ST Chiang, MD FCCP; J undecayed M....

ST Chiang, MD FCCP; J undecayed M.A., R.R.T.; W.F. Wang, BS; YJ Yang, BS; G M Shiao, MD F.C.C.P.;[unkeyable] and SC King, M.T.[unkeyable]

Total respiratory resistance (Rrs) pulmonary resistance (RL) and airway resistance (Raw) of 12 male patients with chronic obstructive lung disease were measured through the partial occlusion method, intraesophageal balloon technique, and corpse plethysmography, respectively. Chest wall resistance (Rcw) and lung tissue resistance (Rti) were comput Percentages of Rcw/Rr RL/Rr Raw/Rrs, Rti/Rrs, Raw/RL, and Rti/RL were calculated. The magnitude of the constitutings of resistance to breathing of this cogitation and the data appearing in the literature are compared. Wide variation between the data reported on various authors was observed. The possible causes of these variations are discussed.

Increased resistance to breathing can make known from a variety of diseases.[1] Therefore, objective measurement of respiratory resistance is important. At quick in emergencies three methods to determine resistance to breathing have been used extensively in research and clinical laboratories,[2] namely: material substance plethysmography for measurement of airway resistance (Raw),[3] esophageal balloon mode for measurement of pulmonary resistance (RL)[4] and the oscillation order for measurement of total respiratory resistance (Rrs)[5] Chest wall resistance (Rcw) and lung tissue resistance (Rti) are usually calculated from the data obtained from these measurements.[6,7] In a review of the literature, we institute little data related to composings of resistance coming from the same subdues or patients.

lately a method to determine total respiratory resistance (Rrs) simply and reproducibly at spontaneous respiratory frequent occurrence has been developed.[8-10] The drifts of this study were: (1) to determine total respiratory resistance, pulmonary resistance and airway resistance according to three methods[3,4,9] performed in the same individuals; (2) to calculate the magnitudes of composings of the resistance including chest wall resistance and lung tissue resistance in the same subjects; (3) to compare these data with those available in the literature. In the literature, data of the like kind as these appear only in fragments. We attempt to inflict them together and to emphasize the importance of resistance determination. a of the factors that may affect resistance measurements, moreover are rarely accounted for, are also systematically analyzed.

METHODS

Total resistance of respiratory plan (Rrs) in this study was obtained by the agency of the partial occlusion method,[8-10] pulmonary resistance (RL) on esophageal balloon method,[4] and airway resistance (Raw) from body plethysmography.[3] Chest wall resistance (Rcw) was calculated as Rrs-RL[67] and tissue resistance (Rti) was calculated as RL-Raw.[6,7]

For the one and the other Rrs and RL, flow was measured using a Fleisch-type pneumotachograph (HP 21071) a differential crushing transducer (Validyne MP45-871[+ or -] 2 cm [Hsub2]O) and a Gould 13-4615-58 amplifier. Signals proportional to liquefy and transpulmonary pressure (Ptp) were recorded using a Gould prototype 2200S recorder and an instrumentation tape recorder (HP 3968A). Breathing oftenness was measured from the oscillograph tracings. Rr and RL were measured during resting tidal breathing with the nasal airway occlud and the cheeks crushed inward.

To measure Rr we transiently increased the resistance external to the enthrall The method and equipment used were those described by the agency of Shaw et al,[8] as modified through Chiang et al.[9,10] Total respiratory resistance was determined as [Mathematical Expression Omitted] [910] The body gives a digital output of Rr within les than 1 s after making the measurement.[10] We measured Rr one time per breath, at or just after the time of tidal peak expiratory melt A mean of at least eight measurements was used as each patient's Rrs

For measurement of RL intraesophageal press changes were taken to indicate changes in intrapleural urgency A 14.5-cm long balloon (1 cm in diameter) upon the end of a plastic catheter was passed by means of the nose into the esophagus, and the tip was positioned 38 cm from the nares. The balloon was inflated with no more than 06 ml of air. The other finis of the catheter was communicateed to one side of a differential compressing transducer (Statham, model PM131TC), and the other side of the transducer was joined to a port on the side of the mouthpiece to measure Ptp Later, recorded spring and Ptp signals were played back at either 25 percent or 125 percent of the original spe The be derived signal went through an analog integrator (Grass 7P10F) and also went directly to an oscilloscope and an X-Y recorder (Gould 3054) where it was displayed against the Ptp signal. A custom-built electrical subtraction circuit was included to allow for a variable signal, proportional to the integrator output to be subtracted from the Ptp signal before it was displayed. The subtraction [i]modus operandi[/i] described by Mead and Whittenberger[4] was then used to measure RL [TABULAR DATA OMITTED]