Respiratory problems in Pregnancy

1. Respiratory Problems in
Pregnancy - TB, Pneumonia &
ARDS
Dr Meenakshi Sharma
MD(AIIMS), FICMCH, FICOG
Senior Consultant Yashoda Superspeciality Hospital & Shanti Mukand Hospital

2. Dr Meenakshi Sharma
MBBS(AIIMS), MD (AIIMS), FICMCH, FICOG
● Consultant Obstetrics & Gynaecology, Yashoda Superspeciality Hospitals & Shanti Mukund Hospital , Delhi
● Ex Registrar and Senior Research Associate AIIMS
● Former Specialist Dr Hedgewar Arogya Sansthan, Govt NCT Delhi
Awards
● 2003- Dr RD Pandit research prize for Best thesis by FOGSI
● 2012- Fellowship of Indian College of Maternal & Child Health
● 2017- Dr Abdul Kalam appreciation award from Delhi Gynaecologist Forum
● 2020- Fellowship of Indian College of Obstetrician & Gynaecologists
● 2020- International Women’s Day Excellence Award by DGF & WOW
Jt Secretary Delhi Gynaecologist Forum -East
Publications in International and National Journals, and Scientific Papers Presented in National/International
Conferences
Area of interest - Gynae endoscopy and Vaginal Surgery
Member Affiliated Societies
● AOGD, FOGSI, Delhi Gynaecologist Forum- East, SFM, KMOGS, , Founder Member GESI,

3. Tuberculosis in Pregnancy

4. Effect of Tuberculosis on pregnancy
● Incidence and transmission of TB not affected
● Pregnancy doesn’t alter clinical course of TB
● Untreated Active TB 30-40% mortality in maternal and neonatal
● Fetal risk due to fetal infection, teratogenesis with ATT drugs- marginal
● Disseminated TB associated with adverse outcome
○ Low Birth Weight
○ Preterm Delivery
○ Increased perinatal mortality
M.TB rarely crosses placenta, true congenital TB is extremely rare
WHO Guidelines in for National Programme 2003

5. Management of TB in pregnancy
● TB in reproductive women - ideally delay pregnancy till completion of ATT
● Strongly positive TST should be treated as TB positive case
● All TST positive(even without active TB) women must be screened for HIV
● INH prophylaxis to be administered in pregnancy to TST positive women if
they are HIV positive, had recent exposure to active TB or recent TST
converter
● If diagnosed TB in pregnancy ATT should be started with Pyridoxine 25-50
mg/day to decrease neurotoxicity in mother
● Close monitoring with LFT to look for any hepatic dysfunction

8. Management of TB in pregnancy
Rifampicin, Isoniazid and Pyrazinamide are FDA class C, and Ethambutol FDA
class B and Streptomycin FDA class D
Vitamin K should be given to mother from 36 weeks till delivery (10 mg PO daily)
and to infant at birth to decrease risk of PPH and HDN, in mothers receiving
Rifampicin and Isoniazid
In postpartum, baby must be separated from mother only if mother has infectious
TB (sputum positive with less than 10 days of ATT)
Breastfeeding to be encouraged
BCG vaccination and INH prophylaxis to neonate if mother infectious at birth

10. Criteria of Congenital TB
Confirmed diagnosis of TB in newborn
● Primary granulomatous complexes in neonatal liver
● In absence of neonatal liver lesions, the diagnosis of TB made in the newborn
in few days of birth (to differentiate from postpartum infection)
Congenital TB is highly fatal - 22% mortality even with therapy,-40% without
chemotherapy

12. MDR TB in Pregnancy
Requires toxic Category 4 drugs
If less than 20 weeks offer MTP followed by ATT Rx for MDR TB
If more than 20 weeks or patient refused MTP
• For patients in the first trimester (≤ 12 weeks), kanamycin and ethionamide are omitted
from the Cat IV regimen and PAS is added.
• For patients who have completed the first trimester (>12 weeks), kanamycin is replaced
with PAS. Post partum, PAS may be replaced with kanamycin and continued until the end of
the Intensive Phase.
RNTCP guidelines, 2010

14. Pneumonia in Pregnancy

15. Pneumonia in pregnancy
Incidence 0.8 to 2.7 cases per 1000 deliveries
Respiratory failure occurs in 10% of pregnant women with pneumonia
Risk factors for developing pneumonia in pregnancy are
● HIV infection
● Asthma
● Cystic fibrosis
● Tocolytic therapy and corticosteroid therapy of fetal lung maturity
● Anaemia
● Smoking, cocaine use, alcoholic abuse

16. Clinical features
Abrupt onset fever with chills, productive cough, tachypnoea, tachycardia, chest
pain and localised harsh sounds on inspiration
Respond well to antibiotic therapy
Varicella and influenza pneumonia can be fatal in pregnancy
Women with HIV prone to pneumocystis carinii pneumonia and require close
monitoring

17. Management of pneumonia in pregnancy
Preventive
● Influenza vaccination in pregnancy, pneumococcal vaccination to splenectomy and
immunocompromised patients
● PCP prophylaxis to HIV with low CD4 counts
Chest X ray should be done with abdominal shield to confirm diagnosis
Sputum and blood cultures should be sent prior to antibiotic therapy
Appropriate antibiotics for 10-14 days, O2 Rx to maintain SPO2 >94%
Tetracyclines and fluoroquinolones should be avoided, Varicella pneumonia treated with Acyclovir.
Crit Care Med 2005 & Arias Practical Guide to high risk pregnancy 4th ed, 2015

18. CURB-65 scoring for Community acquired pneumonia in adults
Guides admission to ICU and parenteral antibiotics administration
● Confusion,
● Urea >7 mmol/L,
● Respiratory rate >30/min,
● Blood pressure (systolic <90 mmHg or diastolic <60 mmHg),
● Age >65yrs

19. Antibiotics Rx for Community Acquired Pneumonia
Outpatient Rx
Azithromycin 500mg PO day 1 followed by 250mg PO daily for 4 days
OR
Erythromycin 250mg QID PO 10-14 days

20. Antibiotics Rx for Community Acquired Pneumonia
Inpatient Rx
I/V Betalactum antibiotic plus Macrolide for 48-72 hrs followed by Oral Rx
First choice - I/V Cefotaxime 2 g q8h plus Azithromycin 500 mg qd
Second choice - I/V Ceftriaxone 1 g q12h plus Azithromycin 500 mg qd
Third choice - I/V Co-amoxyclav 1.2 g q8h plus Azithromycin 500 mg qd
Followed by Oral Azithromycin 500mg OD for 7-10 days plus Cefuroxime axetil
500mg PO BD for 10-14 days
Standard Treatment guideline, India

21. Acute Lung Injury /Acute
Respiratory Distress Syndrome

22. Respiratory Failure
Ventilatory Failure Hypoxemic Failure
Severe asthma
PE
Circulatory Shock
Neuromuscular disorders
Pneumonia
Aspiration
Heart failure
ALI/ARDS
Amniotic fluid embolism

23. Definition -ALI/ARDS
Acute onset of hypoxemic respiratory failure characterised by diffuse
pulmonary infiltrates on CXR, severe hypoxemia not responsive to
supplemental oxygen and reduced lung compliance.

24. Diagnostic Criteria for ALI/ARDS
Acute Lung Injury
● Acute onset
● PaO2/FiO2 < 300 regardless of PEEP
● SpO2/FiO2 < 315
● Bilateral infiltrates on the chest
radiograph
● PCWP < 18 mm Hg, or no clinical
evidence of left atrial hypertension
ARDS
● Acute onset
● PaO2/FiO2 < 200 regardless of PEEP
● SpO2/FiO2 < 235
● Bilateral infiltrates on the chest
radiograph
● PCWP < 18 mm Hg, or no clinical
evidence of left atrial hypertension
American European Consensus Conference on ARDS, 1994

25. ALI/ARDS
Incidence - 17.9 -64 per 100,000 person years for ALI -ARDS network clinical trials
Limited data in pregnancy
Incidence of ALI/ARDS in pregnancy is reported as 1 in 6227 deliveries from a
case series of 28 patients study, others also similar number
Catanzarite, V, Willms, D, Wong, D, Landers, C. “Acute respiratory distress syndrome in pregnancy
and the puerperium: causes, courses, and outcomes”. Obstet Gynecol. vol. 97. 2001. pp. 760-4.
Crit Care Med 2010

26. Clinical Features ALI/ARDS
Acute onset tachypnoea and tachycardia
Bilateral crackles or wheezes
With no signs of Left sided heart failure - absent S3, elevated jugular venous
pressure and peripheral edema
CXR diffuse bilateral alveolar &/or interstitial infiltrates without cardiomegaly
CT alveolar lung infiltrates and atelectasis worse in dependent lung zones

27. Differential Diagnosis of ALI/ARDS
Cardiac valvular disease - Mitral Stenosis
Peripartum Cardiomyopathy with pulmonary Edema
Alveolar Haemorrhage - Pulmonary Vasculitis
If Respiratory failure with clear CXR suspect Asthma, Pulmonary embolism,
Amniotic fluid embolism, and neuromuscular disease like Myasthenia gravis

28. Causes of ALI/ARDS in Pregnancy
Incidental to pregnancy/ Non Obstetric
● Sepsis - appendicitis, bacterial pneumonia
● Chemical pneumonitis
● Venous air embolism
Exacerbated or Facilitated by Pregnancy
● Aspiration - Mendelson syndrome
● Sepsis - pyelonephritis, viral pneumonia, listeriosis
● Severe haemorrhage

29. Causes of ALI/ARDS in Pregnancy
Unique to pregnancy/ Obstetric
● Preeclampsia/HELLP Syndrome/ Eclampsia
● Tocolytic induced pulmonary edema
● Amniotic Fluid Embolism
● Placental abruption
● Neurogenic pulm edema after eclamptic seizure
● Sepsis - Chorioamnionitis, endometritis, septic abortion

30. Physiologic changes in pregnancy
Total lung capacity, FRC,expiratory reserve volume and residual volume all
decrease by 4-20% from nonpregnant status
Maternal minute tidal volume increases - 50%
Mild chronic (compensated) respiratory alkalosis
PaCO2 dropping from 35-45 mmHg at baseline to 27-34 mmHg
Renal compensatory response - increase bicarbonate excretion to maintain
normal pH
Serum bicarb 18-21 mEq/L in pregnancy

31. Pathophysiology of ARDS
Increased permeability edema due to defective pulmonary capillary barrier
● Neutrophilic inflammation
● Activation of complement cascade
● Disordered coagulation and fibrosis
● Biomechanical shear toxicity by repeated opening and closure of alveoli
● Oxygen fraction >60% damage healthy lung tissue
Regenerating type 2 alveolar cells do not produce surfactant, abnormal ion
exchange leads to flooded and collapsed airspace affecting gas exchange.

32. ABG in pregnancy - 7.37/30/70
Ph - 7.37
PaCO2 - 30 mmHg
PaO2 - 70 mmHg
PaCo2 of >40 mmHg due to Co2 retention indicates respiratory failure in
Pregnancy esp if RR is high
It is generally accepted that a higher maternal oxygen saturation (>95%,
corresponding to PaO2 > 67) is favorable to optimize maternal oxygen delivery to
the placenta.

33. Workup of ARDS
Sputum and blood culture, Nasal swab for influenza
Biochemistry - CBC, LFT, KFT
ABG
CXRay
ECG & ECHO - to rule out cardiogenic causes of Pulm edema
Coagulation profile esp if aspiration or amniotic fluid embolism suspected
Bronchoscopy and BAL in refractory cases

34. Multidisciplinary Critical care Management
● Obstetrician
● Neonatologist
● Intensivist
● Pulmonary critical care clinician
● Radiologist
Detailed plan regarding fetal monitoring, labor monitoring, acceptable
pharmacotherapy during pregnancy, and contingency plans if delivery is
imminent.

35. Emergency Management of ARDS
Ensure A, B, C.
Airway - Endotracheal intubation if unconscious or severely hypoxemic
Breathing - NIPPV / IPPV to maintain SPO2 > 95%, Bronchodilators if
bronchospasm associated
Circulation - To maintain MAP > 65 mmHg, urine output >0.5 ml.Kg/hr
○ Fluid restriction
○ Vasopressors if hypotension
○ Inotropic support if associated cardiac cause

36. Management of ARDS -Key Points
ICU management with maintaining airway and supplemental Oxygen therapy
Goal of Rx -PaO2> 65mm Hg & SpO2> 95%
Judicious use of diuretics -IV Furosemide 10mg if BP well maintained
Strict Fluid balance to be maintained with restricting fluids, CVP if not responding to
diuretics or cardiac cause. Inotropic support if hemodynamic unstable
Rx underlying cause discontinuing tocolytics, controlling preeclampsia with active efforts to
delivery, pyelonephritis and sepsis by broad spectrum IV antibiotics as per ICU protocol
If oxygenation not maintained Positive pressure Nasal ventilation BIPAP or elective
intubation should be used

37. Mechanical Ventilation in ARDS
Positive pressure ventilation mainstay of supportive therapy
VILLI (Ventilator induced lung injury)- large tidal volume and and high airway
pressure can worsen lung injury in ARDS which is due to alveolar overdistension
with repeated opening and closing of surfactant depleted atelectatic alveoli
VILLI - initiate release of proinflammatory cytokines contributing to systemic
inflammatory response(SIRS), resulting multiorgan failure
A “lung protective” ventilation strategy is used with reduction of pulmonary and
systemic cytokine response

38. Mechanical ventilation in ARDS
Recommendation from ARDS Network trial has become standard of care in
ARDS
● Low tidal volume approach - 6 ml/Kg instead of 12 ml/Kg ideal body wt
● Titrate FiO2 and PEEP and plateau pressures maintained below 30 cm
H2O
● Bicarbonate infusions to correct respiratory acidosis resulting from
controlled hypoventilation caused by low tidal volume ventilation
No trial in Obstetric patients, approach remains similar

39. Mechanical ventilation in obstetric patients with ARDS
Low tidal volume 6 ml/Kg is the goal as proven mortality benefits in non
pregnant patients
Respiratory acidosis is poorly tolerated in pregnancy
Maintain PaCO2 < 45-50 mmHg while ventilating obstetric patients with
ALI/ARDS
Avoid excessive maternal hyperventilation and hypocapnia as associated
with uteroplacental vasoconstriction, fetal hypoxia and acidosis

40. Mechanical Ventilation in ARDS in Pregnancy
Optimize maternal oxygen delivery to the placenta - maternal O2 saturation (>95%,
corresponding to PaO2 > 67)
Fetus and placenta increase resting O2 consumption by 20%, and may double O2
consumption in the setting of active labor and delivery.
Minimizing oxygen consumption by ventilatory support — invasive or non-invasive —
tocolysis or anesthesia (for labor) can have an important effect on maternal (and thus
fetal) oxygenation.

41. NIPPV/ IPPV
NIPPV - limited role only in carefully selected hemodynamically stable patients
with ALI/ARDS with rapid reversible cause for pulmonary edema but requires
close monitoring for aspiration
Intubation is indicated for refractory hypoxemia, ongoing high work of breathing,
airway obstruction, or shock.
Early endotracheal intubation by expert clinician in obstetric airway with
mechanical ventilation will be preferable

42. NIPPV/IPPV
Non-invasive ventilation can be considered for pregnant patients with a high work of
breathing provided the following:
Patient is conscious
Oxygen deficit is modest (FiO2 < 60% to maintain SaO2 > 95%)
Patient’s condition is expected to improve rapidly (< 24 hours)
Patient is not in shock
Patient does not require transfer (ie, for imaging studies or to another healthcare facility)
Patient has adequate ventilatory drive

43. Fluid Management in ARDS
Restricted fluid management
● Improves pulmonary edema and oxygenation
● Decreased cardiac output
● Decreased renal and other organ perfusion
ARDS network Fluid and Catheter Treatment Trial (FACTT) - RCT 100 patients
conservative/liberal fluid management strategy with pulm artery catheterisation (PAC) vs
CVP
● PAC guided therapy not associated with improvement over CVP guided therapy but had
more catheter related complication in PAC guided group
● Conservative fluid strategy was beneficial with improved oxygenation and less
ventilator days

44. FACTT protocol of fluid management
Conservative fluid therapy aims CVP < 4 mmHg or PAOP < 8 mmHg
● Maintain MAP >60 mmHg without vasopressors
● Urine output > 0.5mL/Kg/hr
● Cardiac index >2.5L/min/m2
● Capillary refill <2s
● Absence of cold mottled skin
Similar approach in Obstetric patients to avoid fluid overload with judicious diuresis and
fluid restriction
Critical care parameters should be adhered to maintain uteroplacental perfusion

45. Prone positioning
Prone positioning of non pregnant ventilated patients improved oxygenation in 70-
80% ALI/ARDS. The proposed mechanisms-
● Reduced ventrodorsal pleural pressure gradient
● Removal of effects of compression by heart and mediastinum on dorsal lung
units
● Increased recruitment of atelectatic alveoli
● Increased functional residual capacity due to unsupported abdomen in prone
position
● Better mobilisation of secretions
Difficult in Obstetric patients, left lateral decubitus position preferred

46. Surfactant therapy
Surfactant produced by type 2 alveolar cells is a phospholipid reduces surface
tension and prevent collapse of alveoli
ALI/ARDS leads to atelectasis, gas exchange abnormalities and reduced lung
compliance
Exogenous aerosolized surfactant in adults with ARDS failed to show
improvement in outcomes in large multicenter study but small studies show some
benefit after bronchoscopic instillation of surfactant
Michael A. Belfort, Critical Care Obstetrics fifth edition, published by Wiley Blackwell, 2010

47. Systemic corticosteroids
Anti inflammatory benefit of high dose corticosteroid in late phase
(fibroproliferative) of ARDS improves survival in a small RCT
ARDS Network large multicenter RCT of methylprednisolone started 7 days
after onset of ARDS failed to show improvement in survival but associated
with increased neuromuscular weakness in corticosteroid group so not
recommended
Michael A. Belfort, Critical Care Obstetrics fifth edition, published by Wiley Blackwell, 2010

48. Fetal monitoring and potential effects of maternal ARDS on
Pregnancy
● Fetal distress due to maternal hypoxemia
● Premature Labor triggered by maternal stress
● Fetal exposure to medications used for ARDS
● Interference of maternal therapies with fetal well being assessment
● Fetal assessment limited to fetal doppler auscultation and ultrasound to look
for fetal tone at 24-26 weeks
● Fetal assessment in gestation > 26 weeks by frequent USG especially if
maternal hypoxemia or acidosis and need to deliver if maternal critical care
parameters worsens
Michael A. Belfort, Critical Care Obstetrics fifth edition, published by Wiley Blackwell, 2010

49. Fetal monitoring and potential effects of maternal ARDS on
Pregnancy
● Fetal movements affected by sedatives
● Vasopressors can cause fetal tachycardia
● Preterm labor triggered by maternal stress can worsen maternal hypoxemia
due to increased oxygen demand so tocolysis may be warranted
● Maternal ARDS with viable fetus optimal timing and mode of delivery must be
individualised based on condition of mother and usual obstetric indications
Michael A. Belfort, Critical Care Obstetrics fifth edition, published by Wiley Blackwell, 2010

50. Prognosis of ALI and ARDS
Improved outcome with timely intensive care
Reduction of mortality from 50-68% in 1980s to 30-40% in 1990s using low tidal
volume trial
Sepsis with multiorgan failure is most common cause of death - 30-50% followed
by respiratory failure 13-19%
Data in pregnancy limited, 39% mortality in a series of 28 pregnant women with
ARDS, other studies 30-40%
Michael A. Belfort, Critical Care Obstetrics fifth edition, published by Wiley Blackwell, 2010

51. Scoring System for Predicting outcome and severity in ARDS
Acute Physiology and chronic health evaluation - APACHE 3
Simplified acute physiologic score - SAPS score
Sequential Organ failure assessment - SOFA score
APACHE 2 / 3 is best predictor of mortality in ICU than SAPS 2 & SOFA, but is
more exhaustive

52. APACHE score
APACHE 3 is released in 1991, with improved statistical power and predicting individual
person outcome and identify factors in ICU influencing patient outcome but is more
complex.
Best predictor but exhaustive
● 17 physiological variables with total score 0-299
● Acid Base disturbances
● GCS score based on worst
● Age score
● 7 Co-morbidities -excluding cardiac, respiratory and renal failure

53. APACHE 2
Scoring
system for
ARDS

56. SAPS 2 score
Simplified acute physiologic score initially in 1984, modified in 1993
12 physiological variables in first 24 hours of ICU
Include weightings for previous admission, health status and age
Total score 0-157

58. SOFA score
Sequential Organ failure assessment -previously known as the sepsis-related
organ failure assessment score
Monitor patient progress in ICU
The score is based on six different scores, one each for the respiratory,
cardiovascular, hepatic, coagulation, renal and neurological systems
Normal to most abnormal = 0-4, total score 24
Worst value each day is recorded

59. SOFA score - Critical care medicine 1998

60. Conclusion
● ALI/ARDS can be due to Obstetric causes (Preeclampsia or AF embolism) or
non obstetric causes (Sepsis, trauma, aspiration, severe pancreatitis)
● Management by prompt treatment of underlying cause and supportive care in
ICU
● In absence of pregnancy specific data, managed as per adult ARDS protocol

61. Conclusion
● Mechanical ventilation is mainstay of supportive treatment with low tidal
volume ventilation with attention to maternal PaCO2 and acid base status to
avoid hypercarbia and hyperventilation should be utilized
● Fluid management, appropriate hemodynamic support and implementing
measures to avoid nosocomial infections should be part of routine care
● None of specific therapy like surfactant and corticosteroid have proven
beneficial in ALI/ARDS in Adults