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