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Biomedical subjects

J M Kinney

Publications and source records attributed to J M Kinney.

At least 73 records · Page 4Linked to original sources
PubMed1986

The influence of preoperative total parenteral nutrition upon morbidity and mortality.

This study was done to examine the criteria for determining the adequacy of preoperative total parenteral nutrition (TPN). We hypothesized that an important criterion for adequate preoperative nutrition should be a contraction of the expanded extracellular fluid compartment known to occur in malnourished patients undergoing surgical treatment. Clinical evidence of this included a rise in the serum albumin level and weight loss. Fifty-nine patients requiring preoperative nutritional support for at least five days were admitted to the study. The patients were divided into three groups (group 1, group 2a and group 2b) based upon the response of the patients to TPN. Group 1 consisted of 23 patients who demonstrated a rise in serum albumin value, loss in body weight and diuresis after seven days of TPN. Group 2 was made up of 36 patients who failed to demonstrate a rise in the albumin level in response to nutritional support for one week. Of these patients, 20 underwent operation at the end of a week of nutritional support (group 2a) while 16 patients received four to six weeks of nutritional support preoperatively (group 2b). The complication rate in the three groups was 4.3 per cent for those in group 1; 45 per cent for those in group 2a and 12.5 per cent for those in group 2b (p less than 0.05), group 2a versus group 2b). The results of this study demonstrate a high mortality and morbidity in patients who fail to increase the serum albumin level after one week of TPN. The data suggest that a prolonged period of parenteral nutrition results in a substantial decrease in perioperative complications in this group of patients.

Body Fluid Compartments↗
PubMed1985

Muscle and plasma amino acids during semi-starvation in normal subjects: hypocaloric glucose vs. amino acid infusions.

Normal subjects were fed hypocaloric amounts of amino acids or glucose for 3 days to separate the effects of these nutrients from those of trauma on muscle and plasma amino acids. Intracellular and plasma levels of Val, Leu and Ile were increased in both groups but were increased to a greater extent when amino acids were infused. Intracellular free glutamine concentration in muscle tissue was not significantly altered. Some of the trauma induced changes in amino acids can be replicated by maintaining normal subjects on hypocaloric amino acids; the decrease in glutamine concentration seen with trauma is not a function of hypocaloric nutrition.

Journal Article↗
PubMed1985

Metabolic changes associated with radical cystectomy.

The present study investigates the metabolic changes associated with cystectomy and the effects of nutritional support on the cystectomy patient. Twelve patients undergoing radical cystectomy and ileal conduit urinary diversion for invasive bladder cancer were randomly assigned to receive either a diet of 5 per cent dextrose (Group I) or total parenteral nutrition (Group II) given as glucose and amino acids. Group I demonstrated a marked negative nitrogen balance throughout the study while Group II had minimal losses for the first three days and achieved positive nitrogen balance by the fourth postoperative day. Over six postoperative days, cumulative nitrogen balance was -1.08 +/- 0.35 and -0.02 +/- 0.16 gm./kg. (p less than .001) in Groups I and II, respectively. Energy expenditure, compared to predicted values, was 15 percent higher (p less than .01) in Group II than in Group I. The respiratory quotient in the total parenteral nutrition group remained below 1.0, an indication of ongoing net fat oxidation despite hypercaloric glucose intake. Patients on total parenteral nutrition tended to show elevations in norepinephrine excretions as well as a transient rise in rectal temperature (p less than .05). The highest body temperature in both groups was recorded on the third postoperative day. The energy cost of radical cystectomy was similar to that in patients undergoing total hip replacement. However, lean tissue losses and norepinephrine concentrations were much higher than for hip patients and were comparable to changes seen in severe accidental injury. The tissue losses were completely abolished by total parenteral nutrition. The observation that nutrition affects temperature regulation in acutely ill patients has implications for interpreting increases in body temperature in injured patients receiving total parental nutrition. Fever may not necessarily indicate the development of infection.

Aged↗
PubMed1985

Evaluation of a non-invasive method for the measurement of metabolic rate in humans.

Measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2) can be used to calculate energy expenditure. Such data are useful in the nutritional management of a variety of pathological conditions. This study is an evaluation in vitro and in vivo of the mating of a canopy and a Beckman metabolic measurement cart 1 (MMC). The canopy allows for the collection of expired gases without facial attachments. Studies in vitro demonstrated the necessity of calibrating the CO2 analyser at the concentrations used in such a system (0.50-0.80% CO2). Measurements of VO2 were within + 12% to -8% of predicted values, and when calibrated at 0.50% and 0.75% CO2, measurements of VCO2 were within + 2% and -7% of predicted values. The studies in vivo revealed that VO2 and VCO2 were within +/- 11% of the values obtained by using a canopy-spirometer-computer system. The MMC plus canopy may provide an alternative method for the clinical measurement of VO2 and VCO2, especially in subjects unable to tolerate a tight-fitting mask for prolonged periods.

Adult↗
PubMed1985

Splanchnic substrate balance in malnourished patients during parenteral nutrition.

Twenty-four-hour values for splanchnic substrate balance, O2 consumption, and CO2 production were estimated in nutritionally depleted patients, once while receiving 5% dextrose (D5W) and again after 6 or more days of glucose-based total parenteral nutrition (TPN). Nitrogen balance and whole body gas exchange were also measured. The majority of protein loss during D5W administration and the net protein synthesis during TPN occurred in the periphery. Increases in whole body and splanchnic O2 consumption occurred with TPN administration, but in both cases the splanchnic region accounted for 20% of whole body O2 consumption. Uptake of substrates by the splanchnic region was sufficient to meet splanchnic energy requirements. During TPN infusion uptake by the splanchnic region accounted for 60% of amino acids infused, whereas peripheral uptake accounted for 40%. Splanchnic uptake of glucose accounted for 20% of the glucose infused during TPN. During TPN the splanchnic region took up more glucose and amino acids than was required for energy needs and protein synthesis. It was assumed that the remainder of this substrate was used for lipogenesis. The splanchnic region accounted for 50 +/- 19% of whole body lipogenesis.

Adipose Tissue↗
PubMed1985

Ventilatory and metabolic effects of glucose infusions.

It has been demonstrated that total parenteral nutrition (TPN) results in increased O2 consumption (VO2), CO2 production (VCO2) and minute ventilation (VE). TPN consists of a mixture of glucose and amino acids. The individual role of each of these nutrients in mediating these changes has not been well established. To examine the effects of the individual nutrients, continuous infusions of glucose in hypo- and hypercaloric amounts were given to four normal volunteer subjects and four acutely ill patients for a six-day period, with three days on each dietary intake. After each three-day period, gas exchange, VO2, VCO2, and ventilatory variables (VE), tidal volume (VT), frequency (f), mean inspiratory flow (VT/TI), inspiratory time (TI) and expiratory time (TE) were measured. With the high carbohydrate diet, CO2 production increased 18 percent (p greater than .05) and 7 percent (p greater than .05) in the normal subjects and the patients, respectively. VO2 did not change, while the RQ rose. VE rose in parallel with VCO2, with no significant change in ventilatory sensitivity to CO2. In light of previous observations, these results suggest that during administration of TPN, the protein component plays a major role in the observed ventilatory changes: a) by bringing about a rise in VO2, which acts to magnify the effect of an increased RQ on VCO2, and b) by increasing ventilatory sensitivity to CO2.

Adult↗
PubMed1985

Needle biopsy of skeletal muscle using suction.

We have modified the percutaneous skeletal muscle biopsy technique by applying suction to the biopsy needle. This has increased the reliability and the average size of the specimen but has allowed the procedure to continue to be safe and simple.

Biopsy, Needle↗
PubMed1984

Effect of protein intake on ventilatory drive.

Previous studies have demonstrated that if isotonic amino acid infusions were administered at a rate that approximated normal daily protein requirements, a leftward shift of the minute ventilation X PaCO2 relationship occurred. This study examined the effect of the administration of parenteral nutrition, at a fixed caloric intake and two levels of nitrogen (N) intake, on the ventilatory response to CO2 in nutritionally depleted patients. The intent was to determine whether increasing protein intake from normal to twice normal requirements would result in a further enhancement of the ventilatory response to CO2. Eight patients with nutritional depletion (greater than 10% weight loss) were studied. The resting energy expenditure (REE) was measured during administration of 5% dextrose, using principles of indirect calorimetry. Each patient received parenteral nutrition for a 2-week period. Two diets were examined for a 1-week period each: 1) a high N intake-15 mg nitrogen per kcal REE (approximately 21 g/day), or b) a low N intake--7.5 mg nitrogen per kcal REE (approximately 11 g/day). The initial diet was assigned randomly. Total energy intake was set at 1.35 X REE as measured during administration of 5% dextrose solution. Nonprotein calories were administered as 50% glucose and 50% fat. Breathing patterns at rest and during inhalations of 2 and 4% CO2 were analyzed using a canopy-computer-spirometer system. With an increased nitrogen intake there was a significant reduction in resting arterial PaCO2 from 39.9 to 37.6 mmHg (P less than 0.05) with no significant change in pH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Measurement of glycerol turnover by infusion of nonisotopic glycerol in normal and injured subjects.

A new technique for measuring glycerol turnover in human subjects is presented using a staged infusion of unlabeled glycerol. A total of 105 measurements was made in normal subjects and postoperative or acutely ill patients. The relation between glycerol turnover rate (R tau) and concentration (C) (R tau = 31 + 2.07C) from 80 staged infusion measurements in 21 normal subjects did not differ significantly from observations of others made by isotope dilution. In 11 patients, glycerol turnover was also measured by dilution of isotopic glycerol. Mean values did not differ significantly between the two methods. The average difference, regardless of sign, for individual values was 17%. This agreement tends to validate the assumptions of both methods. Advantages of the staged infusion method are that it is quicker and easier to perform and does not entail a risk due to administration of radioactive materials. Evidence obtained in this study from a three-stage procedure indicates that satisfactory information may be obtained from a two-stage infusion at successive rates of 250 and 600 mumol/min for 70 min each, with a prime of 2 mmol given as a bolus at the start of each stage.

Adult↗
PubMed1984

Effect of respiratory apparatus on respiration.

A mouthpiece plus noseclip (MP + NC) is frequently used in performing measurements of breathing patterns. Although the effects the apparatus exerts on breathing patterns have been studied, the mechanism of the changes it causes remains unclear. The current study examines the effects on respiratory patterns of a standard (17-mm-diam) MP + NC during room air (RA) breathing and the administration of 2 and 4% CO2 in normal volunteers and in patients 2-4 days after abdominal operation. When compared with values obtained with a noninvasive canopy system, the MP + NC induced increases in minute ventilation (VE), tidal volume (VT), and mean inspiratory flow (VT/TI), but not frequency (f) or inspiratory duty cycle, during both RA and CO2 administration. The percentage increase in VE, VT, and VT/TI caused by the MP + NC decreased as the concentration of CO2 increased. During RA breathing, the application of noseclip alone resulted in a decrease in f and an increase in VT, but VE and VT/TI were unchanged. The changes were attenuated during the administration of 2 and 4% CO2. Reducing the diameter of the mouthpiece to 9 mm abolished the alterations in breathing pattern observed with the larger (17-mm) diameter MP.

Adult↗
PubMed1984

Response to hyperventilation in a group of patients with panic disorder.

Twelve patients with DSM-III diagnoses of panic disorder and four normal volunteers were studied during hyperventilation of room air and increased ventilation stimulated by 5% CO2. Patients also underwent sodium lactate infusion. Eight of the patients had a panic attack during sodium lactate infusion, seven during CO2 inhalation, and three during room-air hyperventilation. Since CO2 increases the firing of the locus ceruleus, and since sodium lactate infusion is known to increase cerebral CO2, these findings are consistent with other evidence implicating the locus ceruleus in panic anxiety.

Adult↗
PubMed1984

Effect of routine intensive care interactions on metabolic rate.

The alterations in metabolic (oxygen consumption [VO2] and carbon dioxide production [VCO2]) and hemodynamic (heart rate and blood pressure) parameters caused by various common intensive care activities were examined in a group of 23 mechanically-ventilated critically-ill patients. The observed variations in metabolic rate can be classified into four categories as follows: (a) the lowest energy expenditure, which was associated with sleeping in the majority (83 percent) of instances; (b) resting, which was defined as a state where the patient was lying motionless with eyes open and responding to surrounding events, where VO2 and VCO2 averaged 9.1 +/- 7.5(SD) percent and 7.5 +/- 7.3 percent, respectively, above the lowest values; (c) a variety of routine daily care activities (eg, bathing, performing a physical examination) that although not particularly painful, caused arousal from the resting state. During these situations, VO2 and VCO2 averaged about 20 percent above lowest values; and (d) chest physical therapy, which was associated with metabolic increases of 35 percent above lowest values as well as increases in both heart rate and blood pressure. This study demonstrates that routine daily ICU activities can significantly alter metabolic rate, and thus, it is important to couple such measurements with astute observations of the patients' activity state. In addition, we have defined an activity state--resting--that can be used in the calculation of energy expenditure as well as for intrapatient and interpatient comparisons.

Carbon Dioxide↗
PubMed1984

Influence of parenteral carbohydrate on fat oxidation in surgical patients.

The administration of parenteral carbohydrate to nutritionally depleted patients in amounts approximating energy expenditure will markedly suppress fat oxidation. If the amount of carbohydrate is increased, net lipogenesis will occur. In contrast, it has been reported that in acutely ill, hypermetabolic patients net fat oxidation continued during the administration of glucose in quantities that exceeded energy requirements. This investigation was undertaken in an attempt to determine to what extent the latter response is due to persistent oxidation of endogenous plasma free fatty acids (FFAs) or stores of lipid in tissue. In this study, carbohydrate intake above energy equilibrium resulted in a 29% increase in CO2 production, a 2% increase in O2 consumption, and an increase in respiratory quotient (RQ) from 0.77 to 0.97 in nutritionally depleted patients. Injured and infected patients displayed a 44% increase in CO2 production and a 15% increase in O2 consumption, while the RQ increased only to 0.9. An isotopic palmitate infusion was used to measure FFA oxidation during parenteral nutrition with variable amounts of carbohydrate. Simultaneous estimates of net fat oxidation were made by indirect calorimetry. At low carbohydrate intakes, oxidation of plasma FFAs accounted for 50% of net fat oxidation in both groups of patients. Suppression of FFA oxidation was greater in the nutritionally depleted patients than in the acutely ill group at intermediate and at high carbohydrate intakes. We conclude that the continued net fat oxidation seen in acutely ill patients receiving high carbohydrate intakes is at least partially due to continuing plasma FFA oxidation. Tissue fat stores that are not in rapid equilibrium with plasma FFAs make a substantial contribution to net fat oxidation.

Energy Metabolism↗
PubMed1983

Protein synthesis rates in rat muscle and skin based on Lysyl-tRNA radioactivity.

Measurement of protein synthesis in individual organs is important in understanding metabolic changes in injury, sepsis, or starvation. Methods, mostly isotopic, for measuring synthesis are plagued by problems of experimental design and interpretation. Thus it is desirable to use a variety of methods based on different assumptions. The present study is the first to isolate radioactive aminoacyl-tRNA in the study of protein synthesis in muscle and skin. Male rats, 200-300 g, trained to eat chow for 4 hr/day were studied at 2 hr (absorptive) or 16 hr (postabsorptive) after a meal. Under ether anesthesia, a tracer dose of L-[4-5-3H(N)]-lysine was infused at a constant rate. At 20, 30, or 40 min 1 ml of arterial blood was withdrawn and 2-g samples of skin and thigh muscle were quickly excised and frozen. Samples were pooled from 4 to 7 rats for each infusion period. Concentrations and specific activities were determined for plasma lysine, and for free, tRNA, and protein-bound lysine in muscle and skin. Protein renewal rates in absorptive and postabsorptive periods averaged 6 and 9% per day in muscle, and 20 and 35% in skin. The data for muscle confirms results of other methods and suggests little contribution of rapidly turning over protein. The contribution of skin to whole body protein synthesis, about 500 mg . 100 g-1 . day-1, is similar in magnitude to the contributions of muscle, liver, or intestine.

Animals↗
PubMed1983

Effects of increasing nitrogen intake on nitrogen balance and energy expenditure in nutritionally depleted adult patients receiving parenteral nutrition.

The effects of increasing nitrogen intake were studied in 10 nutritionally depleted patients receiving total parenteral nutrition. After 1 to 2 days on 5% dextrose, the patients received, in random order, intravenous diets containing either a low (180 mg/kg . day) or high (364 mg/kg . day) nitrogen content. Equicaloric amounts of glucose and fat emulsion were given. Total energy intake averaged 33.0 kcal/kg . day corresponding to 1.31 X resting energy expenditure or 1.08 X total energy expenditure. Nitrogen and energy balances were measured daily. Concentrations of glucose, glycerol, fatty acids, triglycerides, urea, insulin and glucagon in plasma, and of beta-hydroxybutyrate in whole blood were measured during the last 2 days of each diet period. An increase in plasma urea was the only change in hormone or substrate concentrations identified. Resting energy expenditure increased approximately 10%, going from 5% dextrose to the low and from the low to the high N diet. Nitrogen balances were 0.21 and 0.61 mg N/kg . day on the low and high N diets. Nitrogen retention of 21% of the increment in intake, three times that seen in normal adult subjects, indicates that the malnourished patients in this study responded in a manner similar to growing organisms. Attainment of markedly positive N balance at, or close to, zero energy balance indicates that lean body mass can be restored without excessive energy intakes which may often be undesirable.

Adaptation, Physiological↗