Kenneth Axen

Effect of Milk Ingestion on Pulmonary Function in Healthy and Asthmatic Subjects

Since Maimonides, it has been common in folk medicine to proscribe milk for asthmatics because its putative stimulation of mucus production can exacerbate asthma symptoms. A literature review, however, failed to reveal any data supporting this notion. We, therefore, compared the effects of ingesting 16 oz. of whole milk (16 g lipid), skim milk (2 g lipid), and water (each on a separate day) on: (1) forced expiratory volume in 1 second (FEV1), (2) forced expiratory flow at 50% of vital capacity (V50), and (3) pulmonary diffusing capacity (DLCO) in 11 asthmatic and 10 nonasthmatic subjects. Measurements were taken at 30 minute intervals for 3 hours. The two milk types did not significantly change FEV1 or V50 in either group, indicating that the amount ingested did not change airway resistance sufficiently to alter airflow parameters. In the asthmatic group, however, DLCO decreased progressively over the 3 hours by 6.8 +/- 1.4% (mean +/- SE) per hour after whole milk (maximum reduction = 21 +/- 1.4%) but not after water or skim milk. In the nonasthmatic group, no significant effects were observed on DLCO after any of the liquids. These data suggest that milk lipids can disturb gas exchange in asthmatic patients.

Complications after cardiac operations in patients with severe pulmonary impairment

The postoperative courses of 39 patients with severe lung disease (31 with obstructive disease and 8 restrictive) who underwent a cardiac operation were retrospectively reviewed. The stay in the intensive care unit of the study group was 7.9 +/- 10.3 days (mean +/- standard deviation) compared with 2.4 +/- 3.9 days for the control group (100 patients with less impaired pulmonary function) (p less than 0.001). The study group also had a greater number of valve replacements than did the control group (p less than 0.01). Patients with obstructive disease had more respiratory complications than did patients with restrictive disease (p less than 0.05). There were 21 cases of atelectasis. Effusions were noted in 11 patients. Ten patients had bronchospasm. Bronchial secretions were a major problem in 6 patients. Pneumonia developed in 4 patients, and pneumothorax occurred in 3 others. The two in-hospital deaths were not directly related to pulmonary complications. Our findings indicate that (1) patients with severe lung impairment generally do well after a cardiac operation but have more postoperative pulmonary complications than patients with less impairment; (2) patients with restrictive pulmonary disease appear to fare better than those with obstructive disease; (3) pulmonary function tests can alert the clinician to the possible risk of postoperative complications, but they cannot, by themselves, be used to exclude patients from operation; and (4) patients with severe pulmonary impairment facing valve replacement are at greater risk of pulmonary complications than patients having other types of cardiac surgical intervention.

Servo Control of Atrial and/or Arterial Blood Pressures in Experimental Animals

A control system employing two adjustable reservoirs for the independent regulation of atrial and/or arterial blood pressures simultaneously at both sides of the heart is described. Two servo-motors position these reservoirs and thereby automatically regulate atrial filling and hence ventricular output to produce various controlled pressure wave forms.