n=24). While the majority of participants reported being confident with their inhaler technique (MDI 70%, Diskus® 94%), most misused their inhalers pre-intervention (MDI 62%, Diskus® 78%). Post-intervention MDI misuse was significantly lower after TTG vs. BI (12.5 vs. 46%, p=0.01). The results for Diskus® were similar and approached significance (25 vs. 80%, p=0.05). Participants with 30-day acute health-related events were less common in the group receiving TTG vs. BI (1 vs. 8, p=0.02). CONCLUSIONS: TTG appears to be more effective compared with BI. Patients over-estimate their inhaler technique, emphasizing the need for hospital-based interventions to correct inhaler misuse. Although TTG was associated with fewer post-hospitalization health-related events, larger, multi-centered studies are needed to evaluate the durability and clinical outcomes associated with this hospital-based education.

Misuse of respiratory inhalers in hospitalized patients with asthma or COPD.

BACKGROUND: Patients are asked to assume greater responsibility for care, including use of medications, during transitions from hospital to home. Unfortunately, medications dispensed via respiratory inhalers to patients with asthma or chronic obstructive pulmonary disease (COPD) can be difficult to use. OBJECTIVES: To examine rates of inhaler misuse and to determine if patients with asthma or COPD differed in their ability to learn how to use inhalers correctly. DESIGN: A cross-sectional and pre/post intervention study at two urban academic hospitals. PARTICIPANTS: Hospitalized patients with asthma or COPD. INTERVENTION: A subset of participants received instruction about the correct use of respiratory inhalers. MAIN MEASURES: Use of metered dose inhaler (MDI) and Diskus devices was assessed using checklists. Misuse and mastery of each device were defined as <75% and 100% of steps correct, respectively. Insufficient vision was defined as worse than 20/50 in both eyes. Less-than adequate health literacy was defined as a score of <23/36 on The Short Test of Functional Health Literacy in Adults (S-TOFHLA). KEY RESULTS: One-hundred participants were enrolled (COPD n = 40; asthma n = 60). Overall, misuse was common (86% MDI, 71% Diskus), and rates of inhaler misuse for participants with COPD versus asthma were similar. Participants with COPD versus asthma were twice as likely to have insufficient vision (43% vs. 20%, p = 0.02) and three-times as likely to have less-than- adequate health literacy (61% vs. 19%, p = 0.001). Participants with insufficient vision were more likely to misuse Diskus devices (95% vs. 61%, p = 0.004). All participants (100%) were able to achieve mastery for both MDI and Diskus devices. CONCLUSIONS: Inhaler misuse is common, but correctable in hospitalized patients with COPD or asthma. Hospitals should implement a program to assess and teach appropriate inhaler technique that can overcome barriers to patient self-management, including insufficient vision, during transitions from hospital to home.