On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective Propensity-Score-Matched Multicenter Outcome Analysis

We compared perioperative outcomes after on-clamp versus off-clamp robot-assisted partial nephrectomy (RAPN) for >7 cm renal masses. A multicenter dataset was queried for patients who had undergone RAPN for a cT2cN0cM0 kidney tumor from July 2007 to February 2022. The Trifecta achievement (negative surgical margins, no severe complications, and ≤ 30% postoperative estimated glomerular filtration rate (eGFR) reduction) was considered a surrogate of surgical quality. Overall, 316 cases were included in the analysis, and 58% achieved the Trifecta. A propensity-score-matched analysis generated two cohorts of 89 patients homogeneous for age, ASA score, preoperative eGFR, and RENAL score (all p > 0.21). Compared to the on-clamp approach, OT was significantly shorter in the off-clamp group (80 vs. 190 min; p < 0.001), the incidence of sRFD was lower (22% vs. 40%; p = 0.01), and the Trifecta rate higher (66% vs. 46%; p = 0.01). In a crude analysis, >20 min of hilar clamping was associated with a significantly higher risk of sRFD (OR: 2.30; 95%CI: 1.13−4.64; p = 0.02) and with reduced probabilities of achieving the Trifecta (OR: 0.46; 95%CI: 0.27−0.79; p = 0.004). Purely off-clamp RAPN seems to be a safe and viable option to treat cT2 renal masses and may outperform the on-clamp approach regarding perioperative surgical outcomes.

Evaluation of rebreathing in various modifications of the Mapleson-D system

Several modifications of the Bain system for nitrous oxide analgesia or general anesthesia were tested for rebreathing and retention of CO2. The classic Bain circuit causes the most rebreathing as measured by the fractional concentration of CO2 in a sample of inspired gas (FICO2), but stimulation of the respiratory system seems to allow near normal end tidal CO2 and arterial CO2 tensions. The most predictable systems that have the least amount of rebreathing are those that have the least dead space.

Extraction of large tracheal foreign bodies through a tracheostoma under bronchoscopic control

Despite various technical manipulations through contemporary endoscopic equipment, large tracheal foreign bodies may be lost during bronchoscopic extraction, with a 1 to 2% in-hospital mortality. Recently, emergency tracheostomy was performed during bronchoscopy after a tracheal foreign body had become dislodged in the subglottic region causing blockage of the airway, and the results of this procedure provoked its deliberate application in a second patient. In 3 additional infants, aspirated tracheal T tubes (Montgomery tubes), which were producing acute respiratory distress, were brought from the carina to the performed tracheostoma under bronchoscopic manipulation and were withdrawn. Elective application of this simultaneous approach--tracheostomy with bronchoscopy--may decrease morbidity and mortality from large tracheal foreign bodies.

Carbon dioxide absorption system with a simple modification of the Bain circuit

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Respiratory acidosis with the small Storz-Hopkins bronchoscopes: occurrence and management

Carbon dioxide retention in the Storz rigid ventilating bronchoscope with the Hopkins lens system was investigated in the laboratory. The 3.5, 4.0, and 5.0 30-cm Storz bronchoscopes with a 3.95-mm (outside diameter) telescope lens were used in 10 mongrel dogs weighing between 8 and 15 kg. Significant (p less than 0.01) accumulation of arterial carbon dioxide tension (PaCO2) (respiratory acidosis) was observed after 5 and 10 minutes of ventilation through the 3.5 and 4.0 bronchoscopes, but no significant increase in PaCO2 was noted with the 5.0 bronchoscope. There was no significant change in arterial oxygen tension under the same conditions. Manual compression of the upper anterior abdominal wall during expiration was applied during bronchoscopy in 6 children. Arterial blood samples were taken before insertion of the bronchoscope and 5 minutes later with and without abdominal compression during expiration. A significant increase (p less than 0.05) in PaCO2 and a decrease in pH were observed after 5 minutes of the bronchoscopic procedure without manual compression of the abdominal wall, while no significant changes in PaCO2 were observed with abdominal compression.

Is the Bain breathing circuit the future anesthesia system? An evaluation

The Bain breathing circuit, a modified Mapleson D system, was evaluated with regard to oxygenation and CO2 elimination under controlled conditions and compared with the presently popular semiclosed breathing circuit (SCBC) with CO2 absorber. The authors demonstrated that the Bain system compares favorably with the SCBC in regard to oxygenation of manually ventilated patients with fresh gas inflow of 70 ml/kg/min while maintaining a PaCO2 at a mean of 38 torr versus an SCBC mean of 32 torr. The authors were impressed with the clinical simplicity, efficiency, and versatility of the Bain system and believe that it will play a major role in the future of anesthesia-machine design.

Plasma concentration of lidocaine after endotracheal spray

The rate of absorption and plasma concentrations of lidocaine were determined in 15 supine patients under general anesthesia following either endotracheal spray of 200 mg. (average 3.3 mg./kg.) of 4 percent lidocaine hydrochloride solution with a special cannula (LTA Kit, Abbott) (N = 6) or 1 mg./kg. of 2 percent lidocaine solution as an intravenous bolus injection (N = 9). In the 6 patients after endotracheal spray, peak plasma lidocaine levels were reached at 15 to 20 minutes (mean 3.54 plus or minus 0.76 S.E. mug./ml. at 20 minutes). In the 9 patients given 1 mg./kg. intravenously, dose peak concentrations were reached within 2 minutes (mean 5.63 plus or minus 0.18 S.E. mug./ml. at 2 minutes). Plasma concentrations of lidocaine in both groups were within nontoxic ranges.