Neonatal Life Support
Octubre - 2020
II.- INITIAL ASSESSMENT AND INTERVENTION
1.-
Warming Adjuncts (NLS 599: EvUp)
Maintenance of normal temperature is a key initial step in stabilization
of the newborn at birth. There are multiple strategies to prevent
hypothermia of the newborn. The NLS Task Force published the most recent
CoSTR summarizing the evidence supporting warming adjuncts in
2015.1,9,10 In 2020, the NLS Task Force undertook an EvUp to identify
any additional studies that would warrant consideration of a new SysRev.
Population, Intervention, Comparator, Outcome, Study Design, and Time Frame
Population: Preterm neonates less than 32 weeks’ gestational age who are under radiant warmers in the hospital delivery room
Intervention: Increased room temperature, thermal mattress, or another warming adjunct
Comparator: Compared with plastic wraps alone
Outcome21:
Primary: Hypothermia (less than 36.0ºC) on admission to neonatal intensive care unit (NICU)
Secondary:
Survival (critical)
Morbidities associated with hypothermia (important)
Hyperthermia and associated morbidities (important)
The EvUp (see Supplement Appendix C-2) identified 13 studies (5 SysRevs and 8 RCTs) supporting the 2015 CoSTR.1,9,10 Although the 2015 treatment recommendations were limited to very preterm babies born at less than 33 weeks’ gestational age, the recommendations remain relevant. The task force agreed to suggest the need for a SysRev on the topic of warming adjuncts in the near future. The task force also suggests division of the target populations to separately analyze effects and pertinent outcomes for term versus preterm infants.
Treatment Recommendation
These treatment recommendations (below)
are unchanged from 2015.1,9,10
Among newborn preterm infants of less than 32 weeks’ gestation under
radiant warmers in the hospital delivery room, we suggest using a
combination of interventions that may include environmental temperature
23°C to 25°C, warm blankets, plastic wrapping without drying, cap, and
thermal mattress to reduce hypothermia (temperature less than 36.0°C) on
admission to NICU (weak recommendation, very low-certainty evidence). We
suggest that hyperthermia (greater than 38.0°C) be avoided because it
introduces potential associated risks (weak recommendation, very low-certainty
evidence).
2.- Suctioning of Clear Fluid (NLS 596:ScopRev)
Rationale for Review
Transition from an intrauterine
(fetal) to an extrauterine (newborn) physiology involves the replacement
of lung liquid in the airways with air. To support liquid
clearance, oropharyngeal/nasopharyngeal suctioning at birth was
traditionally used to remove oral and nasal secretions in vigorous
infants at birth. The 2010 CoSTR for NLS suggested against this routine
practice for the first time.12–14 Similarly, the 2015 American Heart
Association Guidelines Update for CPR and ECC for neonatal resuscitation
emphasized that “suctioning immediately after birth, whether with a bulb
syringe or suction catheter, may be considered only if the airway
appears obstructed or if PPV is required.”22 The balance of risks and
benefits associated with routine suctioning remain controversial.
Because this literature has not been systematically reviewed in over a
decade, the task force agreed that a ScopRev would determine if there is
sufficient evidence published after 2010 to warrant a new SysRev in the
near future.
Population, Intervention,
Comparator, Outcome, Study Design, and Time Frame
Population: Newborns delivered through clear amniotic fluid
Intervention: Immediate routine suctioning (oropharyngeal or nasopharyngeal)
Comparator: No suctioning or wiping
Outcome21:
Survival (critical)
Need for delivery room resuscitation and stabilization interventions (important)
Oxygen supplementation, use of PPV, intubation, CPR/medications, Apgar scores, time to reach heart rate greater than 100/min (important)
Complications following procedure (desaturation, delay in initiation of PPV, tissue injury, infection)
Respiratory complications (respiratory distress, tachypnea) (important)
Other inpatient morbidities (important)
Study design: RCTs and nonrandomized studies (non-RCTs, interrupted times series, controlled before-and-after studies, cohort studies) were eligible for inclusion
Time frame: All years and languages were included if there was an English abstract; unpublished studies (eg, conference abstracts, trial protocols) were excluded. Literature search was updated to November 30, 2019.
Summary of Evidence
Evidence supporting potential benefits of oropharyngeal/nasopharyngeal
suctioning is limited and the practice remains controversial.
Oropharyngeal suctioning
does not impact liquid removal from the lung.
The procedure can have serious side effects.
It is possible that nasopharyngeal suctioning may result in vagal-induced bradycardia as well as increased risk of infection.23
The procedure may take significant time to complete.24
Suctioning may delay initiation of ventilation in nonbreathing infants.3
Newborns who received suctioning compared with a control group had significantly lower oxygen saturation through the first 6 minutes of life and took longer to reach a normal saturation range.24,25
There is a concern that suctioning may have serious additional consequences, such as irritation to mucous membranes and increased risk of iatrogenic infection,26,27 bradycardia,26,28 apnea,28 hypoxemia and arterial oxygen desaturation,25,27,29 hypercapnia, 30 impaired cerebral blood flow regulation,31,32 increased intracranial pressure,33 and development of subsequent neonatal brain injury.34
The entire ScopRev can be found in Supplement Appendix B-2.
Task Force Insights
The NLS Task Force noted several strengths and limitations of the evidence identified by the ScopRev :
The identified studies were from diverse geographical areas, but the results were similar.
The literature identified by this ScopRev allowed comparisons in 2 types of subgroups (vaginal versus cesarean delivery and preterm versus term infants).
Most new studies appear to be consistent with the current recommendation of “no routine suctioning” of the newborns in the delivery room.
Because of the large number of patients (greater than 1500) reported in studies published since 2015, a new SysRev including these patients is likely to increase the certainty of the evidence through GRADE evaluation.
The NLS Task Force suggests consideration of an updated SysRev for this PICO question: “Among vigorous infants delivered through clear amniotic fluid (P), does immediate routine suctioning (oropharyngeal or nasopharyngeal) (I) compared with no suctioning or wiping C) change outcome (O)?” Until such a SysRev is completed and analyzed, the current 2010 treatment recommendation remains.12–14
Treatment Recommendation
This treatment recommendation (below) is unchanged from 2010.12–14
Routine intrapartum oropharyngeal and nasopharyngeal suctioning for
newborn infants with clear or meconium- stained amniotic fluid is no
longer recommended.
3.- Tracheal Intubation and Suction of Nonvigorous Meconium-Stained Newborns (NLS 865: SysRev)
Meconium-stained amniotic fluid is present in 5% to
15% of all deliveries and is more common in neonates
who are nonvigorous at birth.35,36 Approximately 3%
to 5% of neonates born through meconium-stained
amniotic fluid develop meconium aspiration syndrome
(MAS), which remains a significant cause of neonatal
morbidity and mortality, particularly in developing countries. 37 Optimal management of neonates born through
meconium-stained amniotic fluid remains a topic of debate.
For decades, routine intubation and endotracheal
suctioning for nonvigorous, meconium-exposed neonates
was suggested on the basis of extremely low-certainty
evidence. In 2015, after publication and analysis
of new (although limited) randomized trial data, the NLS
Task Force changed the treatment recommendation to
eliminate routine tracheal intubation and suctioning for
nonvigorous meconium-stained infants.1,9,10
Additional studies have been published since 2015,
prompting the NLS Task Force to complete a new SysRev with meta-analysis.37
Population, Intervention,
Comparator, Outcome, Study Design, and Time Frame
Population: Nonvigorous infants born at 34 weeks’ or greater gestation delivered through meconiumstained amniotic fluid (of any consistency) at the start of resuscitation (nonvigorous defined as heart rate less than 100/min, decreased muscle tone, and/or depressed breathing at delivery)
Intervention: Immediate laryngoscopy with or without intubation and suctioning
Comparator: Immediate resuscitation without direct laryngoscopy at the start of resuscitation
Outcome21:
Primary
Survival to hospital discharge (critical)
Secondary
Neurodevelopmental impairment (critical)
MAS (critical)
Other respiratory outcomes (continuous positive airway pressure or mechanical ventilation, treatment of pulmonary hypertension with inhaled nitric oxide, oral medications or extracorporeal membrane oxygenation) (important)
Delivery room interventions (CPR/medications, intubation for PPV) (important)
Length of hospitalization (important)
Study design: RCTs and nonrandomized studies (non-RCTs, interrupted time series, controlled before-and-after studies, and cohort studies) were included in the review.
Time frame: All years and languages were included if there was an English abstract; unpublished studies (eg, conference abstracts, trial protocols) and animal studies were excluded. The literature search was updated to May 2019.
A Priori Subgroups to Be Examined
Consistency of meconium (thin versus thick), gestational age categories
(late preterm [34 weeks to 36 weeks and 6 days], term [37 weeks to 41
weeks and 6 days],
postterm [42 weeks or greater]), presence or absence of fetal bradycardia, route of
delivery (spontaneous
vaginal, instrumented vaginal, cesarean delivery), direct
laryngoscopy with versus without suctioning.
International Prospective Register of Systematic Reviews
(PROSPERO) Registration: CRD42019122778
Consensus on Science
The SysRev identified 4 eligible studies that included
680 newborn infants.37 Data from 3 RCTs involving 449
newborns38–40 and 1 observational study involving 231
newborn infants41 were included.
A draft CoSTR document based on the SysRev was
posted on the ilcor.org website for a 2-week public commenting
period. During this period, the draft CoSTR was
viewed over 5600 times and 65 comments were provided;
most comments were very positive. However, there were
concerns about clarity, which the task force subsequently
addressed. Suggestions made were used to modify the
wording of the treatment recommendations, justification
and evidence-to-decision framework highlights, and the
knowledge gaps to improve clarity. Although these treatment
recommendations do not preclude the use of carefully
considered clinical judgment for individual cases, the
NLS Task Force cannot use unpublished, personal observations
to inform an international consensus on science
or to guide treatment recommendations.
For the critical primary outcome of survival to discharge,
we identified low-certainty evidence (downgraded
for inconsistency and imprecision) from 3
RCTs38–40 involving 449 nonvigorous newborns delivered
through meconium-stained amniotic fluid
which showed no benefit from the use of immediate
laryngoscopy with or without tracheal suctioning
when compared with immediate resuscitation without
laryngoscopy (relative risk [RR], 0.99; 95% CI,
0.93–1.06; P=0.87); absolute risk reduction, –0.9%;
(95% CI, –6.4% to 5.5%), or 9 fewer patients/1000
survived to discharge with the intervention (95% CI,
64 fewer to 55 more patients per 1000 survived to
discharge with the intervention). For complete data,
see Table 1.
Table 1.- Meta-analysis of RCTs of Immediate Laryngoscopy With or Without Tracheal Suctioning Versus Immediate Resuscitation Without Laryngoscopy for Nonvigorous Infants Born at 34 Weeks’ or Greater Gestation and Delivered Through Meconium-Stained Amniotic Fluid .
For the remainder of the outcomes of interest (eg,
neurodevelopmental impairment (NDI), hypoxic-ischemic
encephalopathy (HIE), MAS, use of mechanical
ventilation, use of respiratory support excluding mechanical
ventilation, endotracheal intubation for PPV
in the delivery room, chest compressions in the delivery
room, use of epinephrine in the delivery room,
treatment of pulmonary hypertension, and length
of hospitalization), evidence of very low certainty
(downgraded for risk of bias, indirectness, and imprecision)
showed no benefit from the use of immediate
laryngoscopy with or without tracheal suctioning
compared with immediate resuscitation without
laryngoscopy for nonvigorous newborns delivered
through meconium-stained amniotic fluid (Table 1).
The neurodevelopmental assessment from the single
study that reported this outcome was performed at
an early and nonstandard time, hence the results are
poorly predictive of longer-term outcomes. Therefore,
the task force concluded that the effect on NDI of immediate
laryngoscopy with or without suctioning remains
uncertain.
In 2015, the treatment recommendation indicated
that there was insufficient human evidence to continue
to suggest routine suctioning of meconium in nonvigorous
babies born through meconium-stained amniotic
fluid.1,9,10 This new 2020 recommendation is more direct in its suggestion against this practice.
Treatment Recommendations
For nonvigorous newborn infants delivered through meconium-stained amniotic fluid, we suggest against routine immediate direct laryngoscopy with or without tracheal suctioning compared with immediate resuscitation without direct laryngoscopy (weak recommendation, low-certainty evidence).
Meconium-stained amniotic fluid remains a significant risk factor for receiving advanced resuscitation in the delivery room. Rarely, an infant may require intubation and tracheal suctioning to relieve airway obstruction.
Justification and Evidence-to-Decision
Framework Highlights
The task force recognizes that, although the direction
of the treatment recommendation has not changed,
several studies published after 2015 provide additional
evidence to support the recommendation. These studies
contributed new evidence, but the certainty of the
findings remains low or very low because it is difficult
to perform unbiased studies of this clinical question.
Finally, even combining the data from all studies does
not provide sufficient power for certainty as the optimal
information size is still not achieved.
The NLS Task Force considered that the procedure
of laryngoscopy and suctioning with or without tracheal
intubation is invasive and has potential to harm, particularly if
initiation of ventilation is delayed. This, together with the evidence
of no benefit of routine tracheal
suctioning, led the task force to suggest against routine practice of
these interventions. It is possible that the infant born through
meconium-stained fluid will require intubation for resuscitation.
Therefore, trained personnel and equipment for intubation should be
readily available for births where meconium-stained
amniotic fluid is present. If meconium is obstructing the trachea,
suctioning by using an endotracheal tube with a meconium aspirator may
be effective in relieving the obstruction.42,43
See Supplement Appendix A-1 for the evidence-todecision table for this SysRev.
Knowledge Gaps
Priorities for research include the following :
Additional RCTs are needed that focus on nonvigorous infants in a variety of populations, such as where the incidence of MAS is low, and in settings with various levels of healthcare resources.
Do risks or benefits of intubation with tracheal suctioning vary with any subgroup (gestational age, thickness of meconium, operator experience)?
Long-term outcomes are needed in future studies. These include neurodevelopmental, behavioral, or educational assessment, which for future studies should be at or beyond 18 months of age and completed with a validated tool.