Striking a balance.
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Hospital Administrators↗
Biomedical subjects
L W Haldeman
Publications and source records attributed to L W Haldeman.
Cardiopulmonary effects of severe thoracic subcutaneous emphysema.
Isolated subcutaneous emphysema appeared to cause significant pulmonary dysfunction in a traumatized child with no demonstrable intrinsic pulmonary injury or disease. We developed an animal model of severe thoracic subcutaneous emphysema to determine whether it alters pulmonary-thoracic compliance such that ventilation-perfusion relationships or cardiac performance are affected adversely. Twelve anesthetized, mechanically ventilated swine were studied. Baseline measurements and calculations included intrapulmonary shunt fraction (Qsp/Qt), total static pulmonary-thoracic compliance, thermodilution cardiac output, systemic and pulmonary arterial pressures, and mean pulmonary arterial occlusion pressure. Measurements and calculations were repeated after each of three consecutive injections of 400 cc of air into the tissue over the sternum. Comparison of the baseline values with those after the injections showed no increase in Qsp/Qt and no change in any other variable (p less than 0.05). We conclude that, in this model, isolated thoracic subcutaneous emphysema does not adversely affect cardiopulmonary function during positive pressure ventilation.
Animals↗
Nitrous oxide administration in the presence of subcutaneous emphysema: an experimental model.
Adverse effects may occur when patients with air in the pleural space or in the cerebral ventricles breathe nitrous oxide. We developed an animal model to learn whether similar adverse effects are associated with the inhalation of nitrous oxide when air is present in the subcutaneous space. We induced extensive subcutaneous emphysema in swine and measured oxygen and carbon dioxide tensions in systemic arterial and mixed venous blood; cardiac output; intravascular, airway, and pre-sternal subcutaneous pressures; total pulmonary-thoracic static compliance; and thoracic girth before and after a 45 minute period of breathing 75 per cent nitrous oxide in oxygen. Cardiac output decreased from 3.13 +/- 0.51 l/min to 2.40 +/- 0.62 l/min (p less than 0.05); no other values changed significantly. No significant adverse cardiorespiratory effects resulted from the transfer of inhaled nitrous oxide to the subcutaneous space in this animal model.
Animals↗
Transcutaneous noninvasive monitoring of carbon dioxide tension.
We evaluated the accuracy of a new device for continuous noninvasive measurement of cutaneous PCO2. The Hewlett-Packard capnometer (model 47210/HA) works by means of an infrared transducer applied to the forearm over an area of skin that has been stripped of the stratum corneum. Capnometer transcutaneous carbon dioxide pressure (CPCO2) was compared with arterial carbon dioxide pressure (PaCO2) during 60 simultaneously obtained measurements in 13 hemodynamically stable patients. Each patient was studied for 1 1/2 to 5 hours, and a wide range of PaCO2 values (21 to 82 mm Hg) was represented. The data show a clinically significant relationship whereby PaCO2 = CPCO2 - 4.13, with a SE of +/- 2.19 mm Hg. Clinical usefulness of noninvasive cutaneous CO2 monitoring can be foreseen in patients whose ventilatory support is being tapered, in those with respiratory depression caused by various neuromuscular disorders, and in patients with chronic obstructive pulmonary disease and acute respiratory failure. Our results indicate that continuous transcutaneous CPCO2 measurements are safe and accurate and strongly suggest that they can be of clinical usefulness in a select group of hemodynamically stable patients.
Adult↗
Customized clinical case management for chronically ill patients. Health system sees remarkable results with teams of case managers, physicians, patients.
Securing excellent care and positive outcomes for seriously ill, high-risk patients requires extraordinary measures. A health system in Georgia is experiencing strong results by taking a team approach to health care with case managers, physicians and patients working together.
Ambulatory Care↗