Table 3

Comparisons of previous cough augmentation studies

Study	Year	Subjects	n	Apparatus	Cough adjunct	FEV₁ (l or % predicted)	CEFR (l/min)	Poes
Present		2001		Normal	9	Pneumotachograph	MAC	3.80 (98%)	668
				COPD	8	Poes and Pabd	MI	0.95 (37%)	370
				RMW with scoliosis	4		MAC + MI	0.73 (19%)	104	12^3-165
				RMW without scoliosis	8			0.80 (33%)	288
Barachet al 17		1953		Normal	15	Differential pressure^3-150	ME	NA	465	NA
				COPD	19				251
				Polio	1				<180
Barachet al 26		1954		COPD	53	Mask pressures	ME	NA	NA	NA
				Polio	12
				Postoperative	8
				Bronchiectasis	23
Bickermanet al 24		1958		Normal	18	Pneumotachograph	Isoproterenol	NA	409	NA
Bickermanet al 24		1958		Asthma	25				187
Kirbyet al 18		1966		Tetraplegics		12		Wedge spirometer		MI (50 cm H₂O)	1.85 litres	218	NA
										MAC
										Abdominal binders
Leineret al 14		1966		Normal	25	Wright peak flow meter	Isoproterenol	85.6%	597.2	NA
				Obstructive	40			56.7%	320.9
				Restrictive	22			77.0%	387.3
				Combined restrictive	50			47.8%	175.5
Loudonet al 19		1967		Normal	9	Pneumotachograph	Maximal voluntary cough	3.9 litres	672	167.3
Loudonet al 19		1967		COPD	9	Poes		1.1 litres	288	153.2
Langlands et al 20		1967		Normal	10	Pneumotachograph	30% citric acid	3.3 litres	487	147
Langlands et al 20		1967		COPD	10	Poes and Pabd		1.4 litres	165	180
Bach et al 32	1993	Neuromuscular	46	Peak flow meter	MI-E	0.44	104
Bach et al 16		1995		ALS		50 (27 successfully treated)		Peak flow meter		MI-E	0.73^3-160	276	NA
Bach et al 16		1995		ALS		50 (27 successfully treated)		Peak flow meter		MAC	0.93^3-160	150

COPD = chronic obstructive pulmonary disease; ALS = amyotrophic lateral sclerosis; Poes = oesophageal pressure; Pabdo = gastric pressure; MI = mechanical insufflation; MI-E = mechanical insufflation and exsufflation; MAC = manually assisted cough; ME = mechanical exsufflation; GPB = glossopharyngeal breathing.
↵3-150 Unable to record less than 180 l/min.
↵3-160 Sitting vital capacity within 3 months of initial ventilator use (second value is that of unsuccessfully treated subjects).
↵3-165 Value for three subjects with respiratory muscle weakness (two without and one with scoliosis).