Factors affecting production of compound A from the interaction of sevoflurane with Baralyme and soda lime

Investigation and Possibilities of Reuse of Carbon Dioxide Absorbent Used in Anesthesiology

Absorbents used in closed and semi-closed circuit environments play a key role in preventing carbon dioxide poisoning. Here we present an analysis of one of the most common carbon dioxide absorbents—soda lime. In the first step, we analyzed the composition of fresh and used samples. For this purpose, volumetric and photometric analyses were introduced. Thermal properties and decomposition patterns were also studied using thermogravimetric and X-ray powder diffraction (PXRD) analyses. We also investigated the kinetics of carbon dioxide absorption under conditions imitating a closed-circuit environment.

Sevoflurane

Sevoflurane has been available for clinical practice for about 20 years. Nowadays, its pharmacodynamic and pharmacokinetic properties together with its absence of major adverse side effects on the different organ systems have made this drug accepted worldwide as a safe and reliable anesthetic agent for clinical practice in various settings.

Performance of a new carbon dioxide absorbent, Yabashi lime® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs

In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime(®) with a conventional CO2 absorbent, Sodasorb(®) as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime(®) with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime(®) did not produce CA. Control CO2 absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime(®) groups and control CO2 absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO2 absorbent group was significantly higher than Yabashi lime(®) group. CA and CO productions are thought to be related to the composition of CO2 absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime(®) with sevoflurane anesthesia in dogs than conventional CO2 absorbent at the point of CA production.

Kidney function in living donors undergoing nephrectomy by sevoflurane or desflurane anesthesia

PURPOSE

Although there is no clinical evidence of nephrotoxicity with the volatile anesthetics currently used in general anesthesia, a better agent should be needed in terms of preserving postoperative renal function in living kidney donors who have only single remaining kidney. The purpose of the current retrospective, single-center study was to evaluate and compare renal function of living kidney donors after nephrectomy under either sevoflurane or desflurane anesthesia.

MATERIALS AND METHODS

From January 2006 through December 2011, a total of 228 donors undergoing video assisted minilaparotomy surgery nephrectomy for kidney donation were retrospectively enrolled in the current study. The donors were categorized into a sevoflurane group or desflurane group based on the type of volatile anesthetic used. We collected laboratory data from the patients preoperatively, immediately after the operation, on the first postoperative day and on the third postoperative day. We also compared renal function of the kidney donors after donor nephrectomy by comparing creatinine level and estimated glomerular filtration rate (eGFR).

RESULTS

The decrease in renal function after surgery in both groups was the most prominent on the first postoperative day. There were no significant differences between the two groups in postoperative changes of creatinine or eGFR.

CONCLUSION

Sevoflurane and desflurane can be used safely as volatile anesthetics in donors undergoing nephrectomy.

Sofnolime with different water content causes different effects in two sevoflurane inhalational induction techniques with respect to the output of compound-A

OBJECTIVE

During sevoflurane anesthesia with Sofnolime for CO(2) absorption, the factors affecting the production of compound A (a chemical is nepherotoxic) are still not clear. This study is designed to investigate the effects of different fresh gas flow during induction, the vital capacity induction (VCI) vs. the tidal volume breath induction (TBI) on the compound-A production with a fresh Sofnolime or a dehydrated Sofnolime using a simulated lung model.

METHOD

The experiments were randomly divided into four groups: group one, VCIf, vital capacity fresh gas inflow with fresh Sofnolime; group two, TBIf, tidal volume breath fresh gas inflow with fresh Sofnolime; group three, VCId, vital capacity fresh gas inflow with dehydrated Sofnolime, and group four, TBId, tidal volume breath fresh gas inflow with dehydrated Sofnolime. The inspired sevoflurane was maintained at 8%, the concentrations of compound-A were assayed using Gas-spectrum technique, and Sofnolime temperatures were monitored at 1-min intervals throughout the experiment.

RESULTS

The mean and maximum concentrations of compound A were significantly higher in the vital capacity group than the tidal volume breath group (P<0.01). At the beginning of anesthesia maintenance, the compound-A concentration in group VCIf was 36.28±6.13 ppm, which was significantly higher than the 27.32±4.21 ppm observed in group TBIf (P<0.01). However, these values decreased to approximately 2 ppm in the dehydrated Sofnolime groups. Sofnolime temperatures increased rapidly in the dehydrated Sofnolime groups but slowly in the fresh Sofnolime groups.

CONCLUSION

With fresh Sofnolime, vital capacity induction increased compound-A production in the circuit system compared with tidal volume breath induction. However, with dehydrated Sofnolime, the effects of the two inhalation induction techniques on compound-A output were not significantly different.

Sevoflurance: approaching the ideal inhalational anesthetic. a pharmacologic, pharmacoeconomic, and clinical review

Sevoflurane is a safe and versatile inhalational anesthetic compared with currently available agents. Sevoflurane is useful in adults and children for both induction and maintenance of anesthesia in inpatient and outpatient surgery. Of all currently used anesthetics, the physical, pharmacodynamic, and pharmacokinetic properties of sevoflurane come closest to that of the ideal anesthetic (200). These characteristics include inherent stability, low flammability, non-pungent odor, lack of irritation to airway passages, low blood:gas solubility allowing rapid induction of and emergence from anesthesia, minimal cardiovascular and respiratory side effects, minimal end-organ effects, minimal effect on cerebral blood flow, low reactivity with other drugs, and a vapor pressure and boiling point that enables delivery using standard vaporization techniques. As a result, sevoflurane has become one of the most widely used agents in its class.