Guidelines for the safe provision of anaesthesia in magnetic resonance units 2019: Guidelines from the Association of Anaesthetists and the Neuro Anaesthesia and Critical Care Society of Great Britain and Ireland.

There has been an increase in the number of units providing anaesthesia for magnetic resonance imaging and the strength of magnetic resonance scanners, as well as the number of interventions and operations performed within the magnetic resonance environment. More devices and implants are now magnetic resonance imaging conditional, allowing scans to be undertaken in patients for whom this was previously not possible. There has also been a revision in terminology relating to magnetic resonance safety of devices. These guidelines have been put together by organisations who are involved in the pathways for patients needing magnetic resonance imaging. They reinforce the safety aspects of providing anaesthesia in the magnetic resonance environment, from the multidisciplinary decision making process, the seniority of anaesthetist accompanying the patient, to training in the recognition of hazards of anaesthesia in the magnetic resonance environment. For many anaesthetists this is an unfamiliar site to give anaesthesia, often in a remote site. Hospitals should develop and audit governance procedures to ensure that anaesthetists of all grades are competent to deliver anaesthesia safely in this area.

Onlay bone grafts from iliac crest: a retrospective analysis.

This study was performed to address the outcomes of patients treated with onlay grafts from the iliac crest to augment the deficient jaw. The results of 173 consecutive patients who underwent bone grafting prior to implant surgery are presented. The grafts were taken from the anterior iliac crest to repair alveolar bone deficiencies that were too large to be corrected using intraoral bone grafts. Three months postoperatively, 869 implants were placed into 190 onlay grafts (167 grafts in the maxilla, 23 in the mandible). The follow-up ranged from 3 months to 23 years post implantation. All patients received a fixed prosthesis. Parameters examined included healing of the donor site and bone grafts, implant survival, peri-implant condition, and donor site morbidity. The overall survival rate for all implants was calculated to be 95%±2.7% according to Kaplan-Meier analysis. The implant survival rate compares favourably with those reported in studies using intraoral and extraoral bone.

Reporting of sex and gender in randomized controlled trials in Canada: a cross-sectional methods study.

BACKGROUND: Accurate reporting on sex and gender in health research is integral to ensuring that health interventions are safe and effective. In Canada and internationally, governments, research organizations, journal editors, and health agencies have called for more inclusive research, provision of sex-disaggregated data, and the integration of sex and gender analysis throughout the research process. Sex and gender analysis is generally defined as an approach for considering how and why different subpopulations (e.g., of diverse genders, ages, and social locations) may experience health conditions and interventions in different or similar ways.The objective of this study was to assess the extent and nature of reporting about sex and/or gender, including whether sex and gender analysis (SGA) was carried out in a sample of Canadian randomized controlled trials (RCTs) with human participants. METHODS: We searched MEDLINE from 01 January 2013 to 23 July 2014 using a validated filter for identification of RCTs, combined with terms related to Canada. Two reviewers screened the search results to identify the first 100 RCTs that were either identified in the trial publication as funded by a Canadian organization or which had a first or last author based in Canada. Data were independently extracted by two people from 10% of the RCTs during an initial training period; once agreement was reached on this sample, the remainder of the data extraction was completed by one person and verified by a second. RESULTS: The search yielded 1433 records. We screened 256 records to identify 100 RCTs which met our eligibility criteria. The median sample size of the RCTs was 107 participants (range 12-6085). While 98% of studies described the demographic composition of their participants by sex, only 6% conducted a subgroup analysis across sex and 4% reported sex-disaggregated data. No article defined "sex" and/or "gender." No publication carried out a comprehensive sex and gender analysis. CONCLUSIONS: Findings highlight poor uptake of sex and gender considerations in the Canadian RCT context and underscore the need for better articulated guidance on sex and gender analysis to improve reporting of evidence, inform policy development, and guide future research.

Prevention of adriamycin induced heart failure by an increase in endogenous adenosine production.

Adenosine (Ado) triggers several protective mechanisms that may attenuate development of heart failure, both locally and systemically. We developed a procedure allowing sustained increase in endogenous Ado production by the combined application of Ado metabolism inhibitors and nucleotide precursors. We found that our procedure attenuate the development of heart failure induced by adriamycin.

Endothelins and the lung.

Since endothelins were discovered by Yanasigawa in 1988 it has been recognised that they may have an important role in lung pathophysiology. Despite their biological importance as vasoconstrictors the physiological role of endothelin has not yet been defined within the lungs. This review explores their role in acute and chronic disease. During acute inflammation and ischaemia-reperfusion injury cytokines may induce release of endothelin. This is important in the realm of acute lung injury and during surgical procedures such as cardiopulmonary operations including lung resections and transplantation. Complications of surgery including primary organ failure resulting in poor gas exchange as well as increased pulmonary vascular resistance have been linked to the presence of excessive endothelin. Endothelin may have an important role in transplantation biology. The complex process leading to successful lung transplantation includes optimising the donor with brain death, harvesting the lungs, managing acute and chronic rejection, and protecting the vital organs from toxic effects of immunosuppressants. During chronic disease processes, the mitotic action of endothelin may be important in vascular and airway remodelling by means of smooth muscle cell proliferation. We also explore recent advances in drug development, animal models and future directions for research.

Inhaled nitric oxide for right ventricular dysfunction following cardiac transplantation.

A 55-year-old man developed postoperative hypotension following orthotopic cardiac transplantation, unresponsive to support with inotropes and counterpulsation. Acute right ventricular failure was confirmed by transoesophageal echocardiography, and the introduction of inhaled nitric oxide resulted in immediate improvement. A beneficial effect persisted for 11 days, with hospital discharge two months postoperatively.

Anaesthetic assessment and management of cardiac patients for non-cardiac surgery. Part 2: Management.

In an earlier article in this journal (June 1999) we discussed the risk that the presence of cardiac disease poses to patients undergoing non-cardiac surgery. We outlined factors in the patient's medical history, examination findings and the value of various tests in arriving at an overall assessment of risk for any given patient. In this article we concentrate on the management of these patients as they undergo surgery itself. We shall consider what measures may usefully be employed in order to minimise the risk of an adverse cardiac event occurring in the perioperative period.

Anaesthetic assessment and management of cardiac patients for non-cardiac surgery. Part I: Assessment.

Cardiac disease is known to increase the risk of non-cardiac surgery to patients who suffer from it. Clinical and investigation data may be used to identify those at increased risk. Attempts have been made to integrate these risk factors into systems that can quantify risk in terms of increased morbidity and mortality. In this article we discuss the various aspects of cardiac illness that are known to increase risk for patients and then look at the different scoring systems that have been produced. We consider the type and urgency of surgery and finish by providing an approach to risk assessment for non-cardiac surgery.

Antiseptic-impregnated central venous catheters reduce the incidence of bacterial colonization and associated infection in immunocompromised transplant patients.

The incidence of bacterial colonization of central venous catheters using a standard polyurethane catheter was compared with that using an antiseptic (silver sulphadiazine and chlorhexidine) impregnated catheter in a group of patients with thoracic organ transplantation. Colonization was reduced from 25 of 35 standard catheters to 10 of 44 study catheters (P < 0.002), a 68% reduction. Similarly, the incidence of concomitant infection, by the same organism at another site was reduced from 10 of 35 standard catheters to 4 of 44 study catheters (P < 0.03), a 63% reduction.

Intraoperative transoesophageal echocardiography for implantation of a pulsatile left ventricular assist device.

We describe the insertion of a permanent implantable left ventricular assist device and intraoperative transoesophageal echocardiography in this instance. We also review the literature on the use of intraoperative transoesophageal echocardiography.

Alfentanil-oxygen anaesthesia for coronary artery surgery.

The anaesthétic properties of alfentanil were evaluated in 15 patients undergoing coronary artery bypass grafting operations. Alfentanil was infused at a rate of 3.0mg min-1 until the patients (breathing pure oxygen) became unconscious. Additional alfentanil 2.5-5.0mg i.v. was given if systolic arterial pressure increased by 15% or more from control values. Alfentanil produced unconsciousness in 75 +/- 18s, but muscle rigidity occurred in 27% of patients. Cardiovascular dynamics were minimally altered during the induction of anaesthesia and throughout most of the operation, although 60% of patients became hypertensive during sternotomy and 73% during sternal spread. Recovery from anaesthesia was rapid with patients regaining consciousness after 1.4 +/- 0.6h and fulfilling out criteria for extubation of the trachea 4.1 +/- 1.2h after operation. No patient was aware of laryngoscopy, endotracheal intubation or any aspect of the operation.

Quinine overdose. Prevention of visual damage by stellate ganglion block.

A case of quinine poisoning is described. Stellate ganglion block was performed immediately on the basis of the clinical history of visual disturbance without waiting for physical signs to develop. There was no residual field defect despite the presence of toxic levels of the drug. It is suggested that stellate ganglion block may prevent development of visual field defects.

A comparison of diazepam and midazolam as sedatives for minor oral surgery.

Diazepam in propylene glycol (Valium, Roche) and midazolam (Hypnovel, Roche) were compared as sedatives in 40 patients undergoing minor oral surgery. Twenty patients received each drug. The cardiovascular effects, the acceptability of the drugs to patients and dentists and the incidence of anterograde amnesia and adverse venous sequelae were investigated. Serum benzodiazepine levels were measured and recovery studied by six psychomotor tests repeated over five hours. Both drugs provided safe and acceptable sedation. More amnesia was reported in the midazolam group and more adverse venous sequelae by the diazepam patients. The recovery tests showed that the time taken to return to pre-sedation scores varied with the tests used and there was no significant evidence of the midazolam group recovering more quickly. In particular, significant impairment of delayed memory recall persisted in both groups throughout the investigation period.

Lorazepam in open-heart surgery--plasma concentrations before, during and after bypass following different dose regimens.

Thirty-six patients (29 males and 7 females) undergoing open-heart surgery received one of three different dose regimens of lorazepam. All received a weight-related oral dose (2 mg, 3 mg or 4 mg) pre-operatively for night sedation. Twenty-four patients had an additional weight-related dose (2 mg, 3 mg or 4 mg intravenously) either as part of the induction (12 patients) or just prior to connection of the heat-lung machine (12 patients). Plasma concentrations of lorazepam were measured 20 minutes after induction, immediately before bypass, 30 and 60 on bypass and 30 minutes after bypass. Only when additional intravenous lorazepam was given prior to connection to the heart-lung machine were plasma lorazepam concentrations obtained compatible with complete amnesia.

The influence of chronic preoperative propranolol therapy on cardiovascular dynamics and narcotic requirements during operation in patients with coronary artery disease.

We measured the dose of sufentanil required for unconsciousness as well as the entire operation in 44 patients (22 taking propranolol and 22 not taking propranolol) undergoing coronary artery bypass grafting (CABG) operations. The incidence of hypertension during operation, requirements for supplements to treat hypertension and recovery times were also determined. The data indicate that patients undergoing CABG operations taking propranolol require significantly less sufentanil for unconsciousness and the entire operation than patients not taking this drug. In spite of requiring less sufentanil, patients taking propranolol had less hypertension during operation and thus required less supplements. However recovery times in both groups were the same. The results of this study may partially explain the varying incidence of hypertension reported during high dose fentanyl and other narcotic-oxygen anaesthetic techniques.

Percutaneous pulmonary artery catheterization via the arm before anaesthesia: success rate, frequency of complications and arterial pressure and heart rate responses.

The success rate, frequency of complications and changes in systolic arterial pressure and heart rate during percutaneous pulmonary artery catheterization via an antecubital vein were evaluated before induction of anaesthesia in 84 patients about to undergo cardiac surgery. Serious complications were angina (2%) and a small tear in the tricuspid valve (one patient). If one of the basilic veins was used, the success rate was 93%. When it was necessary to use a cephalic vein, the success rate decreased to 60%. Overall success rate was 75%. Placing the catheter in the pulmonary artery resulted in an immediate increase in systolic arterial pressure in all patients and a significant increase in heart rate in patients not taking beta-adrenergic blocking drugs. This study demonstrates that percutaneous catheterization of the pulmonary artery via the basilic vein is a simple, safe, effective technique associated with few complications.

Complement activation during cardiopulmonary bypass: quantitative study of effects of methylprednisolone and pulsatile flow.

Forty four patients undergoing open heart surgery were divided into three groups. Group 1 (17 patients) underwent routine anaesthesia and surgery; group 2 (17 patients) received two doses of methylprednisolone (30 mg/kg), one during induction of anaesthesia and the other immediately before induction of cardiopulmonary bypass; and group 3 (10 patients) received pulsatile flow while undergoing pulsatile perfusion by the heart-lung machine. A modification of the previously described technique was used to detect and measure complement activation in plasma before and during the bypass period using crossed immunoelectrophoresis. About 45% of all patients showed measurable complement activation (greater than 4.5%) during cardiopulmonary bypass and the mean activation in this group was 6.4%. There was no significant difference between the three groups in complement activation. In group 2, however, women showed significantly more complement activation than men (p less than 0.05). It is suggested that neither corticosteroids nor pulsatile flow affect complement activation, but caution should be exercised in women receiving methylprednisolone.

Clinical applications of crossed immunoelectrophoresis to the study of complement activation.

The purpose of our study was to set up a reliable method for the measurement of complement activation by adapting the method of crossed immunoelectrophoresis. We utilised anti C3 antiserum and barbitone buffer, containing sufficient EDTA to prevent in vitro activation of complement. We studied 44 patients undergoing open heart surgery, with cardiopulmonary bypass (CPB) by the analysis of plasma samples taken during the operation, and also samples of plasma and dialysate effluent from patients with end stage renal failure undergoing continuous ambulatory peritoneal dialysis (CAPD). Measurements were also carried out on stored blood, aged serum and serum treated with varying doses of lipopolysaccharide (LPS). Complement activation occurs in 95% of patients during CPB with levels ranging from less than 4.5% to 11.3% of total C3, but there was no detectable activation in any pre-bypass sample. Negligible complement activation occurs in the plasma of CAPD patients, but the dialysate effluent gave results from undetectable levels to 31.7%, in the absence of clinical peritonitis. Variable in vitro complement activation occurs in aged serum, but it was not detectable in stored blood. Serum treated with LPS showed levels of activation directly proportional to the dose of LPS and measurable at a level of 0.1 microgram/ml of serum. The method had a coefficient of variation of 4.5%, and provides a reliable way of measuring complement activation in clinical situations such as cardiopulmonary bypass and peritoneal dialysis.