Evaluation of the minimum volume of salvage blood required for the successful use of two different autotransfusion devices.

BACKGROUND: Autotransfusion in pediatric anesthesia is beneficial in several clinical settings; however, more frequent usage is deterred by process-related costs and the fact that the absolute volume of blood returned may be minimal. OBJECTIVE: Two autotransfusion devices (CATS, Fresenius Kabi AG, and Sorin Xtra, Sorin GmbH) with different technologies were evaluated to determine the minimum volume necessary to efficiently process salvage blood. METHODS: Banked blood was diluted to simulate different clinical scenarios. Volume and red cell mass in returned blood were analyzed as a function of initial volume and red cell mass in the collection reservoir using incremental increases in the volume of blood added to the reservoir. RESULTS: The volume of the returned processed blood for infusion was dependent on degree of dilution and blood volume in the reservoir. The CATS required a smaller initial minimum volume to process and successfully return; however, the Xtra provided a more efficient recovery at low initial collected volumes. Using test blood of various degrees of dilution, the CATS and Xtra were able to return blood for retransfusion after a mean initial red cell mass of 48.7 ml (±4.9 ml) and 53.7 ml (±5.0 ml) were processed, respectively. CONCLUSIONS: Red cell mass rather than salvaged blood volume represents a reliable predictor of the successful use of an autotransfusion device. Measuring the hematocrit of the salvaged blood could improve the use of the devices. The investigated devices are likely to be roughly equivalent in effectiveness.

The influence of acupressure on the monitoring of acoustic evoked potentials in unsedated adult volunteers.

Approaches for monitoring depth of anesthesia can be influenced by things other than anesthetics. In this study, we evaluated the influence of acupressure on the A-line autoregressive index (AAI) and on stress levels in unsedated volunteers. Fifteen unsedated adult volunteers received pressure on the acupuncture Extra 1 point (EP) and on a control point for 10 min on different days. AAI was recorded 5 min before, during, and 5 min after the interventions. Before and after the procedures, the volunteers quantified their level of stress by means of a visual analog stress scale (VSS; 0-100). Corresponding data were compared by Wilcoxon's signed rank test (Bonferroni correction, P < 0.05). Data are median (range). AAI decreased from 73 (40-99) to 53 (33-94) after 10 min of pressure on EP (P = 0.0044). Five minutes after release of pressure there was no difference compared with initial values. There was a statistically significant difference between VSS before and after pressure on EP (36 [7-67] to 15 [0-44]; P = 0.0066), but not on control point. In conclusion, there was a wide range of AAI values in awake volunteers. The AAI was influenced by acupressure performed on the EP in unsedated adult volunteers. Acupressure on this point significantly reduced stress levels.

Video-enhanced visualization of the larynx and intubation with the Bullard laryngoscope--equipment report.

PURPOSE: A simple technical solution is presented to provide video transmission from the tip of a Bullard laryngoscope to a bedside video display, while the operator is still able to look through the viewing ocular of the Bullard laryngoscope during tracheal intubation. EQUIPMENT: This is achieved by insertion of an ultrathin fibreoptic video-endoscopic system into the working channel of the Bullard laryngoscope. Thereby the view from the distal blade tip is transmitted to a bedside monitor, without interfering with the use of the Bullards laryngoscope's original eyepiece. The presented technical solution allows video transmission without considerable additional weight normally associated with attaching video endoscopy cameras, light and camera cables to endoscopic devices. Thus, the Bullard laryngoscope remains lightweight and easy to maneuver. A screw-threaded adapter with a side-port is proposed to prevent displacement of the fibreoptic cable while still allowing application of oxygen. CONCLUSION: Experience and skills with tracheal intubation using the presented video-enhanced Bullard laryngoscope can be achieved in the originally intended way, while the supervisor or attending viewers can follow the tracheal intubation procedure on the video display.