Anaesthesia and intensive care
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Anaesth Intensive Care · Oct 2006
Randomized Controlled TrialBispectral index guided timing of intubation without neuromuscular blockade during sevoflurane induction of anaesthesia in adults.
The aim of this study was to assess the effectiveness of bispectral index monitoring (BIS) as a guide to the timing of intubation during sevoflurane induction of anaesthesia without the use of neuromuscular blocking agents in adults, and specifically, whether a target BIS value of 25 provides better intubating conditions than a target BIS of 40. Forty patients were randomized into one of two groups, a target BIS 25 (n =21) or a target BIS 40 (n =19). Patients received premedication with midazolam 20 microg/kg and fentanyl 0.5 microg/kg. ⋯ End-tidal sevoflurane concentration upon reaching the target BIS was higher in the BIS 25 group (5.3% +/- 1.2%) vs the BIS 40 group (3.5% +/- 0.95) (P<0.001). There was no statistical difference in haemodynamic parameters between groups. A target BIS value of 25 provides good to excellent intubating conditions and better intubating conditions than a target BIS of 40 during sevoflurane induction of anaesthesia without the use of neuromuscular blocking agents.
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The aim of the current study was to assess the direct effect of protamine on conventional thrombelastography in vitro. Protamine was added to blood samples collected from 25 adult cardiac surgical patients prior to the induction of anaesthesia and after separation from cardiopulmonary bypass. The final protamine concentrations were 0 (control), 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml (i.e. sufficient to reverse heparin 0, 5, 10 and 20 IU/ml respectively, assuming a 1:1 reversal ratio). ⋯ The results indicate that protamine has a direct anticoagulant effect on conventional thrombelastography in vitro. This effect occurs whether protamine is present alone, or whether protamine is present in excess after neutralization of heparin. Unless this effect is taken into account, excess protamine may confound the interpretation of conventional thrombelastography in cardiac surgical patients.
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Anaesth Intensive Care · Oct 2006
Letter Case ReportsSciatic nerve extension complicating femoral blockade.
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Anaesth Intensive Care · Oct 2006
Randomized Controlled TrialClonidine as an analgesic adjuvant to continuous paravertebral bupivacaine for post-thoracotomy pain.
We prospectively evaluated the effect of clonidine as an adjuvant to bupivacaine for continuous paravertebral intercostal nerve block, measuring pain and sedation scores and pulmonary function tests. Thirty patients scheduled to undergo thoracotomy were randomized to receive either a bolus of 0.125% bupivacaine 2 mg/kg (group BUP) or 0.125% bupivacaine 2 mg/kg with clonidine 2 microg/kg (group BUP+CLO), followed by an infusion of 0.125% bupivacaine at 0.5 mg/kg/h, or 0.125% bupivacaine at 0.5 mg/kg/h with clonidine at 2 microg/kg/h, in respective groups, through a paravertebral intercostal catheter. Haemodynamic parameters, pain and sedation scores and pulmonary function tests were recorded at 6, 12, 24 and 48 hours after arrival in postoperative care unit. ⋯ Patients in the clonidine group had a higher incidence of hypotension (P < 0.01). There was no significant difference in pulmonary function between the groups. We conclude that using clonidine as an adjunct to bupivacaine for continuous paravertebral intercostal nerve block improves pain relief after thoracotomy, but hypotension and sedation are adverse effects interfering with its clinical application.
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Anaesth Intensive Care · Oct 2006
Multicenter StudyRelative adrenal insufficiency in etomidate-naïve patients with septic shock.
A recent study reported that 77% of patients with septic shock had relative adrenal insufficiency. However, all patients were mechanically ventilated and received high-dose inotropes. In addition, at least 24% had prior exposure to etomidate, a drug known to suppress adrenal function. ⋯ We conclude that the incidence of relative adrenal insufficiency in etomidate-naive septic shock patients was lower than observed in the steroid supplementation trial. Further, in those who fulfilled inclusion criteria for the trial, the incidence of relative adrenal insufficiency was half that reported by the trial. Our observations raise concerns about the generalizability of the findings of the above trial to etomidate-naïve patients.