This study aimed to 1) identify effective methods for improving cough strength and 2) examine the conditions requiring therapeutic intervention with gastrostomy based on cough strength and respiratory function in patients with MSA.
The patients diagnosed with probable MSA were participated in this study. Evaluation items included respiratory function tests, maximum insufflation capacity (MIC), and peak cough flow (PCF). Respiratory function tests included vital capacity (VC), % vital capacity (%VC), and % forced vital capacity (%FVC). MIC was measured by connecting a simple flowmeter and pressure gauge to a bag valve mask to apply positive pressure to the patient and measuring the expiration volume and pressure. The supplying air pressure was set to 20 cmH2O. PCF was measured using four different methods: 1) spontaneous coughing (SpC), 2) SpC plus manually assisted cough (MAC) (SpC + MAC), 3) coughing after obtaining MIC (SpC + MIC), and 4) coughing with MAC and MIC (SpC + MAC + MIC). In this study, patients were divided into two groups: the air stacking group, which was able to hold their breath during MIC measurement, and the non-air stacking group, which was unable to hold their breath during MIC measurement. Statistical analysis was performed using paired t-tests, two-sample t-tests, and Fisher's exact test, as appropriate. Receiver operating characteristic (ROC) curves were used to investigate the cutoff values for PCF 270 L/min and 160 L/min for SpC and SpC + MIC in %FVC.
Eighteen patients participated in this study, 12 in the air stacking group and 6 in the non-air stacking group. In terms of inspired volume, MIC was significantly higher than VC in air stacking group (MIC: 3570.8 (± 1174.6) mL v.s. VC: 2884.2 (±1138.4) mL, P 0.01) and non-air stacking group (MIC: 2308.3 (±1040.4) mL v.s. VC: 1701.7 (± 769.3) mL, P 0.05). PCF increased significantly with MIC in the air stacking group (from 316.7 ± 129.0 L/min to 372.5 ± 141.9 L/min, P 0.01). On the other hand, in the non-air stacking group, no significant differences were observed in the cough augmentation measured by the four different methods. PCF could not be maintained at 160 L/min when %FVC fell below 59%, even when MIC was applied (AUC = 0.946, Sensitivity = 0.786, Specificity = 1.0, P 0.01).
PCF increases with MIC in patients with MSA. It may be meaningful to consider the timing of gastrostomy introduction based on the severity of cough and respiratory dysfunction.
Cough function could be improved in patients with MSA. Evaluation of coughing is important when considering the timing of gastrostomy.
cough
gastrostomy
