Background: A double-lumen multiorifice catheter has been developed to potentially enhance accurate electrocardiographic central venous localization and resuscitation from a massive venous air embolism (VAE). This double-lumen multiorifice catheter was compared to a Bunegin-Albin multiorifice catheter for flow characteristics, air aspiration efficiency, and efficacy in resuscitating swine from a lethal VAE.
Methods: Flow characteristics of both catheters were determined by aspirating both agitated and unagitated citrated swine blood with a 50-ml syringe. Swine were anesthetized with halothane and positioned to approximate a modified sitting craniotomy position (45-degree elevation). By a random block method, 24 swine were assigned to either catheter (n = 12 each catheter) for the initial air aspiration. Catheters were positioned, using intravenous electrocardiography, with the distal aspiration orifice in the high right atrium. A 5-ml/kg air embolism was administered over 30 s into the sagittal sinus, and the swine were resuscitated by aspirating air through the multiorifice catheters and then positioning the swine horizontally. Surviving animals were allowed to recover for 60 min. The initial catheter was exchanged and repositioned in the high right atrium using intravenous electrocardiography. A 5-ml/kg air embolus was administered, and the swine were resuscitated as in the first challenge. Surviving swine recovered for 60 min, repositioned, and administered a third 5-ml/kg air embolism. On this final challenge, no attempt was made to resuscitate the animal by aspirating the multiorifice catheter.
Results: Flow characteristics of both catheters were similar in the unagitated blood (195.3 +/- 1.9 vs. 196.7 +/- 2.5 ml/min). The flow rate of agitated blood through the double-lumen multiorifice catheter was 14% greater than through the Bunegin-Albin catheter (136.3 +/- 6.8 vs. 117 +/- 5.9 ml/min, P = 0.001). Forty-three air embolism trials were conducted at 5 ml/kg. All nine trials at 5 ml/kg without air aspiration resulted in death. Five animals died during the embolism dose determination trials, and four died during the third embolism challenge. The use of a multiorifice catheter for aspiration after a VAE enhanced survival after a 5-ml/kg sagittal sinus air embolus (14/34 vs. 0/9, P = 0.02). Although the double-lumen multiorifice catheter was more efficient than the Bunegin-Albin catheter in percentage of air retrieved (37.7 +/- 12.0 vs. 29.7 +/- 10.1, P = 0.042). Aspiration of the VAE with the double-lumen multiorifice catheter successfully rescued 9 of the 15 trials, and aspiration using the Bunegin-Albin catheter resuscitated 5 of the 19 (P = 0.08).
Conclusions: Multiorifice catheters are effective in resuscitating swine from a lethal VAE. The double-lumen multiorifice catheter evaluated aspirated a larger percentage of the VAE but was not statistically more effective than the Bunegin-Albin catheter in resuscitating the animals. Based on these findings of improved flow rate and efficiency in air aspiration, further investigation of this double-lumen multiorifice catheter is warranted.