BACKGROUND: Carbon dioxide embolus has been reported as a rare but clinically important risk associated with transanal total mesorectal excision surgery. To date, there exists limited data describing the incidence, risk factors, and management of carbon dioxide embolus in transanal total mesorectal excision. OBJECTIVE: This study aimed to obtain data from the transanal total mesorectal excision registries to identify trends and potential risk factors for carbon dioxide embolus specific to this surgical technique. DESIGN: Contributors to both the LOREC and OSTRiCh transanal total mesorectal excision registries were invited to report their incidence of carbon dioxide embolus. Case report forms were collected detailing the patient-specific and technical factors of each event. SETTINGS: The study was conducted at the collaborating centers from the international transanal total mesorectal excision registries. MAIN OUTCOME MEASURES: Characteristics and outcomes of patients with carbon dioxide embolus associated with transanal mesorectal excision were measured. RESULTS: Twenty-five cases were reported. The incidence of carbon dioxide embolus during transanal total mesorectal excision is estimated to be ≈0.4% (25/6375 cases). A fall in end tidal carbon dioxide was noted as the initial feature in 22 cases, with 13 (52%) developing signs of hemodynamic compromise. All of the events occurred in the transanal component of dissection, with mean (range) insufflation pressures of 15 mm Hg (12–20 mm Hg). Patients were predominantly (68%) in a Trendelenburg position, between 30° and 45°. Venous bleeding was reported in 20 cases at the time of carbon dioxide embolus, with periprostatic veins documented as the most common site (40%). After carbon dioxide embolus, 84% of cases were completed after hemodynamic stabilization. Two patients required cardiopulmonary resuscitation because of cardiovascular collapse. There were no deaths. LIMITATIONS: This is a retrospective study surveying reported outcomes by surgeons and anesthetists. CONCLUSIONS: Surgeons undertaking transanal total mesorectal excision must be aware of the possibility of carbon dioxide embolus and its potential risk factors, including venous bleeding (wrong plane surgery), high insufflation pressures, and patient positioning. Prompt recognition and management can limit the clinical impact of such events. See Video Abstract at http://links.lww.com/DCR/A961.

We have compared ionized magnesium assays in the Nova 8 electrolyte analyser using dry balanced heparinized syringes and self-prepared heparinized syringes. Thirty blood specimens were obtained into syringes either operator-prepared with liquid sodium heparin or commercially manufactured dry balanced heparinized syringes. There was a good correlation between results from the two syringes. The mean difference between sampling methods was 0.01 mmol litre-1 (95% confidence index -0.05 to 0.08 mmol litre-1). The correlations for sodium, potassium and ionized calcium assays were similarly close. The relationship between sampling methods was close enough to justify the clinical use of self-prepared syringes, with potential economies in clinical costs.

The AnaConDa filter system has been used in intensive care units (ICUs) to deliver low concentrations of volatile anaesthetic agents to treat severe airflow obstruction and for sedation. The manufacturer and a recently published review recommend the use of a scavenging system with the device. It is unclear from the literature what levels of volatile agent staff are exposed to when the device is being used in ICU without a scavenger. We carried out an observational study requested by the local occupational health department to measure the levels of ICU staff exposure to isoflurane when the AnaConDa delivery system was used to treat asthma. This study was carried out using an ambient air analyser while the patient was receiving therapeutic levels of isoflurane via the AnaConDa device. We conclude that gas scavenging may not be necessary when using the AnaConDa device to deliver therapeutic doses of isoflurane.

Introduction Patients on intravenous heparin require regular activated partial thromboplastin time monitoring. Laboratory-based activated partial thromboplastin time assays necessitate a delay between blood sampling and dose adjustment. Point-of-care testing could permit immediate dose adjustments, potentially enabling tighter control of anticoagulation. Aim To assess equivalence of activated partial thromboplastin time measured by conventional laboratory assay and by a novel proprietary point-of-care testing system (Hemochron Response, ITC, Thoratec Corporation, Edison, NJ) among surgical ward patients on intravenous heparin. Methods A total of 39 blood samples from patients on intravenous heparin were tested with both laboratory and point-of-care assays. Assay equivalence was assessed by Bland-Altman analysis. Results. Point-of-care measurements exceeded laboratory activated partial thromboplastin time by a mean of 15 seconds (standard deviation 19). In 19 cases (49%), the point-of-care measurement would have resulted in different heparin dosing from the laboratory activated partial thromboplastin time. Conclusions The Hemochron Response system is not sufficiently accurate for routine ward use compared with laboratory activated partial thromboplastin time assays.

SummaryWe performed a retrospective audit of blood glucose control after introducing a new protocol for insulin infusion. The audit showed a sustained reduction in the median blood glucose, which decreased from 7.0 to 6.8 mmol.l )1 , primarily because of a reduction in the proportion of values above 6 mmol.l )1. When we examined the proportion of readings with previously published 'acceptable' ranges we found that small, probably clinically insignificant, changes in the accepted range have a major effect on apparent compliance with glycaemic control. This is because a large number of results fall within a narrow range of values. As a result there is a nearly 2.5-fold difference in compliance for a change in the upper limit of the target range of just 2.2 mmol.l )1 . Different target ranges have been recommended for tight glycaemic control. When comparing compliance with tight glycaemic control between intensive care units, target ranges should be identical.