Positive end-expiratory pressure increases arterial oxygenation in elderly patients undergoing urological surgery using laryngeal mask airway in lithotomy position.

Elderly patients undergoing urological surgery in the lithotomy position may be vulnerable to perioperative hypoxemia. Positive end-expiratory pressure (PEEP) can improve arterial oxygenation. Although laryngeal mask airway (LMA) is widely utilized in urological surgery, it is not known how PEEP affects arterial oxygenation in these patients. We, therefore, evaluated the effect of PEEP on arterial oxygen partial pressure (PaO2) in elderly patients using LMA during urological surgery in the lithotomy position. Patients randomly received zero end-expiratory pressure (group Z, n = 34) or PEEP of 7 cmH2O (group P, n = 33). Ventilatory, respiratory, and haemodynamic variables were measured at 5 min (T0), 30 min (T1), and 60 min (T2) after LMA Supreme™ (sLMA) insertion. The primary outcome was the difference of PaO2 at T2 between the two groups. Atelectasis score, the incidence of a significant leak, and complications associated with sLMA insertion were also evaluated. PaO2 at T2 was significantly higher in group P than in group Z (20.0 ± 4.9 vs. 14.7 ± 3.7 kPa, P < 0.001). Atelectasis score at T2 was lower in group P than in group Z (5.3 ± 1.7 vs. 8.4 ± 2.3, P < 0.001). However, the incidence of a significant leak and complications associated with LMA insertion did not significantly differ between the two groups. PEEP can improve arterial oxygenation and reduce atelectasis in elderly patients using sLMA during urological surgery in the lithotomy position, suggesting that PEEP may be useful for elderly patients with an increased risk of perioperative hypoxemia when using sLMA.

Dexmedetomidine attenuates the increase of ultrasonographic optic nerve sheath diameter as a surrogate for intracranial pressure in patients undergoing robot-assisted laparoscopic prostatectomy: A randomized double-blind controlled trial.

BACKGROUND: Pneumoperitoneum and steep Trendelenburg position during robot-assisted laparoscopic prostatectomy (RALP) can increase intracranial pressure (ICP). Dexmedetomidine, a highly selective alpha-2 adrenergic receptor agonist, can cause cerebral vasoconstriction and decrease cerebral blood flow by stimulating the postsynaptic alpha-2 adrenergic receptors on cerebral blood vessels. However, the effects of dexmedetomidine on ICP are controversial and have not been evaluated during RALP under the establishment of pneumoperitoneum in the steep Trendelenburg position. Therefore, we evaluated the effect of dexmedetomidine on optic nerve sheath diameter (ONSD) as a surrogate for assessing ICP during RALP. METHODS: Patients were randomly allocated to receive dexmedetomidine (n = 63) (loading dose, 1 µg/kg for 10 minutes and continuous infusion, 0.4 µg/kg/hr) or normal saline (n = 63). The ONSD was measured at 10 minutes after induction of anesthesia in the supine position (T1), 30 minutes (T2) and 60 minutes (T3) after establishment of pneumoperitoneum in the steep Trendelenburg position, and at closing the skin in the supine position (T4). Hemodynamic and respiratory variables were measured at every time point. RESULTS: ONSDs at T2, T3, and T4 were significantly smaller in the dexmedetomidine group than in the control group (5.26 ±â€Š0.25 mm vs 5.71 ±â€Š0.26 mm, 5.29 ±â€Š0.24 mm vs 5.81 ±â€Š0.23 mm, and 4.97 ±â€Š0.24 mm vs 5.15 ±â€Š0.28 mm, all P <.001). ONSDs at T2, T3, and T4 were significantly increased compared to T1 in both groups. Hemodynamic and respiratory variables, except heart rate, did not significantly differ between the 2 groups. The bradycardia and atropine administration were not significantly different between the 2 groups. CONCLUSION: Dexmedetomidine attenuates the increase of ONSD during RALP, suggesting that intraoperative dexmedetomidine administration may effectively attenuate the ICP increase during pneumoperitoneum in the Trendelenburg position.

Comparison of the effect of spinal anesthesia and general anesthesia on 5-year tumor recurrence rates after transurethral resection of bladder tumors.

Non-muscle invasive bladder tumors are early-stage tumors with high recurrence rates. Transurethral resection of bladder tumor (TURB) is performed under spinal or general anesthesia; however, the effect of the two anesthetic techniques on non-muscle invasive bladder tumor recurrence is unknown. Thus, we compared their effects on tumor recurrence rates five years after TURB. Data from 876 patients who underwent TURB from 2000 to 2007 was reviewed. Patients received spinal or general anesthesia based on their choice or the clinician's preference. Tumor recurrence five years after TURB was assessed using multivariate Cox regression model, propensity score analysis (matching and inverse probability of treatment weighting), and Kaplan-Meier method. The five-year tumor recurrence rate after TURB was 42% and 53% for spinal and general anesthesia groups, respectively (P = 0.013). Hazard ratios for tumor recurrence in the spinal anesthesia group compared to that in the general anesthesia group were 0.619 (P <0.001), 0.642 (P = 0.001), and 0.636 (P <0.001) in the Cox regression model, Cox regression model with propensity score matching, and adjusted analysis with inverse probability of treatment weighting, respectively. The five-year tumor recurrence rate was significantly lower in the spinal anesthesia group than in the general anesthesia group in both the unadjusted (P = 0.002) and adjusted Kaplan-Meier curves (P <0.001). Therefore, spinal anesthesia for non-muscle invasive bladder tumor resection was associated with a lower five-year tumor recurrence rate than general anesthesia. This finding provides useful information for an appropriate selection of anesthetic technique for TURB.

Comparison of postoperative pain between laparoscopic and robot-assisted partial nephrectomies for renal tumors: A propensity score matching analysis.

Robot-assisted partial nephrectomy (RAPN) has emerged as an alternative to laparoscopic partial nephrectomy (LPN) for removal of renal tumors. Several advantages of robotic surgery have been reported, but there is no comparative study on postoperative pain between the 2 techniques. Therefore, we compared the postoperative numerical rating scale (NRS) of pain intensity between patients who underwent LPN and those who underwent RAPN.We included 705 patients who underwent either LPN (n = 200) or RAPN (n = 505) for renal tumors between January 2000 and September 2016. After 1:1 propensity score matching, the final analysis included 142 patients each in the LPN and RAPN groups. The primary endpoint was postoperative NRS of pain intensity. The secondary endpoints were opioid requirement, opioid-related complications, and duration of hospital stay.Preoperative and intraoperative values of propensity score matched patients (n = 284) were not significantly different between the LPN and RAPN groups. There was no significant difference in NRS of pain intensity between the 2 groups. Opioid requirement was different between the 2 groups on postoperative day (POD) 0 (12.4 vs 11.3 mg of morphine-equivalent dose), but not from POD 1 to POD 4. The incidence of opioid-related complications and duration of hospital stay were not significantly different between the 2 groups.Postoperative pain was not significantly different between patients who underwent RAPN and those who underwent LPN. This result provides a potentially useful knowledge of postoperative pain characteristics in RAPN and LPN.