Markus Schreiber

Propofol/sufentanil anesthesia suppresses the metabolic and endocrine response during, not after, lower abdominal surgery.

We investigated the influence of propofol/sufentanil anesthesia on metabolic and endocrine responses during, and immediately after, lower abdominal surgery. Twenty otherwise healthy patients undergoing abdominal hysterectomy for benign myoma received either continuous infusions of propofol supplemented with sufentanil (0.01 &mgr;g · kg−1 · min−1, n = 10) or enflurane anesthesia (enflurane, n = 10). Plasma concentrations of glucose, lactate, free fatty acids, triglycerides, insulin, glucagon, cortisol, epinephrine, and norepinephrine were measured before, during, and 2 h after surgery. Pre- and postoperative endogenous glucose production (Ra glucose) was analyzed by an isotope dilution technique by using [6,6-2H2] glucose. Propofol/sufentanil anesthesia prevented the increase in plasma cortisol and catecholamine concentrations and attenuated the hyperglycemic response during surgery without showing any difference after the operation. Mediated through a higher glucagon/insulin quotient (propofol/sufentanil 15 ± 7 versus enflurane 8 ± 4 pg/&mgr;U, P < 0.05), the Ra glucose postoperatively increased more in the propofol/sufentanil than in the enflurane group (propofol/sufentanil 15.6 ± 2.0 versus enflurane 13.4 ± 2.2 &mgr;mol · kg−1 · min−1, P < 0.05). Implications The concept of stress-free anesthesia using propofol combined with sufentanil is valid only during surgery. The metabolic endocrine stress response 2 h after the operation is more pronounced than after inhaled anesthesia.

Low dose clonidine premedication accentuates the hyperglycemic response to surgery.

PurposeTo investigate the influence of low dose clonidine premedication on perioperative glucose homeostasis.MethodsSixteen patients undergoing abdominal hysterectomy for benign uterine myoma were randomly assigned to receive eitheriv clonidine (1 μg·kg−1) 30 min before induction of general anesthesia (clonidine,n = 8) or saline (control,n = 8). Plasma concentrations of glucose, insulin, cortisol, epinephrine and norepinephrine were measured before, during and two hours after surgery. At the same time heart rate, mean arterial pressure and cardiac output were recorded.ResultsIn both groups, glucose concentrations significantly increased during and after surgery. Intraoperative glucose plasma concentration in the clonidine group was higher than in the control group (clonidine: 6.8 ± 0.6 mmol·L−1 vs control: 5.7 ± 0.8 mmol·L−1,P < 0.05). This was accompanied by a lower insulin plasma concentration (clonidine: 3.9 ± 1.9 μU·mL−1 vs control: 6.5 ± 2.8 μU·mL−1,P < 0.05). Heart rate, mean arterial pressure and cardiac output remained unchanged throughout the study period without any differences between the groups. While norepinephrine plasma concentrations increased in the control group only (P < 0.05), the plasma concentrations of epinephrine and cortisol increased in both groups (P < 0.05). Clonidine significantly attenuated the cortisol response as reflected by lower intra- and postoperative cortisol plasma concentrations than in the control group (P < 0.05).ConclusionPremedication with clonidine 1 μg·kg−1 accentuates the hyperglycemic response to lower abdominal surgery caused by the decrease in insulin plasma concentrations.RésuméObjectifExplorer l’influence d’une prémédication avec une faible dose de clonidine sur l’homéostase périopératoire du glucose.MéthodeSeize patientes devant subir une hystérectomie abdominale pour un myome utérin bénin ont été réparties au hasard et ont reçu de la clonidine iv (1 μg·kg−1) 30 min avant l’induction de l’anesthésie générale (groupe clonidine,n = 8) ou une solution salée (groupe témoin,n = 8 ). Les concentrations plasmatiques de glucose, d’insuline, de cortisol, d’épinéphrine et de norépinéphrine ont été mesurées pendant l’intervention et deux heures après. Au même moment, la fréquence cardiaque, la tension artérielle moyenne et le débit cardiaque ont été enregistrés.RésultatsDans les deux groupes, les concentrations de glucose ont significativement augmenté pendant et après l’opération. La concentration plasmatique peropératoire dans le groupe clonidine a été plus élevée que celle du groupe témoin (clonidine : 6,8 ± 0,6 mmol·L−1 vs témoin : 5,7 ± 0,8 mmol·L−1,P < 0,05). Ce changement s’est accompagné d’une concentration plus faible d’insuline plasmatique (clonidine : 3,9 ± 1,9 μU·mL−1 vs témoin : 6,5 ± 2,8 μU·mL−1,P < 0,05). La fréquence cardiaque, la tension artérielle moyenne et le débit cardiaque sont demeurés inchangés tout au long de l’étude et ce, sans différence intergroupe. Les concentrations plasmatiques de norépinéphrine ont augmenté chez les témoins seulement (P < 0,05) alors que celles de l’épinéphrine et du cortisol ont augmenté dans les deux groupes (P < 0,05). La clonidine a diminué de façon significative la réponse du cortisol comme l’indiquent les concentrations plasmatiques peropératoires et postopératoires plus faibles que dans le groupe témoin (P < 0,05).ConclusionLa prémédication avec 1 μg·kg−1 de clonidine augmente la réaction hyperglycémique à une hystérectomie abdominale causée par la baisse des concentrations plasmatiques d’insuline.

Influence of Vaginal Versus Abdominal Hysterectomy on Perioperative Glucose Metabolism

The aim of this study was to investigate the metabolic effects of abdominal versus vaginal hysterectomy with specific regard to perioperative glucose metabolism.Fourteen patients received either abdominal (AH, n = 7) or vaginal hysterectomy (VH, n = 7). Hepatic glucose production was measured before and 2.5 h after the operation by stable isotope technique ([6,6-(2) H2]-glucose). Metabolic substrates (glucose, lactate, nonesterified fatty acids [NEFA], beta-hydroxybutyrate) and hormones (insulin, glucagon, cortisol, catecholamines) were determined pre-, intra-, and postoperatively. VH induced a higher postoperative glucose concentration than the abdominal approach (VH, 148 +/- 25 mg/dL; AH, 111 +/- 16 mg/dL; P < 0.05). Since postoperative enhancement of hepatic glucose production was comparable in both groups, glucose clearance was lower after the vaginal procedure (VH, 1.7 +/- 0.3 mL [centered dot] kg-1 [centered dot] min-1; AH, 2.1 +/- 0.3 mL [centered dot] kg-1 [centered dot] min-1; P < 0.05). NEFA, beta-hydroxybutyrate, and catecholamines similarily increased after surgery. Cortisol levels were more increased after VH (VH, 80 +/- 26 micro g/dL; AH, 37 +/- 14 micro g/dL; P < 0.001). Lactate, glucagon, and insulin concentrations did not change perioperatively. The more pronounced hyperglycemic response to VH was due to lower peripheral glucose use caused by higher postoperative cortisol values. The mechanisms responsible for this marked cortisol enhancement after the vaginal operation as well as the clinical significance for patients with preexisting impaired carbohydrate tolerance, however, remained unclear and warrant further investigation. (Anesth Analg 1996;83:991-5)

Time of peritoneal cavity exposure influences postoperative glucose production.

PurposeTo examine the effect of the duration of peritoneal cavity exposure on glucose metabolism after abdominal surgery.MethodsIn eight otherwise healthy patients (ASA I) with uterine myoma, endogenous glucose production (Ra glucose) was measured immediately before and two hours after abdominal hysterectomy by a stable isotope dilution technique using primed continuous infusions of [6,6-2H2]-glucose. Plasma concentrations of glucose, lactate, insulin, glucagon, cortisol, epinephrine and norepinephrine were determined before, during (5 and 60 min after peritoneal incision, skin closure) and two hours after surgery. Pre- and postoperative glucose clearance was calculated as Ra glucose divided by plasma glucose concentration.ResultsRa glucose increased from 11.8 ± 1.2 to 16.8 ± 3.2 μmol·kg−1 ·min−1 two hours after hysterectomy (P < 0.05) with a correlation between the degree of increase and the time of peritoneal cavity exposure (r = 0.859,P = 0.006), Plasma glucose concentration increased after surgery from 4.7 ± 0.8 to 8.3 ± 1.9 mmol·l−1 (P < 0.05), while glucose clearance decreased from 2.6 ± 0.4 to 2.1 ± 0.4 ml·kg−1 ·min−1 (P < 0.05). Plasma concentrations of cortisol and catecholamines increased after hysterectomy (cortisol from 6 ± 2 to 31 ± 7 μg·dl−1, epinephrine from 25 ± 14 to 205 ±132 pg·ml−1, norepinephrine from 182 ± 82 to 377 ± 132 pg·ml−1,P < 0.05), whereas plasma lactate, insulin and glucagon concentrations remained unchanged.ConclusionThe magnitude of increase of glucose production after abdominal hysterectomy is associated with the duration of peritoneal cavity exposure.RésuméObjectifExaminer l’effet du temps d’exposition de la cavité péritonéale sur le métabolisme du glucose après une chirurgie abdominale.MéthodeChez huit patientes en bonne santé (ASA I) présentant un myome utérin, la production endogène de glucose (glucose Ra) a été mesurée immédiatement avant et deux heures après l’hystérectomie abdominale par une technique de dilution isotopique stable en utilisant des perfusions continues amorcées avec du [6,6-2H2]-glucose. Les concentrations plasmatiques de glucose, lactate, insuline, glucagon, cortisol, épinéphrine et norépinéphrine ont été déterminées avant, pendant (5 et 60 min après l’incision péritonéale, la fermeture cutanée) et deux heures après l’opération. La clairance du glucose préopératoire et postopératoire a été calculée ainsi: glucose Ra divisé par la concentration de glucose plasmatique.RésultatsLe glucose Ra a augmenté de 11,8 ± 1,2 à 16,8 ± 3,2 μmol·kg−1·min−1, deux heures après l’hystérectomie avec une corrélation entre le degré d’élévation et le temps d’exposition de la cavité péritonéale (r = 0,859,P = 0,006). La concentration de glucose s’est accrue après l’intervention, passant de 4,7 ± 0,8 à 8,3 ± 1,9 mmol·l−1 (P < 0,05), pendant que la clairance a diminué de 2,6 ± 0,4 à 2,1 ± 0,4 ml·kg−1·min−1 (P < 0,05). Les concentrations de cortisol et de catécholamines ont augmenté après l’hystérectomie (cortisol: de 6 ± 2 à 31 ±7 μg·dl−1, épinéphrine: de 25 ± 14 à 205 ± 132 pg·ml−1, norépinéphrine: de 182 ± 82 à 377 ± 132 pg·ml−1,P < 0,05), mais les concentrations de lactate, d’insuline et de glucagon sont restées les mêmes.ConclusionL’importance de l’accroissement de la production de glucose à la suite d’une hystérectomie abdominale est associée au temps d’exposition de la cavité péritonéale.

Perioperative intravenous fluid therapy in children: guidelines from the Association of the Scientific Medical Societies in Germany

This consensus‐ based S1 Guideline for perioperative infusion therapy in children is focused on safety and efficacy. The objective is to maintain or re‐establish the childs normal physiological state (normovolemia, normal tissue perfusion, normal metabolic function, normal acid‐ base‐ electrolyte status). Therefore, the perioperative fasting times should be as short as possible to prevent patient discomfort, dehydration, and ketoacidosis. A physiologically composed balanced isotonic electrolyte solution (BS) with 1–2.5% glucose is recommended for the intraoperative background infusion to maintain normal glucose concentrations and to avoid hyponatremia, hyperchloremia, and lipolysis. Additional BS without glucose can be used in patients with circulatory instability until the desired effect is achieved. The additional use of colloids (albumin, gelatin, hydroxyethyl starch) is recommended to recover normovolemia and to avoid fluid overload when crystalloids alone are not sufficient and blood products are not indicated. Monitoring should be extended in cases with major surgery, and autotransfusion maneuvers should be performed to assess fluid responsiveness.

Assessment of perioperative glycerol metabolism by stable isotope tracer technique

The aim of this study was to investigate metabolic changes during and after abdominal hysterectomy with specific regard to glycerol metabolism. Seven otherwise healthy patients with benign uterine myoma were enrolled in this study. Glycerol turnover and hepatic glucose production were measured before and after the operation by using stable-isotope technique ([1,1,2,3,3-2H5]-glycerol, [6,6-2H2]-glucose). Metabolic substrates (glycerol, nonesterified fatty acids, β-hydroxybutyrate, glucose, lactate) and hormones (insulin, glucagon, cortisol, catecholamines) were determined pre-, intra-, and postoperatively. Hysterectomy was associated with an increase of postoperative glycerol turnover from 3.56 ± 1.28 to 6.46 ± 2.44 μmol · kg−1 · min−1 (P < 0.05). This increment was inversely related to the age of the patients (r = 0.872, P < 0.05). Glycerol concentration tended to increase perioperatively. These changes, however, were not of statistical significance. Hepatic glucose production and glucose plasma levels increased postoperatively from 9.75 ± 1.61 to 12.79 ± 1.45 μmol · kg−1·min−1 (P < 0.05) and 4.6 ± 0.9 to 6.2 ± 0.9 mmol/L (P < 0.05), respectively. Cortisol and catecholamine levels rose during and after surgery, while insulin and glucagon remained unchanged. The enhanced rate of lipolysis after hysterectomy was not detectable from plasma glycerol levels alone. The results of this study showed that using stable isotope technique allowed a more differentiated look at metabolic pathways than static plasma substrate concentrations, especially under perioperative conditions.

The effective concentration 50 (EC50) for propofol with 70% xenon versus 70% nitrous oxide.

BACKGROUND: Xenon anesthesia has many favorable properties, such as pain modulation and organ protection. However, due to its MAC of 70%, it cannot be used as a sole anesthetic. We estimated the amount of propofol required to supplement xenon to produce adequate anesthesia in 50% and 95% of patients in comparison with nitrous oxide. METHODS: We randomized 75 premedicated female patients to receive either 70% xenon or 70% nitrous oxide in oxygen supplemented by propofol target-controlled infusion anesthesia starting with 4.5 &mgr;g/mL for the first patient in each group. Dixons up and down method was used to determine the propofol concentration for subsequent patients. After induction of anesthesia with propofol, patients breathed 70% xenon or 70% nitrous oxide in oxygen via a facemask for 15 min. They were then observed for movement in response to skin incision for 60 s after the incision and assigned as movers or nonmovers. Probit analysis was used to estimate the effective concentration 50% and 95% (EC50 and EC95) for propofol in both groups. RESULTS: The EC50 for propofol with 70% xenon was1.5&mgr;g/mL and the EC95 was 2.3 &mgr;g/mL. The EC50 and EC95 values for propofol with nitrous oxide were 2.2 and 8.2 &mgr;g/mL, respectively. This implies a reduction of propofol requirements between 32% (EC50) and 72% (EC95) by xenon compared with nitrous oxide. The suppression of auditory evoked potentials was more pronounced with xenon than with nitrous oxide. CONCLUSION: Xenon seems to be clinically more potent than nitrous oxide, but still requires minimal supplement of a hypnotic anesthetic to suppress noxious stimulation during and after skin incision.

Laparoscopic-assisted vaginal hysterectomy and the hyperglycemic response to surgery: an observational study.

PurposeTo test the hypothesis that laparoscopic-assisted vaginal hysterectomy (LAVH) attenuates the hyperglycemic response to surgery when compared to vaginal hysterectomy (VH).MethodsFourteen patients received either LAVH (n=7) or VH (n = 7). Whole body glucose production was measured before and three hours after surgery using [6.6-2H2] glucose. Before, during and after the operation, plasma concentrations of glucose, insulin, glucagon, cortisol, epinephrine and norepinephrine were determined.ResultsPlasma glucose concentration increased in both groups during and after surgery showing a significantly higher value after VH than after LAVH (VH: 8.3 ± 1.4 mmol·L−1; LAVH: 6.6 ± 0.9 mmol·L−1, P < 0.05). The postoperative increase in glucose production was comparable in both groups. While plasma concentrations of insulin and glucagon remained unchanged, intra- and postoperative plasma cortisol concentrations were significantly higher in the VH group than in the LAVH group. Plasma catecholamine concentrations significantly increased after both types of surgery to the same extent.ConclusionIn this observational study, LAVH appears to blunt the hyperglycemie and cortisol response to surgery when compared to VH.RésuméObjectifVérifier l’hypothèse selon laquelle l’hystérectomie vaginale avec assistance laparoscopique (HVAL), comparée à l’hystérectomie vaginale (HV), diminue la réponse hyperglycémique à l’intervention chirurgicale.MéthodeQuatorze patientes ont subi une HVAL (n = 7) ou un HV (n = 7). La production corporelle totale de glucose a été mesurée avant l’opération et trois heures après au moyen de glucose [6,6-2 H2]. Avant, pendant et après l’opération, les concentrations plasmatiques de glucose, d’insuline, de glucagon, de cortisol, d’épinéphrine et de norépinéphrine ont été déterminées.RésultatsLa concentration plasmatique de glucose a augmenté chez les patientes des deux groupes pendant et après l’opération, affichant une valeur significativement plus élevée après l’HV qu’après l’HVAL (VH : 8,3 ± 1,4 mmol·L−1; HVAL : 6,6 ± 0,9 mmol·L−1, P < 0,05). L’augmentation postopératoire de production de glucose était comparable d’un groupe à l’autre. Les concentrations d’insuline et de glucagon sont demeurées les mêmes, mais celles du cortisol peropératoire et postopératoire ont été significativement plus élevées chez les patientes du groupe HV comparé au groupe HVAL. Les concentrations de catécholamine ont augmenté de façon significative, et avec la même importance, après les deux types d’opérations.ConclusionCette étude par observation semble indiquer que l’HVAL, comparée à l’HV, diminue la réponse du glucose et du cortisol à l’intervention chirurgicale.