Technology and the Delivery Room
Jeffrey M Perlman
Professor of Pediatrics
Weill Cornell Medical College,
New York Presbyterian Hospital
New York, NY
Faculty Disclosure Information
In the past 12 months, I have had the following financial
relationship
Travel Grant from Laerdal Global Health to Oversee the HBB Program
Development in Tanzania
I do not intent to discuss an unapproved/investigative use of a
commercial product/device in my presentation.
Session Title NRP Current Issues Seminar
Session Number
Faculty Name, Jeffrey Perlman MB Ch B, FAAP
Faculty Institution Weill Cornell Medical
College, New York Presbyterian Hospital,
New York City, NY
Outline
• Basic Principals of Cardio-Pulmonary Adaptation at delivery
• Assessing the Effectiveness of Resuscitation/Ventilation
• Determination of Heart Rate
• Can Technology Facilitate Resuscitation
- Detection of mask leak
- Detection of Tidal volume
- Detection of End Tidal CO2
Background
• The birth of the infant is associated with cessation of the
feto-placental circulation with subsequent profound
physiological changes that involve both the cardiac and
respiratory systems.
• Helping the newly born infant successfully make this
transition is the ultimate challenge
• The management of the depressed infant in the first
minutes of life can directly affect the quality of an
individuals life with long lasting consequences.
Requirement for Delivery Room Interventions
• > 95% of term infants will respond to the basic steps
in resuscitation including drying, position, suction
• Approximately 1 to 3 % will require BMV
• < 1 % will require Intubation
• 0.12% will require Intensive Resuscitation
• Intensive resuscitation may occur in the presence or
absence of severe fetal acidemia (cord pH < 7.00)
Conceptual Approach to an Infant as a Function of the
Heart Rate During the Initial Golden Minute Following Birth
Golden Minute
Crying
HR Rate
> 140BPM
Apgar > 7
Breathing
HR ± 120BPM
Apgar 5 to 7
HR 0 to 60
Apneic
Apgar 0 to 1
HR 60 to 100 BPM
± Respirations
Apgar 2 - 4
Four Basic Concepts
• Is the Baby in Primary or Secondary Apnea ?
• Effective Ventilation is key to successful Resuscitation
• Establishing Functional Residual Capacity
• Establishing ROSC
Primary vs Secondary Apnea
Adapted from Dawes et al 1968
Resuscitation in the Delivery Room
PMH experience Sept 91-Sept 93
Live Births
n = 30898
Chest Compressions/ Epinephrine
n = 39 (0.12%)
Term n=15
Preterm n=24
Asphyxia
n=10
Improper ETT
Placement
n=5
Ineffective / Improper
Ventilator support
n=24
From Perlman & Risser Arch Pediatr Adolesc Med 149:20;1995
Fundamental Point
Rapid Increase in Heart Rate is the best
indicator of Effective Ventilation
Determination of Heart Rate
Clinical Assessment of Heart Rate - Comparison of the HR
as Determined by Femoral, Brachial and Cord pulse palpation
• All cases of healthy newborns (n=60), auscultation
of HR was >100 bpm.
• 55% of Cord Palpation identified HR > 100 BPM
• 25% of Brachial and Femoral palpation identified
HR > 100 BPM
Owen CJ , Wyllie JP Resuscitation 50, 213: 2004
Role of Pulse Oximetry (PO) in Determination of HR
• Study Population: 55 infants of BW of 2399g and GA 35 weeks
• Median time taken to acquire HRPO was 68 sec (60 to 118 sec)
• Time to acquire HRECG was 80 sec (64 to 104 sec)
• There were 42 data points from 10 infants in which HR PO was < 100 bpm
when HRECG was > 100 bpm.
• Recommendation Use PO as an adjunct to careful clinical surveillance of
infant HR, especially for very preterm infants who may need resuscitation.
Kamlin et al J Pediatr 152; 756-760:2008
ILCOR Treatment Recommendation (2010)
Assessment of Cardio-Respiratory Transition
• Heart rate should remain the primary vital sign by which to judge the need
for and efficacy of resuscitation.
• Auscultation of the precordium should remain the primary means of
assessing heart rate.
• There is a high likelihood of underestimating heart rate with palpation of
the umbilical pulse, but this is preferable to other palpation locations.
• For babies who require ongoing resuscitation or respiratory support or
both, the goal should be to use pulse oximetry. Because of concerns about
the ability to consistently obtain accurate measurements, pulse oximetry
should be used in conjunction with and should not replace clinical
assessment of heart rate during newborn resuscitation.
ILCOR Treatment Recommendations Circulation. 2010;122:S516-S538
New Data Since 2010
EKG shows Reliable Heart Rate Much Earlier
than PO during Neonatal Resuscitation
• Study Population: 20 infants of BW 2338 g and GA 36 weeks
• The median time (IQR) taken to acquire reliable HR with ECG was 38 s (34–43)
• The time to acquire stable PR values with PO was 122 s (101–146) P < 0.001)
Time
Muzimoto, et al. Pediatrics International (2012) 54, 205–207
Electrocardiogram Provides a Continuous Heart Rate Faster
Than Pulse Oximetry During Neonatal Resuscitation
• Study Population 30 infants (23–30 weeks) had simultaneous ECG and PO data.
• The median total time to place EKG vs PO was (26 vs 38 sec; P = .04),
• Time to achieve an audible HR signal after ECG vs PO was 2 vs 24 sec (p < 0.001)
• During initial resuscitation, 93% of infants had ECG HR vs 56% for PO.
Representative Tracing
Katheria A, et al. Pediatrics 2012;130:e1177-e1181
Use of EKG Clip to Detect HR in Healthy Term Newborns
Average heart rate [bpm] with 95% confidence interval
180
170
160
150
140
130
120
110
100
0
50
Linde et al Ped Res 2014
100
150
Time [s]
200
250
300
Summary
• The optimal method to assess/detect HR will depend on the initial rate.
• A low or absent HR – either EKG, ETCO2 or auscultation
• A HR 60 to 100 – auscultation ± PO ± ETCO2
• A HR > 100 – auscultation ± PO
Assessment of Effective Ventilation
Understanding the Pathophysiology
Establishing Functional Residual Capacity (FRC)
Lung Volumes
Physiologic Pulmonary Measurements of
Spontaneously Breathing Infants at Birth
Following Vaginal Delivery
• Mean inspiratory pressure
= 52 cm H2O (range 25-105)
• Mean Inspiratory Volume
= 37 ml
(range 10-80)
• Functional Residual Capacity
= 15 ml
(range 8-30)
Following Cesarean Section
• Similar Inspiratory pressures and volumes
• Only 50% establish a FRC with the first breath
From Vyas, et al. Pediatr Pulm 787, 1981
Initial Expiratory Effort and Establishing FRC
Initial Expiratory Effort and Establishing FRC
Mechanisms Contributing to a Variable Response
to Either Spontaneous Breathing and/or PPV
The inconsistent response to PPV in some infants in part reflects
the infants response to initial mechanical breaths
• The most common is a REJECTION response with the production of high
intrathoracic pressure, i.e. expiratory effort with no gas exchange.
• A second response is the called “HEADS” paradoxical reflex with production of
high negative intra-esophageal pressure and a marked improvement in the
mechanical characteristics of the lung and the establishment of a functional
residual capacity.
• The third response is PASSIVE inflation with no change in esophageal pressure.
“HEADS” Paradoxical Response
Rejection Response
Passive Inflation
From Boon, et al. Arch Dis Childh 1979, 492
Establishing FRC in Apneic Babies
• Prolonging Inspiratory time
• Role of PEEP
Pressure and Volume Characteristics in Infants
requiring Resuscitation with Varying Inspiratory Times
Measurement
Mean Volume Change (ml)
Functional Residual Capacity (ml)
Inspiratory Time
1 Second
3 Seconds
15.3
33.5
1.0
15.9
Changes in Lung Gas Volume From Birth in Anesthetized
Ventilated Preterm Rabbit Pups Using Plethysmography
SI(20s) + PEEP
FRC
PPV + PEEP
PPV No PEEP
SI(20s) No PEEP
Te Pas, et al. Pediatric Research 2009;65:537
Summary
• Establishing FRC in a non breathing baby maybe extremely difficult because of
several competing factors.
• Appropriate application of a face mask maybe difficult with leak a common problem.
• Inadvertent upper airway obstruction may complicate ventilation.
• Assessment of chest rise is a poor indicator of delivered TV.
• Clinically the MRSOPA pneumonic is used as a tool to achieve effective ventilation.
• A Respiratory Function Monitor that provides objective evidence for Leak, ETCO2
measures and/or expired Tidal volume may facilitate effective ventilation.
Respiratory Function Monitor
Assessment of Chest rise during Mask Ventilation of Preterm Infants in
the DR- Clinical Assessment vs a Respiratory Function Monitor (RFM)
• Airway pressures and expiratory tidal volume (VTe) were measured during neonatal
resuscitation using a RFM.
• After 60 s of PPV, resuscitators standing at the infants’ head (head view) and at the side
(side view) were asked to assess chest rise and estimate VTe.
• 30% of observers felt unable to assess chest rise from the head and 15% from the side.
• Observers tended to underestimate TV by 3.5mL (Head) and 3.3mL (Side)
• Agreement between clinical assessment and measured VTe was poor.
Poulton D, et al. Resuscitation, Volume 82, Issue 2, 2011, 175 - 179
Assessment of Chest rise during Mask Ventilation of Preterm Infants in
the DR- Clinical Assessment vs a Respiratory Function Monitor (RFM)
Expired tidal volume ( V Te ) for the 20 individual infants.
Horizontal lines show the range of VTe which would provide
reasonable ventilation. The Box plots show median (solid
bar), IQR (margins of the box) and 95% confidence interval.
Poulton D. et al, Resuscitation, Volume 82, Issue 2, 2011, 175 - 179
Respiratory Function Monitor (RFM) Guidance of Mask
Ventilation in the DR: A Feasibility Study
Infants receiving mask resuscitation were randomized to have the RFM
Display Visible (airway pressure, flow, and VT waves) or masked.
Repositioning was done in 19 (73%) vs 6 (26%) of
RFM visible vs Masked group (P= .001).
Schmölzer et al J of Pediatrics, Volume 160, Issue 3, 2012, 377 - 381.e2
Mask Respiratory Support in the First 5 Minutes in the
DR Role of a Respiratory Function Monitor
• PPV was delivered with a round silicone
facemask connected to a T-piece device and
RPM which was not visible to the provider.
• Substantial leak was observed during all four
breath types median leaks range - 24% to 59%.
• Median TV were greater during inflations (8.3
ml/kg) and assisted inflations (9.3 ml/kg) than
spontaneous breaths between PPV (3.2 ml/kg)
and breaths during CPAP (3.3 ml/kg).
Kaufman J, et al. Arch Dis Child Fetal Neonatal Ed 2013;98:F405-F410
Role of End Tidal CO2 Monitoring
End-tidal CO2 Detection of an Audible Heart Rate During Neonatal
Cardiopulmonary Resuscitation Following Asystole in Asphyxiated Piglets
•
•
•
Representative tracing of ETCO2 and mean arterial pressure (MAP) during CPR
Chalak et al Pediatric Res 69;401-405: 2011
Study objective was to determine the threshold
ETCO2 associated with ROSC following asphyxiainduced asystole in neonatal swine (n=46)
progressively asphyxiated until asystole occurred.
ETCO2 cut off value of 14 mmHg was the most
sensitive ETCO2 value with the least false
positives.
When using ETCO2 to guide uninterrupted CPR in
experimental asphyxia-induced asystole,
auscultative confirmation of return of an adequate
HR should be performed when ETCO2 ≥14 mmHg
is achieved.
Quantitative End-Tidal Carbon Dioxide Monitoring in
the Delivery Room: A Randomized Controlled Trial
• Prospective randomized controlled trial of
infants who received PPV
• (PPV) to a control versus a monitored arm
with a goal to investigate the utility of
continuous quantitative end-tidal CO2
(EtCO2) monitoring for managing assisted
ventilation in the DR.
Physiologic and intervention data from a representative subject
(top tracing represents ventilating pressures; bottom tracing
represents Et CO 2 levels, x axis represents seconds of life).
Kong , et al Journal of Pediatrics, 163; 2013, 104 - 108.
• The median EtCO2 levels at end of
resuscitation were 44 mm Hg (16-66) in
controls and 43 mm Hg (29-59) in the
monitored arm
• The proportion of admission PCO2 levels
outside of the prespecified range was 33.3%
(control) vs 37.5% (monitored)
Positive Pressure Ventilation, Spontaneous
Respiratory Effort and FRC in Premature Infants
Role of RFM in Detection of TV and ETCO2
Role of PPV Pre, During and Post
Infants Own Respiratory Effort
Relationship of Expiratory Tidal Volume and ETCO2
Pre, During and Post Own Inspiratory Effort
Murphy V. et al, Arch Dis Child Fetal Neonatal Ed 2012;97:F249-F253
Relationship of Expiratory Tidal Volume and ETCO2
Pre, During and Post Own Inspiratory Effort
Pre- Active Inflation
Active Inflation
Post Inflation
Expired tidal volume
(ml/kg)
1.8
(0.7–7.3)
6.3
(1.9–18.4)
4.5
(0.5–18.3)
ETCO2
(kPa)
0.3
(0.1–2.1)
3.4
(0.4–11.5)
2.2
(0.3–9.3)
20.0
(13.8–26.7)
19.6
(13.7–25.9)
20.2
(13.4–25.9)
Inflation pressures
(cm H2O)
(Peak–PEEP)
Murphy V et al Arch Dis Child Fetal Neonatal Ed 2012;97:F249-F253
Summary
• Respiratory Function Monitor may play an important role in infants
needing respiratory support in the DR.
• RFM may facilitate effective ventilation by identifying mask leak
and /or evidence of obstruction.
• ETCO2 monitoring may facilitate detection of ROSC.
• ETCO2 monitoring may provide evidence of establishment of FRC.
• A dedicated individual and not the primary resuscitator should be the
individual who monitors the RFM during a resuscitation
Conclusions
• Resuscitating a Newly Baby is a Dynamic process- one shoe does not fit all cases.
• Establishing FRC in the apneic baby may require using PEEP or prolonging the IT
or a combination of both.
• A RFM maybe useful as an adjunct is some cases when it is unclear whether
ventilation is effective.