Prediction of hypotension after postural change in robot-assisted laparoscopic prostatectomy using esophageal Doppler monitoring: a prospective observational trial.

Postural change from a steep Trendelenburg position to a supine position (T-off) during robot-assisted laparoscopic prostatectomy (RALP) induces a considerable abrupt decrease in the mean arterial pressure (MAP). We investigated the variables for predicting postural hypotension induced by T-off using esophageal Doppler monitoring (EDM). One hundred and twenty-five patients undergoing RALP were enrolled. Data on the MAP, heart rate, stroke volume index (SVI), cardiac index, peak velocity, corrected flow time, stroke volume variation, pulse pressure variation, arterial elastance (Ea), and dynamic arterial elastance were collected before T-off and at 1, 3, 5, 7, and 10 min after T-off using EDM. MAP < 60 mmHg within 10 min after T-off was considered to indicate hypotension, and 25 patients developed hypotension. The areas under the curves of the MAP, SVI, and Ea were 0.734 (95% confidence interval [CI] 0.623-0.846; P < 0.001), 0.712 (95% CI 0.598-0.825; P < 0.001), and 0.760 (95% CI 0.646-0.875; P < 0.001), respectively, with threshold values of ≤ 74 mmHg, ≥ 42.5 mL/m2, and ≤ 1.08 mmHg/mL, respectively. If patients have MAP < 75 mmHg with SVI ≥ 42.5 mL/m2 or Ea ≤ 1.08 mmHg/mL before postural change from T-off during RALP, prompt management for ensuing hypotension should be considered.Trial registration: NCT03882697 (ClinicalTrial.gov, March 20, 2019).

Effect-site concentration of propofol target-controlled infusion at loss of consciousness in intractable epilepsy patients receiving long-term antiepileptic drug therapy.

BACKGROUND: Propofol dose requirement for loss of consciousness (LOC) in epilepsy patients would be probably affected by increasing factors [development of tolerance, up-regulated γ-aminobutyric acid (GABAA) receptors, or antiepileptic activity of propofol] and reducing factors [synergistic interaction between propofol and antiepileptic drugs (AEDs) or reduced neuronal mass in cortex] in complex and counteracting ways. Therefore, we determined the effect-site concentration (Ce) of propofol for LOC in intractable epilepsy patients receiving chronic AEDs in comparison with non-epilepsy patients. METHODS: Nineteen epilepsy patients receiving long-term AEDs therapy and 20 non-epilepsy patients, with the age of 20 to 65 years, were enrolled. The epilepsy patients took their prescribed AEDs until the morning of the operation. Ce of propofol for LOC was determined with isotonic regression method with bootstrapping approach following Dixon's up-and-down allocation. The study was carried out before surgical stimulation. RESULTS: Isotonic regression showed that estimated Ce50 and Ce95 of propofol for LOC were lower in epilepsy group [2.88 µg/mL (83% confidence interval, 2.82-3.13 µg/mL) and [3.43 µg/mL (95% confidence interval, 3.28-3.47 µg/mL)] than in non-epilepsy group [3.38 µg/mL (83% confidence interval, 3.17-3.63 µg/mL) and 3.92 µg/mL (95% confidence interval, 3.80-3.97 µg/mL)] with bootstrapping approach. Mean Ce50 of propofol of epilepsy group was also lower than that of non-epilepsy group without statistical significance (2.8240.19 µg/mL vs 3.16±0.38 µg/mL, P=0.056). CONCLUSIONS: For anesthetic induction of epilepsy patients with propofol target-controlled infusion, Ce may need to be reduced by 10% to 15% compared with non-epilepsy patients.

Caudal analgesia reduces the sevoflurane requirement for LMA removal in anesthetized children.

BACKGROUND: An anesthetic state can reduce adverse airway reaction during laryngeal mask airway (LMA) removal in children. However, the anesthetic state has risks of upper airway obstruction or delayed emergence; so possibly less anesthetic depth is advisable. Caudal analgesia reduces the requirement of anesthetic agents for sedation or anesthesia; it is expected to reduce the sevoflurane requirement for LMA removal. Therefore, we determined the EC(50) of sevoflurane for LMA removal with caudal analgesia and compared that to the EC(50) without caudal analgesia. METHODS: Forty-three unpremedicated children aged 1 to 6 yr were enrolled. They were allocated to receive or not to receive caudal block according to their parents' consent. General anesthesia were induced and maintained with sevoflurane and oxygen in air. EC(50) of sevoflurane for a smooth LMA removal with and without caudal analgesia were estimated by the Dixon up-and-down method. The LMA was removed when predetermined end-tidal sevoflurane concentration was achieved, and the sevoflurane concentration of a subsequent patient was determined by the success or failure of the previous patient with 0.2% as the step size; success was defined by the absence of an adverse airway reaction during and after LMA removal. EC(50) of sevoflurane with caudal block, and that without caudal block, were compared by a rank-sum test. RESULTS: The EC(50) of sevoflurane to achieve successful LMA removal in children with caudal block was 1.47%; 1.81% without caudal block. The EC(50) were significantly different between the two groups (P < 0.001). CONCLUSIONS: Caudal analgesia significantly reduced the sevoflurane concentration for a smooth LMA removal in anesthetized children.