新生儿呼吸困难
陈 超
复旦大学儿科医院
新生儿科
一位 31岁孕妇,G2P1,怀孕已 29周，孕期检
查正常，今天上午感觉开始宫缩，住院检查，宫
口开 3cm,约每 20分钟一次宫缩，已破膜,并有
低热,37.9OC。
产科医师请新生儿科医师会诊，这位孕妇可能
要早产，怎么处理？
各位医师有什么建议？
? Actions:
– Attempt to delay delivery
? Tocolysis at discretion of obstetrician
– Ensure culture and therapy for possible
chorioamnionitis
– Antenatal corticosteroids
? The single most important neonatal intervention
– Ensure that adequate neonatal resuscitation is
available
– Cooperation between pediatricians and
obstetricians is essential!
A single dose of antenatal corticosteroids is
administered,along with antibiotic therapy
and indomethacin tocolysis,
However,labour continues to progress,
the mother delivers a male infant weighing
1100 grams.
A neonatal resuscitation team is present at the
delivery,Heart rate at delivery was 80 per
minute and the infant initially is apneic,
What actions should the
neonatal team take?
? Actions:
– Suction,drying,stimulation.
– If apneic,bag mask ventilation
? If no response,intubation (3.0 ETT)
– Administer oxygen
– If persistently bradycardic despite adequate
ventilation ? cardiac compressions
? If no response,epinephrine per ETT
– Immediate,skilled resuscitation is essential to
optimize outcomes.
The infant begins to breath regularly in response to
stimulation,the heart rate is now 156.
but he is persistently mildly cyanotic,with mild
intercostal chest retractions and mild grunting
respirations.
What actions should the
neonatal team take now?
What are the likely diagnoses?
? Differential Diagnosis:
– NRDS
– Neonatal sepsis with pneumonia
– Pneumothorax secondary to resuscitation
– Retained fetal lung fluid / transitional respirations
? Actions:
– Begin monitoring of oxygen saturations
? Maintain oxygen saturations 88 – 92%
– Keep NPO and place intravenous line
– Draw blood culture and begin antibiotic therapy
– Assess blood pressure,blood sugar etc
– Observe for 1 – 2 hours
? as long as symptoms remain mild and oxygen <30%
Moderate grunting respirations increase,
respiratory rate is 60 - 70 per minute,
and 0.35 oxygen is required to maintain saturations 91%.
What is your next step?
? Actions:
– Obtain chest radiograph
– Obtain arterial or capillary blood gas
Capillary blood gas in 0.35:
pH 7.29
PaCO2 53 mm Hg
PaO2 78 mm Hg
HCO3 21 mmol
What is your next step?
Has your diagnostic list changed?
? Diagnosis:
– NRDS---Surfactant deficiency
? Low lung volumes
? Air bronchograms
? Reticulo-granular pattern (ground-glass appearance)
– Cannot exclude infection as contributor
Actions:
– Given that symptoms are mild,oxygenation maintained,and blood gas
acceptable,consider CPAP
? Pathophysiology is atelectasis ?ventilation/perfusion mismatch
? Maintain lung volumes with nasopharyngeal CPAP 4 – 6 cm H2O
– Monitor oxygenation,respiratory distress,intermittent blood gas
– Consider transfer if ventilation is not possible at the current institution
Over the next 2 hours,the infant develops marked
intercostal indrawing,respiratory rate is 80 - 100 per
minute,and breath sounds are decreased bilaterally,
0.70 oxygen is required to maintain saturations 89%.
A repeat blood gas shows the following:
What is your next step?
Arterial blood gas in 0.70:
pH 7.19
PaCO2 70 mm Hg
PaO2 49 mm Hg
HCO3 20 mmol
What has happened?
? Assessment:
– Natural history of RDS is to worsen over the first 48 h
– Consider pneumothorax etc
? Actions:
– Transilluminate
– Intubate 3.0 ETT
? Intubation criteria:
– Severe respiratory distress
– PaCO2 > 60
– FiO2 in preterm infant > 60%
– Diagnosis of moderate RDS with availability of surfactant
– Place umbilical arterial line
The infant is intubated uneventfully with a 3.0 ETT,
He is receiving bag mask ventilation in 100% O2 and
has saturations of 99%.
Several mechanical ventilators are available,including
models with intermittent mandatory ventilation,
patient triggered ventilation,and high frequency
oscillatory ventilation.
What ventilatory settings and parameters
will you prescribe?
Which ventilator will you select?
Actions:
– Begin with intermittent mandatory ventilation
? Evidence inadequate for elective high frequency
oscillation and there is a risk of intraventricular
hemorrhage or PVL
? Patient triggered modes are an option,but not necessary
for the current clinical situation
– IMV settings:
? PIP – to move chest (usually 15 – 25 cm H2O)
? PEEP – 4 to 6 cm H2O (never less in RDS!)
? Rate – 40 to 60 breaths per minute
? Ti (inspiratory time) – 0.4 to 0.5 seconds
? Oxygen – to maintain SaO2 88 – 92 %
The infant is placed on IMV,PIP 28 (to achieve
adequate chest excursion),PEEP 5,Rate 60,Ti 0.4,
Saturations are 88% on 0.70 FiO2,The initial
pressure-volume curve is shown in the slide.
What is your next step?
Volume
Pressure
Volume
Pressure
Actions:
? Exogenous surfactant (early rescue)
– O2 requirement > 40% with radiological
evidence surfactant deficiency
– Or,gestational age <29 weeks and
respiratory distress
– Use Survanta 4 ml/kg or Exosurf 5 ml/kg
Following surfactant administration,the infant initially
improves clinically,
Six hours later,IMV settings are PIP 26,PEEP 5,Rate
60,Ti 0.4,FiO2 35%,
There is excellent chest movement and breath sounds are
equal on auscultation,with scattered coarse crackles.
The pressure-volume loop is shown on the next slide,
and a repeat blood gas shows the following:
Do you want to make any changes,or
continue with the current plan?
Arterial blood gas in 0.30:
pH 7.58
PaCO2 26 mm Hg
PaO2 75 mm Hg
HCO3 22 mmol
? Assessment:
– Hyperventilation/overdistention
? Excessive chest movement,hypocarbia
? Risk of acute or chronic lung injury
? Actions:
– Reduce PIP until chest rises gently but not
excessively
? Follow changes on P-V curve
– Reduce rate by 10 then by increments of 5 to
maintain PaCO2 45 to 55 cm H2O
– Repeat blood gas
4 hours later,IMV settings are PIP 19,PEEP 4,Rate 35,
Ti 0.4,FiO2 55%,
The infant has gradually become very active,and
breathing irregularly over and through the ventilator
breaths.
The flow volume and pressure volume loops are shown on
the next slide.
Do you want to make any changes?
? Assessment:
– New diagnosis
? Pneumothorax,abdominal pathology,intracranial
pathology,pain
– ‘Fighting the ventilator’
? Actions:
– Exclude other pathology with physical examination
– Consider patient-triggered ventilation mode like
synchronized IMV or Assist-control.
– Sedation only if no plan to extubate and above
measures are ineffective.
The infant is placed on SIMV mode with pressure
support of 12 cm H20,with otherwise similar settings for
unassisted breaths,PIP 19,PEEP 4,Rate 35,Ti 0.4,FiO2
35% with SaO2 92%,
The new flow-volume and pressure-volume curves are
as follows:
Do you want to make any changes?
While you are waiting for the SIMV ventilator to
be connected,the oxygen saturation falls to
70%,With bag-endotracheal ventilation,it
rises to 86%,but the infant is now requiring
100% inspired oxygen,
What is your next step?
What has happened?
Volume
Pressure
? Assessment:
– Pneumothorax
– Extubation or obstruction of endotracheal tube
– Ventilator failure
? Actions:
? Auscultation
? ETT suctioning
? Laryngoscopy to ensure still intubated
? Transillumination
? Stat chest radiograph
Arterial blood gas in 1.00:
pH 7.10
PaCO2 85 mm Hg
PaO2 54 mm Hg
HCO3 19 mmol
What is your next step?
Chest radiograph confirms
findings on
transillumination.
What is the diagnosis? Why has
this occurred?
? Assessment:
– Tension pneumothorax
? Actions:
? Needle thoracentesis
– 18 gauge catheter in 2nd right intercostal space in mid-clavicular
line
? Followed by chest tube placement
– Right 4th intercostal space in mid-axillary line
? Minimize subsequent pressures,but maintain PEEP
– Use triggered mode,with sedation if necessary
Following placement of a chest tube,chest radiograph
confirms that the pneumothorax is drained,
However,the right lung remains atalectatic,and there is
evidence of pulmonary edema from several boluses of
normal saline given to maintain the blood pressure,
As the infant is now sedated following the chest tube
placement,you restart pressure-control ventilation,
What is your next step?
Arterial blood gas in 1.00:
pH 7.15
PaCO2 78 mm Hg
PaO2 52 mm Hg
HCO3 19 mmol
? Actions
? Begin high frequency oscillatory ventilation
– Indications:
?MAP 11.3
?Air leak requiring lower pressure
?Inadequate carbon dioxide elimination
– Initial settings:
?Use low volume strategy (pre-existing air leak)
?Start MAP 11 cm H20 (same as CMV)
?Amplitude 30
?Frequency 12 /s
?FiO2 to maintain SaO2 88-92%
A chest radiograph is obtained at 2 hours after
beginning HFOV,It shows expansion to 10-11 ribs
bilaterally,
What is your next step?
The infant responds well to weaning and after 24 hours
is on the following settings,MAP 8 cm H20,
amplitude 14 cm H2O,frequency 12 / sec,FiO2 24%.
What is your next step?
? Actions
? Switch to conventional mechanical ventilation
– Possible to extubate from HFOV,but usually attempt
CMV to test gas exchange and respiratory drive
– Given previous problems with asynchrony,try to use
patient triggered mode again (SIMV),with pressure
support for weaning
The ventilator is changed back to an SIMV mode with
the following settings,PIP 22 cm H2O,PEEP 4,PS
14,rate 25,FiO2 31%,
Your student asks what changes should be made.
What is your next step?
? Actions
? Begin to wean using pressure support
– Drop rate,pressure as for IMV
– Decrease pressure support in decrements of 1-2
cm H20
The SIMV/PS settings are slowly weaned to the
following,PIP 14 cm H2O,PEEP 4,PS 8,rate
10,FiO2 26%,
Your student suggests that the ventilator rate be
turned off and the infant given only
endotracheal CPAP.
What is your next step?
? Assessment:
– Current ventilatory settings are suitable for extubation:
? PIP <18,rate <15,FiO2 <30%,normal blood gas
– Use of endotracheal CPAP without pressure or volume
support is avoided
? High resistance of endotracheal tube leads to respiratory
fatigue and higher extubation failure rate
? Actions:
? Extubate from current settings
? Follow clinical examination,oxygen saturations
? No need for post-extubation chest radiograph or gas unless
clinical deterioration
Following extubation,the oxygen requirements rise
to 40%,You request a repeat chest radiograph and
blood gas:
What is your next step?
Arterial blood gas in 0.40:
pH 7.32
PaCO2 54 mm Hg
PaO2 63 mm Hg
HCO3 24 mmol
What is the diagnosis?
? Assessment:
– Right lower lobe atelectasis following extubation
? Actions:
? Chest physiotherapy
? Non-invasive (naso-pharyngeal) CPAP
After 2 more days on naso-pharyngeal CPAP,the infant
is successfully transitioned to room air,
Nasogastric feeds started the day prior to extubation are
tolerated well,
The infant is discharged home after 6 weeks in hospital.
陈 超
复旦大学儿科医院
新生儿科
一位 31岁孕妇,G2P1,怀孕已 29周，孕期检
查正常，今天上午感觉开始宫缩，住院检查，宫
口开 3cm,约每 20分钟一次宫缩，已破膜,并有
低热,37.9OC。
产科医师请新生儿科医师会诊，这位孕妇可能
要早产，怎么处理？
各位医师有什么建议？
? Actions:
– Attempt to delay delivery
? Tocolysis at discretion of obstetrician
– Ensure culture and therapy for possible
chorioamnionitis
– Antenatal corticosteroids
? The single most important neonatal intervention
– Ensure that adequate neonatal resuscitation is
available
– Cooperation between pediatricians and
obstetricians is essential!
A single dose of antenatal corticosteroids is
administered,along with antibiotic therapy
and indomethacin tocolysis,
However,labour continues to progress,
the mother delivers a male infant weighing
1100 grams.
A neonatal resuscitation team is present at the
delivery,Heart rate at delivery was 80 per
minute and the infant initially is apneic,
What actions should the
neonatal team take?
? Actions:
– Suction,drying,stimulation.
– If apneic,bag mask ventilation
? If no response,intubation (3.0 ETT)
– Administer oxygen
– If persistently bradycardic despite adequate
ventilation ? cardiac compressions
? If no response,epinephrine per ETT
– Immediate,skilled resuscitation is essential to
optimize outcomes.
The infant begins to breath regularly in response to
stimulation,the heart rate is now 156.
but he is persistently mildly cyanotic,with mild
intercostal chest retractions and mild grunting
respirations.
What actions should the
neonatal team take now?
What are the likely diagnoses?
? Differential Diagnosis:
– NRDS
– Neonatal sepsis with pneumonia
– Pneumothorax secondary to resuscitation
– Retained fetal lung fluid / transitional respirations
? Actions:
– Begin monitoring of oxygen saturations
? Maintain oxygen saturations 88 – 92%
– Keep NPO and place intravenous line
– Draw blood culture and begin antibiotic therapy
– Assess blood pressure,blood sugar etc
– Observe for 1 – 2 hours
? as long as symptoms remain mild and oxygen <30%
Moderate grunting respirations increase,
respiratory rate is 60 - 70 per minute,
and 0.35 oxygen is required to maintain saturations 91%.
What is your next step?
? Actions:
– Obtain chest radiograph
– Obtain arterial or capillary blood gas
Capillary blood gas in 0.35:
pH 7.29
PaCO2 53 mm Hg
PaO2 78 mm Hg
HCO3 21 mmol
What is your next step?
Has your diagnostic list changed?
? Diagnosis:
– NRDS---Surfactant deficiency
? Low lung volumes
? Air bronchograms
? Reticulo-granular pattern (ground-glass appearance)
– Cannot exclude infection as contributor
Actions:
– Given that symptoms are mild,oxygenation maintained,and blood gas
acceptable,consider CPAP
? Pathophysiology is atelectasis ?ventilation/perfusion mismatch
? Maintain lung volumes with nasopharyngeal CPAP 4 – 6 cm H2O
– Monitor oxygenation,respiratory distress,intermittent blood gas
– Consider transfer if ventilation is not possible at the current institution
Over the next 2 hours,the infant develops marked
intercostal indrawing,respiratory rate is 80 - 100 per
minute,and breath sounds are decreased bilaterally,
0.70 oxygen is required to maintain saturations 89%.
A repeat blood gas shows the following:
What is your next step?
Arterial blood gas in 0.70:
pH 7.19
PaCO2 70 mm Hg
PaO2 49 mm Hg
HCO3 20 mmol
What has happened?
? Assessment:
– Natural history of RDS is to worsen over the first 48 h
– Consider pneumothorax etc
? Actions:
– Transilluminate
– Intubate 3.0 ETT
? Intubation criteria:
– Severe respiratory distress
– PaCO2 > 60
– FiO2 in preterm infant > 60%
– Diagnosis of moderate RDS with availability of surfactant
– Place umbilical arterial line
The infant is intubated uneventfully with a 3.0 ETT,
He is receiving bag mask ventilation in 100% O2 and
has saturations of 99%.
Several mechanical ventilators are available,including
models with intermittent mandatory ventilation,
patient triggered ventilation,and high frequency
oscillatory ventilation.
What ventilatory settings and parameters
will you prescribe?
Which ventilator will you select?
Actions:
– Begin with intermittent mandatory ventilation
? Evidence inadequate for elective high frequency
oscillation and there is a risk of intraventricular
hemorrhage or PVL
? Patient triggered modes are an option,but not necessary
for the current clinical situation
– IMV settings:
? PIP – to move chest (usually 15 – 25 cm H2O)
? PEEP – 4 to 6 cm H2O (never less in RDS!)
? Rate – 40 to 60 breaths per minute
? Ti (inspiratory time) – 0.4 to 0.5 seconds
? Oxygen – to maintain SaO2 88 – 92 %
The infant is placed on IMV,PIP 28 (to achieve
adequate chest excursion),PEEP 5,Rate 60,Ti 0.4,
Saturations are 88% on 0.70 FiO2,The initial
pressure-volume curve is shown in the slide.
What is your next step?
Volume
Pressure
Volume
Pressure
Actions:
? Exogenous surfactant (early rescue)
– O2 requirement > 40% with radiological
evidence surfactant deficiency
– Or,gestational age <29 weeks and
respiratory distress
– Use Survanta 4 ml/kg or Exosurf 5 ml/kg
Following surfactant administration,the infant initially
improves clinically,
Six hours later,IMV settings are PIP 26,PEEP 5,Rate
60,Ti 0.4,FiO2 35%,
There is excellent chest movement and breath sounds are
equal on auscultation,with scattered coarse crackles.
The pressure-volume loop is shown on the next slide,
and a repeat blood gas shows the following:
Do you want to make any changes,or
continue with the current plan?
Arterial blood gas in 0.30:
pH 7.58
PaCO2 26 mm Hg
PaO2 75 mm Hg
HCO3 22 mmol
? Assessment:
– Hyperventilation/overdistention
? Excessive chest movement,hypocarbia
? Risk of acute or chronic lung injury
? Actions:
– Reduce PIP until chest rises gently but not
excessively
? Follow changes on P-V curve
– Reduce rate by 10 then by increments of 5 to
maintain PaCO2 45 to 55 cm H2O
– Repeat blood gas
4 hours later,IMV settings are PIP 19,PEEP 4,Rate 35,
Ti 0.4,FiO2 55%,
The infant has gradually become very active,and
breathing irregularly over and through the ventilator
breaths.
The flow volume and pressure volume loops are shown on
the next slide.
Do you want to make any changes?
? Assessment:
– New diagnosis
? Pneumothorax,abdominal pathology,intracranial
pathology,pain
– ‘Fighting the ventilator’
? Actions:
– Exclude other pathology with physical examination
– Consider patient-triggered ventilation mode like
synchronized IMV or Assist-control.
– Sedation only if no plan to extubate and above
measures are ineffective.
The infant is placed on SIMV mode with pressure
support of 12 cm H20,with otherwise similar settings for
unassisted breaths,PIP 19,PEEP 4,Rate 35,Ti 0.4,FiO2
35% with SaO2 92%,
The new flow-volume and pressure-volume curves are
as follows:
Do you want to make any changes?
While you are waiting for the SIMV ventilator to
be connected,the oxygen saturation falls to
70%,With bag-endotracheal ventilation,it
rises to 86%,but the infant is now requiring
100% inspired oxygen,
What is your next step?
What has happened?
Volume
Pressure
? Assessment:
– Pneumothorax
– Extubation or obstruction of endotracheal tube
– Ventilator failure
? Actions:
? Auscultation
? ETT suctioning
? Laryngoscopy to ensure still intubated
? Transillumination
? Stat chest radiograph
Arterial blood gas in 1.00:
pH 7.10
PaCO2 85 mm Hg
PaO2 54 mm Hg
HCO3 19 mmol
What is your next step?
Chest radiograph confirms
findings on
transillumination.
What is the diagnosis? Why has
this occurred?
? Assessment:
– Tension pneumothorax
? Actions:
? Needle thoracentesis
– 18 gauge catheter in 2nd right intercostal space in mid-clavicular
line
? Followed by chest tube placement
– Right 4th intercostal space in mid-axillary line
? Minimize subsequent pressures,but maintain PEEP
– Use triggered mode,with sedation if necessary
Following placement of a chest tube,chest radiograph
confirms that the pneumothorax is drained,
However,the right lung remains atalectatic,and there is
evidence of pulmonary edema from several boluses of
normal saline given to maintain the blood pressure,
As the infant is now sedated following the chest tube
placement,you restart pressure-control ventilation,
What is your next step?
Arterial blood gas in 1.00:
pH 7.15
PaCO2 78 mm Hg
PaO2 52 mm Hg
HCO3 19 mmol
? Actions
? Begin high frequency oscillatory ventilation
– Indications:
?MAP 11.3
?Air leak requiring lower pressure
?Inadequate carbon dioxide elimination
– Initial settings:
?Use low volume strategy (pre-existing air leak)
?Start MAP 11 cm H20 (same as CMV)
?Amplitude 30
?Frequency 12 /s
?FiO2 to maintain SaO2 88-92%
A chest radiograph is obtained at 2 hours after
beginning HFOV,It shows expansion to 10-11 ribs
bilaterally,
What is your next step?
The infant responds well to weaning and after 24 hours
is on the following settings,MAP 8 cm H20,
amplitude 14 cm H2O,frequency 12 / sec,FiO2 24%.
What is your next step?
? Actions
? Switch to conventional mechanical ventilation
– Possible to extubate from HFOV,but usually attempt
CMV to test gas exchange and respiratory drive
– Given previous problems with asynchrony,try to use
patient triggered mode again (SIMV),with pressure
support for weaning
The ventilator is changed back to an SIMV mode with
the following settings,PIP 22 cm H2O,PEEP 4,PS
14,rate 25,FiO2 31%,
Your student asks what changes should be made.
What is your next step?
? Actions
? Begin to wean using pressure support
– Drop rate,pressure as for IMV
– Decrease pressure support in decrements of 1-2
cm H20
The SIMV/PS settings are slowly weaned to the
following,PIP 14 cm H2O,PEEP 4,PS 8,rate
10,FiO2 26%,
Your student suggests that the ventilator rate be
turned off and the infant given only
endotracheal CPAP.
What is your next step?
? Assessment:
– Current ventilatory settings are suitable for extubation:
? PIP <18,rate <15,FiO2 <30%,normal blood gas
– Use of endotracheal CPAP without pressure or volume
support is avoided
? High resistance of endotracheal tube leads to respiratory
fatigue and higher extubation failure rate
? Actions:
? Extubate from current settings
? Follow clinical examination,oxygen saturations
? No need for post-extubation chest radiograph or gas unless
clinical deterioration
Following extubation,the oxygen requirements rise
to 40%,You request a repeat chest radiograph and
blood gas:
What is your next step?
Arterial blood gas in 0.40:
pH 7.32
PaCO2 54 mm Hg
PaO2 63 mm Hg
HCO3 24 mmol
What is the diagnosis?
? Assessment:
– Right lower lobe atelectasis following extubation
? Actions:
? Chest physiotherapy
? Non-invasive (naso-pharyngeal) CPAP
After 2 more days on naso-pharyngeal CPAP,the infant
is successfully transitioned to room air,
Nasogastric feeds started the day prior to extubation are
tolerated well,
The infant is discharged home after 6 weeks in hospital.
