METABOLIC ASPECTS OF DEEP SURGICAL HYPOTHERMIA IN INFANCY

PEDIATRICS ◽  
1968 ◽  
Vol 42 (1) ◽  
pp. 93-105
Author(s):  
David Baum ◽  
David H. Dillard ◽  
Hitoshi Mohri ◽  
Edward W. Crawford

Aspects of carbohydrate and lipid metabolism were examined in 10 infants whose core temperatures were lowered by external cooling to 15 to 20°C during cardiovascular surgery. Modest hyperglycemia, found with ether anesthesia, persisted in three patients not given glucose, but it was markedly increased in others given glucose infusions. Despite continued glucose infusion, plasma glucose returned toward prehypothermic levels with rewarming, provided epinephrine was not administered. When epinephrine was given, the return was slowed. These observations suggest diminished glucose utilization during hypothermia and arouse speculation concerning a related insulin abnormality. In general, plasma lactate and glycerol levels increased during hypothermia, reaching a peak after circulatory arrest and with rewarming. Plasma free fatty acid concentrations changed little until rewarming when they usually became depressed. Death occurred in all five infants in whom plasma glycerol and lactate levels were rising at the procedure's end, while plasma glycerol and lactate concentrations were falling on completion of the operation in patients who did well. These findings and the known importance of the liver in lactate and glycerol metabolism suggest that the course of plasma lactate and glycerol levels may prove useful as a reflection of hepatic dysfunction in patients undergoing hypothermic surgery.

1978 ◽  
Vol 56 (4) ◽  
pp. 578-584 ◽  
Author(s):  
E. Hohtola ◽  
H. Rintamäki ◽  
R. Hissa

A dose-controlled chemical sympathectomy with 6-hydroxydopamine (6-OHDA) did not disrupt thermostasis in the pigeon at +38 °C. At +6 °C, thermogenesis was impaired, but the lower body temperature and oxygen consumption were stable and vasoconstriction was normal. The stability may partly be explained by a massive release of adrenaline from the adrenals (50% in 20 min). Despite a deficit in heat production both after sympathectomy and after acute 6-OHDA, no change in muscle electrical activity was observed. Plasma free fatty acid (FFA) concentration was significantly elevated after sympathectomy, but no changes occurred in blood glucose or plasma lactate levels. The results indicate a major compensatory role for the adrenals in avian thermogenesis. They also suggest a sympathetically mediated auxiliary thermogenic mechanism independent of muscle electrical activity and coupled to FFA metabolism.


1978 ◽  
Vol 56 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Elizabeth A. Dittmar ◽  
G. Hetenyi Jr.

The effect of an intravenous infusion of ethanol was examined on the rates of hepatic glucose production (Ra) and overall glucose utilization (Rd) in conscious dogs in the postabsorptive state under basal conditions and in insulin-induced hypoglycaemia, after a 4-day fast or in diabetes. The rates were calculated by a tracer infusion method with 3H-labelled glucose as the tracer. The concentrations of glucose, lactate, insulin, and ethanol in plasma or blood were determined, and the rate of ethanol utilization estimated. The infusion of 0.04 or 0.24–0.29 mmol ethanol/kg per minute did not change the concentration of glucose in normal or diabetic dogs in the postabsorptive state, whereas a small decrease in fasted dogs was observed especially when ethanol was infused at the lower rate. Plasma lactate levels were increased; insulin levels did not change. Ra was transiently decreased in fasted dogs, but not in the postabsorptive state in normal or diabetic animals. Ethanol had no effect on the magnitude of the increase in Ra during insulin-induced hypoglycaemia. The estimated rate of ethanol utilization was reduced by fasting but not in diabetes. In conclusion, ethanol did not decrease the elevated rate of gluconeogenesis in diabetic dogs, nor did it interfere with the hepatic response to hypoglycaemia.


1989 ◽  
Vol 257 (1) ◽  
pp. E35-E42 ◽  
Author(s):  
P. De Feo ◽  
G. Perriello ◽  
E. Torlone ◽  
M. M. Ventura ◽  
C. Fanelli ◽  
...  

To test the hypothesis that cortisol secretion plays a counterregulatory role in hypoglycemia in humans, four studies were performed in eight normal subjects. In all studies, insulin (15 mU.m-2.min-1) was infused subcutaneously (plasma insulin 27 +/- 1 microU/ml). In study 1, plasma glucose concentration and glucose fluxes [( 3-3H]glucose), substrate, and counterregulatory hormone concentrations were simply monitored, and plasma glucose decreased from 89 +/- 2 to 52 +/- 2 mg/dl for 12 h. In study 2, (pituitary-adrenal-pancreatic clamp), insulin and counterregulatory hormone secretion (except for catecholamines) was prevented by somatostatin (0.5 mg/h, iv) and metyrapone (0.5 g/4 h, per os), and glucagon, cortisol, and growth hormone were infused to reproduce the concentrations of study 1. In study 3 (lack of cortisol increase), the pituitary-adrenal-pancreatic clamp was performed with maintenance of plasma cortisol at basal levels, and glucose was infused, whenever needed, to reproduce plasma glucose concentration of study 2. Study 4 was identical to study 3, but exogenous glucose was not infused. Isolated lack of cortisol increase caused a approximately 22% decrease in hepatic glucose production (P less than 0.01) and a approximately 15% increase in peripheral glucose utilization (P less than 0.01), which resulted in greater hypoglycemia (37 +/- 2 vs. 52 +/- 2 mg/dl, P less than 0.01) despite compensatory increases in plasma epinephrine. Lack of cortisol response also reduced plasma free fatty acid, beta-hydroxybutyrate, and glycerol concentrations approximately 50%. We conclude that cortisol normally plays an important counterregulatory role during hypoglycemia by augmenting glucose production, decreasing glucose utilization, and accelerating lipolysis.


1993 ◽  
Vol 264 (6) ◽  
pp. E943-E950 ◽  
Author(s):  
A. A. Young ◽  
G. J. Cooper ◽  
P. Carlo ◽  
T. J. Rink ◽  
M. W. Wang

The actions of intravenous glucagon and amylin, a newly discovered hyperglycemic pancreatic islet hormone, have been compared in 20-h fasted and fed, lightly anesthetized rats, and in rats made hypoglycemic with an insulin infusion. In fasted animals, amylin (75 nmol/kg) was more effective than glucagon (90 nmol/kg) in increasing plasma glucose (glucose increment 4.55 vs. 1.71 mM, P < 0.001). Amylin elicited a marked increase in plasma lactate, as previously reported, whereas glucagon did not alter plasma lactate. In fed animals, glucagon elicited twice as much increase in plasma glucose as did amylin; amylin again elicited a marked lactate increase that was greater (increment 1.45 vs. 0.97 mM, P < 0.05) and more prolonged than in the fasted state, whereas glucagon was without effect on lactate levels. These findings are consistent with glucagon's known action to promote hyperglycemia from hepatic glycogenolysis and amylin's demonstrated action to promote muscle glycogenolysis and increase lactate supply to the liver. Infusions of sodium lactate that produced plasma lactate increments similar to those evoked by 75 nmol/kg amylin evoked patterns of glucose response in fasted and fed rats similar to those evoked by amylin. Thus increased lactate supply to the liver may account for amylin's hyperglycemic effects. Amylin and glucagon could each restore plasma glucose to control levels in fasted animals made hypoglycemic by insulin infusion (plasma glucose reduced to 3.3 mM). A bolus of 75 nmol/kg amylin was more effective than 180 nmol/kg glucagon, restoring basal glucose levels for > 3 h, whereas glucagon restored it for < 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 7 (6) ◽  
pp. 1213
Author(s):  
Rashmi Patil ◽  
Chikkanarasareddy P. S. ◽  
Mallesh K.

Background: Severe sepsis and septic shock are the major causes of admission and deaths in the ICU, killing one in four (and often more) and increasing in incidence. In order to improve the clinical outcomes in these patients, it is crucial to obtain early recognition of patients who are at risk of death and to optimize the clinical decision making in a timely manner. In order to monitor the metabolic consequences of shock and hemodynamic management, plasma lactate levels can be used in critical illness. Objective of the study is to estimate plasma lactate and lactate clearance in sepsis and septic shock patients and to correlate plasma lactate and lactate clearance as predictors of mortality.Methods: This study is a prospective observational study conducted over 18months. Children with age of 1 month to 18 years admitted to the Paediatric intensive care unit with sepsis and septic shock were enrolled in the study. ABG at admission to document plasma lactate and lactate repeated at 6 and 24 hrs. Lactate clearance calculated at 6 and 24 hrs. The final outcome in terms of survival or death will be recorded.Results: Majority of the children fall in the class between 1-6 months 51(48.11%). Male comprises 69(65.09%). Among these, Sepsis 36(33.96%); followed by Pneumonia 34(32.07%). Survivors group were 35(33.02%) and non-survivor was 71(66.98%). The Non survivor group was observed to have lower mean values of lactate clearance and found to be statistically significant. Specificity of Lactate clearance was 63.52% and Sensitivity 76.02% respectively. The results were positively associated with lactate level at 24 hours found to be significant effect of survivability when compared to non-survivor.Conclusions: Lactate clearance is vital and markable sign for screening of septic shock at early stage for therapeutic option. Further, 24-hours lactate estimation (cut off values) clearance appears superior to 6 h lactate clearance in predicting mortality in such patients.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Marijan Koprivanac ◽  
Ahmed Aly ◽  
Jonathan Magruder ◽  
Andrew Acker ◽  
Joshua Grim ◽  
...  

Introduction: Our clinical experience in cardiac surgery teaches us that a subset of patients show signs of unexplained end-organ hypoperfusion after an otherwise unremarkable procedure. The objective of this study is to comprehensively examine cardiopulmonary bypass (CPB) management parameters and end-organ perfusion. Hypothesis: Despite advancements in CPB management, CPB does not provide adequate end-organ perfusion. Methods: Retrospective analysis was performed using data from 1462 cardiac operations performed from 2/2019 to 4/2020, excluding circulatory arrest and non-CPB cases. CPB management parameters included cardiac index (CI), mean arterial pressure (MAP), vasopressor-phenylephrine use, lines and bladder temperatures, hemoglobin (Hgb), indexed oxygen delivery (iDO 2 ), and intravenous fluid infusion. End-organ perfusion markers included lactate levels, mixed venous oxygen saturation (SvO 2 ), oxygen consumption (VO 2 ), and arterial pH. Results were expressed as means with first standard deviation. Results: During CPB, CI, MAP, iDO 2 and Hgb were 2.2 ± 0.4 l/min/m 2 , 67 ± 16 mmHg, 270 ± 71 ml/min/m 2 , and 9.3 ± 1.6 g/dl respectively (Figure 1). Phenylephrine cumulative dose increased with CPB duration, 11 ± 9 mg at 1h and 20 ± 15 mg at 2h. Fluid administration showed similar trend. Core mean temperature was maintained with nadir being 33.5 ± 3.4°C. SvO 2 rapidly increased with institution of CPB, peaking at 85%, and then slowly declined. Inversely, VO 2 dropped and then slowly increased. Lactate continuously increased with duration of CPB. Conclusions: Our findings suggest that despite hemodynamic values being maintained at goal by continuously high vasopressor use and fluid administration during CPB, tissue perfusion was inadequate.Our study suggests that, using data-driven approaches, it may be time to revisit the assumptions regarding all aspects of managing CPB.


2020 ◽  
Vol 8 (1) ◽  
pp. e001457
Author(s):  
Jiun-Ruey Hu ◽  
Yingfei Wu ◽  
Frank M Sacks ◽  
Lawrence J Appel ◽  
Edgar R Miller III ◽  
...  

IntroductionPlasma lactate is a marker of non-oxidative glucose metabolism associated with progression to diabetes. We examined the effect of carbohydrate quality (glycemic index (GI)) and amount (%kcal) on plasma lactate. We hypothesized that low GI (≤45 (g)) versus high (≥65 (G)) and low %kcal from carbohydrate (40% kcal (c)) versus high (58% kcal (C)) each would reduce lactate levels.Research design and methodsWe measured lactate in OmniCarb, a randomized, cross-over trial of four diets in overweight/obese adults without diabetes or cardiovascular disease (N=163). The four diets were high carbohydrate+high GI (CG, reference), high carbohydrate+low GI (Cg), low carbohydrate+high GI (cG), and low carbohydrate+low GI (cg). Participants (N=163) consumed each of the four diets over a 5-week period, separated by 2-week washout periods. Plasma lactate levels were measured at baseline, during which the participants consumed their own diets, and after each 5-week period.ResultsBaseline plasma lactate was 1.2 mmol/L. In the setting of high carbohydrate amount, reducing GI lowered plasma lactate non-significantly by 0.08 mmol/L (Cg vs CG: 95% CI −0.16 to 0.00; p=0.06). In the setting of high GI, reducing carbohydrate amount lowered plasma lactate by 0.10 mmol/L (cG vs CG: 95% CI −0.19 to −0.02; p=0.02). The combined effect of reducing GI and carbohydrate proportion in the diet (cg vs CG) was similar (cg vs CG: −0.08; 95% CI −0.16 to 0.00; p=0.04). All four diets reduced plasma lactate compared with baseline.ConclusionsCompared with a diet with high GI and high carbohydrate amount, diets with low GI and/or low carbohydrate amount reduced plasma lactate. Whether this change in lactate leads to long-term change in glucose metabolism needs to be examined.Trial registration numberNCT00608049.


1986 ◽  
Vol 251 (1) ◽  
pp. R137-R142 ◽  
Author(s):  
H. B. John-Alder ◽  
R. M. McAllister ◽  
R. L. Terjung

The functional significance of gluconeogenesis in prolonging endurance during submaximal activity was assessed in untrained and endurance-trained rats. Gluconeogenesis was inhibited at the phosphoenolpyruvate carboxykinase reaction by 3-mercaptopicolinic acid (3-MPA). Endurance was significantly reduced by 3-MPA in untrained (-32%; P less than 0.005) and in trained rats (-26%; P less than 0.001). Metabolic correlates of fatigue were examined in trained rats. At exhaustion, 3-MPA-treated rats had only 3% of resting hepatic glycogen, 46% of resting white quadriceps glycogen, and 37% of resting blood glucose. All of these substrates were at higher levels in sham-injected controls after the same duration of running (130 min). Glycogen levels in red quadriceps, blood lactate levels, and blood glycerol levels were not different between groups. Plasma free fatty acid levels were elevated to the same extent in both groups after 90 min of activity, remained high at 130 min in controls, but had returned to resting levels in the severely hypoglycemic 3-MPA-treated rats at exhaustion. The results indicate that gluconeogenesis is important for maintaining blood glucose levels and for prolonging endurance time during submaximal activity.


Author(s):  
Stephen R. Stannard ◽  
Martin W. Thompson ◽  
Janette C. Brand Miller

Consumption of low glycemic index (GI) foods before submaximal endurance exercise may be beneficial to performance. To test whether this may also be true for high intensity exercise. 10 trained cyclists began an incremental exercise test to exhaustion 65 min after consuming equal carbohydrate portions of glucose (HGI), pasta (LGI), and a noncarbohydrate control (PL). Time to fatigue did not differ significantly (p = 0.05) between treatments. Plasma glucose concentration was significantly lower after LGI vs. HGI from 15 to 45 min of rest postprandial. During exercise, plasma glucose concentration was significantly lower after HGI vs. LGI from 200 W until exhaustion. Plasma lactate concentration following HGI was significantly higher than PL from 30 min of rest postprandial through to the end of the 200-W workload. Plasma lactate concentration following LGI was significantly lower than after HGI from 45 min of rest postprandial through to the end of the 100-W workload. At higher exercise intensities, there was no significant difference in plasma lactate levels between treatments. These findings suggest that a high GI carbohydrate meal (1 g/kg body wt) 65 min prior to exercise decreases plasma glucose and increases plasma lactate levels compared to a low GI meal, but not enough to be detrimental to incremental exercise performance.


Sign in / Sign up

Export Citation Format

Share Document