Antje Gottschalk

Review article: the role of the perioperative period in recurrence after cancer surgery.

A wealth of basic science data supports the hypothesis that the surgical stress response increases the likelihood of cancer dissemination and metastasis during and after cancer surgery. Anesthetic management of the cancer patient, therefore, could potentially influence long-term outcome. Preclinical data suggest that beneficial approaches might include selection of induction drugs such as propofol, minimizing the use of volatile anesthetics, and coadministration of cyclooxygenase antagonists with systemic opioids. Retrospective clinical trials suggest that the addition of regional anesthesia might decrease recurrence after cancer surgery. Other factors such as blood transfusion, temperature regulation, and statin administration may also affect long-term outcome.

Intravenous lidocaine is as effective as epidural bupivacaine in reducing ileus duration, hospital stay, and pain after open colon resection: a randomized clinical trial.

Background: Both postoperative epidural analgesia and intravenous (IV) infusion of local anesthetic have been shown to shorten ileus duration and hospital stay after colon surgery when compared with the use of systemic narcotics alone. However, they have not been compared directly with each other. Methods: Prospective, randomized clinical trial was conducted comparing the 2 treatments in open colon surgery patients. Before induction of general anesthesia, patients were randomized either to epidural analgesia (bupivacaine 0.125% and hydromorphone 6 &mgr;g/mL were started at 10 mL/hr within 1 hr of the end of surgery) or IV lidocaine (1 mg/min in patients <70 kg, 2 mg/min in patients ≥70 kg). Markers of return of bowel function, length of stay, postoperative pain scores, systemic analgesic requirements, and adverse events were recorded and compared between the 2 groups in an intent-to-treat analysis. Results: Study enrollment took place from April 2005 to July 2006. Twenty-two patients were randomized to IV lidocaine therapy and 20 patients to epidural therapy. No statistically significant differences were found between groups in time to return of bowel function or hospital length of stay. The median pain score difference was not statistically significant. No statistically significant differences were found in pain scores for any specific postoperative day or in analgesic consumption. Conclusions: No differences were observed between groups in terms of return of bowel function, duration of hospital stay, and postoperative pain control, suggesting that IV infusion of local anesthetic may be an effective alternative to epidural therapy in patients in whom epidural anesthesia is contraindicated or not desired.

Systemic lidocaine decreased the perioperative opioid analgesic requirements but failed to reduce discharge time after ambulatory surgery.

BACKGROUND: In this randomized, blinded, placebo-controlled trial, we evaluated whether systemic lidocaine would reduce pain and time to discharge in ambulatory surgery patients. METHODS: Sixty-seven patients were enrolled to receive lidocaine or saline infusion perioperatively. RESULTS: Length of postanesthesia care unit (PACU) stay did not differ between groups. Intraoperative opioid use was significantly less in the lidocaine group, both in the PACU and during the total study period but not after discharge. In the PACU, patients in the lidocaine group reported less pain (visual analog scale score 3.1 ± 2.04 vs 4.5 ± 2.9; P = 0.043). There were no differences in postoperative nausea and vomiting. CONCLUSION: Perioperative systemic lidocaine significantly reduces opioid requirements in the ambulatory setting without affecting time to discharge.

Intraoperative Methadone Improves Postoperative Pain Control in Patients Undergoing Complex Spine Surgery

BACKGROUND:Patients undergoing complex spine surgery frequently experience severe pain in the postoperative period. The combined opiate receptor agonist/N-methyl-D-aspartate receptor antagonist methadone may be an optimal drug for these patients given the probable involvement of N-methyl-D-aspartate systems in the mechanism of opioid tolerance and hyperalgesia. METHODS:Twenty-nine patients undergoing multilevel thoracolumbar spine surgery with instrumentation and fusion were enrolled in this prospective study and randomized to receive either methadone (0.2 mg/kg) before surgical incision or a continuous sufentanil infusion of 0.25 &mgr;g/kg/h after a load of 0.75 &mgr;g/kg. Postoperative analgesia was provided using IV opioids by patient-controlled analgesia. Patients were assessed with respect to pain scores (visual analog scale from 0 to 10), cumulative opioid requirement, and side effects at 24, 48, and 72 hours after surgery. RESULTS:Demographic data, duration, and type of surgery were comparable between the groups. Methadone reduced postoperative opioid requirement by approximately 50% at 48 hours (sufentanil versus methadone group, median [25%/75% interquartile range]: 63 mg [27.3/86.1] vs 25 mg [16.5/31.5] morphine equivalents, P = 0.023; and 72 hours: 34 mg [19.9/91.5] vs 15 mg [8.8/27.8] morphine equivalents, P = 0.024) after surgery. In addition, pain scores were lower by approximately 50% in the methadone group at 48 hours after surgery (sufentanil versus methadone group [mean ± SD] 4.8 ± 2.4 vs 2.8 ± 2.0, P = 0.026). The incidence of side effects was comparable in both groups. CONCLUSION:Perioperative treatment with a single bolus of methadone improves postoperative pain control for patients undergoing complex spine surgery.

Effect of intravenous lidocaine on postoperative recovery of patients undergoing mastectomy: a double-blind, placebo-controlled randomized trial.

Background One of the modalities of treatment for breast cancer surgery pain is opioids, and opioids are associated with adverse effects such as itching and postoperative nausea and vomiting (PONV). Intravenous (IV) lidocaine has been shown to reduce opioid consumption and to improve overall postoperative outcomes in abdominal surgery. In this study, we tested the effect of intraoperative IV lidocaine infusion on the quality of postoperative recovery after breast cancer surgery. Methods Seventy-one patients undergoing breast cancer surgery were randomly assigned to receive either placebo (group P; n = 34) or IV lidocaine (group L; n = 37, bolus 1.5 mg/kg at induction, then infusion at 2 mg/kg/h, stopped 2 hours after the end of surgery) in a prospective double-blind design. Intraoperative and postoperative morphine consumption was calculated. Postoperative pain scores, PONV, and fatigue were assessed at 2, 24, and 48 hours after surgery. Duration of postoperative hospital stay was recorded. Results Demographics were the same between the groups. There was no statistically significant difference in intraoperative or postoperative morphine consumption (P = 0.188 and P = 0.758) between groups. Overall pain scores either at rest or activity (P = 0.348 and P = 0.810, respectively), PONV (P = 0.350), fatigue (P = 0.758), or duration of postoperative hospital stay (P = 0.218) were not statistically different. Conclusions Our findings did not show a significant effect of IV lidocaine during breast cancer surgery on opioid consumption, pain score, PONV, or fatigue, indicating that the benefit of this approach does not generalize across all types of surgery.

HbA1c and Diabetes Predict Perioperative Hyperglycemia and Glycemic Variability in On-Pump Coronary Artery Bypass Graft Patients

OBJECTIVE Perioperative hyperglycemia and glycemic variability are considered independent predictors of morbidity and mortality in critically ill patients. The purpose of this study was to investigate the relation of HbA1c and/or a prior diagnosis of diabetes mellitus and intra- and postoperative hyperglycemia and glycemic variability. DESIGN A retrospective data analysis from a single-center database. SETTING A single university hospital. PARTICIPANTS Diabetic and nondiabetic patients undergoing isolated on-pump coronary artery bypass graft (CABG) surgery. MEASUREMENTS One hundred twenty patients undergoing isolated CABG surgery were evaluated. Glucose values were acquired pre-, intra-, and postoperatively on the day of surgery as well as on the first postoperative day. The extent of hyperglycemia within and between groups was compared using mean and maximum glucose values. As a measure of the patients individual intra- and postoperative glucose variability, the standard deviation (SD) and the coefficient of variation (CV) of glucose values were calculated. Outcomes were analyzed using a multiple logistic regression model. RESULTS Diabetics and/or patients with elevated HbA1c had higher postoperative glucose levels, a higher SD, and a higher CV of postoperative glucose values; however, higher glucose variability was not associated with higher rates of complication. Intraoperative glucose values and variation did not differ significantly between groups. Increased mean blood glucose values were associated with increased risk of infection. CONCLUSIONS Diabetic status and/or elevated HbA1c are predictors of postoperative glucose variability and hyperglycemia in CABG surgery patients. However, in the intraoperative period, these groups show similar glycemic responses to operative stress.

Spinal anesthesia protects against perioperative hyperglycemia in patients undergoing hip arthroplasty

STUDY OBJECTIVE To determine whether spinal anesthesia blunts surgical stress reactions and results in less perioperative hyperglycemia. DESIGN Prospective, randomized controlled study. SETTING Operating room of a university hospital. PATIENTS 68 adult, nondiabetic (n = 40) and diabetic (n = 28), ASA physical status 1, 2, and 3 patients patients undergoing elective total hip replacement. INTERVENTIONS General or spinal anesthesia was administered. MEASUREMENTS Blood HbA1C was measured preoperatively to identify patients with undiagnosed diabetes. Glucose levels were checked preoperatively, then immediately after, and one hour after surgery. A conventional glucose control protocol was used, where insulin was given when blood glucose concentrations exceeded 250 mg/dL. MAIN RESULTS Preoperative glucose levels in general and spinal anesthesia patients were comparable and not significantly different in nondiabetic and diabetic patients. At the end of surgery and one hour after surgery, glucose levels were significantly higher in patients undergoing general anesthesia compared with baseline values in both diabetic and nondiabetic patients (P < 0.05). In nondiabetic and diabetic patients, a significant increase in glucose level was found in patients undergoing general anesthesia versus spinal anesthesia (P < 0.05). In patients receiving spinal anesthesia, glucose levels remained stable. Two diabetic patients undergoing general anesthesia received insulin. CONCLUSION Spinal anesthesia attenuates the hyperglycemic response to surgical stimuli in diabetics and nondiabetic patients.

Systemic lidocaine decreases the Bispectral Index in the presence of midazolam, but not its absence ☆ ☆☆ ★

STUDY OBJECTIVE To evaluate the effects of intravenous (IV) lidocaine on the Bispectral Index (BIS) in the presence or absence of midazolam. DESIGN Prospective, randomized, double-blinded, placebo-controlled clinical study. SETTING Operating room of a university hospital. PATIENTS 96 ASA physical status 1, 2, and 3 patients undergoing general anesthesia. INTERVENTIONS Patients were assigned to one of 6 treatment groups to receive IV midazolam (0.03 mg/kg) or placebo, followed 5 minutes later by one of three IV preinduction doses of lidocaine: 0.5, 1.0, or 1.5 mg/kg. MEASUREMENTS BIS values were recorded before administration of lidocaine and at 30-second intervals afterwards for three minutes. The primary endpoint was the average BIS level recorded. MAIN RESULTS Baseline BIS values were lower in the midazolam group (94 ± 4 vs. 90 ± 7, P < 0.001). There was no significant decrease in BIS values in the placebo group for any of the three lidocaine doses. However, in the midazolam groups, significant decreases in BIS levels versus baseline values were measured. CONCLUSION IV lidocaine decreases BIS in the presence of midazolam, suggesting that the effect of lidocaine on BIS is not direct, but rather results from modulation by midazolam.

Heparin-Induced Thrombocytopenia During Extracorporeal Membrane Oxygenation

HEPARIN-INDUCED THROMBOCYTOPENIA (HIT) is an immune-mediated adverse effect of heparin therapy. Two clinical entities of HIT can be distinguished: HIT I and HIT II. HIT I is a harmless pharmacologic phenomenon associated with decreased platelet count within 24–48 h after initiation of heparinization. Unlike HIT II, it is not associated with thrombosis and does not necessitate discontinuation of heparin. In contrast, HIT II can cause both bleeding and thrombotic complications. It is the most important and most frequent drug-induced immunologic thrombocytopenia. Besides orthopedic and vascular surgery patients, patients after cardiac surgery are at highest risk of developing HIT II (1–5%). Its clinical importance is based on its strong association with venous and arterial thrombosis and thromboembolism (heparin-induced thrombocytopenia with associated thrombosis, HITT). HIT is caused by the development of an IgG antibody that recognizes multimolecular complexes of platelet factor 4 (PF4) and heparin. This so-called heparin-PF4-IgG complex leads to platelet activation and release of additional PF4 from alpha granules in platelets when bound to the platelet Fc receptor. Note that heparin forms a necessary part of the complex leading the further PF4 release. PF4 released in excess binds to heparin-like molecules on the surface of endothelial cells leading to immunemediated endothelial cell injury and heightening the risk for HITT and disseminated intravascular coagulation (DIC). The mainstay of therapy in HIT/HITT is the avoidance of further exposure to heparin in any form, avoidance of platelet transfusions and deferral of vitamin-K-antagonists until platelet recovery. Early use of alternative anticoagulants is inevitable when the indication for anticoagulation persists or in individuals with HITT. Extracorporeal membrane oxygenation (ECMO) remains a last line life-saving therapeutic option in patients suffering from

Continuous Glucose Monitoring in Patients Undergoing Extracorporeal Ventricular Assist Therapy

Background Dysregulations of blood glucose (BG) are associated with adverse outcome in critical illness; controlling BG to target appears to improve outcome. Since BG-control is challenging in daily intensive care practice BG-control remains poor especially in patients with rapidly fluctuating BG. To improve BG-control and to avoid deleterious hypoglycemia, automated online-measurement tools are advocated. We thus evaluated the point-accuracy of the subcutaneous Sentrino® Continuous Glucose Monitoring System (CGM, Medtronic Diabetes, Northridge, California) in patients undergoing extracorporeal cardiac life support (ECLS) for cardiogenic shock. Methods Management of BG was performed according to institute’s standard aiming at BG-levels between 100–145 mg/dl. CGM-values were recorded without taking measures into therapeutic account. Point-accuracy in comparison to intermittent BG-measurement by the ABL-blood-gas analyzer was determined. Results CGM (n = 25 patients) correlated significantly with ABL-values (r = 0.733, p<0.001). Mean error from standard was 15.0 mg/dl (11.9%). 44.2% of the readings were outside a 15% range around ABL-values. In one of 635 paired data-points, ABL revealed hypoglycemia (BG 32 mg/dl) whereas CGM did not show hypoglycemic values (132mg/dl). Conclusions CGM reveals minimally invasive BG-values in critically ill adults with dynamically impaired tissue perfusion. Because of potential deviations from standard, CGM-readings must be interpreted with caution in specific ICU-populations.