Luc De Baerdemaeker

Modulation of Portal Graft Inflow: A Necessity in Adult Living-donor Liver Transplantation?

ObjectiveTo evaluate the clinical significance of modulating the recipient portal inflow (rPVF) through perioperative ligation of the splenic artery in adult living-donor liver transplantation (ALDLTx) by focusing on vascular complications, intractable ascites production, and the prevention of small-for-size syndrome (SFSS). Summary Background DataIn ALDLTx, portal graft flow is enhanced to at least twice the donor value, raising the total liver inflow. Recipient hepatic arterial flow (rHAF) is lower than expected. Portal hyperperfusion of small grafts in larger recipients is thought to be one of the main causes of posttransplant graft dysfunction/SFSS. MethodsSeventeen ALDLTx were reviewed for a minimum of 2 months. Patients were divided retrospectively into two groups: G1 (n = 7), without modulation of rPVF, and G2 (n = 10), with splenic artery ligation to decrease rPVF perioperatively. Donor and recipient hepatic hemodynamics were evaluated against graft function and outcome, including correlations between rPVF, graft weight, graft:recipient body weight ratio, and recipient weight. ResultsFollowing portal and arterial reperfusion, mean rPVF and rPVF/graft weight were much higher than in the donors, whereas mean rHAF and rHAF/graft weight were much lower. No differences were found between groups, except for rPVF and rHAF, which were much more higher and lower, respectively, before splenic artery ligation. In G1 patients, SFSS was seen in two patients and vascular complications occurred in two others. In G2 patients, splenic artery ligation permitted a significant decrease in rPVF, an improvement in rHAF, and the resolution of refractory ascites. Neither SFSS nor vascular complications were seen in G2 patients. ConclusionsWhen a suboptimal graft:recipient body weight ratio is accompanied by high rPVF in ALDLTx, the portal flow should be modulated perioperatively; splenic artery ligation is a simple and safe method that is sufficient to allow this modulation in most patients.

A paravenous approach for the saphenous nerve block

Background and Objectives This study assesses a paravenous approach for saphenous nerve block at approximately the level of the tibial tuberosity, and compares it with the conventional technique of blind subcutaneous infiltration between the tibial tuberosity and the gastrocnemius muscle. Methods In dissections of 5 cadavers, the saphenous nerve was found very close to the saphenous vein bilaterally. Subsequently, in 20 volunteers, a bilateral saphenous nerve block was performed with 5 mL mepivacaine on each side. Randomly assigned, the block was performed by blind subcutaneous injection using a 23-gauge needle of 2.5 cm on one side and by a paravenous subcutaneous approach on the other. Results The paravenous approach produced a saphenous nerve block in all 20 volunteers whereas the blind subcutaneous approach was successful in only 6 (33%) (P < .05). Seven volunteers had a painless minor hematoma at the paravenous site and 2 had a hematoma at the classical site. Conclusion The saphenous nerve can be blocked effectively by a paravenous approach using only 5 mL of local anesthetic solution. This approach is advantageous because of its easily identifiable landmark.

Ambulatory electrical external cardioversion with propofol or etomidate

STUDY OBJECTIVE To compare, in pairwise fashion, the effects of propofol and etomidate during ambulatory cardioversion and early recovery. DESIGN Clinical, prospective, randomized, blinded, monocenter, pairwise, comparative study SETTING OR and recovery area of the electrophysiological department, University Hospital Ghent, Belgium. PATIENTS 34 patients with atrial arrhythmia who were scheduled for repetitive electrical cardioversion, of whom 25 patients completed the study. INTERVENTIONS Nonpremedicated patients received during the first cardioversion either propofol (1 mg/kg) or etomidate (0.2 mg/kg) until loss of consciousness, followed by electrical external cardioversion. If after restoration of sinus rhythm for at least 1 day, atrial arrhythmia reoccurred, a second session was performed a week later, using the other induction drug. MEASUREMENTS Systolic and diastolic blood pressure values taken before drug administration, at loss of consciousness, 60 seconds after cardioversion, and awake; the number of shocks, the total amount of energy, the number of patients in which we failed to restore sinus rhythm, the time before opening eyes, answering simple questions and be able to sit, were all noted. Aldrete scores and the Steward postanesthetic recovery scores were noted every minute until 10 minutes after the external cardioversion. Recovery tests were performed and evaluated 5, 10, 15, and 20 minutes after energy delivery. MAIN RESULTS Number of shocks, amount of energy, and blood pressure values were comparable in both groups. Recovery times and Aldrete and Steward postanesthetic recovery scores showed a faster awakening in patients who were induced with propofol. Overall performance of the psychomotor test was better in the propofol group, and most pronounced at 10 and 15 minutes. CONCLUSIONS Etomidate and propofol are both useful during ambulatory external electrical cardioversion. The described doses maintain stable hemodynamic conditions in nonpremedicated patients. Recovery scores and psychomotor test indicate a faster recovery in the propofol group. However, no intergroup differences were noted at 20 minutes after the cardioversion. A safe discharge of all patients from the critical care unit or postanesthesia care unit to the ward can be considered after 30 minutes.

Best anaesthetic drug strategy for morbidly obese patients.

Purpose of review The purpose of this review is to describe an evidence-based drug strategy applicable to any obese patient, rather than to present one standard ‘ideal’ anaesthetic drug combination. The ultimate choice of specific drugs in any given situation will depend upon clinician experience, patient specifics, and drug availability. The fundamental principle in anaesthesia for the obese patient is to use the shortest acting, least fat soluble agents to ensure rapid recovery to safe levels of alertness and mobility. Recent findings No new drugs have been introduced over the past few years, but we have seen an introduction of enhanced recovery after surgery-based protocols into bariatric surgery. Our understanding of how obesity affects pharmacokinetics/dynamics of our drugs is improving, with new and better use of established drugs. Allometric scaling is being tested in the different pharmacokinetic/dynamic models used in target controlled infusion devices, with improved performance as a result. Obstructive sleep apnoea has a significant impact upon outcome and utilization of clinical resources, including critical care beds. If an improved drug dosing strategy will reduce this impact, then this would be a step forward. Summary This review introduces newer findings to help us use anaesthetic and analgesic drugs more safely in the morbidly obese. However, there remain many areas of uncertainty with a lack of consensus on many issues.

Comparable results with 3-year follow-up for large-pore versus small-pore meshes in open incisional hernia repair

BACKGROUND Decreasing the amount of polypropylene by increasing pore size produces a lighter weight mesh that may improve tissue ingrowth and, functional properties of the abdominal wall and diminish mesh-related complications. It was the aim of this prospective observational cohort study to analyze the outcome of incisional hernia repair using small-pore versus large-pore meshes and using a standardized, open, retromuscular surgical technique. METHODS Across a 6-year period we analyzed 205 patients treated with a heavyweight mesh (group I) and 235 patients treated with a large-pore mesh (group II) for incisional hernias. Patients with a body mass index greater than 40 kg/m(2) and patients with hernias with a transverse diameter of more than 10 cm were not treated by a retromuscular mesh repair and are not included in this analysis. Recurrent incisional hernias also were not included. Both groups had 3 years of follow-up. Patients were evaluated for pain, discomfort, feeling of foreign material, and recurrences. RESULTS Pre-operative characteristics were comparable between the groups, including body mass index, diabetes, and smoking. The mean total hernia surface was 56 cm(2) for group I versus 48 cm(2) in group II. The mesh surface area was 448 cm(2) for group I and 425 cm(2) for group II. Considering pain scores, there was only a minor difference between the 2 groups at 1-month follow-up, at which time, the Visual Analogue Scale was 5.8 in group I and 4.9 in group II (P = .16). All other scores were comparable between the groups. In group I, 7 recurrences (3.4%) were recorded after 3 years, of which 6 were already apparent 1 year after initial repair. In group II, 9 recurrences (3.8%) were diagnosed, again 6 within the first year after repair. CONCLUSION Large-pore meshes can be used safely for open primary incisional hernia repair with an equal outcome compared with small-pore meshes in nonobese patients with defects smaller than 10 cm in width, in regard to both recurrence rates and chronic discomfort.

Why hydroxyethyl starch solutions should NOT be banned from the operating room

This review summarises the new insights into the physiology of perioperative fluid therapy and analyses recent studies of the safety of the use of HES solutions in the fluid management of critically ill patients. This analysis reveals a number of methodological issues in the three major studies that have initiated the recommendation of the European Medicine Agency to ban hydroxyethyl starches from clinical practice. It is concluded that, when used in the proper indication, and taking into account the recommended doses, hydroxyethyl starches continue to have a place in perioperative fluid management.

Dose requirements and recovery profile of an infusion of cisatracurium during liver transplantation

STUDY OBJECTIVE To examine the dose requirements and recovery profile of an infusion of cisatracurium during liver transplantation. DESIGN Open-label, descriptive study. SETTING University hospital. PATIENTS 6 ASA physical status III and IV patients with end-stage liver disease, undergoing liver transplantation. INTERVENTIONS Neuromuscular transmission was monitored electromyographically. After recovery of T1/T0 to 10%, cisatracurium was infused at an initial rate of 1.5 microg/kg/min. The infusion rate was adjusted to maintain T1/T0 at 10%. At the end of surgery, spontaneous recovery from the neuromuscular block was awaited. MEASUREMENTS AND MAIN RESULTS The infusion rate of cisatracurium was 1.6 +/- 0.4 microg/kg/min. Before the anhepatic phase, this rate was 1.5 +/- 0.4 microg/kg/min; during the anhepatic phase it was 1.7 +/- 0.5 microg/kg/min; and after reperfusion it was 1.9 +/- 0.4 microg/kg/min. There was a significant difference between the cisatracurium infusion rates before and after the anhepatic phase (p < 0.05). Following termination of the infusion, the time to 25% recovery of T1/T0 was 19.2 +/- 6.1 minutes, the recovery index (25% to 75%) was 28.8 +/- 7.0 minutes, and the time for the train-of-four (TOF) ratio to reach 0.7 was 50.2 +/- 7.1 minutes. The time for the TOF ratio to reach 0.9 was 61.4 +/- 6.6 minutes. There was no difference in body temperature or pH during the consecutive stages of transplantation. CONCLUSIONS The infusion dose requirement for cisatracurium during liver transplantation tended to be higher than previously reported in healthy patients; recovery appeared prolonged. In continuous infusion of cisatracurium during liver transplantation, the tendency toward higher dose requirements, the protracted duration of infusion, the non-Hofmann elimination and/or other pharmacokinetic changes during transplantation might influence recovery from the neuromuscular block. Potential temperature or pH change during surgery seemed irrelevant in explaining the delayed recovery.

Postoperative complications in cardiac patients undergoing noncardiac surgery

Purpose of reviewIn this article we review the current knowledge on the underlying mechanisms of perioperative myocardial injury, the preoperative methods of predicting these complications, the diagnostic tools for detecting perioperative myocardial injuries, and the available protective strategies to prevent or attenuate the extent of myocardial injury. Recent findingsThe last years’ new insights have provided a better understanding of the problem of perioperative myocardial injury and infarction. Specifically, the importance of early diagnosis and prompt treatment are increasingly getting attention. Concomitantly, the results of recent large multicenter studies have challenged classical therapeutic approaches in the perioperative treatment of cardiac patients undergoing noncardiac surgery. SummaryThese new insights will help to better tailor individual strategies to prevent or minimize perioperative cardiac complications. Especially, early diagnosis and intensification of treatment will get specific interest in the coming years.

The LAS VEGAS risk score for prediction of postoperative pulmonary complications : an observational study

BACKGROUND Currently used pre-operative prediction scores for postoperative pulmonary complications (PPCs) use patient data and expected surgery characteristics exclusively. However, intra-operative events are also associated with the development of PPCs. OBJECTIVE We aimed to develop a new prediction score for PPCs that uses both pre-operative and intra-operative data. DESIGN This is a secondary analysis of the LAS VEGAS study, a large international, multicentre, prospective study. SETTINGS A total of 146 hospitals across 29 countries. PATIENTS Adult patients requiring intra-operative ventilation during general anaesthesia for surgery. INTERVENTIONS The cohort was randomly divided into a development subsample to construct a predictive model, and a subsample for validation. MAIN OUTCOME MEASURES Prediction performance of developed models for PPCs. RESULTS Of the 6063 patients analysed, 10.9% developed at least one PPC. Regression modelling identified 13 independent risk factors for PPCs: six patient characteristics [higher age, higher American Society of Anesthesiology (ASA) physical score, pre-operative anaemia, pre-operative lower SpO2 and a history of active cancer or obstructive sleep apnoea], two procedure-related features (urgent or emergency surgery and surgery lasting ≥ 1 h), and five intra-operative events [use of an airway other than a supraglottic device, the use of intravenous anaesthetic agents along with volatile agents (balanced anaesthesia), intra-operative desaturation, higher levels of positive end-expiratory pressures > 3 cmH2O and use of vasopressors]. The area under the receiver operating characteristic curve of the LAS VEGAS risk score for prediction of PPCs was 0.78 [95% confidence interval (95% CI), 0.76 to 0.80] for the development subsample and 0.72 (95% CI, 0.69 to 0.76) for the validation subsample. CONCLUSION The LAS VEGAS risk score including 13 peri-operative characteristics has a moderate discriminative ability for prediction of PPCs. External validation is needed before use in clinical practice. TRIAL REGISTRATION The study was registered at Clinicaltrials.gov, number NCT01601223.

Reply to: adjusting tracheal tube cuff pressure

To clarify the discussion and the interpretation of statements, it is essential to make the difference between what is considered to be a good clinical practice and what is actually a routine clinical practice. In this specific case, data from the literature clearly indicate that regular control and adjustments of cuff pressures prevent aspiration pneumonia. With these available data, good clinical practice would therefore imply that this strategy should be part of the routine anaesthetic management. We agree with Dr Kunstyr that this is probably not the case in a number of centres. However, it is not because a protective management is not applied during routine management that this routine strategy becomes the reference of good clinical practice. It is specifically this point that we wanted to underscore in our Commentary. In clinical studies, we need to make sure that patients in the control group get a treatment according to good clinical practice and not simply the ‘routine’ treatment, certainly when this implies that no protective actions are undertaken.