PubMed Health⌕ Search

Biomedical subjects

L H Aulick

Publications and source records attributed to L H Aulick.

11 recordsLinked to original sources
PubMed1992

Effect of burn wound bacterial colonization on sleep and respiratory pattern.

This study examined the effect of bacterial colonization of a burn wound on the sleep pattern and respiration during sleep. Sleep patterns of adult rats were monitored for one week before and two weeks after a 30 percent total body surface, full skin thickness burn with and without seeding the fresh wound with nonvirulent Pseudomonas aeruginosa. Unseeded rats were euthermic and exhibited a normal sleep pattern during the first-week post burn; however, rapid eye movement (REM) sleep percent was significantly decreased by the second week due to a reduction in the frequency rather than duration of REM periods. Rats with seeded wounds were febrile and had a significantly lower REM sleep percent throughout the two-weeks post burn due to a reduction in frequency but not duration of REM periods. The increase in respiratory rate from the non-REM to REM sleep state observed before injury was abolished in the seeded group post burn. There was an immediate but transient 24 h drop in REM sleep following thermal injury. Bacterial colonization of the burn wound by either immediate, artificial seeding or by delayed, spontaneous means significantly decreased REM sleep with and without fever, respectively. These results indicate that noninvasive bacterial colonization of a burn wound was capable of decreasing REM sleep without causing fever and that REM sleep reduction was a more sensitive indicator of the extent of burn wound bacterial colonization than was colonic temperature.

Animals↗
PubMed1979

Increased peripheral amino acid release following burn injury.

Turnover rates of 10 amino acids were determined in four normal subjects and 18 burned patients (mean burn size, 41% of total body surface) by measuring leg blood flow by venous occlusion plethysmography and arterial (A) and femoral venous (FV) amino acid concentrations. Patient arterial plasma amino acid concentrations generally were low or normal, although phenylalanine was elevated. Only alanine demonstrated significant A-FV concentration difference (-9 +/- 2 mumole/100 ml in patients vs -5 +/- 1in controls, mean +/- SEM). Leg blood flow was 6.26 +/- 0.57 ml/100 ml of leg volume . min in the patients and 2.62 +/- 0.57 in controls. While the net peripheral release of the 10 amino acids was accelerated following injury, only alanine release was consistently greater in the patients (0.27 plus or minus 0.05 mumole/100 ml in leg volume . min) as compared with that of controls (0.08 +/- 0.02). The increased alanine release from legs of patients generally was related to the extent of total body surface injury and oxygen consumption of the patient, but was unrelated to size of limb burn or leg blood flow. The accelerated rate of alanine release from limbs of burn patients relates to the generalized catabolic effects of injury rather than to local inflammatory or metabolic events which may occur in the injured extremity.

Adult↗
PubMed1978

Metabolic changes in burned patients.

The systemic metabolic and circulatory alterations following thermal injury are directed to support the healing wound. The open wound is an immediate priority of the body; structural and functional components of uninjured tissue undergo breakdown to provide energy, substrate, and micronutrients for the healing wound. Glucose is synthesized by the liver and utilized by granulation tissue. Wound blood flow is elevated and the injured surface is heated to enhance repair. These changes in systemic metabolism and directed by alterations in neurohumoral control; the exact mechanisms ultilized by the wound to initiate these changes are presently not known.

Animals↗
PubMed1978

Muscle blood flow following thermal injury.

Peripheral circulation is markedly increased during the hyperdynamic-hypermetabolic phase of thermal injury and appears to be directed primarily to the burn wound. To determine whether any portion of this extra blood flow reaches another major peripheral vascular bed, blood flow in the tibialis anterior muscle of the lower leg was measured by 133Xe clearance in ten hemodynamically stable, nonseptic burn patients (mean burn size = 42.5% total body surface) and five control subjects. Muscle blood flow was 3.52 +/- 0.26 ml/100 g.min (mean +/- S.E.M.) in these patients and 3.29 +/- 0.24 in controls, indicating that resting muscle perfusion was unaffected by the extent of total body surface injury, size of leg burn, or elevated rectal temperature (38.2 +/- 0.2 degrees C) of the patients. These results confirm the interpretations of previous studies suggesting that most of the increased peripheral blood flow following thermal injury is directed to the surface wound. Local and systemic factors responsible for the maintenance of muscle perfusion in the face of alterations in muscle metabolism following thermal injury are discussed.

Adolescent↗
PubMed1977

Influence of the burn wound on local and systemic responses to injury.

Total resting leg blood flow, measured by venous occlusion plethysmography; leg oxygen consumption; substrate turnover; and leg surface temperature were determined in 21 nonseptic burn patients and four normals. The patients studied during the second to third week postinjury sustained total body surface injuries averaging 45% (range 12-86%) and leg injuries of 35% total leg surface (0-82.5%). To integrate the peripheral metabolic and circulatory events with the systemic responses to injury, total body oxygen consumption, cardiac output, rectal and mean skin temperatures were also measured. Leg blood flow and leg surface temperature generally increased with total burn size but did not correlate with cardiac output, total body oxygen consumption, or body temperature. However, leg blood flow was closely related to the extent of the leg burn (r(2) = 0.73). To evaluate the metabolic determinants of the wound blood flow, patients were matched for burn size (40.5% total body surface in one group vs. 42%), resulting in similar systemic responses to injury (cardiac index 7.8 +/- 0.7 L/min m(2) vs. 7.5 +/- 0.8, VO(2) 204 +/- 12 ml/min m(2) vs. 241 +/- 22, rectal temperature 38.5 +/- 0.3 degrees vs. 38.3 +/- 0.3 degrees , NS). One group (n = 7) had extensive leg burns (58% of the leg surface), the other (n = 9) minimal leg injuries (9.5%). Leg oxygen consumption was similar in the two groups (0.24 +/- 0.01 ml/100 ml leg min vs. 0.19 +/- 0.04, NS), although leg blood flow was markedly increased in the injured extremities (8.0 +/- 0.5 ml/100 ml leg min vs. 4.2 +/- 0.4, p < 0.001). Glucose uptake and lactate production were enhanced in the burned extremities (glucose 0.34 +/- 0.08 mg/100 ml leg mmn vs. 0.04 +/- 0.03, p < 0.01, lactate 0.30 +/- 0.08 mg/100 ml leg min vs. 0.06 +/- 0.06, p < 0.05) and related in a general manner with size of the leg burn. Increased peripheral blood flow following injury is directed to the wound and unrelated to aerobic metabolic demands of the extremity. The selectively perfused wound consumes glucose and produces lactate. The increased systemic cardiovascular and metabolic responses to thermal injury are essential for the enhanced circulatory and anaerobic demands of the healing wound.

Adolescent↗
PubMed1977

Influence of the burn wound on peripheral circulation in thermally injured patients.

Simultaneous measurements of resting leg blood flow and surface and rectal temperatures were made in 45 studies of 9 normal subjects and 28 burn patients. The patients had burns from 3-86% of the total body surface with leg injury ranging from 0-87.5% of the leg surface. In the patient group, blood flow was essentially normal in the uninjured legs, increased in a curvilinear manner with the size of the leg burn, and approached a plateau of 8.0 ml/100 ml-min as the percent of leg burn exceeded 60%. Increasing the leg surface temperature by 5 degrees C increased blood flow in patients with burned and unburned extremities to the same extent as in normal subjects. Increased peripheral blood flow following thermal injury is directed primarily to the burn wound. Variations in surface temperature modify this peripheral vascular response to injury.

Adolescent↗
PubMed1975

Effect of warm-up on metabolic responses to strenuous exercise.

Aerobic and anaerobic energy transformations were measured in two trained runners during 90-sec treadmill runs at 23.6 km/hr (2% grade). The runs were preceded by rest or either of two warm-ups: 1) 15-min run at 10 km/hr, or 2) 15-min run at 10 km/hr followed by 3-min standing. Compared with runs without warm-up, during the third half minute of runs following both types of warm-up 11% greater heart rates (HR), 8% greater oxygen consumption (Vo2), and unchanged ventilation were recorded. The rate constant of the approach of Vo2 to O2 in the first minute of work was unaffected by warm-up. Runs following either warm-up resulted in 25% lower lactate production; during these runs 3 to 4 degrees C higher gastrocnemius muscle temperatures (Tm) were maintained. The differences in HR, Vo2, and Tm continued throughout exhausting 5-min runs at 20.9 km/hr (2% grade). An elevated muscle temperature may therefore be requisite for the maximal aerobic response to a short exhausting run.

Adaptation, Physiological↗