Peak cough flow

It is difficult to predict if a neurologically injured patient will successfully be extubated. Salam et alstudied 88 patients prospectively, measuring cough peak flow (CPF), endotracheal secretions, and the ability to complete four simple tasks prior to extubation. In patients who failed extubation, they had a lower CPF p = 0.03), higher amount of secretions (RR 3.0, 95% Cl 1.0-8.8), and diminished ability to complete the four simple tasks (RR 4.3, 95% Cl 1.8-10.4). 

Smina M, Salam A, Khamiees M, et al. Cough peak flows and extubation outcomes. Chest 2003 124(l) 262-268. 

Human Toxicology. Male volunteer subjects acutely exposed to 70 mg m cinnamic acid for 10 min had only transient minimal irritant symptoms (slight excess lacrimation, mild rhinorrhea, and bouts of nonproductive coughing) with minor increases in breathing rate, tidal volume, and minute volume, which remrned to control values within 5-10 min of the end of exposure peak flow rate, forced vital capacity, and forced expiratory volume were not significantly altered. Pre- and postexposure chest radiographs were normal (Ballantyne and Clifford, 1978). 

Suarez AA, Pessolano FA, Monteiro SG, et al. Peak flow and peak cough flow in the evaluation of expiratory muscle weakness and bulbar impairment in patients with neuromuscular disease. Am J Phys Med Rehabil 2002 81 506-511. 

Sancho J, Servera E, Diaz J, et al. Comparison of peak cough flows measured by pneumotachograph and a portable peak flow meter. Am J Phys Med Rehabil 2004 83 608-612. 

Respiratory Even non-asthmatic patients should be carefully monitored for respiratory adverse effects when they are first given cardioselective beta-blockers. A 79-year-old man developed a wheeze without dyspnea or cough. After withdrawal of celiprolol, which he had taken for 7 years before the onset of the wheeze and for 3 years after, his peak expiratory flow rate improved as did his respiratory symptoms... 

The use of peak cough flow (PCF) and peak expiratory flow (PEF) are also useful in monitoring expiratory muscle weakness and bulbar involvement (32,33). When PCF is... 

Bach JR. Mechanical insufflation-exsufflation. Comparison of peak expiratory flows with manually assisted and unassisted coughing techniques. Chest 1993 104(5) 1553-1562. 

Airway mucus elimination can be impaired by factors external to the lungs and airways. When mucociliary clearing fails and coughing is indispensable for bronehial elearanee, the effectiveness in eliminating secretions is determined by the amount of flow generated in the expulsive phase. These factors depend on the linear veloeity of gas flow, the diameter of the segment, and dynamic compression, and they are manifested basically in the peak cough flow (PCF) (26). 

Figure 1 Air stacking with manual resuscitator via a mouthpiece in a high spinal cord patient with low vital capacity and suboptimal peak cough flow.

Figure 2 PCF measured from the maximally air stacked volume (MIC) in supine position in a neuromuscular patient. Abbreviations. PCF, peak cough flow MIC, maximum insufflation capacity.

Figure 8 Manually assisted cough with abdominal thrust to measure PCF in sitting position. Abbreviation. PCF, peak cough flow.

Clough JB, Williams JD, Holgate ST. Effect of atopy on the natural history of symptoms, peak expiratory flow, and bronchial responsiveness in 7- and 8-year-old children with cough and wheeze. Am Rev Respir Dis 1991 143 755-760. 

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