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Biomedical subjects

Thomas Schricker

Publications and source records attributed to Thomas Schricker.

At least 19 recordsLinked to original sources
PubMed2006

Postoperative infusion of amino acids induces a positive protein balance independently of the type of analgesia used.

BACKGROUND: Net loss of body protein is a prominent feature of the catabolic response to surgical tissue trauma. Epidural analgesia with hypocaloric dextrose has been demonstrated to attenuate leucine oxidation but was unable to make protein balance positive. The current study was set to determine whether an infusion of amino acids on the second day after colon surgery would revert the catabolic state and promote protein synthesis while maintaining glucose homeostasis in patients receiving epidural analgesia as compared with patient-controlled analgesia with morphine (PCA). METHODS: Sixteen patients undergoing colorectal surgery were randomly assigned to receive epidural blockade or PCA as analgesic techniques and underwent a 6-h stable isotope infusion study (3 h fasted, 3 h fed) on the second postoperative day. Whole body glucose kinetics and protein turnover were measured using [6,6-2H2]glucose and l-[1-13C]leucine as tracer. RESULTS: The infusion of amino acids caused a decrease in endogenous glucose rate of appearance in both groups (P < 0.05), with greater changes in the PCA group (P < 0.05). Administration of amino acids suppressed the appearance of leucine from protein breakdown in both groups (P < 0.05), although the decrease was greater in the PCA group (P < 0.05). Leucine oxidation increased in both groups (P < 0.05), with greater change in the epidural group (P < 0.05). Protein synthesis increased to the same extent in both groups (P < 0.05). Protein balance became positive after the infusion of amino acids, and the effect was greater in the PCA group (P < 0.05). CONCLUSIONS: Infusion of amino acids decreased the endogenous glucose production and induced a positive protein balance independent of the type of anesthesia provided, although such effects were greater in the PCA group.

Adult↗
PubMed2006

Intraoperative infusion of amino acids induces anabolism independent of the type of anesthesia.

BACKGROUND: The infusion of dextrose in patients receiving epidural and light general anesthesia or general anesthesia alone failed to achieve a positive protein balance. We sought to verify the hypothesis that nutritional supplementation with i.v. amino acids induced a greater protein balance in patients receiving epidural blockade compared with those receiving general anesthesia. METHODS: Sixteen patients were randomly assigned to receive either general anesthesia with desflurane (control group) or general anesthesia combined with epidural analgesia (EDA group). A primed constant infusion of stable isotope tracers L-[1-(13)C]leucine and [6,6-(2)H2]glucose was started after a 32-h fast before surgery, (3 h of fasted state), and continued for 3 h during surgery during which amino acids were infused i.v. (fed state). RESULTS: Compared with the fasted state, the endogenous rate of appearance of leucine decreased to a similar extent in both groups, and protein synthesis increased, with no difference between the two groups. Leucine oxidation did not change in either group. After amino acids infusion, endogenous glucose production remained unchanged and glucose clearance decreased in both groups. Blood glucose, plasma cortisol, serum insulin, and glucagon concentrations increased to the same extent in both groups. CONCLUSIONS: Epidural anesthesia provided no additional benefit beyond the anabolism obtained with amino acids.

Adult↗
PubMed2006

Effect of laparoscopic versus open gastric bypass surgery on postoperative pain and bowel function.

BACKGROUND: This study was designed to assess postoperative pain and bowel function in morbidly obese patients undergoing Roux-en-Y gastric bypass (RYGBP) performed either by open or laparoscopic technique. METHODS: We prospectively studied patients scheduled for RYGBP between July 2002 and June 2003. Patients were assigned to the laparoscopic or open procedure by one surgeon. All patients received patient controlled analgesia (PCA) with intravenous morphine and rectal naproxen 500 mg every 12 hours. Postoperative analgesia was assessed daily using a visual analog scale (VAS) at rest, on walking and coughing. The amount of morphine used during the first 48 hours, the time of return of gastrointestinal motility and the time until first oral food intake were recorded. RESULTS: 53 patients were enrolled and studied (laparoscopic group n=33, open group n=20). Patients undergoing laparoscopic RYGBP requested less morphine (P=0.0001) and showed lower VAS pain scores than patients undergoing open RYGBP. The return of bowel movement in the laparoscopic group occurred 1 day earlier than in the open group (P=0.01). The time to first passage of gas (P=0.01) and oral food intake (P=0.06) was shorter after laparoscopic than after open RYGBP. Patients in the laparoscopic group were discharged 1(1/2) days earlier than patients in the open group (P=0.01). CONCLUSION: The laparoscopic RYGBP operation was associated with less postoperative pain and morphine consumption than the open RYGBP, thereby facilitating an earlier recovery of intestinal motility.

Administration, Rectal↗
PubMed2005

How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To determine the effect of perioperative beta blocker treatment in patients having non-cardiac surgery. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Seven search strategies, including searching two bibliographic databases and hand searching seven medical journals. STUDY SELECTION AND OUTCOMES: We included randomised controlled trials that evaluated beta blocker treatment in patients having non-cardiac surgery. Perioperative outcomes within 30 days of surgery included total mortality, cardiovascular mortality, non-fatal myocardial infarction, non-fatal cardiac arrest, non-fatal stroke, congestive heart failure, hypotension needing treatment, bradycardia needing treatment, and bronchospasm. RESULTS: Twenty two trials that randomised a total of 2437 patients met the eligibility criteria. Perioperative beta blockers did not show any statistically significant beneficial effects on any of the individual outcomes and the only nominally statistically significant beneficial relative risk was 0.44 (95% confidence interval 0.20 to 0.97, 99% confidence interval 0.16 to 1.24) for the composite outcome of cardiovascular mortality, non-fatal myocardial infarction, and non-fatal cardiac arrest. Methods adapted from formal interim monitoring boundaries applied to cumulative meta-analysis showed that the evidence failed, by a considerable degree, to meet standards for forgoing additional studies. The individual safety outcomes in patients treated with perioperative beta blockers showed a relative risk for bradycardia needing treatment of 2.27 (95% CI 1.53 to 3.36, 99% CI 1.36 to 3.80) and a nominally statistically significant relative risk for hypotension needing treatment of 1.27 (95% CI 1.04 to 1.56, 99% CI 0.97 to 1.66). CONCLUSION: The evidence that perioperative beta blockers reduce major cardiovascular events is encouraging but too unreliable to allow definitive conclusions to be drawn.

Adrenergic beta-Antagonists↗
PubMed2005

Effect of laparoscopic colon resection on postoperative glucose utilization and protein sparing: an integrated analysis of glucose and protein metabolism during the fasted and fed States using stable isotopes.

HYPOTHESIS: Using a stable isotope method to quantify postoperative changes in glucose and protein metabolism, patients undergoing laparoscopic-assisted colon resection and receiving 4 mg . kg(-1) . min(-1) of dextrose intravenously will (1) have more pronounced suppression of endogenous glucose production, leading to (2) a greater reduction in whole-body protein breakdown. DESIGN: Randomized protocol study. SETTING: Tertiary health care center in Montreal, Quebec. PATIENTS: Twelve patients scheduled for colonic resection were randomly allocated to undergo either laparoscopic (n = 6) or open (n = 6) surgery. INTERVENTIONS: Patients underwent a 6-hour stable isotope infusion study (3 hours fasted and 3 hours fed with dextrose infusion) on postoperative day 2. Whole-body protein breakdown and synthesis, amino acid oxidation, and endogenous glucose production and clearance were measured during the postabsorptive state using L-[1-(13)C]leucine and [6,6-(2)H(2)]glucose. Gas exchange and plasma concentrations of metabolites and hormones were also measured. MAIN OUTCOME MEASURES: Endogenous glucose production and whole-body protein breakdown during the fasted and fed states. RESULTS: In the fasted state, laparoscopy did not affect protein and glucose metabolism. Dextrose infusion suppressed endogenous glucose production in both groups, with the greatest extent in the laparoscopic group (P = .01). Higher respiratory quotients (P = .001) in the latter group also indicated increased exogenous glucose oxidation. Neither surgical approach nor nutrition affected aspects of protein metabolism. CONCLUSIONS: Laparoscopy for colon resection facilitates whole-body glucose uptake and utilization and oxidation of exogenous glucose with no protein-sparing effect. The laparoscopic approach modulates gluconeogenesis, although it is not sufficient in the presence of exogenous energy to promote nitrogen retention.

Carbon Isotopes↗
PubMed2005

Type 2 diabetes mellitus and the catabolic response to surgery.

BACKGROUND: The authors tested the hypothesis that the catabolic responses to colorectal surgery are amplified in the presence of type 2 diabetes mellitus. METHODS: Seven nondiabetic and seven diabetic patients underwent a 6-h stable isotope infusion study (3 h fasted, 3-h glucose infusion at 4 mg . kg . min) on the second postoperative day. Leucine rate of appearance (Ra), leucine oxidation, nonoxidative leucine disposal, and glucose Ra were assessed by L-[1-C]leucine and [6,6-H2]glucose. Circulating concentrations of glucose, lactate, insulin, glucagon, and cortisol also were determined. RESULTS: Diabetic patients had a higher leucine oxidation than nondiabetic patients (P = 0.0003), whereas leucine Ra and nonoxidative leucine disposal were not different. Administration of glucose did not affect leucine kinetics regardless of whether patients were diabetic. In diabetic patients, glucose Ra was greater than in the nondiabetic group (P = 0.0032). Glucose infusion suppressed the endogenous glucose Ra to a lesser extent in diabetic than in nondiabetic patients (P = 0.0048). Plasma glucose concentrations were higher in diabetic than in nondiabetic patients (P = 0.0203), both in the postabsorptive and the fed state. Circulating concentrations of glucagon were higher (P = 0.0065) and concentrations of insulin were lower (P = 0.0146) in the presence of diabetes, resulting in a lower insulin/glucagon ratio (P = 0.0002). In diabetic patients, the insulin/glucagon ratio increased during glucose infusion to a lesser extent than in the nondiabetic group (P = 0.0014). CONCLUSION: Protein catabolism after colorectal surgery is increased in patients with type 2 diabetes mellitus as reflected by an increased oxidative protein loss.

Adult↗
PubMed2005

Intraoperative protein sparing with glucose.

We examined the hypothesis that glucose infusion inhibits amino acid oxidation during colorectal surgery. We randomly allocated 14 patients to receive intravenous glucose at 2 mg x kg(-1) x min(-1) (glucose group) starting with the surgical incision or an equivalent amount of normal saline 0.9% (control group). The primary endpoint was whole body leucine oxidation; secondary endpoints were leucine rate of appearance and nonoxidative leucine disposal as determined by a stable isotope tracer technique (L-[1-(13)C]leucine). Circulating concentrations of glucose, lactate, insulin, glucagon, and cortisol were measured before and after 2 h of surgery. Leucine rate of appearance, an estimate of protein breakdown, and nonoxidative leucine disposal, an estimate of protein synthesis, decreased in both groups during surgery (P < 0.05). Leucine oxidation intraoperatively decreased from 13 +/- 3 to 4 +/- 3 micromol x kg(-1) x h(-1) in the glucose group (P < 0.05 vs. control group) whereas it remained unchanged in the control group. Hyperglycemia during surgery was more pronounced in patients receiving glucose (9.7 +/- 0.5 mmol/l, P < 0.05 vs. control group) than in patients receiving normal saline (7.1 +/- 1.0 mmol/l). The administration of glucose caused an increase in the circulating concentration of insulin (P < 0.05) resulting in a lower glucagon/insulin quotient than in the control group (P < 0.05). Intraoperative plasma cortisol concentrations increased in both groups (P < 0.05), whereas plasma concentrations of lactate and glucagon did not change. The provision of small amounts of glucose was associated with a decrease in amino acid oxidation during colorectal surgery.

Abdomen↗
PubMed2004

Epidural ropivacaine versus epidural morphine and the catabolic response to colonic surgery: stable isotope kinetic studies in the fasted state and during infusion of glucose.

BACKGROUND: The authors examined the hypothesis that epidural administration of local anesthetic, in contrast to epidural analgesia with morphine, inhibits postoperative protein oxidation during administration of glucose. METHODS: Fourteen patients were randomly assigned to undergo a 6-h stable isotope infusion study (3 h fasted, 3 h feeding with 4 mg.kg(-1).min(-1) glucose) on the second day after colorectal surgery using epidural analgesia with either continuous ropivacaine or intermittent morphine. Protein synthesis, breakdown and oxidation, and glucose production were measured by L-[L-13C]leucine and [6,6-2H2]glucose. Substrate oxidation rates were determined by indirect calorimetry. Plasma concentrations of metabolic substrates and hormones were also measured. RESULTS: Whole body protein breakdown, oxidation, synthesis, and glucose production in the fasted state were similar between the two groups. Glucose administration decreased protein breakdown (P = 0.01), protein synthesis (P = 0.001), and glucose production (P = 0.001) to the same extent in both groups, whereas protein oxidation was not significantly affected. The type of epidural analgesia did not significantly influence the circulating concentrations of metabolic substrates and hormones in the fasted or in the fed state. Carbohydrate oxidation rate in the ropivacaine group was greater than in patients receiving morphine (P = 0.04), regardless of whether glucose was infused. CONCLUSION: Epidural analgesia achieved with ropivacaine or morphine does not suppress the catabolic response to surgery, either under fasting conditions or in the presence of an energy supply.

Adult↗
PubMed2004

Postoperative protein sparing with epidural analgesia and hypocaloric dextrose.

OBJECTIVE: We examined the hypothesis that epidural analgesia prevents the increase in amino acid oxidation after elective colorectal surgery in patients receiving hypocaloric infusion of dextrose. SUMMARY BACKGROUND DATA: Increased oxidative protein loss after surgery may adversely affect postoperative outcome. We have previously shown that effective segmental pain relief by epidural analgesia improves postoperative substrate utilization, resulting in less protein catabolism. METHODS: We randomly allocated 10 patients to receive general anesthesia combined with epidural analgesia using bupivacaine/fentanyl and 10 to receive general anesthesia followed by patient-controlled analgesia with intravenous morphine. All patients received a peripheral 72-hour infusion of dextrose 10% from the day before until the second day after surgery. The dextrose infusion rate was adjusted to provide 50% of the patients' resting energy expenditure. The primary end point was whole-body leucine oxidation as determined by a stable isotope tracer technique (l-[1-C]leucine). RESULTS: In the intravenous analgesia group, leucine oxidation increased from 19 +/- 4 to 28 +/- 6 micromol kg h after surgery. Epidural analgesia prevented this increase of leucine oxidation (preoperative 21 +/- 6 micromol kg h, postoperative 21 +/- 5 micromol kg h). This difference was statistically significant (P = 0.01; analysis of variance for repeated measures). CONCLUSION: Perioperative epidural analgesia and hypocaloric dextrose infusion suppress the postoperative increase in amino acid oxidation, thereby saving more than 100 g of lean body mass per day.

Aged↗
PubMed2004

Maintenance of normoglycemia during cardiac surgery.

We used the hyperinsulinemic normoglycemic clamp technique, i.e., infusion of insulin at a constant rate combined with dextrose titrated to clamp blood glucose at a specific level, to preserve normoglycemia during elective cardiac surgery. Ten nondiabetic and seven diabetic patients entered the clamp protocols. Perioperative glucose control was also assessed in 19 nondiabetic and 11 diabetic patients (control group) receiving a conventional insulin infusion sliding scale. In patients of the clamp group, a priming bolus of insulin (2 U) was started before the induction of anesthesia followed by infusions of insulin at 5 mU. kg(-1). min(-1) and of variable amounts of dextrose. Arterial blood glucose was measured every 5 min in the clamp group and every 20 min in the control group. Control of normoglycemia was defined as > or =95% of the glucose levels within 4.0-6.0 mmol/L. Glucose concentration was recorded before surgery, 15 min before cardiopulmonary bypass (CPB), during early and late CPB, and at sternal closure. Patients of the control group became progressively hyperglycemic during surgery (late CPB; nondiabetics, 9.0 +/- 3.2 mmol/L; diabetics, 10.1 +/- 3.6 mmol/L), whereas normoglycemia was achieved in the study group (late CPB; nondiabetics, 5.5 +/- 0.7 mmol/L; diabetics, 4.9 +/- 0.6 mmol/L; P < 0.05 versus control group). In conclusion, it seems that normal blood glucose concentration during open heart surgery can be reliably maintained in nondiabetic and diabetic patients by using the hyperinsulinemic normoglycemic clamp technique.

Aged↗