Pocket ObGyn – Influenza / Asthma in Pregnancy

Pocket ObGyn – Influenza / Asthma in Pregnancy
See Abbreviations

Vaccination and Prevention
  • Pregnant women are at ­ risk for sev infxn & death than the general pop (Obstet Gynecol

2010;116:1006)

  • ACOG & the CDC’s Advisory Committee on Immunization Practices recommend that all pregnant women be vaccinated against influenza, regardless of trimester (MMWR 2010;59(rr08)) mat/fetal safety of influenza vaccination in Preg is well established (Am J Obstet Gynecol 2012;207(3 Suppl)). Antepartum vaccination ® decreased stillbirth, neonat death & premature deliv, w/ no ­ in congen anomalies (Obstet Gynecol 2012;120:532).

 

  • Mat vaccination provides passive immunity to the neonate through 6 mo of age (N Engl J Med 2008;359(15):1555). Pregnant women should receive the trivalent inactivated (killed) injection vaccine only, & not the LAIV;
  • Pregnant/postpartum women do not need to avoid contact w/ those who have received Postpartum/breastfeeding women can receive LAIV.
  • Data do not support adverse effects attributable to preservative thimerosal (MMWR 2010;59(rr08)). Preservative eliminated or reduced in most Proven protection against serious dz outweighs theoretical concerns regarding preservative.

Prophylaxis and Treatment (MMWR 2011;60(1):1)

  • Clinical dx is preferred (abrupt onset fever, cough, myalgia) to lab dx for rapid rx
  • Oseltamivir & zanamivir are both Preg Category Zanamivir may be preferable in Preg b/c of limited systemic Absorp, but avoid in pts w/ comorbid respiratory dz. Most effective if £48 h of sx (Obstet Gynecol 2010;115(4):717).
  • For ppx after exposure during Preg or up to 2 w postpartum: Zanamivir 10 mg (2 puffs inhaled) daily

Oseltamivir 75 mg PO daily

Duration: 10 d (household exposure), 14 d (hospital exposure), 7 d (other)

  • For rx w/ onset of sx

Zanamivir 10 mg (2 puffs inhaled) daily ´ 5 d Oseltamivir 75 mg PO twice daily ´ 5 d

Can consider longer rx for severely ill pts

Additional Considerations
  • Women w/ influenza hospitalized on labor & deliv wards should have respiratory precautions per hospital std for influenza
  • Discuss the need for neonat antivirals or mat–neonat separation w/ pediatricians
  • Postpartum, women w/ influenza should express breast milk, rather than Milk may still go to the infant, as oseltamivir is poorly excreted (Int J Infect Dis 2008;12:451).

Asthma and Pregnancy

(Obstet Gynecol 2008;111:457; NIH pub no. 08-4051)

Definitions/Pathophysiology
  • Chronic airway inflammation w/ hyperresponsiveness to various stimuli & partially reversible airway obst
  • Sev cases a/w increased prematurity, cesarean deliv, preeclampsia, growth restriction, & mat morbidity/mortality
  • Mat–fetal pathology caused by mat Decreased FEV1 ® ­ low birth weight/ prematurity.
Diagnosis
  • Wheeze, cough, SOB, chest tightness; fluctuating; often worse at night; worse w/ known triggers (allergens, exercise, infections). Consider GERD, postnasal drip w/ cough, bronchitis in diff
  • Airway obst on spirometry, reversible w/ bronchodilator therapy
  • Document h/o hospitalization, ICU stay, intubation, & steroid Preg may improve,

worsen or have no effect on asthma severity (rule of 1⁄³’s). Past pregnancies may better predict course of subseq pregnancies.

 

Asthma severity classification
 

Severity

Symptom

freq

Nighttime

awakening

Interference

w/ activity

FEV1 or peak

flow (% of best)

Mild

intermittent

<2 d/w <2´/mo None >80
Mild persistent 2–6 d/w >2´/mo Minor >80
Mod persistent Daily >1´/w Some 60–80
Sev persistent All day >4´/w Extreme <60
From Dombrowski MP, Schatz M, ACOG Committee on Practice Bulletins-Obstetrics. ACOG practice bulletin: Clinical management guidelines for obstetrician-gynecologists number 90, February 2008: Asthma in pregnancy. Obstet Gynecol. 2008;111(2 Pt 1):457–464. doi:10.1097/AOG.0b013e3181665ff4.

 

Treatment

 

Asthma management, outpatient therapies
Severity Mgmt
Mild intermittent Short-acting b-agonist (albuterol) as needed
Mild persistent ADD: Low-dose inhaled Cort. Alternative: Cromolyn, leukotriene receptor antag (montelukast), or theophylline.
Mod persistent ADD: Long-acting b-agonist (salmeterol), OR change to mediumdose inhaled Cort ± salmeterol. Alternative: Low-dose or medium-dose inhaled Cort + leukotriene receptor antag or theophylline.
Sev persistent CHANGE to high-dose inhaled Cort + salmeterol ± oral Cort (prednisone). Alternative: High-dose inhaled Cort w/ theophylline ± oral Cort.
From Dombrowski MP, Schatz M, ACOG Committee on Practice Bulletins-Obstetrics. ACOG practice bulletin: Clinical management guidelines for obstetrician-gynecologists number 90, February 2008: Asthma in pregnancy. Obstet Gynecol. 2008;111 (2 Pt 1):457–464. doi:10.1097/AOG.0b013e3181665ff4.
  • Rx for acute asthma exacerbation

Supplemental O2 to maintain sat >95% (important for fetal oxygenation) Albuterol nebulizer q20min ´ 3, then q4h

Consider inhaled ipratropium on presentation (0.5 mg neb/8 puffs MDI) Systemic corticosteroids; prednisone 40–80 mg PO ´ 5–10 d (until PEFR >70%)

•   Triage for acute presentation of asthma in Preg

FEV1 or PEFR >70% after rx, no distress, reassuring fetal status ® discharge FEV1 or PEFR 50–70% after rx ® individualize disposition

FEV1 or PEFR <50% after rx ® hospitalize

If poor resp/sev sx, drowsiness, confusion, pCO2 >40 mmHg consider ICU admission ± intubation

Arrange follow-up w/i 5 d postdischarge

Surveillance During Pregnancy
  • Assess asthma status w/ PEFR at each prenatal visit; adjust maint regimen
  • Prepare Asthma Action Plan & instruct on Eg, www.nhlbi.nih.gov/health/public/ lung/asthma/asthma_actplan.pdf.
  • Focus on avoidance of allergens/irritants (eg, tobacco smoke, GERD, mold, dust mites, dander, cockroaches)
  • Albuterol & budesonide are preferred short-acting b-agonist/inhaled steroid in Preg. Consider weekly fetal testing (NST, AFI, or BPP) from 32–34 w if mod–sev asthma or poor
Intrapartum Considerations
  • Maintain hydration, continue asthma meds, including systemic steroids
  • Consider cesarean deliv if unstable asthma & mature fetus
  • Avoid carboprost tromethamine (Hemabate)
  • ASA, indocin, other NSAIDs can cause asthmatic bronchospasm
  • No contraindication to breastfeeding postpartum for asthma meds above

See Abbreviations