Heike Vogelsang

Survival after long-term isoflurane sedation as opposed to intravenous sedation in critically ill surgical patients: Retrospective analysis.

BACKGROUND Isoflurane has shown better control of intensive care sedation than propofol or midazolam and seems to be a useful alternative. However, its effect on survival remains unclear. OBJECTIVE The objective of this study is to compare mortality after sedation with either isoflurane or propofol/midazolam. DESIGN A retrospective analysis of data in a hospital database for a cohort of consecutive patients. SETTING Sixteen-bed interdisciplinary surgical ICU of a German university hospital. PATIENTS Consecutive cohort of 369 critically ill surgical patients defined within the database of the hospital information system. All patients were continuously ventilated and sedated for more than 96 h between 1 January 2005 and 31 December 2010. After excluding 169 patients (93 >79 years old, 10 <40 years old, 46 mixed sedation, 20 lost to follow-up), 200 patients were studied, 72 after isoflurane and 128 after propofol/midazolam. INTERVENTIONS Sedation with isoflurane using the AnaConDa system compared with intravenous sedation with propofol or midazolam. MAIN OUTCOME MEASURES Hospital mortality (primary) and 365-day mortality (secondary) were compared with the Kaplan–Meier analysis and a log-rank test. Adjusted odds ratios (ORs) [with 95% confidence interval (95% CI)] were calculated by logistic regression analyses to determine the risk of death after isoflurane sedation. RESULTS After sedation with isoflurane, the in-hospital mortality and 365-day mortality were significantly lower than after propofol/midazolam sedation: 40 versus 63% (P = 0.005) and 50 versus 70% (P = 0.013), respectively. After adjustment for potential confounders (coronary heart disease, chronic obstructive pulmonary disease, acute renal failure, creatinine, age and Simplified Acute Physiology Score II), patients after isoflurane were at a lower risk of death during their hospital stay (OR 0.35; 95% CI 0.18 to 0.68, P = 0.002) and within the first 365 days (OR 0.41; 95% CI 0.21 to 0.81, P = 0.010). CONCLUSION Compared with propofol/midazolam sedation, long-term sedation with isoflurane seems to be well tolerated in this group of critically ill patients after surgery.

Occupational Chronic Sevoflurane Exposure in the Everyday Reality of the Anesthesia Workplace

BACKGROUND:Although sevoflurane is one of the most commonly used volatile anesthetics in clinical practice, anesthesiologists are hardly aware of their individual occupational chronic sevoflurane exposure. Therefore, we studied sevoflurane concentrations in the anesthesiologists’ breathing zones, depending on the kind of induction for general anesthesia, the used airway device, and the type of airflow system in the operating room. Furthermore, sevoflurane baselines and typical peaks during general anesthesia were determined. METHODS:Measurements were performed with the LumaSense Photoacoustic Gas Monitor. As we detected the gas monitor’s cross-sensitivity reactions between sevoflurane and disinfectants, regression lines for customarily used disinfectants during surgery (Cutasept®, Octeniderm®) and their alcoholic components were initially analyzed. Hospital sevoflurane concentrations were thereafter measured during elective surgery in 119 patients. The amount of inhaled sevoflurane by anesthesiologists was estimated according to mVA = cVA × V × t × &rgr;VA aer. RESULTS:Induction of general anesthesia stopped after tracheal intubation with the patient’s expiratory sevoflurane concentration of 1.5%. Thereby, inhalational inductions (INH) caused higher sevoflurane concentrations than IV inductions (mean [SD]: [ppm] INH 2.43 ±1.91 versus IV 0.62 ± 0.33, P < 0.001; mVA [mg] INH 1.95 ± 1.54 versus IV 0.30 ± 0.22, P < 0.001). The use of laryngeal mask airway (LMA™) led to generally higher sevoflurane concentrations in the anesthesiologists’ breathing zones than tracheal tubes ( [ppm] tube 0.37 ± 0.16 versus LMA™ 0.79 ± 0.53, P = 0.009; [ppm] tube 1.91 ± 0.91 versus LMA™ 2.91 ± 1.81, P = 0.057; mVA [mg] tube 1.47 ± 0.64 versus LMA™ 2.73 ± 1.81, P = 0.019). Sevoflurane concentrations were trended higher during surgery in operating rooms with turbulent flow (TF) air-conditioning systems compared with laminar flow (LF) air-conditioning systems ( [ppm] TF 0.29 ± 0.12 versus LF 0.13 ± 0.06, P = 0.012; mVA [mg/h] TF 1.16 ± 0.50 versus LF 0.51 ± 0.25, P = 0.007). CONCLUSIONS:Anesthesiologists are chronically exposed to trace concentrations of sevoflurane during work. Inhalational inductions, LMA™, and TF air-conditioning systems in particular are associated with higher sevoflurane exposure. However, the amount of inhaled sevoflurane per day was lower than expected, perhaps because concentrations in previous measurements could be overestimated (10%–15%) because of the cross-sensitivity reaction.

Mortality and recovery after inhalational compared to intravenous ICU sedation: A-809

There is a small rise in bilirubin and small fall in albumin post hepatic resection. ALT levels peak day 1 post resection and return to normal by day 9. ALP levels fall immediately post resection and then progressively rise. Conclusion: Hepatic resection results in a distinctive pattern of changes in liver function tests. References: 1 Stewart GD, et al. The extent of resection influences outcome following hepatectomy for colorectal liver metastases. Eur J Surg Oncol. 2004 May; 30(4): 370–6. 2 Rees, et al. One hundred and fifty hepatic resections. BJS 1995; 83:1526–9.

Comparison of perioperative strategies in ICD patients: The perioperative ICD management study (PIM study)

The prevalence of patients with implanted cardioverter defibrillators (ICDs) and the frequency of surgery on these patients are steadily on the rise. Guidelines recommend preoperative ICD reprogramming, although this is sometimes difficult in clinical practice. Placing a magnet on the ICD is a practical alternative and even no inactivation is possible in selected cases.

Environmental safety: Air pollution while using MIRUS™ for short-term sedation in the ICU

MIRUS™ is a device for target‐controlled inhalational sedation in the ICU in combination with use of isoflurane, or sevoflurane, or desflurane. The feasibility of this device has recently been proven; however, ICU staff exposure may restrict its application. We investigated ICU ambient room pollution during daily work to estimate ICU personnel exposure while using MIRUS™.

The child's behavior during inhalational induction and its impact on the anesthesiologist's sevoflurane exposure

Sevoflurane is commonly used for inhalational inductions in children, but the personnels exposure to it is potentially harmful. Guidance to reduce gas pollution refers mainly to technical aspects, but the impact of the childs behavior has not yet been studied.