| Chest optimization is an evidence-based, protocol-guided clinical intervention for improving cardiopulmonary function of ventilator-dependent patients with cervical spinal cord injury (CSCI), and facilitating respiratory rehabilitation and ventilator weaning. Chest optimization consists of recumbent body positioning, sputum mobilization, airway bronchodilation and lung hyperinflation. The current study determined whether type of recumbent body positioning was associated with an extension in the duration of subsequent spontaneous breathing trials (SBTs). Twelve ventilator-dependent patients with CSCI received both Trendelenburg chest optimization (TCO) and supine chest optimization (SCO) in a randomized clinical intervention trial with crossover experimental design. All effects were statistically significant at the .05 level.;Results indicated a significant difference in SBT duration between TCO (M = 87.7, SD = 38.4) versus SCO (M = 33.5, SD = 30.3), t(11) = 6.26, p = .0001. There were also significant differences in cardiac output (CO), F(1,11) = 33.59, p < .0001, alveolar minute volume (MValv), F(1,11) = 14.71, p < .003, carbon dioxide elimination (VCO2), F(1,11) = 19.42, p < .001, static compliance (Cstat), F(1,11) = 16.04, p < .002, alveolar minute volume during SBT (MValv-SBT), F(1,11) = 6.17, p < .03 and rapid shallow breathing index during SBT (RSBI-SBT), F(1,11) = 15.44, p < .002, indicating that patients who underwent TCO experienced significant improvements in these cardiopulmonary variables.;Cardiopulmonary variables measured post-TCO predicted a significant, F (7,2227.88) = 13.69, p = .012, portion of the variance (R2 = .96) in Trendelenburg SBT duration. Sputum wet weight (beta = .93, p = .016), cardiac output (beta = 1.31, p = .003), pulse oxymetric saturation (beta = -.53, p = .017), alveolar minute volume (beta = .35, p = .048), carbon dioxide elimination (beta = .51, p = .02) and static chest compliance (beta = .68, p = .0007) were significant predictors of TSBT duration. Cardiopulmonary variables measured post-TSBT predicted a significant, F (4,3570.33) = 12.77, p = .002, portion of the variance (R2 = .88) in TSBT duration. Rapid shallow breathing index (beta = -.88, p = .001) was a significant predictor of TSBT duration. TCO was associated with significant extension in TSBT duration. Results support the use of TCO in rehabilitating and weaning ventilator-dependent patients with CSCI. |
