Articles: closed-circuit-anesthesia.
-
Sevoflurane, a new inhalational anesthetic agent has been shown to produce degradation products upon interaction with CO2 absorbants. Quantification of these sevoflurane degradation products during low-flow or closed circuit anesthesia in patients has not been well evaluated. The production of sevoflurane degradation products was evaluated using a low-flow anesthetic technique in patients receiving sevoflurane anesthesia in excess of 3 h. ⋯ Mean maximum inhalation concentration of compound A using baralyme was 20.28 +/- 8.6 ppm (mean +/- SEM) compared to 8.16 +/- 2.67 ppm obtained with soda lime, a difference that did not reach statistical significance. A single patient achieved a maximal concentration of 60.78 ppm during low-flow anesthesia with baralyme. Exhalation concentrations of compound A were less than inhalation concentrations, suggesting patient uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
-
We report a case of malfunction of an anesthetic ventilator by an unusual cause. A 48-year-old male with gastric cancer was scheduled for gastrectomy. Anesthesia was maintained with enflurane, N2O, O2 and epidural blockade using a semiclosed circuit system. ⋯ After the surgery, we recognized that the controller unit of expiratory valve of the ventilator was obstructed by a Tamper Proof Film, which seals the outlet of a commercial bag of lactated Ringer's solution (Solulact, Terumo Co.). It seems that the film dropped accidentally between the main part and the ventilator system of anesthetic machine when the bellows was exchanged before the surgery, and moved on to the controller unit of the expiratory valve of the ventilatory system during surgery. In conclusion, it is necessary for anesthetists to understand the inner structure and system of the anesthetic machine and to check the anesthetic machine to avoid the troubles and accidents related to anesthetic machine.
-
Randomized Controlled Trial Clinical Trial
Effect of low fresh gas flow rates on inspired gas composition in a circle absorber system.
To determine the effects of fresh gas flow on inspired gas composition during low-flow anesthesia. ⋯ The same initial period of denitrogenation is not adequate to denitrogenate the circle system in all cases. The lower the fresh gas flow, the longer the initial period of denitrogenation should be. Various levels of fresh gas flow for low-flow anesthesia have been suggested, but none guarantees adequate control of inspired gas composition unless flowmeters are continuously adjusted.
-
Capnography is a useful technique in monitoring the integrity of anaesthetic equipment such as the malfunctioning of unidirectional valves in circle system. However, the lack of a precise mechanism in existing capnographs to identify the start of inspiration and the beginning of expiration in the capnograms, makes the analysis of the carbon dioxide waveforms during inspiration difficult and thus results in inaccurate assessment of rebreathing. We report a case where, during the malfunction of the inspiratory unidirectional valve in the circle system, the capnograph failed to detect the presence of substantial rebreathing. Critical analysis of the capnogram recorded during the malfunction revealed that there was substantial rebreathing which was underestimated by the capnograph as it reports only the lowest CO2 concentration rebreathed during inspiration in such abnormal situations.