Changes in the sublingual microcirculation during major abdominal surgery and post-operative morbidity.

BACKGROUND: Little is known about perioperative microcirculatory changes during major abdominal surgery, and the main objectives of this study were to evaluate perioperative microcirculatory alterations in this setting, and if changes in microcirculatory parameters are associated with post-operative morbidity and/or with changes in parameters reflecting oxygen delivery. METHODS: Patients scheduled for major abdominal surgery with an estimated Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) score of > 30 and operation time > 3 h were eligible for inclusion. Perioperative microcirculatory alterations were evaluated in the sublingual mucosa using Sidestream Dark Field (SDF) imaging. Perfused vessel density (PVD), vessel perfusion [microvascular flow index (MFI)], and flow heterogeneity [heterogeneity index (HI)] were analysed. Central venous oxygen saturation (ScvO2) and lactate were measured simultaneously. During a 30-day follow-up period, post-operative complications were registered according to predefined criteria. RESULTS: Forty-two patients with a median P-POSSUM of 33 were included in the study. MFI was higher during anaesthesia than pre- and post-anaesthesia. PVD and HI did not change during the observation period. Lactate and ScvO2 increased during surgery. Perioperative lactate and ScvO2 values were not correlated with microcirculatory parameters. Complications occurred in 16 patients. No differences in microcirculatory parameters were detected between patients with and without complications. CONCLUSIONS: Perioperative changes in the sublingual microcirculatory parameters measured with the SDF-imaging technique appear to be minor, and no association with outcome after major abdominal surgery could be demonstrated. Changes in ScvO2 and serum lactate do not reflect sublingual microcirculatory alterations in this setting.

Induction dose of propofol in patients using cannabis.

BACKGROUND AND OBJECTIVE: An estimated 150 million people worldwide use cannabis. The effect of cannabis on anaesthetic requirements in humans does not appear to have been studied. METHODS: In this prospective, randomized, single-blinded study, 30 male patients using cannabis more than once per week (group C) and 30 nonusers (group NC), aged 18-50 years, were induced with propofol 1.5, 2, 2.5, 3 or 3.5 mg kg. Additional doses were given when required. The primary outcome was the 50% effective dose of propofol and successful induction was determined by loss of consciousness with a bispectral index value of less than 60 and satisfactory insertion of a laryngeal mask. Propofol requirements to achieve these outcomes were recorded. RESULTS: The dose required to achieve the target bispectral index value was not significantly higher in group C, but group C required a significantly higher propofol dose to achieve laryngeal mask insertion (314.0 +/- 109.3 vs. 263.2 +/- 69.5 mg, P < 0.04). The estimated effective propofol induction dose in 50-95% of patients did not significantly differ between groups. CONCLUSION: We conclude that cannabis use increases the propofol dose required for satisfactory clinical induction when inserting a laryngeal mask.

Could benefits of epidural analgesia following oesophagectomy be measured by perceived perioperative patient workload?

BACKGROUND: A controversy exists whether beneficial analgesic effects of epidural analgesia over intravenous analgesia influence the rate of post-operative complications and the length of hospital stay. There is some evidence that favours epidural analgesia following major surgery in high-risk patients. However, there is a controversy as to whether epidural analgesia reduces the intensive care resources following major surgery. In this study, we aimed at comparing the post-operative costs of intensive care in patients receiving epidural or intravenous analgesia. METHODS: Clinical data and rates of post-operative complications were extracted from a previously reported trial following thoraco-abdominal oesophagectomy. Cost data for individual patients included in that trial were retrospectively obtained from administrative records. Two separate phases were defined: costs of pain treatment and the direct cost of intensive care. RESULTS: Higher calculated costs of epidural vs. intravenous pain treatment, 1,037 vs. 410 Euros / patient, were outweighed by lower post-operative costs of intensive care 5,571 vs. 7,921 Euros / patient (NS). CONCLUSION: Higher costs and better analgesic effects of epidural analgesia compared with intravenous analgesia do not reduce total costs for post-operative care following major surgery.

Physiological restitution after night-call duty in anaesthesiologists: impact on metabolic factors.

BACKGROUND: Several studies have shown impaired mental well-being and performance in physicians work on call, but knowledge of the physiological effects is scarce. The aims of the present study were to investigate if there was a metabolic stress response in the restitutional phase after night-call duty, indicating potential negative health effects, and determine whether there were differences between physician specialities. METHODS: Anaesthesiologists (n = 19) were compared with paediatricians/ear, nose and throat (ENT) surgeons (n = 18). On an ordinary workday, 1 and 3 days after work on night call, blood samples were taken for analysis of glucose, thyroid-stimulating hormone (TSH), free thyroxine, testosterone, insulin growth factor-1 (IGF-1), high- and low-density lipoprotein cholesterol (HDL and LDL), triglycerids (TG) and insulin. Saliva cortisol was sampled on an ordinary working day, a day including 16-h night call, the third day following, and for anaesthesiologists also on a day off work. RESULTS: TSH differed significantly between days in both groups, with a 26% lower level 1 day after on-call duty (P < 0.001). A 48% cortisol rise in the morning preceding night duty was found for paediatricians/ENT surgeons (P < 0.01). CONCLUSION: The significant dip in TSH level 24 h after night-call duty indicates a metabolic effect of working on night call and should be studied further. However, the levels were within the normal range and the overall results do not imply any serious metabolic changes and only minor differences were seen between specialist groups.

Thoracic epidural anesthesia and epidural hematoma.

This report involves a 74-year-old-male who developed a thoracic epidural hematoma with paraparesis on the second postoperative day in conjunction with thoracic epidural anesthesia established before surgery for acute abdominal aortic dissection. The finding indicates that laminectomy can be performed successfully as late as three days after diagnosis of the hematoma, with a complete restitution of neurological function. High-dose steroid treatment may have been a contributing factor for the positive outcome.

Pain relief after esophagectomy: Thoracic epidural analgesia is better than parenteral opioids.

OBJECTIVE: To compare postoperative pain relief and pulmonary function in patients after thoracoabdominal esophagectomy treated by continuing perioperative thoracic epidural anesthesia or changing to parenteral opioids. DESIGN: Prospective, randomized study. SETTING: University teaching hospital. PARTICIPANTS: Thirty-three patients undergoing thoracoabdominal esophagectomy. INTERVENTIONS: General anesthesia was combined with thoracic epidural anesthesia during surgery. The patients either continued with thoracic epidural analgesia (n = 18) or were switched to patient-controlled analgesia with intravenous morphine (n = 15) for 5 postoperative days. Pain scores were estimated twice daily, at rest and after mobilization. Peak expiratory flow, forced expiratory volume, and vital capacity were measured the day before surgery, postoperative day 2, and postoperative day 6. Adverse events and complications were recorded. MEASUREMENTS AND MAIN RESULTS: At rest, there were no differences in pain relief between the groups. Pain scores at mobilization showed a significantly lower value in the epidural group (p < 0.027). No intergroup differences were found regarding pulmonary function, which decreased on postoperative day 2, but was improved on postoperative day 6. CONCLUSION: Continuation of intraoperative thoracic epidural anesthesia for 5 postoperative days provides better pain relief at mobilization compared with a switch to patient-controlled analgesia with intravenous morphine. There was no intergroup difference in the impact on measures of pulmonary function.

A comparison of the effects on postoperative pain relief of epidural analgesia started before or after surgery.

In a randomized, prospective clinical study pain relief and pulmonary function were compared after upper abdominal surgery when thoracic epidural analgesia was instituted either before or after surgery. Twenty-six patients admitted for surgery to treat gastro-oesophageal reflux received thoracic epidural analgesia as an adjunct to general anaesthesia either before or after surgery. Twelve patients received epidural mepivacaine 20 mg mL(-1) and morphine perioperatively. Another 14 patients received an epidural bolus of bupivacaine 2.5 mg mL(-1) and morphine after skin closure. Bupivacaine 2.5 mg mL(-1) with morphine was adminstered to all patients for three postoperative days. No intergroup differences were found regarding pain at rest and mobilization. The requirement for additional analgesics was similar in both groups as well as peak expiratory flow. Thoracic epidural analgesia that had already been induced before surgery, and was continued into the postoperative period, does not seem to add any advantage regarding pain relief and lung function compared with thoracic epidural analgesia instituted in the immediate postoperative period.

Pain relief and safety after major surgery. A prospective study of epidural and intravenous analgesia in 2696 patients.

BACKGROUND: Adverse effects may still limit the use of continuous epidural and intravenous analgesia in surgical wards. This study postulated that postoperative epidural analgesia was more efficient, and had fewer side-effects than intravenous morphine. The aim was to investigate efficacy, adverse effects and safety of the treatments in a large patient population. METHODS: During a five-year period 2696 patients undergoing major surgery, received either epidural or intravenous analgesia for postoperative pain relief. The patients were prospectively monitored in surgical wards. Pain was evaluated with a numeric rating scale (0-10) at rest/mobilization. Treatment duration, respiratory depression, sedation/hallucinations/nightmares/confusion, nausea/vomiting, pruritus, orthostatism/leg weakness, and insufficient pain relief were registered. Pain relief for all patients aimed at a pain scoring of less than 4 at rest. RESULTS: Epidural analgesia was used in 1670 patients, and intravenous morphine in 1026 patients. Patients with epidural analgesia experienced less pain both at rest and during mobilization. Insufficient treatment effects such as dose adjustments, orthostatism/leg weakness, and pruritus were more common in the epidural group. Respiratory depression and sedation/hallucinations/nightmares/confusion occurred more often in the intravenous group. Thoracic epidural catheters caused a lower incidence of motor blockade compared to lumbar catheter placements. CONCLUSION: In a large patient population the use of epidural and intravenous postoperative analgesia was considered safe in surgical wards, and the incidence of adverse effects was low. Patients with epidural analgesia experienced overall less pain, while opioid related side-effects were more common with intravenous morphine analgesia.

Local metabolic changes in subcutaneous adipose tissue during intravenous and epidural analgesia.

BACKGROUND: This clinical study aimed at investigating the impact of postoperative thoracic epidural analgesia on extracellular glycerol concentration and glucose metabolism in subcutaneous adipose tissue, using the microdialysis technique. The sympathetic nervous activity, which can be attenuated by epidural anesthesia, influences lipolysis and the release of glycerol. METHODS: Fourteen patients who underwent major abdominal or thoraco-abdominal surgery were studied postoperatively over 3 days. For postoperative analgesia the patients were prospectively randomized to receive either thoracic epidural analgesia with a bupivacaine/morphine infusion (EPI-group, n=6) or a continuous i.v. infusion of morphine (MO-group, n=8). The concentration of glycerol, glucose and lactate in the abdominal and deltoid subcutaneous adipose tissue were measured using a microdialysis technique. RESULTS: The abdominal glycerol levels were equal in both groups. In the deltoid region of the EPI-group, glycerol concentrations started to increase on Day 2, and reached significantly higher levels on Day 3 compared with the MO-group. The glucose and lactate levels showed no differences between groups in the two regions. CONCLUSION: The uniform glycerol levels in abdominal subcutaneous adipose tissue in conjunction with the difference in glycerol levels in the deltoid area indicate that the local lipolysis is different in the two study groups. This might be explained by a regional metabolic influence of thoracic epidural analgesia, possibly via the sympathetic nervous system.