Xenon anesthesia improves respiratory gas exchanges in morbidly obese patients

The Modification and Performance of a Large Animal Anesthesia Machine (Tafonius®) in Order to Deliver Xenon to a Horse

Introduction

Xenon, due to its interesting anesthetic properties, could improve the quality of anesthesia protocols in horses despite its high price. This study aimed to modify and test an anesthesia machine capable of delivering xenon to a horse.

Materials and methods

An equine anesthesia machine (Tafonius, Vetronic Services Ltd., UK) was modified by including a T-connector in the valve block to introduce xenon, so that the xenon was pushed into the machine cylinder by the expired gases. A xenon analyzer was connected to the expiratory limb of the patient circuit. The operation of the machine was modeled and experimentally tested for denitrogenation, wash-in, and maintenance phases. The system was considered to consist of two compartments, one being the horse’s lungs, the other being the machine cylinder and circuit. A 15-year-old, 514-kg, healthy gelding horse was anesthetized for 70 min using acepromazine, romifidine, morphine, diazepam, and ketamine. Anesthesia was maintained with xenon and oxygen, co-administered with lidocaine. Ventilation was controlled. Cardiorespiratory variables, expired fraction of xenon (FeXe), blood gases were measured and xenon was detected in plasma. Recovery was unassisted and recorded.

Results

FeXe remained around 65%, using a xenon total volume of 250 L. Five additional boli of ketamine were required to maintain anesthesia. PaO₂ was 45 ± 1 mmHg. The recovery was calm. Xenon was detected in blood during the entire administration time.

Conclusion

This pilot study describes how to deliver xenon to a horse. Although many technical problems were encountered, their correction could guide future endeavors to study the use of xenon in horses.

Comparison of recovery parameters for xenon versus other inhalation anesthetics: systematic review and meta-analysis

STUDY OBJECTIVE

To summarize and evaluate the available data describing the recovery parameters of xenon anesthesia.

DESIGN

Systematic review and meta-analysis.

SETTING

Anesthesia for elective surgeries.

PATIENTS

Systematic review of randomized controlled trials (RCTs) from databases including Medline (1964-2013), the Cochrane Central Register of Controlled Trials (CENTRAL, 1990-2012), and Google Scholar (1966-2013).

INTERVENTIONS

Inhalation of xenon or other anesthetics was administered in elective surgery.

MEASUREMENTS

Recovery parameters (time to recovery, alertness/sedation scale scores at "eye opening," bispectral index at "reaction on demand," time to extubation, and time to orientation).

MAIN RESULTS

Eleven RCTs (N = 661 patients) met the inclusion criteria. Recovery from xenon anesthesia was significantly faster in terms of the time to eye opening (mean difference [MD], -4.18 minutes; 95% confidence interval [CI], -5.03 to -3.32 minutes; P < .00001), the time to reaction on demand (MD, -5.35 minutes; 95% CI, -6.59 to -4.11 minutes; P < .00001), the time to extubation (MD, -4.49 minutes; 95% CI, -5.40 to -3.58 minutes; P < .00001), and the time to orientation (MD, -4.99 minutes; 95% CI, -6.45 to -3.52 minutes; P < .00001).

CONCLUSIONS

This meta-analysis confirmed that recovery from xenon anesthesia is faster than other inhalation anesthesia.

Xenon anesthesia reduces TNFα and IL10 in bariatric patients

BACKGROUND

Anesthesia is able to modulate the balance between proinflammatory and anti-inflammatory cytokine production during surgery. The aim of this study is to assess the effect of three anesthesia approaches, total intravenous anesthesia (TIVA), inhalation anesthesia, and xenon anesthesia, on sieric levels of nitric oxide (NO), IL6, IL10, and TNFα in obese patients undergoing Roux-en-Y laparoscopic gastric bypass.

METHODS

Thirty adult morbidly obese patients (BMI > 35) scheduled for Roux-en-Y laparoscopic gastric bypass were randomly recruited and allocated to TIVA (N = 10), inhalation anesthesia (SEV, N = 10), and xenon anesthesia (XE, N = 10). Exclusion criteria were ASA IV, age <18 or >60 years, and Mallampati IV. Opioid dosage and ventilation parameters were standardized. Sieric levels of NO, IL6, IL10, and TNFα were assessed at T0 (before induction of anesthesia), T1 (end of surgery), and T2 (12 h after the end of surgery). We compared the relative cytokine level variations (delta) at T1 and T2 and the cytokine exposure levels calculated as the area under the curve (AUC) between T0 and T2 in the XE and non-XE (SEV + TIVA) groups.

RESULTS

At T1, we found a significant ΔIL10 (reduction) and ΔTNFα (reduction) between XE and SEV (p < 0.05) and XE and TIVA (p < 0.05) groups. At T2, ΔIL10 was still significant. Furthermore, we found a reduced AUC value for TNFα in the XE group.

CONCLUSIONS

Xenon anesthesia seems able to inhibit postoperative proinflammatory cytokine imbalance in morbidly obese patients undergoing Roux-en-Y laparoscopic gastric bypass; the reduced ΔTNFα at T1 and the reduced global exposition to TNFα in the XE group may explain the reduced ΔIL10 at T1 and T2.