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D J Gillespie

Publications and source records attributed to D J Gillespie.

27 records · Page 2Linked to original sources
PubMed1985

Pulmonary dysfunction during paraquat-induced lung injury: a model of acute alveolar injury.

Acute lung injury produced by paraquat causes progressive pulmonary insufficiency. To define the pattern of this injury, the sequence of changes in respiratory mechanics and pulmonary gas exchange was studied in eight mongrel dogs which received repetitive doses of paraquat intraperitoneally. Four other dogs served as controls. All dogs were studied while supine during halothane anesthesia. After baseline measurements, saline (control) or paraquat was administered and the studies repeated at 2, 4, 7, and 9 days. Control dogs showed no significant changes. Dogs receiving paraquat had reduced lung volume, decreased lung compliance with a shift of the static deflation pressure-volume curve downward and to the right, and hypoxemia which could not be entirely accounted for by an increased right-to-left intrapulmonary shunt. This study demonstrated that repeated doses of paraquat given intraperitoneally produced a pattern of acute lung injury in the dog which permitted the study of respiratory mechanics and gas exchange during progressive stages of lung injury.

Animals↗
PubMed1983

High-frequency ventilation. A new concept in mechanical ventilation.

High-frequency ventilation has been shown to provide adequate pulmonary gas exchange in patients who require mechanical ventilation. The advantage of this method of ventilation is that it may allow effective gas transport without high airway pressure or depression of hemodynamic function and thus avoid barotrauma or decreased cardiac output. Currently, three major systems have evolved. (1) High-frequency positive-pressure ventilation uses frequencies of 60 to 120/min, and gas is delivered through a pneumatic valve system. It has been successfully used during surgical procedures, laryngoscopy, and bronchoscopy. (2) High-frequency jet ventilation uses compressed gas delivered through a small-bore cannula at frequencies of up to 400/min. This technique has been used during laryngoscopy and seems to be promising for ventilation of patients with disruption of the airway. (3) High-frequency oscillation uses a wide range of frequencies, up to 40 HZ, and small quasi-sinusoidal volume excursions. It has been reported to provide adequate pulmonary gas exchange in human volunteers and patients in respiratory failure requiring mechanical ventilation. The mechanism of gas transport during high-frequency, low-tidal-volume ventilation is not well understood, but theoretic models suggest that enhanced diffusion, interregional mixing, and intra-airway velocity profiles may be important factors.

Adult↗
PubMed1982

Comparison of intraesophageal balloon pressure measurements with a nasogastric-esophageal balloon system in volunteers.

Recently, an esophageal balloon incorporated into a nasogastric tube was designed that allowed measurement of intraesophageal pressure. To define the performance of this nasogastric-esophageal balloon (NG-EB) system, comparative measurements were made with a standard esophageal balloon while subjects were in the sitting, supine, and left lateral decubitus and right lateral decubitus positions. Values for dynamic pulmonary compliance, pulmonary resistance, and cough pressure were not statistically different between the two systems. Mean static deflation pressure-volume (P-V) curves using the NG-EB were shifted to the left of the esophageal balloon P-V curve in all body positions, but static lung compliance (CL) was not statistically different. For both balloon systems, CL showed no significant difference between sitting and right lateral decubitus positions. Results from this study indicate that the NG-EB system acceptably reflects esophageal balloon pressure measurements and should be useful in estimating lung and chest wall mechanics in acutely ill patients requiring mechanical ventilation.

Adult↗
PubMedDate not supplied

Reduced work of breathing after single lung transplantation for emphysema.

BACKGROUND: Pulmonary emphysema, with or without chronic bronchitis, has emerged as the most common indication for successful single lung transplantation. Although gas exchange can be expected to improve after successful transplantation, such changes do not adequately explain the improvement in dyspnea experienced by these patients and resulting in improved quality of life. METHODS: We prospectively studied the respiratory mechanics of 14 single lung transplantation recipients with pulmonary emphysema, of whom 10 have been followed up beyond 1 year. The mean age of the group was 48.8 years (range, 42 to 60 years) for the seven men and seven women. Average donor-predicted total lung capacity was 0.6 L (+0.2 [standard error]) greater than recipient-predicted total lung capacity. Comparison of pulmonary resistance, dynamic lung compliance, and static lung compliance were taken to examine the possible role of reduced airways resistance and of improved elastic recoil in the reduced work of breathing. Results were analyzed by means of a one-tailed paired Student t test and linear regression analysis (both stepwise and multivariate); results are tabulated by mean (+/- 1 [standard error]). RESULTS: Between preoperative measurements and 12 months postoperatively, maximum lung elastic recoil increased from 8.1 (+/- 0.7) to 11.3 (+/- 1.0) cm H2O, p < 0.01; pulmonary resistance fell from 8.3 (+/- 0.8) to 5.4 (+/- 0.7) cm H2O sec/L, p < 0.01. Dynamic lung compliance fell from 0.23 (+/- 0.04) to 0.12 (+/- 0.02) L/cm H2O, p < 0.02, and static lung compliance fell from 0.66 (+/- 0.13) to 0.22 (+/- 0.05) L/cm H2O, p < 0.001. CONCLUSIONS: The decline in lung compliance after single lung transplantation reflects the importance of improvement in elastic recoil and reduced chest wall distention, improving the work of breathing. The 67% decline in static lung compliance (300% increase in elastic recoil) is probably the single most important mechanical factor leading to reduced dyspnea after single lung transplantation for emphysema.

Airway Resistance↗