Blood pressure control with phenylephrine or dobutamine: a randomized controlled trial comparing effects on cerebral and paravertebral tissue oxygen saturation measured with near-infrared spectroscopy.

Preserving haemodynamics is expected to positively affect tissue oxygen saturation. We hypothesized that maintaining mean arterial blood pressure (MAP) (using phenylephrine (PE) or dobutamine (Dobu)) would equally affect regional cerebral and paravertebral tissue saturation (rScO2 and rSpvO2, respectively). Thirty-four patients were randomly assigned to receive either PE or Dobu, in order to keep MAP within 20% of the preoperative value. Their effect on haemodynamics, rScO2 and rSpvO2 at thoracic level T3-T4, T9-T10 and lumbar level L1-L2 was calculated at different doses. Drug-induced haemodynamic effects differed between groups (∆MAP: -2%±21 and - 19%±17, ∆CI: -14.6%±14.6 and 24.1%±49.9, ∆HR: -21%±21 and 0%±16 for PE and Dobu, respectively). Both groups exhibited a significant decrease in rScO2, with a more pronounced decline in the PE group (-14.1%±16.1) compared to the Dobu group (-5.9%±10.6). There were no significant changes at the paravertebral level in either group, but a slight but statistically significant difference was detected between the two groups at T3-T4 and L1-L2. Current guidelines advocate maintaining adequate systemic blood pressures to prevent spinal cord ischaemia in specific procedures. However, it is still unknown which circulatory supportive drug is more beneficial for maintaining spinal cord perfusion. Our data indicates that, when used for maintenance of blood pressure within a 20% range of preoperative values, neither phenylephrine nor dobutamine affect paravertebral tissue saturation.

Ephedrine and phenylephrine induce opposite changes in cerebral and paraspinal tissue oxygen saturation, measured with near-infrared spectroscopy: a randomized controlled trial.

While the effects of phenylephrine (PE) and ephedrine (E) on cerebral oxygen saturation (rScO2) already has been studied, the effect on paraspinal oxygen saturation (rSpsO2) is still unexplored. This study aims to assess the effect of PE and E on rScO2 and rSpsO2, measured with near-infrared spectroscopy. A randomized 4-treatment cross-over trial was designed in 28 patients under BIS-titrated anaesthesia with sevoflurane. If MAP decreased more than 20% from baseline, incremental doses of PE and/or E were given according to the randomization (group I: E-PE-E, group II: PE-E-PE, group III: E-E-E, group IV: PE-PE-PE). rScO2 and rSpsO2 on T3-T4, T9-T10 and L1-L2 were recorded. Differences in rSO2 (post-pretreatment) within each group were analyzed with paired Student's t test. Differences in effects of PE and E on rScO2 and rSpsO2 were analyzed with linear mixed-modelling. Following PE administration, rScO2 decreased significantly (- 2.7% ± 3.5), while it remained stable following E (- 0.6% ± 3.6). Contrastingly, rSpsO2 at T3-T4, T9-T10 and L1-L2 slightly increased following PE (0.4% ± 2.5, 0.7% ± 2.0 and - 0.1% ± 1.4, respectively), while it decreased after E administration (- 1.3% ± 3.4%, - 0.7% ± 2.6% and - 1.3% ± 2.7%, respectively). Compared to E, PE administration was associated with a significant decrease in rScO2 (- 2.1%, 95% CI [- 3.1%, - 1.2%], p < 0.001). In contrast, compared to PE, E was associated with a significant decrease in rSpsO2 at T3-T4, T9-T10 and L1-L2 (- 2.0%, 95% CI [- 2.8, - 1.1], p < 0.001; - 1.4%, 95% CI [- 2.4%, - 0.4%], p = 0.006; and - 1.5%, 95% CI [- 2.3%, - 0.8%], p < 0.001, respectively). An opposite effect on rScO2 and rSpsO2 was observed after bolus administration of PE and E.

Ambulatory electrical external cardioversion with propofol or etomidate.

STUDY OBJECTIVE: To compare, in pairwise fashion, the effects of propofol and etomidate during ambulatory cardioversion and early recovery. DESIGN: Clinical, prospective, randomized, blinded, monocenter, pairwise, comparative study SETTING: OR and recovery area of the electrophysiological department, University Hospital Ghent, Belgium. PATIENTS: 34 patients with atrial arrhythmia who were scheduled for repetitive electrical cardioversion, of whom 25 patients completed the study. INTERVENTIONS: Nonpremedicated patients received during the first cardioversion either propofol (1 mg/kg) or etomidate (0.2 mg/kg) until loss of consciousness, followed by electrical external cardioversion. If after restoration of sinus rhythm for at least 1 day, atrial arrhythmia reoccurred, a second session was performed a week later, using the other induction drug. MEASUREMENTS: Systolic and diastolic blood pressure values taken before drug administration, at loss of consciousness, 60 seconds after cardioversion, and awake; the number of shocks, the total amount of energy, the number of patients in which we failed to restore sinus rhythm, the time before opening eyes, answering simple questions and be able to sit, were all noted. Aldrete scores and the Steward postanesthetic recovery scores were noted every minute until 10 minutes after the external cardioversion. Recovery tests were performed and evaluated 5, 10, 15, and 20 minutes after energy delivery. MAIN RESULTS: Number of shocks, amount of energy, and blood pressure values were comparable in both groups. Recovery times and Aldrete and Steward postanesthetic recovery scores showed a faster awakening in patients who were induced with propofol. Overall performance of the psychomotor test was better in the propofol group, and most pronounced at 10 and 15 minutes. CONCLUSIONS: Etomidate and propofol are both useful during ambulatory external electrical cardioversion. The described doses maintain stable hemodynamic conditions in nonpremedicated patients. Recovery scores and psychomotor test indicate a faster recovery in the propofol group. However, no intergroup differences were noted at 20 minutes after the cardioversion. A safe discharge of all patients from the critical care unit or postanesthesia care unit to the ward can be considered after 30 minutes.