Comparison of hollow-fiber membrane oxygenators with different perfusion modes during normothermic and hypothermic CPB in a simulated neonatal model

Abstract

Purpose: The objectives of this investigation were (1) to compare two hollow-fiber membrane oxygenators (Capiox Baby RX versus Lilliput 1-D901) in terms of pressure drops and surplus hemodynamic energy (SHE) during normothermic and hypothermic cardiopulmonary bypass (CPB) in a simulated neonatal model; and (2) to evaluate pulsatile and non-pulsatile perfusion modes for each oxygenator in terms of SHE levels.

Methods: In a simulated patient, CPB was initiated at a constant pump flow rate of 500 mL/min. The circuit was primed with fresh bovine blood. After 5 min of normothermic CPB, the pseudo-patient was cooled down to 25°C for 10 min followed by 30 min of hypothermic CPB. The pseudo-patient then underwent 10 min of rewarming and 5 min of normothermic CPB. At each experimental site (pre- and post-oxygenator and pre-aortic cannula), SHE was calculated using the following formula {SHE (ergs/cm³) = 1332 [((ffpdt)/(ffdt))-mean arterial pressure]} (f = pump flow and p = pressure). A linear mixed-effects model that accounts for the correlation among repeated measurements was fit to the data to assess differences in SHE between oxygenators, pumps, and sites. Tukey’s multiple comparison procedure was used to adjust p-values for post-hoc pairwise comparisons.

Results: The pressure drops in the Capiox group compared to the Lilliput group were significantly lower during hypothermic non-pulsatile (21.3∓0.5 versus 50.7∓0.9 mmHg, p B < 0.001) and pulsatile (22∓0.0 versus 53.3∓0.5 mmHg, p < 0.001) perfusion, respectively. Surplus hemodynamic energy levels were significantly higher in the pulsatile group compared to the non-pulsatile group, with Capiox (1655∓92 versus 10 008∓1370 ergs/cm³, p < 0.001) or Lilliput (1506∓112 versus 7531∓483 ergs/cm³, p < 0.001) oxygenators. During normothermic CPB, both oxygenators had patterns similar to those observed under hypothermic conditions.

Conclusions: The Capiox oxygenator had a significantly lower pressure drop in both pulsatile and non-pulsatile perfusion modes. For each oxygenator, the SHE levels were significantly higher in the pulsatile mode.

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References

Ündar A , Lodge AJ , Daggett CW , Runge TM , Ungerleider RM , Calhoon JH. The type of aortic cannula and membrane oxygenator affect the pulsatile waveform morphology produced by a neonate-infant cardiopulmonary bypass system in vivo . Artif Organs 1998; 22: 681-686 .

Ündar A , Koenig KM , Frazier OH , Fraser CD. Impact of membrane oxygenators on pulsatile versus nonpulsatile perfusion in a neonatal model . Perfusion 2000; 15: 111-120 .

Ündar A. The ABCs of research on pulsatile versus nonpulsatile perfusion during cardiopulmonary bypass [Editorial] . Med Sci Monit 2002; 8: ED21-ED24 .

Ündar A. Myths and truths of pulsatile and nonpulsatile perfusion during acute and chronic cardiac support [Editorial] . Artif Organs 2004; 28: 439-443 .

Ündar A. Principles and practices of pulsatile perfusion in pediatric and adult open-heart surgery . Turk J Thorac Cardiovasc Surg 2004; 12: 215-219 .

Ündar A. Pulsatile versus non-pulsatile cardiopulmonary bypass procedures in neonates and infants: from bench to clinical practice [Invited Editorial] . ASAIO J 2005; 51: vi-x .

Ji B , Ündar A. An evaluation of the benefits of pulsatile vs. non-pulsatile perfusion during cardiopulmonary bypass procedures in pediatric and adult cardiac patients [Invited Editorial] . ASAIO J 2006; 52: 357-361 .

Ündar A , Owens WR , McGarry M et al . Comparison of hollow-fiber membrane oxygenators in terms of pressure drop of the membranes during normothermic and hypothermic cardiopulmonary bypass in neonates . Perfusion 2005; 20: 135-138 .

Dubois J , Jamaer L , Mees U et al. Ex vivo evaluation of a new neonatal/infant oxygenator: comparison of the Terumo Capiox Baby RX with Dideco Lilliput 1 and Polystan Safe Micro in the piglet model . Perfusion 2004; 19: 315-321 .

10.

Shepard RB , Simpson DC , Sharp JF. Energy equivalent pressure . Arch Surg 1966; 93: 730-740 .

11.

Gu YJ , Boonstra PW , Graaff R , Rijnsburger AA , Mungroop H , van Oeveren W. Pressure drop, shear stress, and activation of leukocytes during cardiopulmonary bypass: a comparison between hollow-fiber and flat sheet membrane oxygenators . Artif Organs 2000; 24: 43-48 .

12.

Ündar A , Masai T , Yang SQ , Finegold J , Frazier OH , Fraser CD. Effects of perfusion mode on regional and global organ blood flow in a neonatal piglet model . Ann Thorac Surg 1999; 68: 1336-1343 .

13.

Ündar A , Masai T , Yang SQ et al . Pulsatile perfusion improves regional myocardial blood flow during and after hypothermic cardiopulmonary bypass in a neonatal piglet model . ASAIO J 2002; 48: 90-95 .

14.

Ündar A , Masai T , Beyer EA et al . Pediatric physiologic pulsatile pump enhances cerebral and renal blood flow during and after cardiopulmonary bypass . Artif Organs 2002; 26: 919-923

15.

Ündar A , Eichstaedt HC , Bigley JE et al. Effects of pulsatile and nonpulsatile perfusion on cerebral hemodynamics investigated using a new pediatric pump . J Thorac Cardiovasc Surg 2002; 124: 413-416 .

16.

Alkan A , Akcevin A , Ündar A , Turkoglu H , Paker T , Aytac A. Effects of pulsatile and nonpulsatile perfusion on vital organ recovery in pediatric heart surgery: a pilot clinical study . ASAIO J 2006; 52: 530-535 .