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Biomedical subjects

J M Kinney

Publications and source records attributed to J M Kinney.

At least 127 records · Page 7Linked to original sources

Muscle and plasma amino acids after injury: hypocaloric glucose vs. amino acid infusion.

This study examines the effect of three different hypocaloric diets on the patterns of muscle and plasma amino acids in patients undergoing total hip replacement. Group I (seven patients) received 90 g/day of glucose, Group II (seven patients) received 70 g/day of amino acids, Group III (eight patients) received both 90 g of glucose and 70 grams of amino acids per day. Utilizing the percutaneous biopsy technique of Bergström, free amino acid patterns in muscle and plasma were analyzed pre- and postoperatively (day 4). The postoperative pattern of amino acids was characterized by elevated levels in muscle and plasma of the branched chain amino acids, phenylalanine, tyrosine and methionine. There was a marked decrease in muscle glutamine and smaller decreases in the basic amino acids in both muscle and plasma. Muscle:plasma concentration ratios increased for the neutral amino acids, decreased for glutamine and the basic amino acids and were unchanged for the acidic amino acids. The patterns seen after hip replacement are almost identical to those seen after colectomy or accidental injury. There was little effect of diet on amino acid concentrations in muscle. In plasma, concentrations of leucine, isoleucine, valine and proline were higher in Group II in the absence of glucose intake, than in the other groups. Lysine was lower in Group I with no amino acid intake than in the other groups. Thus, there is a unique amino acid pattern associated with operative trauma which is relatively unaffected by hypocaloric, intravenous nutrition.

Amino Acids↗

Muscle and plasma amino acids following injury. Influence of intercurrent infection.

The present study was undertaken to determine intracellular amino acid patterns in patients with multiple trauma, whether or not complicated by sepsis and during convalescence. A percutaneous muscle biopsy was performed three to four days following major accidental injury in ten patients and analyzed for muscle free amino acids. Venous blood was drawn at the time of the biopsy and analyzed for plasma free amino acids. Five patients developed sepsis and a repeat biopsy was performed on days 8 to 11. In five of the patients a biopsy was performed during the late convalescent period (anabolic phase). A marked depletion of nonessential amino acids in muscle occurred in both injury and sepsis due to a decrease (50%) in glutamine, which was equally marked in both states. The essential amino acids in muscle increased in injury. During sepsis, a further increase was observed with a return toward normal in the convalescent period. In injury, the most marked rise was in the branched-chain amino acids, phenylalanine, tryosine and methionine. With sepsis, a further rise in muscle branched-chain amino acids, phenylalanine and tryosine occurred, while plasma levels remain unchanged. During convalescence, muscle glutamine, arginine, histidine and plasma branched-chain amino acids were below normal, whereas muscle phenylalanine and methionine were elevated. The muscle free amino acid pattern observed after major trauma was essentially the same as earlier described following elective operation. This suggests a common response of intracellular amino acids irrespective of the degree of injury, and may indicate that the pump settings which regulate amino acid transport follow the "all or none" rule. The high intracellular levels of branched-chain amino acids in sepsis suggest that the energy deficit of this state is due to an impairment of substrate use rather than intracellular availability. The high concentrations of the aromatic amino acids and methionine may be due to altered liver function. During the late convalescent period (anabolic phase) the low levels of certain key amino acids suggests inadequate nutrition. The difficulties in nourishing the injured or septic patient are well recognized. The period following these catabolic states may be an important period for the application of an optimal, aggressive nutritional regimen.

Abdomen, Acute↗

Increased body temperature secondary to total parenteral nutrition.

Administration of total parenteral nutrition (TPN) (glucose/amino acids), on the 2nd day after surgery, to a 26-year-old male with multiple fractures resulted in a rise in rectal temperature from 37.6 to 39 degrees C. Resting energy expenditure showed a sustained 23% increase when the nutritional intake was changed from 5% dextrose to TPN. This case demonstrates that the increased metabolic rate associated with administration of TPN in acutely injured patients may be associated with an increase in body temperature.

Adult↗

Use of the ventilatory equivalent to separate hypermetabolism from increased dead space ventilation in the injured or septic patient.

Normal subjects and surgical patients were studied with a noninvasive canopy-spirometer system which provides prolonged measurements of gas exchange and pattern of breathing. Values for normal subjects agreed with published values. Twenty-nine patients undergoing uncomplicated elective operation had a mean preoperative minute ventilation of 3.44 +/- 0.84 L/min/m2, a VO2 of 0.132 +/- 0.022 L/min/m2, and VCO2 of 0.105 +/- 0.017 L/min/m2, and the postoperative values on the third to fifth day were not statistically different. The ventilatory equivalent (V.E.CO2) or the liters of air moved per liter of CO2 excreted has been used instead of the dead space/tidal volume (VD/VT) ratio for the indication of levels of minute ventilation, which are excessive for the associated metabolic demands for gas exchange. Thirty-eight runs on 18 acutely ill surgical patients showed mean increases in minute ventilation of 85%; the associated increases in metabolism averaged 17%. Therefore, their V.E.CO2 increased from a normal of 31 +/- 6 to 50.7 +/- 8, indicating a sharp increase in dead space ventilation. The additional clinical information provided by the serial graphic presentation of V.E.CO2 supplements what is learned from successive numbers representing the trend in VD/VT.

Bacterial Infections↗

Effect of injury and sepsis on high-energy phosphates in muscle and red cells.

Changes in muscle high-energy phosphates in varying degrees of resting hypermetabolism were studied. Eleven patients were investigated before and 4 days after total hip replacement. The postoperative results were compared with those seen in major traumas and sepsis. High-energy phosphates were not significantly changed in muscle after total hip replacement or moderate injury; muscle lactate and pyruvate increased. Increased degrees of hypermetabolism such as severe trauma and sepsis were associated with reduction of muscle ATP and PC; AMP, free CR, lactate, and pyruvate rose. Simultaneously determined levels of high-energy phosphates in red blood cells did not reflect muscle changes, confirming the need for continued direct tissue measurements. Alterations in the ATP--ADP--AMP system in the muscle cell suggest a low-energy charge following severe trauma especially if accompanied by sepsis. This would indicate a decreased capcity for biosynthetic reactions and production of storage compounds. Tissue high-energy phosphates and cellular energy levels thus may be the cellular expression of the catabolic state.

Adenosine Diphosphate↗

Effects of respiratory apparatus on breathing pattern.

The effects of ventilatory apparatus on breathing pattern and gas exchange were studied in normal supine subjects. Using a canopy system, measurements of O2 consumption, CO2 production, tidal volume (VT), frequency (f), minute ventilation, mean inspiratory flow, and inspiratory, and expiratory time (TI and TE) were made and compared to data obtained with the use of a mask (m) and mouthpiece plus noseclip (mp + nc). Use of the m or mp + nc caused a 32.5 and 15.5% increase in VT, respectively, whereas f, TI, and TE remained unchanged. As TI did not change the increase in VT was caused entirely by increased inspiratory flow.

Adult↗

Kinetics of intravenously administered 15N-L-alanine in the evaluation of protein turnover.

After a pulse injection of 15N-L-alanine to a healthy male subject, the distribution of 15N in the various components of blood and urine were determined as function of time. The rapid appearance of the isotope both in the urinary urea and ammonia and in the plasma amide and urea suggests that transamination (and not deamination) may be the key step in the interaction. After 30 to 60 min postinjection, the tracer dynamics represents the overall metabolic pool characteristics and does not reflect the metabolism of alanine only. The nitrogen of alanine is used effectively in the synthesis of body protein.

Adult↗

Changes in nitrogen balance of depleted patients with increasing infusions of glucose.

Depleted patients were maintained on intravenous infusions of amino acids and glucose with constant N intake (173 mg/kg body weight), and three different levels of energy intake (15.4, 37.6, and 58.5 kcal/kg) given sequentially for 4 days each. Changes in N balance were abrupt and maximal in 1 to 2 days. Maximal changes in N balance preceded, and were not dependent on maximal changes in fat and glucose metabolism. N retention increased 1.7 mg/kcal of increased energy balance, during both hypocaloric and hypercaloric intakes, a value similar to that observed in normal adults. No increase in resting energy expenditure occurred with increasing energy intake during negative energy balance. During positive energy balance resting energy expenditure increased by 1 kcal for each 5 of intake. It seems likely that increasing energy restores mainly that portion of lean body mass associated with fat deposition; and rapid restoration of lean body mass requires high N intakes. At zero energy balance, N balance in these depleted patients was only slightly positive at an intake of 173 mg N per kilogram. This is about twice the intake of N required to maintain zero N balance in normal adults.

Adult↗

Influence of increasing carbohydrate intake on glucose kinetics in injured patients.

The metabolic and hormonal effect of glucose loads, ranging from 125 to 504 g/70 kg/day, were studied in severely injured patients. There was little or no correlation of glucose intake with nitrogen balance, plasma glucose, fatty acid concentrations, or epinephrine excretion. Increased norepinephrine excretion correlated with and may have resulted from increased glucose intake. Serum glucagon concentrations averaged 320 pg/ml and were not depressed by glucose intake. Insulin concentrations rose with glucose intake but were low for the level of plasma glucose. Glucose oxidation and non-oxidative metabolism, including glycogen deposition, correlated well with glucose intake. Gluconeogenesis from alanine was much higher than normal but was completely suppressed at very high intakes. The data imply that cycling of glucose, with glycerol, glycogen, or both, increased with increasing glucose intake.

Adult↗

Patterns of ventilation in postoperative and acutely ill patients.

Acutely ill patients commonly increase minute ventilation (V) to varying degrees. The pattern of breathing utilized to increase V was analyzed in normal subjects and acutely ill surgical patients. V = tidal volume (VT) x frequency (f), or V = inspiratory flow x (TI/TTOT, inspiratory time/total cycle time). CO2 inhalation and exercise were used to induce supine hyperventilation in normal subjects. This was compared to hyperventilation in acutely ill surgical patients. Measurements were made of O2 consumption, CO2 production, V, VT, f, inspiratory flow, TI, and TTOT. With small increases in V (up to twice control), normal subjects increased inspiratory flow and TI/TTOT with both CO2 and exercise. CO2 inhalation increased VT with no change in f, while exercise increased both VT and f. When V increased beyond twice control, TI/TTOT remained constant and increases in inspiratory flow accounted for the entire increase in V. In acutely ill patients with increased V, average f was elevated and VT decreased, but there was no constant relationship of f and VT with increasing V. However, TI/TTOT was relatively constant at 0.40- 0.46; therefore, in order to increase V, inspiratory flow had to increase! Patients also showed a tendency to breathe at a relatively fixed VT while normal subjects did not show this phenomenon, even with increases of up to 3 times control V. Continuous, rapid analysis of gas exchange and breathing patterns holds promise for early detection of patients with V inappropriate to metabolic demands, and serves as a sensitive indicator of abnormal patterns used by acutely ill patients to increase V.

Acute Disease↗

Changes in metabolism and muscle composition associated with total hip replacement.

Metabolic changes in 10 patients undergoing total hip replacement were studied. Metabolic expenditure postoperatively remained within 5--10% of preoperative values. Net nitrogen loss for the postoperative period was less than 35 gm for the first 4 postoperative days, well below changes seen in major nonsurgical trauma. Fluid balance was positive in all patients for the first 4 postoperative days. Patients not in negative fluid balance by the fourth postoperative day should be closely monitored for complications. Recognition of delayed fluid excretion is essential in order to avoid the complications of further fluid loading in the postoperative period. Muscle composition reveals predictable changes in extracellular water, sodium, and chloride composition following surgery. Our data showed that metabolic changes following total hip replacement are in the order of major general surgical procedures and well below that observed with major trauma.

Adult↗

Effects of hypercaloric glucose infusion on lipid metabolism in injury and sepsis.

UNLABELLED: Lipolysis was studied by measuring glycerol turnover (GTO) in injured and infected patients. GTO was elevated two to three times the normal values in five injured and four infected patients during D5W infusion. No correlation was found between GTO and plasma glycerol concentration in the two patient groups. GTO showed similar levels when measured during TPN in five injured and three infected patients. During TPN, plasma FFA levels remained unchanged in injured but decreased by 48% in septic patients. B-OH butyrate concentrations were high during D5W and dropped in both groups during TPN. Norepinephrine urinary output was high in both groups during D5W and TPN. CONCLUSIONS: 1) GTO was elevated two to three times the normal range in injury and infection; plasma glycerol concentration was not related to GTO. 2) In face of high catecholamine output, the insulin response to TPN did not inhibit TG breakdown but did decrease plasma ketone body concentrations.

Adult↗

Influence of exercise and CO2 on breathing pattern of normal man.

Ventilatory patterns during rest, CO2 inhalation (2, 3, and 4%) and three levels of exercise were analyzed in supine men using a canopy system for noninvasive measurements. Changes in tidal volume (VT) and breathing frequency (f) with equal increases in minute ventilation (VE) differed significantly during exercise and CO2 inhalation. Increases in VE during exercise was accompanied by increases in VT and f. During CO2 inhalation, the change in frequency was less than during exercise. However, when analyzed in terms of inspiratory flow (VT/TI) and inspiratory duty cycle (TI/Ttot), the response to both stimuli was similar. With increases to twice control VE both TI/Ttot and VT/VI increased. Thereafter only VTTI increased with increasing VE. At rest, inspiratory time on a breath by breath basis increased minimally with VT, while changes in inspiratory flow accounted for the variability in VT. These two respiratory stimulants appear to increase ventilation through different mechanisms when analyzed in terms of VT and f. However, changes in inspiratory flow and duty cycle are similar in both.

Adult↗