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While insulin remains the mainstay of managing type 1 diabetes, much has changed over the last 15 years. These changes should help in managing patients with type 1 diabetes during the perioperative period. More flexible insulin therapy has three components: (1) basal, (2) prandial and (3) corrective. Many patients, particularly younger patients, are using genetically modified recombinant human insulin analogues. Two of these analogues, aspart and lispro insulin, are rapid-acting with faster onset and offset than subcutaneous regular insulin, allowing both prandial and corrective boluses. Other insulin analogues, particularly glargine and possibly detemir have a flat profile of up to 24 hours, providing improved basal insulin delivery. Basal insulin can also be provided by a continuous subcutaneous infusion of rapid-acting insulin via a computerised pump that also provides boluses on demand. There is little evidence to help choose the best management of patients with type 1 diabetes during surgery. Some authors still recommend glucose-potassium-insulin infusions for all patients with type 1 diabetes. We challenge this approach, given the flexibility of the newer insulin analogues and delivery systems. We suggest that for many procedures, patients' usual regimens can be maintained in the perioperative period, providing less disruption and, possibly, greater safety. Both hyperglycaemia and hypoglycaemia reflect poor management: we suggest a target glucose range of 5 to 10 mmol/l. The importance of frequently measuring blood glucose and appropriate responses cannot be overemphasised. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that a cardiopulmonary bypass prime with lactate would be associated with less acidosis than a prime with only chloride anions because of differences in the measured strong-ion-difference. We randomised 20 patients to a 1500 ml bypass prime with either a chloride-only solution (Ringer's Injection; anions: chloride 152 mmol/l) or a lactated solution (Hartmann's solution; anions: chloride 109 mmol/l, lactate 29 mmol/l). Arterial blood was sampled before bypass and then two, five, 15 and 30 minutes after initiating bypass. We used repeated measures analysis of variance to compare groups. In both groups, the base-excess and measured strong-ion-difference decreased markedly from baseline after two minutes of bypass. The chloride-only group had greater acidosis with lower base-excess and pH (P < 0.05), greatest after five minutes of bypass (C5). Contrary to our hypothesis, however, the difference between the groups was not due to a difference in the measured strong-ion-difference, P = 0.88. At C5 when the difference in standard base-excess between the groups was greatest, 1.9 mmol/l (95% confidence interval: 0.1 to 3.6 mmol/l, P < 0.05), the difference in the measured strong-ion-difference was only 0.2 mmol/l (95% confidence interval: -2.4 to 2.7 mmol/l, P > 0.05). There was, however a difference in the net-unmeasured-ions (strong-ion-gap). We conclude that acid-base changes with cardiopulmonary bypass may differ with the prime but that the early differences between chloride-only and lactated primes appear not to be due to differences in the measured strong-ion-difference. We suggest future studies examine other possible mechanisms including unmeasured ions. [ABSTRACT FROM AUTHOR]

Little is known about the amount of anaesthesia waste that is recyclable. We tested the hypotheses: 1) that anaesthetists produce a small proportion (< 10%) of total operating suite waste, 2) that much of this waste (> 30%) is recyclable and 3) that there is little (< 10%) cross-contamination of infectious and non-infectious waste. For five weekdays in a metropolitan hospital with six operating theatres, we weighed waste and determined the proportion of anaesthesia waste that was recyclable. Waste was routinely divided into general and infectious streams. For safety reasons the infectious waste was considered unavailable for recycling, leaving the general waste as potentially recyclable. Anaesthesia waste (90 kg) was 25% (95% confidence interval: 22 to 29%) of the total 357 kg of operating suite waste. Of 66 kg of general anaesthesia waste, 38 kg was recyclable (58%; 95% confidence interval: 47 to 67%). Most cardboard waste, however was included in the operating suite waste; therefore we under-estimated the total amount of recyclable anaesthesia waste. Of 24 kg of anaesthesia infectious waste, 2 kg (8%) was recyclable. The general waste contained 4 kg (7%; 95% confidence interval: 3 to 13%) of infectious items. No sharps were found. Anaesthesia waste was a quarter of total operating suite waste. Almost 60% of anaesthesia general waste could be recycled. Failure to eliminate infectious waste from general waste could be a barrier to recycling. [ABSTRACT FROM AUTHOR]

We developed a risk score for 30-day postoperative mortality: the Perioperative Mortality risk score. We used a derivation cohort from a previous study of surgical patients aged 70 years or more at three large metropolitan teaching hospitals, using the significant risk factors for 30-day mortality from multivariate analysis. We summed the risk score for each of six factors creating an overall Perioperative Mortality score. We included 1012 patients and the 30-day mortality was 6%. The three preoperative factors and risk scores were ("three A's"): 1) age, years: 70 to 79 = 1, 80 to 89 = 3, 90+ = 6; 2) ASA physical status: ASA I or II = 0, ASA III = 3, ASA IV = 6, ASA V = 15; and 3) preoperative albumin < 30 g/l = 2.5. The three postoperative factors and risk scores were ("three I's") 1) unplanned intensive care unit admission = 4.0; 2) systemic inflammation = 3; and 3) acute renal impairment = 2.5. Scores and mortality were: < 5 = 1%, 5 to 9.5 = 7% and > or = 10 = 26%. We also used a preliminary validation cohort of 256 patients from a regional hospital. The area under the receiver operating characteristic curve (C-statistic) for the derivation cohort was 0.80 (95% CI 0.74 to 0.86) similar to the validation C-statistic: 0.79 (95% CI 0.70 to 0.88), P = 0.88. The Hosmer-Lemeshow test (P = 0.35) indicated good calibration in the validation cohort. The Perioperative Mortality score is straightforward and may assist progressive risk assessment and management during the perioperative period. Risk associated with surgical complexity and urgency could be added to this baseline patient factor Perioperative Mortality score. [ABSTRACT FROM AUTHOR]

Double-lumen endotracheal tubes and bronchial blockers allow lung isolation for one-lung ventilation. Few studies, however, directly compare these devices. Further, a new endobronchial blocker (Coopdech) is available in some countries. Our primary hypothesis was that bronchial blockers would be associated with less sore throat or hoarse voice than double-lumen tubes. Secondary outcomes were successful one-lung ventilation and surgical access. In this prospective trial, 120 Chinese patients undergoing elective surgery were randomly assigned to one of four groups of 30 patients: Coopdech blocker, Arndt blocker Univent tube or double-lumen tube. Postoperative sore throat and hoarse voice were assessed in the recovery room and 24 hours after surgery. The incidence and severity of sore throat or hoarse voice was less in the blocker groups than double-lumen tube group: Coopdech 13%, Arndt 20%, Univent 30% and double-lumen tube 60%, P < 0.001. The blocker groups did not significantly differ P = 0.28. Compared to the double-lumen tubes the bronchial blockers took about two minutes less to position but five minutes longer for lung deflation. Surgical exposure was uniformly good across the four groups. We conclude that clinical use of the Coopdech endobronchial blocker is similar to the Arndt and Univent blockers and that all three are associated with less sore throat or hoarse voice than double-lumen tubes. [ABSTRACT FROM AUTHOR]

Multislice computed tomography coronary angiography is emerging as a reliable non-invasive method for the assessment of coronary artery disease, coronary anatomy and cardiac function. Improvements in computed tomography technology hold the promise of replacing the standard invasive procedure of conventional coronary angiography in selected patient groups. The ability of a six-second scan to identify flow-limiting coronary artery stenoses as well as characterising coronary atheromatous plaque components provides valuable information that can assist in refining perioperative cardiovascular risk. Multislice computed tomography's high negative predictive value and high specificity for stenoses allows it to effectively rule out coronary artery disease in patients with cardiac risk factors who have non-diagnostic or equivocal non-invasive cardiac stress tests. Other uses include evaluating patients who are symptomatic following percutaneous coronary intervention, evaluating coronary artery bypass grafts and coronary stent patency, detecting coronary stenosis prior to valve surgery and assessing coronary anatomy in patients with technically difficult arterial access. Avoiding the small but definite risks of conventional coronary angiography makes cardiac computed tomography an appealing alternative. An overview of multislice computed tomography is presented with particular attention placed on its role in the risk stratification of selected patients in the perioperative period. A risk stratification algorithm is suggested. [ABSTRACT FROM AUTHOR]