Post on 14-Jan-2016
description
Pulse oximetry/SpO2
Target values
RED(660nm)
INFRARED(910nm)
Wavelength
Absorbance
Absorbance
Jubran A. Crit Care, 1999Limitations : MetHb !
HbO2
HbR
MetHb
Target SpO2 ?
• BOOST Trial (Askie LM et al. NEJM, 2003)
Aim the study To compare targets SpO2 : 91-94% vs 95-98%
End-PointChronic Lung Disease
Neurodevelopmental outcome at 12 months
PopulationPreterm infants < 30 weeks GAO2 dependant at 32 weeks PCA
Askie LM et al. NEJM, 2003
Askie LM et al. NEJM, 2003
N=358
SpO2 91-94%N=178
SpO2 95-98%N=180
CLD (36 w) 46% 64%*Home O2 17% 30%*Duration O2 17d 40d*Death 3% 5%
Askie LM et al. NEJM, 2003
N=358
SpO2: 91-94%N=178
SpO2: 95-98%N=180
Major neurodevelopmental anomalies 24% 23%
Weight 9.1 kg 9.2kg
Askie LM et al. NEJM, 2003
At the age of 12 months
Target SpO2 ?
• BOOST Trial (Askie LM et al. NEJM, 2003)• STOP-ROP study (Pediatrics, 2000)
Aim of the study To compare target SpO2 : 89-94% vs 96-99%
End-PointROP
Chronic Lung Disease
PopulationPreterm infants with Retinopathy
N=649
SpO2 89-94%N=324
GA=25.4 weeksPCA=35.3
SpO2 96-99%N=325
25.4 weeks35.4
ROP progression 48% 41%At 3 months correctedage : hospitalization 6% 12%*Death 3% 5%
Pediatrics, 2000
Target SpO2 ?
• BOOST Trial (Askie LM et al. NEJM, 2003)• STOP-ROP study (Pediatrics, 2000)
Summary 1Compared with target SpO2 96-99%,
target SpO2 between 89 and 94%reduces the risk of CLD, duration of O2
therapy, and home O2 need…
… but what about lower SpO2 target ?
Target SpO2 ?
• BOOST II Trial, NEJM 2013
Aim the study To compare targets SpO2 : 85-89% vs 91-95%
End-PointDisability-free survival
PopulationPreterm infants < 28 weeks GA (N=2448)
To 36 weeks PCA
Stenson et al. NEJM, 2013
Stenson et al. NEJM, 2013
Stenson et al. NEJM, 2013
Target SpO2 ?
• B Schmidt, JAMA 2013
Aim the study To compare targets SpO2 : 85-89% vs 91-95%
End-PointDeath or Disability at age 18 months
PopulationPreterm infants < 28 weeks GA (N=1201)
To 36-40 weeks PCA
Smidt B et al, JAMA 2013
Take home message
In preterm infants < 28 weeks GA :
• SpO2 > 96 est associée à : CLD O2 duration ROP• Hyperoxemia can occur with SpO2 target between
90-96%;
• SpO2 < 89% est associée à: mortality ( NEC ?)
• ROP
Target SpO2 between 89 and 96 %
Dates à retenir !
• Le 14 Février 2014 de 9h à 18h : Formation EIRENE/GEN aux Soins Palliatifs (Inscription nécessaire);
• Le 5 Juin 2014 à Rouen : 9ème Journée Paramédicale du G4 en Médecine Néonatale;
• Le 12 Juin 2014 à Roncq, Amphytrion : 5ème réunion commune Collège Obstétriciens / GEN
• Le 19 Juin 2014 à Lille: Journée Régionale de Pédiatrie
Target SpO2 ?
• SpO2 Hyperoxemia can occur with SpO2 target between 90-96%;
• Physiologic evidence suggest that O2 delivery can be normal when SpO2 is lower than 88%, providing adequate cardiac output and hemoglobin concentration ;
• Clinical data suggest that target SpO2 between 70 and 90% reduces ROP, O2 need without increasing neurological impairment in very preterm infants.
Stenson et al. NEJM, 2013
Stenson et al. NEJM, 2013
Time
Absorbance
Tissue (myoglobin, bone…)
No pulsatile blood flow (venous, capillary)
Pulsatile blood flow (arterial)
Elimination ofthe nonpulsatile
component of the absorbance
Red/Infrared Absorbance (SpO2)
Limitations : Low distal perfusion ! = SvO2
+ distal perfusion index
Evidence for a benefit of SpO2 < 90-95% in the preterm infant ?
1. Physiologic data• Evidence for deleterious effects of
high PaO2 (>80mmHg?)• Increase the risk of ROP and
respiratory morbidity (Askie LM. Cochrane, 2001)
• Risk of hyperoxemia with SpO2 range 90-95% ?SpO2
PaO2 (mmHg)
90
95
42 110
Jubran A. Crit Care, 1999
Evidence for a benefit for SpO2 < 90-95% in the preterm infant ?
1. Physiologic data• Components of the tissue oxygenation
Fetal circulation
PaO2 = 18 mmHg !SaO2 = 60 % !
O2 consumption
O2 delivery = 1.3 x AoFlow x Hb x SpO2
PvO2
VO2
CriticalDO2
Anaerobicmetabolism
Lactate
Aerobic metabolism
O2 Delivery= 1.3 x AoFlow x Hb x SpO2
EO2
PvO2PvO2
Evidence for a benefit for SpO2 < 90-95% in the preterm infant ?
1. Physiologic data• Lack of evidence for hypoxia in hypoxemic preterm infants (Petrova A et al.
Pediatr Crit Care Med, 2006) • Prospective study• 10 preterm infants 24-32 weeks GA• Mesurement of tissular oxygenation (NIRS, brain and kidney) when SpO2 < 80% ;
No tissular hypoxia(Tissular SO2 and Fractional O2 Extraction : Adequate)
Evidence for a benefit for SpO2 < 90-95% in the preterm infant ?
2. Clinical data• Tin W et al. Arch Dis Child Fetal Ed, 2001
• Retrospective study• 295 preterm infants < 28 weeks GA
• Comparison of different policies : Target SpO2 70-90% vs 88-98%
Tin W et al. Arch Dis Child Fetal Ed, 2001
Outcome of the preterm infants according to the policy of target SpO2
Tin W et al. Arch Dis Child Fetal Ed, 2001
Respiratory outcome
Tin W et al. Arch Dis Child Fetal Ed, 2001
Evidence for a benefit for SpO2 < 90-95% in the preterm infant ?
2. Clinical data• Deulofeut R et al. J Perinat, 2006
• Retrospective study• Comparison of 2 historical periods :
– 2000-2002 : Target SpO2 92-100% – 2003-2004 : Target SpO2 85-92%
502 preterm infants < 1250g
Period 2003-2004 :• Less ROP• Less CLD• Higher Mental Developmental Index (89 vs 80)
Target SpO2 : Pre- and/or Post ductal ?
DA Pre-ductal : higher SpO2
Post-ductal : lower SpO2
Persistent Pulmonary HypertensionOf the Newborn/Preterm :
• Premature Rupture of the Membranes• Sepsis• Severe HMD
RA
RVLV
PA
DO2= 1.3 x AoFlow x Hb x SpO2
Target SpO2 : Pre- and/or Post ductal ?
DA Pre-ductal : higher SpO2
Post-ductal : lower SpO2
RA
RVLV
PA
DO2= 1.3 x AoFlow x Hb x SpO2
In the premature infant, Pre-ductal SpO2 should
be used to set FiO2 !
Target PCO2/TcPCO2 ?
Evidence for adverse effects of low PCO2 < 35mmHg
• Increase the risk of BPD/CLD (Avery ME et al Pediatrics 1987. Garland et al Arch Pediatr Adolesc Med, 1995);
• Increase the risk of Periventricular Leucomalacia (Graziani LJ, et al. Pediatrics 1992. Fujimoto S, et al. Arch Dis Child 1994);
Premature infants 400 à 1200 g
No severe IVH N=670
Severe IVHN=179
PaCO2 in the first 4 days after birth
Pediatrics 2007;119:299
Fabre J et al. Pediatrics 2007;119:299
Effects of the fluctuations of PaCO2 on the risk of IVH
Target PCO2 ?
Summary 1
Adverse lung and brain effects of :
• Low PCO2 <35 mmHg ;
• Fluctuating PCO2
Target PCO2/TcPCO2 ?2. Evidence for beneficial effects of moderate hypercapnia 45-55 mmHg
Premature infants 600 à 1200 g, < 24 hrs
MV
35-45 mmHg N=24
26 weeks850 g
45-55 mmHgN=25
26 weeks850 g
End-point : Duration of mechanical ventilation
Target PCO2
Mariani. Pediatrics, 1999
Mariani. Pediatrics, 1999
Actual values of PaCO2 according the target PaCO2
Mariani. Pediatrics, 1999
Effects of the target PaCO2 on the peak inspiratory pressure
Mariani. Pediatrics, 1999
Effects of the target PaCO2 on the duration of MV
Mariani. Pediatrics, 1999
Effects of the target PaCO2 on the nonrespiratory outcomes
Target PCO2/TcPCO2 ?
3. Why not > 55 mmHg ???
Premature infants 400 à 1200 g
No severe IVH N=670
Severe IVHN=176
PaCO2 in the first 4 days after birth
Fabre J et al. Pediatrics 2007;119:299
Fabre J et al. Pediatrics 2007;119:299
Target SpO2 / PCO2 in the preterm infant ?
Back home messageSpO2 :
• Preductal SpO2, instead of postductal, should be monitered during the first days after birth;
• Target SpO2 should not be > 95% :
• Target SpO2 < 92% may be preferred in extremely preterm infants
Target SpO2 / PCO2 in the preterm infant ?
Back home messagePCO2:
• Special care should be taken to prevent hypocapnia (<35 mmHg) and acute fluctuations of PCO2;
• Moderate hypercapnia (45-55 mmHg) is associated with lower morbidity than normal PCO2;
• Too much of a good thing (CO2) may cause adverse cerebral effects, at least within the first few days of life (PaCO2 > 60 mmHg) !
Hypotension : Preterm : AoP < GA + 2 mmHg/d, until 35
mmHg ; Full-term : AoP < 40 mmHg ;
Ischemic Threshold ?
aEEG
CBF
Kissack, Pediatr Res 2004Victor, Pediatr Res 2006
La PA n’est pas la perfusion
Kucklow M, J Pediatr. 1996Pladys P, Eur J Pediatr. 1999
45 preterm infants <1500gAge <36hMechanically ventilatedNo DA ou <1.5mm
O2
Delivery=1.3 x Qc x Hb x SpO2
Systemic Blood flow (Qc)
Heart Rate Preload Contractility Afterload
AoP= Qc x SVR
SystemicVascular
Resistances (SVR)
Tibby SM, Arch. Dis. Child. 2003
2. Characteristics of shock in the newborn infant
2.a. Clinical symptoms :
Skin color : grey, pallor ; Tachycardia > 160 / min ; Capillary Refill Time > 3 s ;
Temps de recoloration cutané
Pladys Crit Care Med 1998
N=40GA = 31 ± 4 Weeks PCA = 31 ± 3 WeeksNo DA
Cutaneous Refill Time
r = -0,74, p < 0,001
Oliguria < 1 ml/kg.h ; Apneas ; Hypotonia; Hyperglycemia ; Metabolic acidosis …
CAUTION : Neonates with shock can have :
• Normal AoP !;
• Red color of the skin ! ;
• No tachycardia (preterm) !
Alarmes redondantes ! : TcPO2 – SpO2 SpO2 – Fréquence respiratoire SpO2 pré- et post-ductale TcPCO2 – Vt - Vmin
Alarmes : pour faire quoi ? Gestes immédiats pour urgence vitale
Bradycardie Désaturation
Ou Alerter : Urgence différée Tachycardie
Tin W et al. Arch Dis Child Fetal Ed, 2001 B = BirthD = Discharge