[en] Given their high apparent variability, bedside continuous respiratory mechanics (RM) parameters (excepting tidal volume (VT)) remain infrequently used for adjustment of neonatal ventilatory settings. RM parameters provided by ventilator (VRC) from 10 recordings of newborns (10 minutes in synchronized intermittent mandatory ventilation and Assist/control (A/C)) were compared to those computed from visually selected assisted leak-free optimal respiratory cycles (SRC). Mean values, variability and ability to distinguish patients were compared between VRC and SRC. Dynamic resistances were more correlated (r²=0.95) than compliances (r²=0.42). VT’s were correlated only in A/C (r²=0.78). C20/C was significantly higher in VRC (1.81±0.67) than in SRC (1.23±0.36) and frequently out of neonatal reference range. In A/C ventilation, VT was higher in VRC (5.6 ±1.8 ml/kg) than in SRC (4.8 ±1.0 ml/kg) (p<0.05). Displayed VT’s don’t reflect those found in optimal assisted breaths and therefore have incomplete value in assessing adequacy of ventilator settings. The variability of RM parameters provided by the ventilator is large, and coefficients of variation were significantly lower with optimal respiratory cycles (for Resistance, Compliance, VT and C20/C: 27, 26, 18, 24% in SRC, 36, 35, 40, 33% in VRC). Selecting optimal cycles yields RM with a 2-3 times higher discriminating power between patients.
Conclusion: Current ventilator’s RM parameters have limited clinical use. Using optimal breaths to calculate RM parameters improves precision and discriminating power. For integration to ventilatory care, automation of this selection must be implemented first.
Disciplines :
Pediatrics
Author, co-author :
RIGO, Vincent ; Centre Hospitalier Universitaire de Liège - CHU > Néonatologie CHR
Graas, Estelle; Nomics, Liège
RIGO, Jacques ; Centre Hospitalier Universitaire de Liège - CHU > Néonatologie CHR
Language :
English
Title :
Precision of continuous neonatal ventilator respiratory mechanics is improved with selected optimal respiratory cycles.
Beck J, Tucci M, Emeriaud G, Lacroix J, Sinderby C (2004) Prolonged neural expiratory time induced by mechanical ventilation in infants. Pediatr Res 55:747-754 (Pubitemid 38520439)
Cappa P, Sciuto SA, Silvestri S (2006) Experimental evaluation of errors in the measurement of respiratory parameters of the newborn performed by a continuous flow neonatal ventilator. J Med Eng Technol 30:31-40 (Pubitemid 43062217)
Chow LC, Vanderhal A, Raber J, Sola A (2002) Are tidal volume measurements in neonatal pressure-controlled ventilation accurate? Pediatr Pulmonol 34:196-202 (Pubitemid 34971072)
De Luca D, Conti G, Piastra M, Paolillo PM (2009) Flow-cycled versus time-cycled sIPPV in preterm babies with RDS: a breathto- breath randomised cross-over trial. Arch Dis Child Fetal Neonatal Ed 94:F397-F401
Donn SM, Sinha SK (2006) Minimising ventilator induced lung injury in preterm infants. Arch Dis Child Fetal Neonatal Ed 91: F226-F230 (Pubitemid 43667625)
Dräger Medical (1999) Babylog 8000 plus infant care ventilator. Operating instructions, software 5.n
Fisher JB, Mammel MC, Coleman JM, Bing DR, Boros SJ (1988) Identifying lung overdistention during mechanical ventilation by using volume-pressure loops. Pediatr Pulmonol 5:10-14
Greenough A, Morley C, Davis J (1983) Interaction of spontaneous respiration with artificial ventilation in preterm babies. J Pediatr 103:769-773 (Pubitemid 14235446)
Irazuzta J, Pascucci R, Perlman N, Wessel D (1993) Effects of fentanyl administration on respiratory system compliance in infants. Crit Care Med 21:1001-1004 (Pubitemid 23206191)
Kano S, Lanteri CJ, Pemberton PJ, Lesouef PN, Sly PD (1993) Fast versus slow ventilation for neonates. Am Rev Respir Dis 148:578-584 (Pubitemid 23263763)
Kapasi M, Fujino Y, Kirmse M, Catlin EA, Kacmarek RM (2001) Effort and work of breathing in neonates during assisted patienttriggered ventilation. Pediatr Crit Care Med 2:9-16
Keszler M, Abubakar K (2004) Volume guarantee: stability of tidal volume and incidence of hypocarbia. Pediatr Pulmonol 38:240-245 (Pubitemid 39095683)
Klimek J, Morley CJ, Lau R, Davis PG (2006) Does measuring respiratory function improve neonatal ventilation? J Paediatr Child Health 42:140-142 (Pubitemid 43356869)
Lanteri CJ, Kano S, Nicolai T, Sly PD (1995) Measurement of dynamic respiratory mechanics in neonatal and pediatric intensive care: the multiple linear regression technique. Pediatr Pulmonol 19:29-45
Manczur T, Greenough A, Nicholson GP, Rafferty GF (2000) Resistance of pediatric and neonatal endotracheal tubes: influence of flow rate, size, and shape. Crit Care Med 28:1595-1598 (Pubitemid 30324546)
McEvoy C, Sardesai S, Schilling D, Durand M (2007) Acute effects of vecuronium on pulmonary function and hypoxemic episodes in preterm infants. Pediatr Int 49:631-636 (Pubitemid 47414896)
Miller JD, Carlo WA (2008) Pulmonary complications of mechanical ventilation in neonates. Clin Perinatol 35:273-281 (Pubitemid 351232002)
Neve V, de la Roque ED, Leclerc F, Leteurtre S, Dorkenoo A, Sadik A, Cremer R, Logier R (2000) Ventilator-induced overdistension in children: dynamic versus low-flow inflation volumepressure curves. Am J Respir Crit Care Med 162:139-147 (Pubitemid 30469811)
Neve V, Leclerc F, de la Roque ED, Leteurtre S, Riou Y (2001) Overdistension in ventilated children. Crit Care 5:196-203 (Pubitemid 32734335)
Raju TN, Stevenson DK, Higgins RD, Stark AR (2009) Safe and effective devices and instruments for use in the neonatal intensive care units: NICHD Workshop summary. Biomed Instrum Technol 43:408-418
Sweet DG, Carnielli V, Greisen G, Hallman M, Ozek E, Plavka R, Saugstad OD, Simeoni U, Speer CP, Halliday HL (2010) European consensus guidelines on the management of neonatal respiratory distress syndrome in preterm infants - 2010 update. Neonatology 97:402-417
Uhl RR, Lewis FJ (1974) Digital computer calculation of human pulmonary mechanics using a least squares fit technique. Comput Biomed Res 7:489-495
van Kaam AH, Rimensberger PC, Borensztajn D, De Jaegere AP (2010) Ventilation practices in the neonatal intensive care unit: a cross-sectional study. J Pediatr 157(767-771):e761-e763