A summary of pulmonary causes of peripartum hymoxia

1. Pulmonary causes
of Peripartum
Hypoxia
By/ Islam Ezz Eldin Osman
Assistant lecturer of Anesthesia, intensive care and pain management
Ain Shams University, 2016

2. Introduction
The respiratory system undergoes a number
of anatomic and physiologic changes during
the course of a normal pregnancy.
Some of these changes predispose to
development of several acute pulmonary
disorders.
Pregnancy can also affect the course of some
chronic pulmonary diseases, most notably,
asthma and sarcoidosis.

3. Chronic causes
• Pneumonia
• Bronchial asthma
• Tuberculosis
• Interstitial lung
disease(Sarcoidosis,
Cystic fibrosis,…etc)
Acute causes
• Venous
thromboembolism
• Aspiration Pneumonia
• Amniotic fluid embolism
• ARDS
• Pulmonary edema
• Anesthetic complications
causing hypoxia
• Pneumothorax
Pulmonary causes of Peripartum
Hypoxia

4. Pneumonia
• Although infrequent, it is the most common non-
obstetric infection to cause complications as well as
maternal and fetal mortality in the peripartum
period.
• The most common bacterial pathogens
include Pneumococcus and H.influenzae.
Diagnosis
History taking Clinical signs and
examination
Investigations
(CBC, culture
results, …etc).

5. Pneumonia
Antibiotics (penicillins and cephalosporins
are usually preferred)
Hospitalization , administration of IV
antibiotics, oxygen therapy
In severe cases ICU admission and
possible need for mechanical ventilation.
Management

6. Bronchial Asthma
Some studies
suggest that poor
asthma control
may have an
adverse effect on
pregnancy
decreased birth weight
Preterm Birth
increased rates of neonatal
and maternal mortality
Although the mechanisms for these findings are still unclear,
maternal hypoxia and alkalosis may play a role.

7. Bronchial Asthma
Diagnosis
History or
presence of
typical symptoms
Wheezes
Chest tightness
Cough
Dyspnea
Reversible airway
obstruction on
spirometry

8. Bronchial Asthma
Management
of Asthma
Attention should be paid to preventing fetal
hypoxemia during attacks. Thus, administration of
supplemental oxygen to keep maternal oxygen
saturation greater than 95% is recommended.
Patient education on avoiding triggers for asthma, decresing
frequency of attacks.
Drug therapy including :
1. Reliever medications (short actingβ2agonists).
2. Controller medications ( Corticosteroids, cromolyn
sodium, nedocromil sodium, sustained-release
theophylline, and long-acting β-agonists).

9. Bronchial asthma
Special considerations during labor and
delivery :
It is recommended that stable patients be given their usual
medications during labor and delivery.
If the patient has required chronic oral glucocorticoids, stress doses
of parenteral steroids should be given until 24 hours postpartum to
prevent exacerbations during labor.
Oxytocin is the drug of choice for labor induction, a
PGE2 suppository may be the safest of additional alternatives, since
both methylergonovine and PGF2α have been associated with
bronchospasm and should be avoided.

10. Venous Thromboembolism
• Decreased venous tone and blood
flow in the lower extremities, leading
to venous stasis.
• Compression of the inferior vena cava
and left iliac vein by the uterus,
leading to venous outflow
obstruction and stasis.
• An increase in several clotting factors
and a decrease in fibrinolytic activity,
leading to a hypercoagulable state.
Pregnant
patients are at
increased risk for
thromboembolic
disease for
several reasons

11. Venous Thromboembolism
Symptoms of a DVT include calf pain
and swelling, however some patients
are asymptomatic.
Clinical symptoms of pulmonary
embolism (PE) include the sudden onset
of dyspnea, tachypnea, tachycardia, and
pleuritic chest pain. In massive PE,
arrhythmias, syncope, and
cardiovascular collapse may develop.

12. Venous Thromboembolism
Diagnosis
DVT
Duplex
ultrasound
No fetal exposure to
radiation and contrast
media
However, this method spares iliac
and pelvic veins as well as having
the disadvantage of bias and
operator dependence.
PE
Pulmonary
angiogram
Ventilation
/perfusion
scan

13. Venous ThromboembolismAnticoagulants
• Warfarin is
contraindicated
• Heparin is the
drug of choice
• Low molecular
weight heparin
is a solid
alternative.
Thrombolytictherapy • Pregnancy is a
relative
contraindication to
the use of
thrombolytic
therapy, and these
should be used
only in patients
suffering from
massive PE and
cardiovascular
instability
Venacavalfilter
• The use of vena
cava filters is
indicated for
those patients
who cannot be
anticoagulated or
for those who
have recurrent PE
while on
adequate
anticoagulant
therapy.
Management of DVT and PE

14. Amniotic Fluid Embolism
Amniotic fluid
containing :
o Fetal Debris
o Desquamated
cells
o Meconium
o Lanugo hair
o Mucin
Damaged
fetal
membrane
Disruption of
uterine veins
Amniotic
Fluid
Embolism
Pathogenesis

15. Amniotic Fluid Embolism
Premature rupture of
membranes
Advanced age
Use of uterine stimulants
Multiparity
Meconium staining of amnion
Occurs during / shortly
after delivery
Severe Dyspnea Hypoxemia,
cyanosis
Skin rash may be present
CVS collapse
Seizures, Coma
DIC , ARDS
Sudden onset
Mechanical obstruction of the
pulmonary vasculature
Alveolar capillary leak (ARDS)
secondary to extensive microembolic
insult.
Pulmonary edema due to left
ventricular failure.
Anaphylaxis due to sudden
exposure to fetal antigen
Risk factors Clinical Picture

16. Amniotic Fluid EmbolismDiagnosis
• Mainly by exclusion,
the only sure way of
diagnosis is by cytologic
examination of blood
removed from the
distal lumen of a
pulmonary artery
catheter showing
contents of amniotic
fluid
Treatment
• Largely supportive
Mortality ranges from
80-90 %

17. Aspiration pneumoniaClinicalpicture
•Tachypnea
•Cyanosis
•Hypoxemia
•Hypotension
•Tachycardia
•Bronchospasm
Diagnosis
•Witnessed event
•Suspicion
supported by
radiographic
findings of isolated
or diffuse lung
infiltrates.
Treatment
•Mainly supportive:
•Oxygen
•Bronchodilators
•Ventilation
•Antibiotics should
be started early if
bacterial infection
is suspected

18. Adult Respiratory Distress Syndrome
ARDS is diagnosed on the basis of:
Acute onset (within 1 week of known clinical insult)
Bilateral opacities on CXR (not explained by effusions, collapse, or nodules)
Respiratory failure not fully explained by heart failure or fluid overload (objective
assessment such as echocardiogram recommended)
Severity of ARDS
•Mild: 300 ≥PaO2/FiO2 >200 with PEEP >5 cm H2O
•Moderate: 200 ≥PaO2/FiO2 >100 with PEEP >5 cm H2O
•Severe: 100 ≥PaO2/FiO2 with PEEP >5 cm H2O.

19. Adult Respiratory Distress Syndrome
• Eleminate the cause if possible
• Deliver the baby if patient can tolerate and baby is at
safe gestational age
• Supportive care:
• IV fluids
• Nutritional support
• Antiinflammatories ( steroids)
• Antibiotics
• Cardiovascular support
• Ventilatory support weather invasive or non invasive
• ECMO
Treatment
of ARDS
with
pregnancy

20. Pulmonary edema with pregnancy
Extra pulmonary
causes
Pulmonary
causes
Preeclampsia
Tocolytic pulmonary edema
Cardiogenic pulmonary
edema
Etc…
Advanced pneumonia
Aspiration pneumonia
ARDS
Negative pressure pulmonary
edema

21. Negative pressure pulmonary edema (NPPE)
3 Mechanisms have been incriminated in NPPE
Marked negative
intrathoracic pressure
Increased venous
return
Sudden increase in
pulmonary
microvascular
pressure
Hypoxia and metabolic
acidosis increase
vasoconstriction at the
pre capillary level
Elevation of
pulmonary
microvascular pressure
alters pulmonary
capillary permeability
Acute relief of
obstruction
Dissapearance of
autoPEEP
Negative
intrapulmonary
pressure
Pulmonary Edema

22. Negative pressure pulmonary edema (NPPE)
Stridor
Working accesory
muscles of respiration
Hypoxia and declining
SPO2
Frothy pink sputum
Clinical
Picture
Develops within one
hour, may be delayed
Mainly based on history
of precepitating event.
Chest Xray supports
diagnosis
Diagnosis
o First priority is to releif obstruction and
correct hypoxemia
o Mainainance of airway patency and
supplemental O2
o Diuretics are often administered
o Ventilatory support by non-invasive or
invasive modalities may be required
TreatmentTreatment

23. • Spontaneous pneumothorax rarely occurs during
pregnancy and labor
• Traumatic pneumothorax may occur and needs
prompt evaluation and control
Causes
• Pleuritic chest pain associated with dyspnea,
tachypnea and cyanosis
• Unilateral diminished air entry and limited chest
expansion
Clinical
presentation
• History and clinical examination
• Confirmation by imaging studies if possibleDiagnosis
Pneumthorax

24. Pneumothorax
• Conservative in mild cases, hospitalization,
supplementary O2 and follow up.
• Needle aspiration, needle drainage and chest tube
insertion.
• For patients who have not received definitive
surgical therapy, epidural anesthesia and forceps
assistance are recommended to prevent increased
intrathoracic pressure due to the expulsive efforts
during the second stage of labor and possible
worsening or recurrence of pneumothorax.
Treatment