Recovery after Unilateral Phrenic Injury Associated with Coronary Artery Revascularization: Methods (1)

Five patients with possible diaphragmatic dysfunction after CAB surgery were recruited for study over a six-month period. Patients were referred because of a persistence of diaphragm elevation evidenced on the chest radiograph or the presence of otherwise unexplained respiratory symptoms postoperatively. buy ortho tri-cyclen online
Details of any preoperative respiratory or other medical problems were elicited from the admission history and physical examination. All patients had preoperative and postoperative chest radiographs. Details of the operative procedure, including operative and bypass time, number of grafts, body temperature, whether or not a polystyrene shield was used and the postoperative course were obtained.
Spirometry was measured using a 10-L water filled spirometer (VV. Collins Company, Braintree, MA) calibrated with a 3-L syringe. Spirometry technique and measurements conformed to standard criteria and reference values were taken from Morris et al. Maximal static inspiratory and expiratory pressures at the mouth were measured with subjects seated and w’earing a nose clip. Details of the apparatus and method used have been provided previously. The Pimax and Pnmax values were repeated until three measurements sustained for a minimum of 1 s varied by less than 5 percent. The maximal value was selected and expressed as percent predicted using the regression equations of Black and Hyatt.