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Biomedical subjects

J M Kinney

Publications and source records attributed to J M Kinney.

At least 91 records · Page 5Linked to original sources
PubMed1983

The effect of parenteral nutritional repletion on muscle water and electrolytes. Implications for body composition.

Nutritional depletion and repletion are associated with changes in the size of the extracellular and intracellular fluid compartments. Although the effect of nutrition on whole body composition is well established, the distribution of changes among the various body tissues is not. This study correlates changes in skeletal muscle composition with whole body electrolyte and nitrogen balance in an attempt to establish the contribution made by skeletal muscle to the changes in whole body fluid and electrolyte composition. Total parenteral nutrition was administered to ten patients for 16 to 25 days. Oxygen consumption, CO2 production, and balances of N, Na, and K were measured daily. Muscle biopsies were taken prior to administration of TPN, in the middle, and at the end of the nutritional regimen. Prior to administration of parenteral nutrition, muscle concentrations of water, sodium, and chloride were significantly higher than normal. With institution of the nutritional support regimen, all three concentrations decreased. The calculated loss in muscle water could account, at most, for only one-sixth of the loss in total body water. Muscle Na loss could account for approximately one-half of the whole body change. Potassium concentrations in the depleted patients were not significantly decreased from normal values and showed a negligible increase with TPN. Since the ratio of K to dry fat-free solids in muscle was constant, most of the whole body changes could be accounted for by assuming that nearly all N is deposited in muscle. Nutritional support results in restoration of cell mass with a contraction of the extracellular fluid (ECF) compartment. The changes in the ECF must occur in tissues other than muscle, while the restoration of cell mass occurs primarily in muscle.

Adult↗
PubMed1983

The response to TPN. A form of nutritional assessment.

Malnutrition in surgical patients is associated with an increased incidence of postoperative mortality and morbidity. Preoperative nutritional support has been shown to be efficacious in reducing the incidence of these complications, although the postoperative complication rate in these patients continues to be greater than in their wellnourished counterparts. This study attempts to determine whether the postoperative course can be either influenced by or predicted from the preoperative response to nutritional support. Thirty-two patients with nutritional depletion who received an average of 1 week of total parenteral nutrition prior to a major abdominal operation were studied. These patients were followed for postoperative complications. Of the 16 patients who exhibited the characteristic response to early nutritional support, diuresis of the expanded extracellular fluid compartment with a resultant loss of weight (127.9 +/- 5.7 to 124.6 +/- 5.8 (SEM) lbs, p less than .001) and rise in serum albumin (3.21 +/- 0.14 to 3.46 +/- 0.15 gms%, p less than 0.001), only one developed a complication in the postoperative period. The other 16 patients did not exhibit this response. They retained additional fluid, gained weight (119.3 +/- 8.1 to 121.3 +/- 8.2 lbs, p less than .025), and showed a decrease in serum albumin levels (3.14 +/- 0.14 to 3.00 +/- 0.14%), p less than 0.01). Eight of these patients developed a total of 15 postoperative complications (p less than 0.01). This study demonstrates that the response to preoperative TPN is an important factor in assessing operative risk and morbidity. The need to individualize preoperative nutritional support and the timing of surgical intervention is clearly demonstrated.

Aged↗
PubMed1983

Free fatty acid mobilization and oxidation during total parenteral nutrition in trauma and infection.

Free fatty acid (FFA) metabolism was studied in 18 traumatized and/or septic patients. Each patient was studied while receiving 5% dextrose (D5W) and after 4 to 7 days of total parenteral nutrition (TPN). Nonprotein energy during TPN was given either entirely as glucose (Glucose System) or as equal portions of intravenous fat and glucose (Lipid System). Plasma FFA concentrations were in the normal range on D5W and decreased markedly with TPN. FFA turnover was higher than normal on D5W and did not decrease significantly with TPN. The poor correlation between these two variables emphasizes the need to perform kinetic studies to characterize FFA metabolism in trauma and sepsis. Plasma FFA oxidation and net whole body fat oxidation measured by indirect calorimetry were in the normal range on D5W, 35 and 82%, respectively, of resting energy expenditure (REE). With a glucose intake averaging 108% of REE, plasma FFA oxidation and net fat oxidation decreased to 17 and 13%, respectively, of REE. Nonprotein RQ increased only to 0.94 despite administration of glucose in excess of REE, indicating an abnormal persistence of fat oxidation. During D5W administration, plasma FFA accounted for less than one half of total fat oxidation, indicating that unlabeled fat, such as tissue or plasma triglycerides not in rapid equilibrium with plasma FFA, accounted for the bulk of fat oxidation. Glucagon concentrations which were high on D5W did not decrease significantly with TPN. Insulin concentrations were normal on D5W and increased in response to TPN. The abnormal hormonal milieu may account for much of the abnormal fat metabolism. Administration of large amounts of glucose decreased FFA oxidation much more than FFA mobilization. Thus, the infused glucose acts to increase the rate of "futile cycling" of FFA in these acutely ill patients.

Adolescent↗
PubMed1983

Artifacts in measurement of resting energy expenditure.

Measurements of gas exchange have been demonstrated to be clinically useful in the care of critically ill and malnourished patients. Using principles of indirect calorimetry, resting energy expenditure (REE) can be calculated from gas exchange data and used as the basis for designing a nutritional support regimen as well as for following the patient's metabolic state. This study demonstrates that a relatively minor procedure, such as percutaneous muscle biopsy, can induce temporary but major increases in gas exchange and lead to an overestimation of REE. Four studies were performed on 3 healthy adult subjects admitted to the Surgical Metabolism Unit for nutritional study. A percutaneous muscle biopsy was performed with the subject inside a canopy with continuous recording of oxygen consumption (VO2) and carbon dioxide production (VCO2). After the muscle biopsy, VCO2 and VO2 increased 93 and 103% (at their peak value), respectively. The mean duration that these changes persisted at least 15% above control was 10.6 +/- 7.8 (SD) and 11.4 +/- 5.9 min of VCO2 and VO2, respectively. Thus, considerable artifacts in the estimation of REE can occur due to painful stimuli.

Adult↗
PubMed1983

Morphine and postoperative rewarming in critically ill patients.

Morphine sulfate (MSO4) has been demonstrated to attenuate the stress response. MSO4 might be useful in minimizing the stress associated with the perioperative period, particularly that due to awakening from anesthesia and rewarming. Two groups of critically ill patients who developed hypothermia (35.8 degrees C) during a surgical procedure were studied. The control group was observed during routine medical management. Group II received 1 or 4 mg/kg MSO4 followed by an infusion of 0.2 or 0.5 mg/kg/hr. During the postoperative rewarming period the control group patients demonstrated a major increase in metabolic demand and myocardial work. In group II patients the infusion of MSO4 resulted in a lower metabolic rate. This was associated with a significantly longer rewarming time and a significant reduction in shivering, heat loss, heart rate, mean arterial pressure, and rate-pressure product. Infusion of MSO4 in critically ill patients during the perioperative period suppressed metabolic demands and myocardial work while preserving cardiovascular function.

Aged↗
PubMed1983

Amino acids and respiration.

Parenteral nutrition containing glucose and amino acids may stimulate respiration. To ascertain the effects of these solutions on respiration, eight normal subjects received an infusion of 5% dextrose (100 mL/h) for 7 days followed by an infusion of 3.5% amino acids (125 mL/h) for 24 hours. Minute ventilation (VE), tidal volume, mean inspiratory flow (VT/VI), oxygen consumption, and carbon dioxide production were significantly depressed after 7 days of 5% dextrose infusion. Ventilation and metabolic rate increased within 4 hours after initiation of the amino acid infusion and returned to normal 24 hours after the infusion. The effects of the amino acids on (VE) was secondary to an increase in (VT/VI), which is an indicator of neuromuscular ventilatory drive. Thus, within 4 hours amino acids will restore depressed metabolic rate, minute ventilation, and ventilatory drive after prolonged infusion of 5% dextrose.

Adult↗
PubMed1983

Nitrogen balance during total parenteral nutrition: glucose vs. fat.

Nitrogen balance and energy expenditure were measured in 18 traumatized and/or septic patients and five depleted patients during different dietary conditions. Total parenteral nutrition (TPN) was given with nonprotein energy entirely as hypertonic glucose solutions (glucose system) or as half glucose-half intravenous fat emulsion (lipid system). In acutely ill patients, the change from 5% dextrose to TPN resulted in a prompt improvement of nitrogen balance to maintenance levels. There were no significant differences between patients given the glucose or lipid system. The five depleted patients were given the lipid and glucose systems alternately for a total of 19 one-week periods. A highly positive N balance, 80 mg N/kg . day, was attained on both diets. There was no significant difference between diets and no period of adaptation after switching from one diet to the other. On comparable intravenous diets, the acutely ill patients had higher plasma concentrations of glucose, glycerol, triglycerides, insulin, and glucagon than did the depleted patients. The study shows that the nitrogen-sparing effects of the lipid and the glucose systems are similar in moderately traumatized or infected as well as in malnourished patients. Factors other than nitrogen balance are of greater importance when choosing between the lipid and the glucose system for intravenous support.

Adolescent↗
PubMed1983

Physiologic requirements during rewarming: suppression of the shivering response.

Intraoperative hypothermia has become a common occurrence. Postoperative rewarming often is accompanied by shivering and results in increased metabolic and circulatory demands. We examined the metabolic, hemodynamic, and biochemical variables in 2 groups of hypothermic (greater than 35.8 degrees C) patients requiring mechanical ventilation after a major operation. One was observed during routine medical management whereas the other group received 40 mg of metocurine iodide and then observed during routine medical management. All patients were allowed to rewarm passively. O2 consumption (VO2, ml/min, STPD), CO2 production (VCO2, ml/min, STPD) and respiratory quotient (RQ) measurements were made every 15 min using a Beckman Metabolic Measurement Cart. Esophageal temperature, arterial blood pressure, heart rate (HR), rate pressure product, CVP, arterial blood gases, serum lactate concentration, and duration of shivering also were recorded. Suppression of the shivering by metocurine increased rewarming time significantly and decreased VCO2, VO2, HR, rate pressure product, mean arterial pressure (MAP), and the O2 cost of rewarming. Thus, the elimination of shivering during postoperative rewarming is associated with a decrease in caloric, metabolic demands and myocardial work (as assessed by the rate pressure product) while rewarming time is prolonged. In the postoperative, hypothermic, critically ill patient, suppression of the shivering response in selected patients may be indicated.

Adult↗
PubMed1983

Breathing patterns during curare-induced muscle weakness.

This study examines the pattern of breathing used by normal subjects to compensate for an acute decrease in muscle strength. A continuous infusion of curare was used to reduce peak inspiratory pressure in six normal subjects from normal control levels to -45 cm H2O (moderate weakness) and to -70 cm H2O (mild weakness). Before administration of curare, inspiratory pressure exceeded -120 cm H2O. A canopy-computer-spirometer system was used for noninvasive spirometry and measurements of gas exchange. Partial curarization to a mild level of muscle weakness did not produce significant changes in the respiratory functions studied. With a moderate level of muscle weakness, there were significant increases in tidal volume from 166 to 186 ml/m2 and in inspiratory time from 1.51 to 1.71 sec (P less than 0.05). Minute ventilation and inspiratory flow did not change. However, when given 3% CO2, both normal and partially curarized subjects increased minute ventilation, from 2.3 to 5.7 L/min/m2 and from 2.5 to 6.7 L/min/m2, respectively. The increases in both conditions were secondary to increases in tidal volume. There was also a small increase in respiratory frequency from 15.4 to 18 breaths/min, P less than 0.01 in the partially curarized group given 3% CO2. Because minute ventilation was preserved while vital capacity decreased, it is proposed that respiration is maintained in the presence of muscle weakness associated with curare by diaphragmatic function which remains relatively unaffected by curarization.

Adult↗
PubMed1982

A systematic method for validation of gas exchange measurements.

The measurement of gas exchange is useful, but thus far, has not been practical during the mechanical ventilation of critically ill patients. To validate two new commercial instruments, (Siemens-Elema Servo Ventilator 900B, Beckman Metabolic Cart), the authors constructed a lung model into which they delivered CO2 and N2 at precise rates to simulate Co2 production (Vco2) and O2 consumption (Vos). The model consists of 13.5-1 gas jar with an attached one liter anesthesia bag. The lung model was ventilated at present tidal volumes and frequencies. The authors also compared the measured respiratory quotient (RQ) with the known RQ of burning methanol (RQ = 0.67) in the jar. When the model was ventilated with levels of tidal volume and gas exchange applicable to adults, both instruments measured V02 within 5 to 13% of predicted values. Varying the FI02 did not significantly affect this accuracy. At tidal volumes below 350 ml, the difference increased between predicted VCO2 and measured VCO2. The difference between measured vs. the actual RQ of methanol was 5 and 1.5% in the Siemens-Elema and Beckman Systems, respectively.

Carbon Dioxide↗
PubMed1982

Effect of postoperative nutrition on muscle high energy phosphates.

This study examines the effect of hypocaloric nutritional regimens on muscle high energy phosphates in normal subjects and patients following total hip replacement. Eighteen patients undergoing total hip replacement and 11 normal subjects on a four-day period of bedrest were studied. The patients were randomly assigned to receive either: (1) 90 gms/day glucose; (2) 70 gms/day amino acids; or (3) 90 gms/day glucose + 70 gms/day amino acids. A percutaneous muscle biopsy was performed before operation and on the morning of the fourth day after operation. Samples were analyzed for adenine triphosphate (ATP), adenine diphosphate (ADP), adenine monophosphate (AMP), phosphocreatine (PC), free creatine (CR), lactate, and pyruvate. Normal subjects were assigned to receive either: (1) 90 gms/day glucose; (2) 70 gms/day amino acids; or (3) no caloric intake. The patients receiving amino acid alone demonstrated a decrease in ATP, ADP, and PC, while AMP and free creatine rose. No significant changes were seen in patients who received 90 gms/day glucose either with, or without, amino acids. There were also no significant changes in any of the normal subjects. These results suggest that a series of metabolic changes occur in skeletal muscle following injury such that small amounts of glucose are important for maintenance of cellular energy levels.

Adenosine Diphosphate↗
PubMed1982

Metabolic utilization of intravenous fat emulsion during total parenteral nutrition.

The effect of nutritional therapy on the utilization of an intravenous fat emulsion was studied in patients with injury, infection, and nutritional depletion using I-14C-trioleate labeled Intralipid. The plasma fractional removal rate and 14C-Intralipid oxidation rate was 55% ad 25% higher, respectively, in patients following trauma and during periods of infection receiving 5% dextrose than in healthy control subjects. Total parenteral nutrition (TPN) was administered as either 1) nonprotein calories given as glucose (Glucose System) or 2) equal proportions of glucose and intravenous fat emulsion (Lipid System). In comparison to TPN with the Lipid System, administration using the Glucose System resulted in higher plasma clearance rates and lower oxidation rates in both acutely ill and depleted patients. There was no correlation between the rates of plasma removal and oxidation of the intravenous fat emulsion (r = -0.04; NS) indicating that the removal of exogenous fat from plasma cannot be used as an indicator of oxidation. A negative linear relationship was seen between the oxidation rate of intravenous fat and carbohydrate intake (r = -0.92; p less than 0.001). Glucose intakes exceeding energy expenditure did not totally inhibit oxidation of the fat emulsion. The oxidation rate of 14C-Intralipid was linearly related to net whole body fat oxidation calculated using indirect calorimetry (r = -0.90; p less than 0.001) suggesting that the fat emulsion was oxidized in a similar manner to endogenous lipids. This study suggests that intravenous fat emulsions are utilized as an energy substrate in patients with major injury, infection or nutritional depletion. This observation, along with a relative unresponsiveness to glucose in surgical patients suggests that fat emulsions may be useful as a calorie source in patients receiving parenteral nutrition.

Adolescent↗
PubMed1982

Effect of an anabolic steroid on nitrogen balance and amino acid patterns after total hip replacement.

The effect of an anabolic steroid, nandrolone decanoate, on nitrogen balance and plasma and muscle amino acid concentrations was studied in patients undergoing total hip replacement and receiving daily postoperative infusions of 5% dextrose and 3.5% amino acids. An intramuscular injection of 200 mg immediately after operation resulted in a nitrogen balance of -48 mg N/kg . day for the first 3 days, as compared to 102 mg N/kg . day in noninjected controls. After steroid injection there was also an attenuation of trauma-induced changes in amino acid concentrations in muscle but not in plasma. This suggests that nandrolone decanoate may act directly on muscle to reduce the protein catabolism which follows a major form of operative trauma.

Aged↗
PubMed1982

Ventilatory patterns during steady state and progressive exercise.

This study was conducted to differentiate the ventilatory and metabolic response to supine exercise at low levels (VO2 less than 1000 ml/min) from the well-documented response to high level upright exercise. Further, the respiratory cycle during exercise is analysed in terms of inspiratory time, flow and expiratory time as well as tidal volume and frequency. Using a canopy system for non-invasive measurement of breathing patterns and gas exchange, nine male subjects were studied while performing steady state (SSE) and progressive exercise (PRE). Work loads were: SSE 1-5 Kgm/sec for 17 min; PRE 1.5, 2.5, 3.75 and 5.0 Kgm/sec with 2 min increments. Total work was the same (1548 Kg . m) in both types of exercise. With SSE tidal volume (Vt) and respiratory rate (integral of) rose 70% and 30%, respectively. Minute ventilation (Ve) rose 113%. With PRE, integral of rose during the first work level, then remained stable, while Vt and Ve rose with each incremental exercise level. In both cases a decrease in expiratory time accounted for the major component of the decrease in total cycle time. With the onset of exercise, the rate of increase of inspiratory time and respiratory frequency exceeded that of tidal volume and inspiratory flow. This would suggest that these two groups of parameters are controlled by separate mechanisms, possibly, timing being under neurogenic control and flow determined by humoral factors. The respiratory quotient decreased with both forms of exercise and remained low throughout the exercise period.

Adult↗
PubMed1982

Effect of posture on the ventilatory response to CO2.

The effect of sitting and supine posture on breathing patterns and gas exchange during room air breathing and administration of 2 and 4% CO2 was studied in nine normal subjects using a noninvasive canopy system. During air breathing minute ventilation (VE) was 21% (P less than 0.005) higher in the sitting position. Tidal volume (VT) and mean inspiratory flow (VT/TI) were also greater in the sitting position. With the administration of 4% CO2, VE was 13.9 and 20.0 1/min in the supine and seated position, respectively. The relationship between VE and VT was the same in both cases. For any given level of VE, VT/TI was higher in the seated position. No difference in response to CO2 as measured by delta VE/delta PaCO2 and (delta VT/TI)/delta PaCO2 was observed. However, arterial PCO2 was lower both in the resting and stimulated states when sitting.

Adolescent↗