The effect of sevoflurane on the transmural dispersion of repolarisation in patients with type 2 diabetes mellitus: a prospective observational study.

The 'torsadogenic' property of a drug is linked to its ability to increase the transmural dispersion of repolarisation, represented by the interval between the peak of, and the end of, the T-wave (Tp-e interval) in an electrocardiogram. Reports have consistently shown that sevoflurane does not increase the Tp-e interval. Type 2 diabetes is a risk factor for increased QTc (rate-corrected QT interval), QTcd (rate-corrected QTc dispersion: difference between the maximum and the minimum QTc interval), and Tp-e, as well as the rate-corrected Tp-e (Tp-e/QTc ratio). The study aimed to ascertain whether sevoflurane increased the Tp-e interval and Tp-e/QTc ratio in patients with diabetes, thereby increasing their risk of torsades. We enrolled 35 female patients; 17 with type 2 diabetes and 18 controls undergoing non-laparoscopic surgery under sevoflurane anaesthesia. The Tp-e interval, Tp-e/QTc ratio, QTc and QTcd were recorded after intubation, 5, 10, 30 and 60 minutes into the anaesthetic, and were compared between the groups. No significant increase in the Tp-e interval or Tp-e/QTc was observed between or within the groups (a 13 ms increase was considered significant). In the control group, the QTc was significantly increased from baseline immediately after intubation (449 versus 414 ms, P <0.001); at 5 minutes (434 versus 414 ms, P=0.01); at 10 minutes (444 versus 414 ms, P=0.002); at 30 minutes (439 versus 414 ms, P=0.001) and at 60 minutes (442 versus 414 ms; P <0.001) (a 20 ms increase was considered significant). No significant increase in QTc was observed in the diabetic group. There were no between or within group differences observed for QTcd. Our findings suggest that sevoflurane does not have a significant predictable pro-arrhythmic effect in type 2 diabetic patients in the absence of other factors affecting ventricular repolarisation.

Sugammadex hypersensitivity-a case of anaphylaxis.

We describe a case of a patient undergoing open abdominal aneurysm surgery who developed a severe, life-threatening allergic reaction immediately after administration of sugammadex. The manifestation was purely a cardiovascular collapse. The mainstay of treatment was administration of high-dose adrenaline and fluid resuscitation. The diagnosis of anaphylaxis was supported by a positive serum mast cell tryptase (93 µg/l) at one hour post-event. Sugammadex was confirmed as the cause of the anaphylaxis by a positive intradermal allergy test (25 mm diameter response to 1:100 dilution), with a normal saline control and a negative response to the other drugs used during the event. This case report is a reminder that the use of sugammadex is associated with rare but serious risks.

Intraoperative hypothermia is associated with an increased intensive care unit length-of-stay in patients undergoing elective open abdominal aortic aneurysm surgery: a retrospective cohort study.

Intraoperative hypothermia in open elective abdominal aortic aneurysm repair may be associated with increased hospital morbidity. This retrospective, single centre study investigated whether there was an association between intraoperative hypothermia in open elective abdominal aortic aneurysm repair and postoperative in-hospital morbidity. The data of 119 patients who underwent open infrarenal abdominal aortic aneurysm repair between January 2006 and January 2011 were collected. The electronic databases from the hospital, intensive care unit, transfusion medicine and operating theatres were linked by the patient's unique identifiers including date of birth and unit record number. Intraoperative nasopharyngeal temperature measurements were collected manually from paper-based anaesthetic records. The study group included 102 out of the 119 patients. Sixty-six patients (64.6%) had intraoperative hypothermia as defined by temperature <36°C. Intraoperative temperature was not predictive of hospital length-of-stay or any of the other perioperative complications such as acute renal failure, acute respiratory complications, acute myocardial infarction, transfusion requirements or postoperative infection. In the normothermic group, the number of hours in the intensive care unit was 35% lower (ratio of means=0.65; 95% confidence interval 0.51 to 0.84; P=0.0008), even after adjusting for possible confounders such as age, duration of anaesthesia, size of aneurysm, comorbidities and transfusion. Intraoperative hypothermia is a persisting problem and more aggressive warming strategies may need to be identified and employed to achieve normothermia.

Cardiac pacing in patients with a cervical spinal cord injury.

STUDY DESIGN: Retrospective medical record review. OBJECTIVES: To compare patients, admitted to an intensive care unit (ICU) with an acute cervical spinal cord injury (SCI) and documented motor deficit, who did, with those who did not, require a cardiac pacemaker. SETTING: South Australian Tertiary Referral Intensive Care and Spinal Injury Unit. METHODS: Retrospective medical record review and data set linkage. RESULTS: From 1995 to 2007, 465 patients sustained a cervical SCI. Of these, 30 (6.5%) were admitted to ICU with a clinically assessable motor deficit and 3 (0.6% of all patients, or 10% of those admitted to ICU) required a cardiac pacemaker. All three patients had a cervical SCI, C5 (American Spinal Injury Association A) tetraplegia, and required invasive mechanical respiratory and inotropic support and a tracheostomy for weaning. Two patients (66%) were discharged alive to rehabilitation. Patients requiring a pacemaker had bradycardic episodes over a longer period (11 vs 4 days, P=0.01), a trend towards a later onset of bradycardia (8 vs 1.5 days, P=0.05) and a longer ICU length of stay (37 vs 10 days, P=0.02). CONCLUSION: Patients with a cervical SCI requiring a cardiac pacemaker are characterized by a higher level of SCI injury and motor loss, require mechanical respiratory and inotropic support, a tracheostomy to wean, and bradycardic episodes of a later onset and over a longer period of time. These findings suggest that such patients should be managed at hospitals with specialized acute spinal injury, intensive care and cardiac pacemaker services.