Injuries causing major loss of scalp.

Long hair worn by both sexes in a majority of the rural population of Punjab (India) increases the hazard of descalping injuries. Forty-six cases seen over a period of 10 years are reported. Agricultural machinery accounted for 83 percent of these injuries. Males were most commonly involved (63 percent), and 48 percent of the patients were minors. Nearly all cases reported had at least half the scalp avulsed, 56.5 percent being total scalp avulsions, with bare bone exposed in 48 percent of the total. The method of chiseling the outer portion of the exposed bone down to bleeding points and immediately applying a split-thickness skin graft is presented as the procedure of choice for wound closure. This reduced the average hospitalization period by 49 percent as compared with older methods. Follow-up of 67 percent of patients has revealed a surprising instability of the grafted skin, with an ultimate danger of malignant degeneration.

Endogenous and exogenous infection with Pseudomonas aeruginosa in a burns unit.

Twenty patients who were admitted to the Burns Unit from December, 1969 through October, 1970 were studies to determine the sources of infection caused by Pseudomonas aeruginosa. The pyocine typing method was employed for finger printing of 383 isolates recovered from wounds and 67 isolates from environmental cultures of nurses' hands, sinks, floors, bed rails, walls and baths. In addition, cultures of moist rectal swabs were carried out daily for the first six days of hospitalization to assess the importance of endogenous infection. In six patients, the rectum was identified as the source of infection. However, in these patients, pyocine types of Ps. aeruginosa which were not obtained from rectal cultures, were also recovered. Pyocine types 1b, 10 and 31 were isolated more frequently than others. Clustering of common pyocine types suggests cross-contamination. Sinks were found to be consistently contaminated with Ps. aeruginosa. Amongst the environmental sources, positive cultures were occasionally obtained from floors, bed rails and nurses' hands. It is suggested that sinks are probably the most important reservoir of Pseudomonas infection in burns.

Radio-frequency probe for bubble size and velocity measurements.

A radio frequency (rf) probe that can provide local void fraction and interface velocity measurements in a gas-liquid two-phase flow was developed. The probe response to bubble passage was investigated with single-bubble controlled experiments. For a fixed geometry, the probe response was dependent on the dielectric constant of the medium surrounding the probe tip (air or water) and on the frequency of the carrier signal supplied to the probe. Bubble lengths (< 1 cm) and average bubble approach velocities (< 160 cm/s) were independently measured by two light sources and detectors placed at a known distance from each other and sensing the passage of each bubble. By choosing a sensitive probe tip length of 2.75-3 mm, the rf probe output provided enough information to determine the bubble length and velocity. The results obtained by the two independent methods show reasonable agreement (+/-10%).

The early acidosis of burns: its relationship to extent of burn and management.

Acid-base studies were carried out on 76 consecutive burn patients admitted within 36 hours of injury. Admission blood pH and base excess (BE) values all decreased in a linear relationship to the extent of the burn. Blood Pco-2 changes were unrelated to the extent of the burn. Significant acidosis developed within 2 hours of burn injury. Base requirements for the first two 24 hour periods after burn were linearly proportional to the extent of burn. Base requirements for these two periods were determined and were expressed as: (1) base needed the first 24 hours (milliequivalents per kilogram) equals percent of body surface burned/8; and (2) base needed the second 24 hours (milliequivalents per kilogram) equals base needed the first 24 hours/4. These formulas were found to work satisfactorily in a prospectively treated series of patients.