Respiratory care最新文献

Background: The interaction between nebulizer technology and mechanical ventilation can be confusing. Mesh technology has recently been quantified using the mass balance, a technique that measures all aerosol delivered and lost in ventilator circuits. Data for jet nebulizers are limited, and ventilator technology has changed over time. The present study was designed to better define aerosol behavior during jet nebulization by testing device position, gas source, humidification, inspiratory time (T_I), and circuit compliance.

Methods: Using radiolabeled particles, mass balance and output rate were measured for the AeroTech nebulizer placed close to the ventilator (IP), Y-piece (YP), and proximal to ETT (DY) in aerosol HME or humidified settings. The nebulizer was driven continuously (8 L/m, 50 PSIG) or by breath actuation (BA) during volume control ventilation at two inspiratory times (T_I 0.7 and 0.55 s). Five ventilators and two circuits with different tubing compliance were tested. Radiolabeled saline (3 mL, Tc^99m) was nebulized. A well counter measured filters inhaled and expiratory mass (IM, EM), and nebulizer residual (NR). Tubing deposition was measured with a gamma camera. A shielded ratemeter measured output rate and treatment time.

Results: Mass balance ranged from 96 to 104% (no. = 66). IM obtained with IP, HME circuit, continuous nebulization (29.8 ± 5%), IP, and BA (26.8 ± 4%); with humidification, continuous (15 ± 1%), BA (27.1 ± 4). Lowest IM at YP position, HME (8.8 ± .6%). Circuit losses ≤20%. EM was lowest for IP (19.2 ± 2%) and highest for YP and DY (46 ± 3%). NR was higher with BA (43.1 ± 6 vs 37.1 ± 3, P = .002). Higher tubing compliance lowered IM (21.8 ± .7% vs 28.3 ± 3% [no. = 9], P = .01). Treatment time for IP, continuous, HME circuit (10 min), and BA circuit (50 min). Changing T_I (0.55 s) reduced IM and further increased treatment time.

Conclusions: Optimal conditions for jet nebulization were IP position, HME circuit, continuous nebulization, and stiff tubing. Humidification should be supplied with an aerosol HME. If active humidification, IP breath-actuated was most efficient but with marked increase in treatment time.

Background: There is limited evidence comparing center and home-based sit-to-stand (STS) tests in individuals with chronic respiratory disease (CRD). This study aimed to estimate the level of agreement and performance differences among center-based, remotely supervised, and self-administered STS tests in individuals with CRD.

Methods: A repeated-measures design was used to compare the 30-s and 1-min STS across 3 test conditions. The sample size was one of convenience and included subjects with CRD from an out-patient pulmonary rehabilitation program in Toronto, Canada. Bland-Altman analysis was used to estimate STS agreement across conditions, reporting mean difference and 95% limits of agreement (LoA). Analysis of variance was used to estimate differences in STS performance across conditions, controlling for testing order. Secondary measures included indicators of safety and acceptability of the remotely supervised and self-administered conditions. All analyses were completed using Stata/BE 17.0 with a significance level of P ≤ .05.

Results: Twenty-seven participants (mean age 69.4 ± 11.8 years, 52% female) completed STS testing in all 3 conditions. Bland-Altman plots revealed limited bias across all comparisons (mean difference < 1 repetition). LoA illustrated individual variation across comparisons for the 30-s STS (LoA -3.4 to 4.1) and 1-min STS (LoA: -7.4 to 8.6). Analysis of variance models indicated no effect of test condition on either 30-s STS (P = .12) or 1-min STS (P = .33). There was an observed order effect for the 30-s STS (P = .005) and 1-min STS (P = .005). There were no serious adverse events for remotely supervised and self-administered tests. The majority (≥ 80%) of participants found the instructions clear, and felt safe and confident while performing the remotely supervised and self-administered STS.

Conclusions: Performance on the 30-s and 1-min STS did not differ across test conditions. Remotely supervised and self-administered tests may be safe and acceptable.