Intubating conditions and side effects of propofol, remifentanil and sevoflurane compared with propofol, remifentanil and rocuronium: a randomised, prospective, clinical trial.

BACKGROUND: Tracheal intubation without muscle relaxants is usually performed with remifentanil and propofol or sevoflurane. Remifentanil 1.0 to 4.0 µg·kg(-1) and propofol 2.0-3.0 mg·kg(-1) or sevoflurane up to 8.0 Vol% provide acceptable, i.e. excellent or good intubating conditions. We hypothesized that sevoflurane 1.0 MAC would provide acceptable intubating conditions when combined with propofol and remifentanil. METHODS: Eighty-three patients to be intubated were randomised to two groups. The SEVO group received propofol 1.5 mg kg(-1), remifentanil 0.30 µg kg min(-1) and sevoflurane 1.0 MAC; the MR group received the same doses of propofol and remifentanil plus rocuronium 0.45 mg kg(-1). We evaluated intubation and extubation conditions, mean arterial pressure (MAP), heart rate (HR) and bispectral index (BIS). The vocal cords were examined for injury by videolaryngoscopy before and 24 hours after surgery. RESULTS: ACCEPTABLE INTUBATING CONDITIONS WERE SEEN MORE FREQUENTLY WITH ROCURONIUM THAN WITH SEVOFLURANE: 97% versus 82%; p = 0.03; the subscore for vocal cords was comparable: 100% versus 98%. MAP before intubation decreased significantly compared with the MAP at baseline to the same extent in both groups; ephedrine IV was given in 15 (SEVO) versus 16 (MR) patients; p = 0.93. BIS at tracheal intubation was 27 (13-65) in the SEVO group, 29 (14-62) in the MR group; p = 0.07. Vocal cord injuries (oedema, haematoma) were similar: 4 patients in each group. CONCLUSIONS: Overall intubating conditions were better when rocuronium was used; the subscore for vocal cords was comparable. The incidence of side effects was the same in the two groups. TRIAL REGISTRATION: ClinicalTrials.Gov: NCT 01591031.

The influence of residual neuromuscular block on the incidence of critical respiratory events. A randomised, prospective, placebo-controlled trial.

CONTEXT: Residual paralysis is associated with post-operative pulmonary complications, including critical respiratory events. OBJECTIVE: We determined the incidence of critical respiratory events, such as hypoxaemia, in patients with minimal residual neuromuscular blockade and compared these data with those from patients with full recovery of blockade. DESIGN: Randomised, prospective, placebo-controlled trial. SETTING: Single centre; Rostock, Germany, from January 2007 to February 2008. PATIENTS: One hundred and thirty-two adult patients, aged 18-80 years, with the American Society of Anesthesiology I-III physical status, undergoing orthopaedic surgery under general anaesthesia, including rocuronium to produce neuromuscular blockade; 114 patients were randomised to one of two groups: neostigmine group (neostigmine 20 µg kg-1) or placebo group (saline). INTERVENTIONS: In the patients in the neostigmine group, the tracheal tube was removed at a train-of-four (TOF) ratio of 1.0; in the patients in the placebo group, the trachea was extubated at a TOF ratio less than 1.0, but without fade in TOF and double-burst stimulation (DBS). Neuromuscular monitoring was assessed simultaneously with qualitative TOF/DBS monitoring, and with quantitative calibrated acceleromyography. Critical respiratory events, such as hypoxaemia, were assessed in the post-anaesthesia care unit. MAIN OUTCOME MEASURES: Forty-five patients (39.5%) became hypoxaemic (SaO2 < 93%); there was a significant difference between the groups (29 patients in the placebo group versus 16 in the neostigmine group; P = 0.021). RESULTS: In the neostigmine group, all patients were extubated at a TOF ratio of 1.0. In the placebo group, the median TOF ratio was 0.7 (range: 0.46-0.9; P < 0.001). The median time for spontaneous recovery in the placebo group was 16 min (range 3-49 min). Neostigmine 20 µg kg was effective in antagonising rocuronium-induced blockade without fade in TOF and DBS. CONCLUSION: In this randomised, prospective, placebo-controlled trial, minimal residual block was associated with hypoxaemia in the post-anaesthesia care unit. Neostigmine 20 µg kg was effective in antagonising rocuronium-induced (minimal) blockade.

Sevoflurane at 1.0 MAC together with remifentanil and propofol produces clinically acceptable intubation conditions at the vocal cords: A prospective randomized study.

Objective The overall intubation conditions after tracheal intubation with remifentanil, propofol, and sevoflurane at 1.0 minimum alveolar concentration (MAC) are worse than with rocuronium at 0.45 mg/kg. Therefore, we compared the intubation conditions and laryngeal morbidity (vocal cord injuries, hoarseness, and sore throat) with sevoflurane at 1.2 and 1.4 MAC versus 1.0 MAC. Methods In this prospective clinical trial, 90 patients were randomized to 3 groups: the sevoflurane 1.0, 1.2, and 1.4 MAC groups. At 3 min, tracheal intubation was performed and the patients' intubation conditions were assessed. The vocal cords were examined for injury by videolaryngoscopy. Additionally, the incidence and severity of laryngeal morbidity were compared between women and men. Results Acceptable intubation conditions were seen in 72% of the patients without significant differences between the groups. Overall, vocal cord injuries (oedema) occurred in three (4%) patients. Women reported sore throat more often than men (51% vs. 21%, respectively). Conclusions Intubation conditions were not improved with higher sevoflurane concentrations. The incidence and severity of sore throat were greater in women than men. TRIAL REGISTRATION: ClinicalTrials.Gov: NCT 01896245.

Rocuronium is not associated with more vocal cord injuries than succinylcholine after rapid-sequence induction: a randomized, prospective, controlled trial.

Postoperative hoarseness (PH), sore throat (ST), and vocal cord injuries (VCI) are common complications after general anesthesia. Excellent endotracheal intubating conditions are associated with less laryngeal morbidity than good or poor intubating conditions. Thus, we tested the hypothesis that a rapid-sequence induction (RSI) with succinylcholine would lead to less PH and VCI than with rocuronium. In this prospective trial, 160 patients were randomized in 2 groups to receive thiopental 5.0 mg/kg, fentanyl 3.0 microg/kg, succinylcholine 1.0 mg/kg, or rocuronium 0.6 mg/kg during RSI. PH and ST were assessed at 24, 48, and 72 h after surgery, VCI were examined by stroboscopy in those patients who had PH >3 days. Excellent and clinically acceptable intubating conditions were significantly increased in the succinylcholine group compared with the rocuronium group: 57% versus 21% and 89% versus 59%, respectively (P < 0.001). The incidence and severity of PH, and VCI between the succinylcholine and the rocuronium groups did not differ significantly: PH: 50% versus 51% (P = 0.99) and VCI: 3% versus 1% (P = 0.98), respectively. Similar findings were found for ST, 39% versus 28% (P = 0.22), and postoperative myalgia, 39% versus 29% (P = 0.25), respectively. Intubating conditions were significantly better in the succinylcholine group compared with the rocuronium group. The incidence and severity of ST and myalgia were not increased in the patients receiving succinylcholine. However, the rate of PH and VCI was similar to the rocuronium group.

Does the timing of tracheal intubation based on neuromuscular monitoring decrease laryngeal injury? A randomized, prospective, controlled trial.

Vocal cord injuries (VCI) and postoperative hoarseness (PH) are common complications after general anesthesia. Poor muscle relaxation at the moment of tracheal intubation may result in VCI. There is a large interindividual variation in neuromuscular depression after administration of neuromuscular blocking drugs. Therefore, the optimal individual timing of tracheal intubation based on neuromuscular monitoring (monitoring) may decrease VCI. In this prospective trial, 60 patients were randomized into 2 groups: Monitoring group: tracheal intubation at maximum block based on monitoring after atracurium 0.5 mg/kg and 2-min group: tracheal intubation 2 min after injection of atracurium 0.5 mg/kg. Intubating conditions were evaluated with the Copenhagen score. VCI were examined by stroboscopy before and 24 and 72 h after surgery. PH was assessed at 24, 48, and 72 h after surgery by a standardized interview. Excellent intubating conditions were significantly increased in the monitoring group compared with the 2-min group: 8 versus 2 patients, respectively (P = 0.036). The incidence of PH between the study groups was comparable: 7 (monitoring) versus 8 patients (2-min) (P = 0.860). Similar findings were observed for VCI: 9 versus 5 patients; respectively (P = 0.268); type of VCI: thickening of the vocal cords: 8 (monitoring) versus 5 (2-min) patients (P = 0.423), hematomas: 2 patients in each group (not significant). The present study demonstrated that neuromuscular monitoring improved endotracheal intubating conditions. However, tracheal intubation at maximum intensity of neuromuscular block was not associated with a decrease in vocal cord injuries.

Lipid peroxidation early after brain injury.

The role of lipid peroxidation after brain injury is still not completely understood, and results of different studies have been equivocal. In this study, three proposed peroxidation markers were determined in patients early after isolated head injury and results compared to healthy controls. Malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) were measured in plasma, and n-pentane was determined in patients' exhaled air. For MDA and TBARS no significant differences could be shown (0.267 vs. 0.358 ng/mL, and 0.896 vs. 0.814 ng/mL in patients vs. healthy volunteers, respectively). n-Pentane, however, was significantly increased in the expired air of patients (0.471 vs. 0.118 nmol/L in healthy volunteers). Similar results for n-pentane were obtained when only male patients and volunteers were considered (0.510 vs. 0.113 nmol/L). Stratification according to clinical outcome showed significantly higher values for n-pentane in male patients with poor outcome (0.656 nmol/L) in comparison with healthy male volunteers (0.113 nmol/L). No difference was found when patients were stratified according to the presence or absence of subarachnoid hemorrhage. It is concluded that, only in a sub-population of patients with brain injury, lipid-peroxidation is a crucial mechanism. n-Pentane seems to be a valuable marker to detect lipid peroxidation early after brain trauma. Malondialdehyde may be of value only later in the course of the disease. TBARS are not a specific marker and should therefore not be used.

Thoratec left ventricular assist device for bridging to recovery in fulminant acute myocarditis.

Fulminant acute myocarditis can be the cause of rapid cardiac decompensation that is resistant to maximal medical therapy. Successful weaning from left ventricular mechanical support is very rare in fulminant myocarditis. We report the case of a young patient with viral myocarditis who was successfully weaned from a Thoratec left ventricular assist device with full recovery of myocardial function.

Diagnostic potential of breath analysis--focus on volatile organic compounds.

Breath analysis has attracted a considerable amount of scientific and clinical interest during the last decade. In contrast to NO, which is predominantly generated in the bronchial system, volatile organic compounds (VOCs) are mainly blood borne and therefore enable monitoring of different processes in the body. Exhaled ethane and pentane concentrations were elevated in inflammatory diseases. Acetone was linked to dextrose metabolism and lipolysis. Exhaled isoprene concentrations showed correlations with cholesterol biosynthesis. Exhaled levels of sulphur-containing compounds were elevated in liver failure and allograft rejection. Looking at a set of volatile markers may enable recognition and diagnosis of complex diseases such as lung or breast cancer. Due to technical problems of sampling and analysis and a lack of normalization and standardization, huge variations exist between results of different studies. This is among the main reasons why breath analysis could not yet been introduced into clinical practice. This review addresses the basic principles of breath analysis and the diagnostic potential of different volatile breath markers. Analytical procedures, issues concerning biochemistry and exhalation mechanisms of volatile substances, and future developments will be discussed.

TLR2-deficiency of cKit+ bone marrow cells is associated with augmented potency to stimulate angiogenic processes.

OBJECTIVE: Toll-like receptor 2 (TLR2)-deficiency is associated with the preservation of vascular function and TLR2-deficient (TLR2(-/-)) mice exhibit increased neovascularization following induction of hindlimb ischemia. Hematopoietic stem cells play an important role in ischemia-induced angiogenesis and we now investigated whether the effects observed in TLR2(-/-) mice may be attributed to TLR2 deficiency on bone marrow-derived stem cells. APPROACH AND RESULTS: cKit-positive (cKit(+)) bone marrow cells (BMC) were isolated from wild type (WT) and TLR2(-/-) mice employing MACS-bead technology. Co-incubation of TLR2(-/-)cKit(+) BMC with mature endothelial cells (ECs) resulted in increased tube formation of ECs on matrigel, augmented sprouting in a 3D-collagen matrix and increased migratory capacity compared to co-incubation with WT cKit(+) BMC. In an in vivo matrigel plug assay, TLR2(-/-)cKit(+) BMC exhibited enhanced formation of capillary-like networks. In a murine model of hindlimb ischemia, administration of TLR2(-/-) cKit(+) BMC to WT mice augmented capillary density and reperfusion of ischemic M. gastrocnemius muscle tissue to the level of TLR2(-/-) mice. Western Blot analysis revealed comparable expression of CXCR4 on TLR2(-/-)cKit(+) BMC but increased activation of the PI3K downstream signaling molecule protein kinase B (PKB/AKT) compared to WT cKit(+) cells. CONCLUSIONS: The absence of TLR2 on cKit(+) BMC is associated with augmented potency to support angiogenic processes in vitro and in vivo. Functional inhibition of TLR2 may therefore provide a novel tool to enhance stem cell function for the treatment of vascular diseases.

Anesthesia with Propofol versus Sevoflurane: Does the Longer Neuromuscular Block under Sevoflurane Anesthesia Reduce Laryngeal Injuries?

Anesthesia can be maintained with propofol or sevoflurane. Volatile anesthetics increase neuromuscular block of muscle relaxants. We tested the hypothesis, that sevoflurane would cause less vocal cord injuries than an intravenous anesthesia with propofol. In this prospective trial, 65 patients were randomized in 2 groups: SEVO group, anesthesia with sevoflurane, and TIVA group, total intravenous anesthesia with propofol. Intubating and extubating conditions were evaluated. Vocal cord injuries were examined by stroboscopy before and 24 and 72 h after surgery; hoarseness and sore throat were assessed up to 72 h after surgery. Hoarseness and sore throat were comparable between both groups (not significant). Similar findings were observed for vocal cord injuries: 9 (SEVO) versus 5 (TIVA) patients; P = 0.36; the overall incidence was 24%. Type of vocal cord injuries: 9 erythema and 5 edema of the vocal folds. Neuromuscular block was significantly longer in the SEVO group compared with the TIVA group: 71 (range: 38-148) min versus 52 (range: 21-74) min; P < 0.001. Five patients (TIVA group) versus 11 patients (SEVO group) needed neostigmine to achieve a TOF ratio of 1.0 (P = 0.14). Under anesthesia with propofol laryngeal injuries were not increased; the risk for residual curarization, however, was lower compared with sevoflurane.