Nicholas E. O'Connor

Permanent coverage of large burn wounds with autologous cultured human epithelium

WHEN burns are so extensive that skin grafts obtainable from remaining donor sites are insufficient to provide wound coverage, a new source of autograft must be found. Human epidermal cells from a ...

Cultured epithelial autografts for giant congenital nevi

Eight pediatric patients with giant congenital nevi confluent over 21 to 51 percent body surface area were treated by excision and grafting. The nevus was excised to the muscle fascia, and the open wound was grafted with cultured epithelial autografts and split-thickness skin grafts. The patients have been followed from 17 to 56 months. Seventeen operations were performed in the eight patients, excising a mean of 6.9 percent body surface area at each procedure. The mean duration of anesthesia was 3.7 hours, and the mean operative blood loss was 12.3 percent estimated blood volume. The mean “take” for the cultures epithelial autografts was 68 percent, and for the split-thickness skin grafts, 84 percent. Epithelialization of open wound areas adjacent to the grafts was somewhat slower for the cultured epithelial autografts than for the split-thickness skin grafts, but it led to a healed wound in all patients except one. Ten of the 17 areas grafted with cultured epithelial autografts resultee in small open wounds that required regrafting. Wound contraction under the cultured epithelial autografts and under split-thickness skin grafts was similar and depended more on the anatomic site grafted than on the type of graft employed. In 16 of 17 operations, the cultured epithelium remained as a permanent, durable skin coverage. The use of cultured epithelial autografts allowed a larger area of excision than would have been possible with split-thickness skin grafts alone and, therefore, a more rapid removal of nevus. Cultured epithelial autograft are an important new technique in the care of patients with giant congenital nevi.

Acute Hemodilution: Its Effect on Hemodynamics and Oxygen Transport in Anesthetized Man

: The effects of acute normovolemic hemodilution on hemodynamics, oxygen transport, tissue perfusion and blood volume were studied. The subjects were four patients undergoing total hip replacement with prebleeding and hemodilution under fluoroxene and nitrous oxide anesthesia. The hematocrit was reduced to 29% and 21% by bleeding in two steps with simultaneous infusion of plasmanate and lactated Ringers solution. The major compensation was a rise in CO to 123% and 136%. Systemic oxygen transport (COX arterial O(2) content) was only slightly reduced and the arteriovenous oxygen difference decreased. Tissue perfusion remained excellent. Blood volume was slightly expanded. The procedure was well tolerated by this group of selected patients, and homologous blood utilization was markedly reduced.

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.

Response of the Lung to Six to 12 Hours of 100 per Cent Oxygen Inhalation in Normal Man

Abstract To assess the early effects of 100 per cent oxygen breathing in normal human lungs without pre-existing pulmonary disease, mechanical ventilation and blood transfusions, 11 carefully informed, healthy young men were studied. Nine breathed 100 per cent oxygen at ambient pressure for six to 12 hours, and two served as controls. To study the changes at the pulmonary vasculature level, the following determinations were made: alveolar-arterial oxygen gradient, physiologic pulmonary shunt, pulmonary artery pressure, total pulmonary resistance, cardiac output and pulmonary extravascular water volume. A comparison of the values during the equilibration period with those throughout the 100 per cent oxygen breathing period revealed no statistically significant changes.

A simple technique for detecting small defects of the atrial septum

Abstract A sensitive technique for detecting small defects of the atrial septum is described. A Valsalva maneuver is used to cause right atrial pressure to exceed left atrial pressure. This reversal of the normal interatrial pressure gradient causes a transient right to left shunt across the defect. The right to left shunt is detected by noting an early appearance deflection in standard indicator-dilution curves performed by injecting indocyanine green dye into the inferior vena cava during the Valsalva maneuver. By means of this technique, 7 of 8 surgically induced defects, from 1 to 12 mm in diameter, were detected. There were no false positive results among 9 control animals with an intact atrial septum. This technique presents a sensitive and simple method for detecting small atrial septal defects. The only equipment required is that used to perform standard indicator-dilution curves.

Fiberoptics: morbidity and cost.

The authors report on the success of using fiberoptic instruments for laparoscopy, colonoscopy, and polypectomy, thus reinforcing a previous report by Wolff and Shinya of similar successes. The results showed numerous advantages for using fiberoptics: 1) reduced complications, 2) reduced costs, 3) earlier return to employment and normal activities, and 4) shorter hospital stay. It is hoped that endoscopic procedures will soon be able to be done under local anesthesia and on an outpatient basis, reducing costs even more.

Effects of the fiberoptic laparoscope and colonoscope on morbidity and cost.

A study was conducted to determine whether new surgical technology could achieve important reductions in morbidity and cost. Surgical operations which have been greatly simplified by 2 advances in fiberoptics were considered: the laparoscope to replace transvaginal or transabdominal tubal ligations and the colonoscope to replace transabdominal pedunculated colonic polypectomies. With the laparoscope serious operative complications were reduced from 23% to 3% while cost was reduced by 30%. With the colonoscope serious operative complications were eliminated while average cost decreased by two-thirds. The performance of both procedures via fiberoptic scope appears to have important advantages for the patient in reduction of complications and cost.

The Influence of Clinically Undetectable Pulmonary Edema on Small Airway Closure in the Dog

The relationship between elevated pulmonary extravascular water volume (PEWV) and small airway closure was examined. The slow accumulation of lung water was achieved by a combination of pulmonary venous hypertension and mild hemodilution. PEWV was measured using a double indicator method based on the differential right to left transit time for simultaneously injected Evans blue dye and tritiated water. Trapped gas volume (VTG) was measured by the helium equilibration technique. Clinically undetectable levels of pulmonary engorgement and edema were reproducibly associated with an increase in gas trapping. Positive end expiratory pressure reduced, but did not abolish, edema formation. Evaluation of airway closure, with consequent gas trapping and pulmonary shunting, is currently non-invasive, simple and safe. Determination of gas trapping or closing volume should be incorporated into the routine pre-operative evaluation of patients prior to major surgery.