Hospital policy of tranexamic acid to reduce transfusion in major non-cardiac surgery (TRACTION): protocol for a phase IV randomised controlled trial.

INTRODUCTION: Tranexamic acid (TXA) is an inexpensive and widely available medication that reduces blood loss and red blood cell (RBC) transfusion in cardiac and orthopaedic surgeries. While the use of TXA in these surgeries is routine, its efficacy and safety in other surgeries, including oncologic surgeries, with comparable rates of transfusion are uncertain. Our primary objective is to evaluate whether a hospital-level policy implementation of routine TXA use in patients undergoing major non-cardiac surgery reduces RBC transfusion without increasing thrombotic risk. METHODS AND ANALYSIS: A pragmatic, registry-based, blinded, cluster-crossover randomised controlled trial at 10 Canadian sites, enrolling patients undergoing non-cardiac surgeries at high risk for RBC transfusion. Sites are randomised in 4-week intervals to a hospital policy of intraoperative TXA or matching placebo. TXA is administered as 1 g at skin incision, followed by an additional 1 g prior to skin closure. Coprimary outcomes are (1) effectiveness, evaluated as the proportion of patients transfused RBCs during hospital admission and (2) safety, evaluated as the proportion of patients diagnosed with venous thromboembolism within 90 days. Secondary outcomes include: (1) transfusion: number of RBC units transfused (both at a hospital and patient level); (2) safety: in-hospital diagnoses of myocardial infarction, stroke, deep vein thrombosis or pulmonary embolism; (3) clinical: hospital length of stay, intensive care unit admission, hospital survival, 90-day survival and the number of days alive and out of hospital to day 30; and (4) compliance: the proportion of enrolled patients who receive a minimum of one dose of the study intervention. ETHICS AND DISSEMINATION: Institutional research ethics board approval has been obtained at all sites. At the completion of the trial, a plain language summary of the results will be posted on the trial website and distributed in the lay press. Our trial results will be published in a peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: NCT04803747.

An anesthetic management protocol to decrease respiratory complications after adenotonsillectomy in children with severe sleep apnea.

BACKGROUND: A high incidence of respiratory morbidity after adenotonsillectomy is reported in children with obstructive sleep apnea syndrome (OSAS). In an effort to decrease this morbidity, we implemented perioperative guidelines recommending an adjustment in the administration of opioids, dexamethasone, and atropine in children with OSAS who demonstrated recurrent episodes of profound hypoxemia during the perioperative sleep study. METHODS: We performed a retrospective review and compared results with historic data from 2001. The primary outcome variable was a major respiratory medical intervention (MMI(Respiratory)). The severity of OSAS was classified with the McGill Oximetry Scoring (MOS) system, and our focus was on those children demonstrating repetitive desaturation <80% (MOS4). RESULTS: The medical records of 292 children who underwent adenotonsillectomy between October 2002 and February 2006 met the inclusion criteria and 97 had been assigned MOS4. Eleven children (11.3%) required an MMI(Respiratory). In 2001, 8 children (29.6%), assigned MOS4, required an MMI(Respiratory). Comparing the new and old guidelines, the adjusted odds ratio for MMI(Respiratory) in MOS4 was 0.30 (95% CI: 0.10-0.85). The key elements achieving this reduction in MMI(Respiratory) were dexamethasone administration and a reduced opioid dosage. In 2002 to 2006, the intraoperative opioid dose, expressed in morphine equivalents, administered to the MOS4 group was 0.10 mg . kg(-1) (0.06-0.12 mg . kg(-1)), and the postoperative morphine dose was 0.02 mg . kg(-1) (0-0.07 mg . kg(-1)). Both doses were lower than the ones administered to the concurrent comparison group, P values <0.001. CONCLUSIONS: A change in practice that included a dexamethasone administration and a reduction in opioid administration to children with profound recurrent hypoxia reduced the incidence of MMI(Respiratory) by >50%.

Postoperative urinary retention: anesthetic and perioperative considerations.

Urinary retention is common after anesthesia and surgery, reported incidence of between 5% and 70%. Comorbidities, type of surgery, and type of anesthesia influence the development of postoperative urinary retention (POUR). The authors review the overall incidence and mechanisms of POUR associated with surgery, anesthesia and analgesia. Ultrasound has been shown to provide an accurate assessment of urinary bladder volume and a guide to the management of POUR. Recommendations for urinary catheterization in the perioperative setting vary widely, influenced by many factors, including surgical factors, type of anesthesia, comorbidities, local policies, and personal preferences. Inappropriate management of POUR may be responsible for bladder overdistension, urinary tract infection, and catheter-related complications. An evidence-based approach to prevention and management of POUR during the perioperative period is proposed.

Metabolic syndrome and insulin resistance: perioperative considerations.

Metabolic syndrome represents a constellation of risk factors associated with increased incidence of cardiovascular disease and progression to diabetes mellitus. Insulin resistance, a state of decreased biologic response to physiologic concentrations of insulin, is a key component of this syndrome and seems to be the result of a primary defect at the skeletal muscle glucose transporter. Acute illness and the perioperative period are characterized by a state of insulin resistance that manifests as hyperglycemia and leads to various other metabolic and biochemical alterations that adversely affect end organ function. Hyperglycemia in acutely ill patients adversely affects outcome. Achieving euglycemia seems beneficial in certain clinical situations, but considerable disagreement exists regarding the target blood sugar levels, the duration of therapy, and the modality. Pharmacotherapy, exercise, and nutrition to improve insulin sensitivity seem promising but require further evaluation to confirm their efficacy for perioperative risk reduction. This review discusses the pathophysiology and the clinical implications of metabolic syndrome and insulin resistance in the acutely ill patient with an emphasis on perioperative modulation strategies.

Effect of a continuous peripheral nerve block on the inflammatory response in knee arthroplasty.

BACKGROUND AND OBJECTIVES: Experimental nerve block in animals inhibits the inflammatory response. The purpose of this study was to determine to what extent a 48-hour local anesthetic block of all afferent and efferent nerve fibers of the knee area has an impact on postoperative inflammatory response. METHODS: Twelve patients scheduled for primary total knee arthroplasty received spinal anesthesia, and then were randomly allocated to either patient-controlled analgesia with morphine (n = 6) or a combination of continuous lumbar plexus and sciatic nerve blocks (continuous peripheral nerve block; CPNB) with ropivacaine 0.2% for 48 hours. Blood samples were collected before surgery and at 3, 8, 24, and 48 hours after surgical incision to measure plasma glucose, serum insulin and cortisol, C-reactive protein, interleukin-6, and leukocyte count. Pain visual analog scale at rest and on knee flexion were recorded and complications classified. RESULTS: Visual analog scale was lower in the CPNB group at rest and on knee flexion on postoperative days 1 and 2 (P < .05). There were no differences in circulating levels of glucose, insulin, and cortisol. C-reactive protein and leukocyte count were lower in the CPNB group (P < .05). There was a positive correlation between the peak leukocyte count and the inflammatory markers (P < .03). Three patients in the patient-controlled analgesia group and one in the CPNB group had complications requiring conservative management. CONCLUSIONS: Continuous lumbar plexus and sciatic nerve blocks with ropivacaine contribute to the attenuation of the postoperative inflammatory response.

Spread of radioopaque dye in the epidural space in infants.

BACKGROUND: This prospective study aimed to assess the extent of spread of dye in the epidural space and whether it would vary in direct proportion to the volume when injecting two volumes of dye. METHODS: Ten infants, aged 2-36 days (mean +/- SD, 13.30 +/- 13.68 days) and weighing 1.8-4.5 kg (mean +/- SD, 2.60 +/- 0.97 days), who were undergoing major thoracoabdominal surgery under epidural and general anaesthesia, were studied. At the end of surgery, two volumes of radioopaque dye (omnipaque) 0.5 ml.kg(-1) and 1 ml.kg(-1) were injected into the epidural space at a rate of 1 ml.2 min(-1). The spread was studied by taking X-rays after both injections in the left lateral position. RESULTS: There were 10 different patterns of spread in the 10 cases. Uniformly circumferential and cylindrical spread was seen only in one infant. In the others, there were segregated patches of anterior and posterior spread with or without interspersed patches of circumferential spread. There was variation in the extent, location and the density of spread, filling defects and skipped segments with both volumes. Back leak of dye along the needle track was seen in three cases. Statistically, segments were 9.30 +/- 3.68 for 0.5 ml.kg(-1), for 1 ml.kg(-1) 11.50 +/- 3.03, 3.03, S, P=0.014; circumferential spread for 0.5 ml.kg(-1) 2.70 +/- 2.16, for 1 ml.kg(-1) 5.90 +/- 3.14 3.59, P=0.006; anterior spread for 0.5 ml.kg(-1) 3.60 +/- 1.58, for 1 ml kg(-1) 7.90 +/- 2.33 5.88, P=0.001; posterior spread for 0.5 ml.kg(-1) 8.20 +/- 3.71, for 1 ml.kg(-1) 9.80 +/- 3.68 3.54, P=0.006. Doubling of spread with doubling of the volume occurred in only one patient. There was a variable increase in extent or in the density of spread with reduction of skipped segments with the 1 ml.kg-1. The probable reasons for this variable spread and the mechanism of epidural anaesthesia in the presence of such spread are discussed. CONCLUSIONS: There is a difference in quantitative as well as qualitative spread in different patients and in the same patient with different volumes. There were statistically significant increases in the number of segments, circumferential, anterior and posterior locations in the 1.0 ml group. Both extent and density of spread improve with the higher volume but not in direct proportion to volume. 1 ml.kg(-1) has a better quantitative as well as qualitative spread than 0.5 ml and has a better chance of producing adequate anaesthesia.

Anaesthetic management of a case of nesidioblastosis for subtotal pancreatectomy.

Hyperinsulinism is a rare cause of severe persistent hypoglycaemia in the neonatal period. It is associated with a high incidence of brain damage and mental retardation as a consequence of repeated episodes of hypoglycaemia. Subtotal to near total pancreatectomy is indicated as a matter of urgency to decrease the amount of circulating insulin. The perioperative management of a 45-day-old, 5 kg male infant with hyperinsulinaemia (nesidioblastosis) is described. He had a history of generalized tonic clonic seizures 4 h after birth. The blood sugar at that time was 0.66 mmol x l(-1) (12 mg x dl(-1)) and serum calcium was 2.4 mmol x l(-1) (9.82 mg x dl(-1)). The insulin : glucose ratio was 1.6 (normal < 0.4). Occasional episodes of hypoglycaemia persisted in spite of medical line of management with intravenous dextrose 12%, 2 h gastric tube feeds, hydrocortisone (5 mg x kg(-1) x day(-1) i.v.) and oral diazoxide 10 mg x kg(-1), 8 h for 3 weeks. A CT scan and USG did not reveal any abnormality of the pancreas. However, the EEG varied from one of abnormally low amplitude to an isoelectric record. Renal, liver function tests and coagulation profile were normal. The patient was scheduled for elective subtotal pancreatectomy. The anaesthetic management with emphasis on glucose homeostasis and fluid balance is discussed.