Intraoperative Extracorporeal Carbon Dioxide Removal During Apneic Oxygenation with an EZ-Blocker in Tracheal Surgery

Y-shaped catheter improves carbon dioxide clearance during apnoeic oxygenation in tracheal surgery

OBJECTIVES:

Apnoeic oxygenation is a ventilation method in tracheal surgery, but has the disadvantage of causing progressive hypercapnia. The aim of this experimental study was to evaluate the efficacy of a Y-shaped catheter for the prevention of accumulation of carbon dioxide (CO2) in tracheal surgery.

METHODS:

Surgery for tracheal resection and reconstruction was performed in 10 beagles under general anaesthesia. Before transecting the trachea, the dogs were hyperventilated for 10 min with pure oxygen. After the airway was opened, ventilation was maintained with a small catheter for apnoeic oxygenation for 30 min until the end of the tracheal reconstruction. Y-shaped catheters were used in 5 dogs and straight catheters were used in 5 dogs for oxygen insufflation. Haemodynamic values and blood gas values were evaluated and compared between the 2 groups.

RESULTS:

The mean elevation in the CO2 partial pressure value per minute from 5 min after the start of the procedure to the end of apnoeic oxygenation was 1.34 mmHg [95% confidence interval (CI) 1.00-1.68] in the Y-shaped catheter group and 2.03 mmHg (95% CI 1.54-2.53) in the straight catheter group (P < 0.018). The total CO2 partial pressure elevation value was 59.5 mmHg in the Y-shaped catheter group and 89.0 mmHg in the straight catheter group (P < 0.006). There were no significant differences in haemodynamic values between the 2 groups.

CONCLUSIONS:

Apnoeic oxygenation using a Y-shaped catheter represses the accumulation of CO2 compared with a straight catheter in canine tracheal resection-reconstruction surgery.

New Approaches to Airway Management in Tracheal Resections-A Systematic Review and Meta-analysis

OBJECTIVES

Although endotracheal intubation, surgical crossfield intubation, and jet ventilation are standard techniques for airway management in tracheal resections, there are also reports of new approaches, ranging from regional anesthesia to extracorporeal support. The objective was to outline the entire spectrum of new airway techniques.

DESIGN

The literature databases PubMed/Medline and the Cochrane Library were searched systematically for prospective and retrospective trials as well as case reports on tracheal resections.

SETTING

No restrictions applied to hospital types or settings.

PARTICIPANTS

Adult patients undergoing surgical resections of noncongenital tracheal stenoses with end-to-end anastomoses.

INTERVENTIONS

Airway management techniques were divided into conventional and new approaches and analyzed regarding their potential risks and benefits.

MEASUREMENTS AND MAIN RESULTS

A total of 59 publications (n = 797 patients) were included. The majority of publications (71.2%) describe conventional airway techniques. Endotracheal tube placement after induction of general anesthesia and surgical crossfield intubation after incision of the trachea were used most frequently without major complications. A total of 7 new approaches were identified, including 4 different regional anesthetic techniques (25 cases), supraglottic airways (4 cases), and new forms of extracorporeal support (25 cases). Overall failure rates of new techniques were low (1.8%). Details on patient selection and procedural specifics are provided.

CONCLUSIONS

New approaches have several theoretical benefits, yet further research is required to establish criteria for patient selection and evaluate procedural safety. Given the low level of evidence, it currently is impossible to compare methods of airway management regarding outcome-related risks and benefits.