S W Kang1, J R Bach. 1. University Hospital, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark 07103, USA.
Abstract
OBJECTIVE: To investigate the relationships between vital capacity (VC), maximum insufflation capacity (MIC), and both unassisted and assisted peak cough flows (PCFs). DESIGN: The 108 patients were divided into two groups, those whose MICs were greater than their VCs (group 1) and those whose MICs could not exceed their VCs (MIC = VC, or group 2). RESULTS: The MIC correlated positively with the VC for group 1 patients, but the percent increase in MIC correlated negatively with VC. Both VC and MIC correlated significantly with both unassisted and assisted PCF, respectively. Assisting the cough increased the PCF of 37 patients over a previously defined critical level of 2.7 L/sec. The MIC VC difference and percent increase in MIC also correlated significantly with the difference between unassisted and assisted PCF. Although the group 2 patients did not have true cough flows because of inability to close the glottis, their peak expiratory flows were significantly less than the unassisted and assisted PCF of the group 1 patients. CONCLUSIONS: The greater the MIC VC difference, the greater the PCF, and, thereby, the ability to expel airway mucus and avert respiratory complications. The lower the VC, the greater the percent increase in MIC and the greater the percent increase in assisted PCF. Maximal insufflations are extremely important to increase PCF for patients with neuromuscular conditions who have VCs of < 1500 ml.
OBJECTIVE: To investigate the relationships between vital capacity (VC), maximum insufflation capacity (MIC), and both unassisted and assisted peak cough flows (PCFs). DESIGN: The 108 patients were divided into two groups, those whose MICs were greater than their VCs (group 1) and those whose MICs could not exceed their VCs (MIC = VC, or group 2). RESULTS: The MIC correlated positively with the VC for group 1 patients, but the percent increase in MIC correlated negatively with VC. Both VC and MIC correlated significantly with both unassisted and assisted PCF, respectively. Assisting the cough increased the PCF of 37 patients over a previously defined critical level of 2.7 L/sec. The MIC VC difference and percent increase in MIC also correlated significantly with the difference between unassisted and assisted PCF. Although the group 2 patients did not have true cough flows because of inability to close the glottis, their peak expiratory flows were significantly less than the unassisted and assisted PCF of the group 1 patients. CONCLUSIONS: The greater the MIC VC difference, the greater the PCF, and, thereby, the ability to expel airway mucus and avert respiratory complications. The lower the VC, the greater the percent increase in MIC and the greater the percent increase in assisted PCF. Maximal insufflations are extremely important to increase PCF for patients with neuromuscular conditions who have VCs of < 1500 ml.
Authors: Enrico M Clini; Francesca Degli Antoni; Michele Vitacca; Ernesto Crisafulli; Mara Paneroni; Sheila Chezzi-Silva; Maurizio Moretti; Ludovico Trianni; Leonardo M Fabbri Journal: Intensive Care Med Date: 2006-10-24 Impact factor: 17.440
Authors: Deanna Britton; Joshua O Benditt; Albert L Merati; Robert M Miller; Cara E Stepp; Louis Boitano; Amanda Hu; Marcia A Ciol; Kathryn M Yorkston Journal: Dysphagia Date: 2014-07-19 Impact factor: 3.438