Ferit KULALI, Canan TÜRKYILMAZ, Ebru ERGENEKON, Selma AKTAŞ, Sezin ÜNAL, Yıldız ATALAY, İbrahim Murat HİRFANOĞLU, Ebru KAZANCI

Effects of a closed system suction connector on airway resistance in ventilated neonates

Background/aim: Increased airway resistance reduces the effectiveness of ventilation treatment. Endotracheal tubes (ETTs) and connectors contribute to resistance. However, the effect of a closed system suction (CSS) connector is not well known. We compared the in vivo resistance occurring with a CSS connector with that of the standard connector. Materials and methods: This prospective study was conducted at Gazi University Hospital s neonatal intensive care unit. Intubated neonates were studied for two cycles; each cycle contained two periods of ETT + connector pairs (15 min/period) as follows: cycle 1 [A: long ETT + standard connector; B: long ETT + CSS connector] and cycle 2 [C: shortened ETT + standard connector; D: shortened ETT + CSS connector]. Resistance of 40 breaths/period was averaged for each case, and the means were analyzed by Wilcoxon test for pairwise comparisons between standard and CSS connectors. As each case provided two cycle data, 16 cycle data were compared. Results: The CSS connector increased resistance by 13.8% (range: 3.0% 22.1%) compared to the standard connector; P < 0.001. The resistance increase was similar between long [17.3% (range: 3.0% 17.7%)] and shortened ETTs [15.3% (range: 5.0% 29.6%)]; P = 0.834. Conclusion: CSS connectors were found to increase airway resistance in ventilated neonates. The contribution of CSS should be considered during ventilation, particularly in the presence of difficulty in providing sufficient tidal volume.

PDF

___

1. Keszler M, Abubakar K. Physiologic Principles In: Goldsmith JP, Karotkin EH, editors. Assisted Ventilation of The Neonate 5th ed. Philadelphia, PA, USA: Saunders; 2011. pp. 19-47.
2. Blom H, Rytlander M, Wisborg T. Resistance of tracheal tubes 3.0 and 3.5 mm internal diameter. A comparison of four commonly used types. Anaesthesia 1985; 40: 885-888.
3. Hatch DJ. Tracheal tubes and connectors used in neonates dimensions and resistance to breathing. Br J Anaesth 1978; 50: 959-964.
4. Kazanci E, Kulali F, Altuntas N, Unal S, Aktas S, Ergenekon E. Different endotracheal tubes, different endotracheal connectors, different lengths: impact on resistance and dead space. Arch Dis Child. 2012: 97: A1-A539.
5. Wright PE, Marini JJ, Bernard GR. In vitro versus in vivo comparison of endotracheal tube airflow resistance. Am Rev Respir Dis 1989; 140: 10-16.
6. Ivanov VA. Reduction of endotracheal tube connector dead space improves ventilation: a bench test on a model lung simulating an extremely low birth weight neonate. Respir Care 2016; 61: 155-161.
7. Cordero L, Sananes M, Ayers LW. Comparison of a closed (Trach Care MAC) with an open endotracheal suction system in small premature infants. J Perinatol 2000; 20: 151-156.
8. Cereda M, Villa F, Colombo E, Greco G, Nacoti M, Pesenti A. Closed system endotracheal suctioning maintains lung volume during volume-controlled mechanical ventilation. Intensive Care Med 2001; 27: 648-654.
9. Estay A, Claure N, DUgard C, Organero R, Bancalari E. Effects of instrumental dead space reduction during weaning from synchronized ventilation in preterm infants. J Perinatol 2010; 30: 479-483.