Alfred P. Morgan

A method for continuous measurement of gas exchange and expired radioactivity in acutely III patients

Abstract Many problems of current metabolic and physiologic interest could be explored if a method were available for the continuous measurement of over-all gas exchange together with the pattern of expired radioactivity following the administration of tracer amounts of labelled foodstuffs. Equipment has been designed to collect and record continuously a patients expired CO 2 O 2 , and C 14 O 2 . It is a closed system using a rigid transparent collection canopy which is practical for long runs with sick patients. Close control of temperature and pressure, with provision for internal calibration, permit ± 2 per cent system accuracy. Concentration measurements are automatically integrated; readout is in chart and printed digital form.

Endocarditis with the indwelling balloon-tipped pulmonary artery catheter in burn patients.

The postmortem finding of acute right-sided bacterial endocarditis in a burn patient monitored with an indwelling pulmonary artery (Swan-Ganz) catheter for 14 days prompted a review of burn autopsies in which the catheter had been used. Autopsies of six consecutive burn patients monitored with a pulmonary artery catheter and who then died showed septic or aseptic endocarditis. In two of the six patients, right-sided staphylococcal endocarditis was the anatomic cause of death. In the remaining four, the lesions were aseptic thrombotic vegetations involving primarily the right atrium, tricuspid valve, right ventricle, and pulmonic valve. Several factors in the severely burned patient would favor endocarditis where a foreign object impacts on the heart valves. These include intermittent bacteremia, hypercoagulability, hyperdynamic cardiovascular function, and the use of antibiotics resulting in resistant strains. While an indwelling pulmonary artery catheter can provide useful monitoring information, it is sometimes responsible for serious complications in burned or septic patients.

Lung water changes after thermal burns. An observational study.

Pulmonary extravascular water has been measured as lung thermal volume (LTV) in a group of nine burned patients. Transducer-detectable indicators were used to permit frequent repetition and quick results. Concurrent recordings were made of cardiac output, pulmonary capillary wedge pressure and the usual hemodynamic variables. Moderate elevation of LTV was seen in all, reaching a maximum value before peripheral edema formation was complete. Left heart filling pressures were low as was plasma albumin concentration. Clinical pulmonary edema occurred in one patient treated mostly with crystalloid solution. In several, a secondary peak coincided with edema mobilization.

Evaluation of muscle mass measurement by 14C-creatine dilution in the dog

Dogs were given a tracer dose of 14C-creatine. A substantial fraction of the administered radioactivity is excreted in urine (27.5% in 5 days, 67% in 17 days); residual activity is concentrated in skeletal and smooth muscle (3–6% in other major viscera). However, tissue radioactivity of muscle tissue, when referred to weight, potassium, or nitrogen is not uniform, and no reasonable estimate of muscle mass can be made from a single biopsy specimen in this species.