Respiratory Flashcards
Structural pulmonary adaptations in pregnancy
- As uterus enlarges, level of diaphragm elevates to a peak of 4cm @ 37wks
- AP and transverse diameter of thorax and chest circumference increase, and subcostal angle widens.
- Changes allow lung volume and inspiratory capacity to inc by 5-10%
- Total lung capacity preserved throughout pregnancy
URI caused by viruses
- common cold
- otitis media
- sinusitis
- pharyngitis
- bronchitis
- pneumonia
*pregnant women with common cold at inc risk for developing sinusitis and otitis media d/t congestion from hormonal effects on nasal mucosa
Treatment for URI
- Self limiting, generally resolves within 3-10 days
- OTC meds for symptom relief
- Acetaminophen for pain
- Cough suppressants
- Decongestants
- Antihistamines
- Expectorants
Pregnant women with the following should be treated with Antibiotics:
- s/s for 10 days w/o improvement
- severe s/s or temp >102.2 for 3-4 days
- worsening s/s after 5-6 days of improving s/s
Functional pulmonary changes in pregnancy
- Maternal and fetal metabolic needs = increased gas exchange
- RR stays the same
- Increase in tidal volume and resting minute ventilation
- Decreased functional residual capacity
- Progesterone stimulates respiratory drive – increased level of progesterone –> hypothalamus to accept lower level of PCO2 at ~32mmHg (vs. normal 40mmHg) –> this change favors transfer of CO2 from fetus to the mother
- Compensated respiratory alkalosis – Mild hyperventilation to blow off excess CO2 begins in early pregnancy (prevents maternal acidosis) –> pregnant woman feels SOB even without exertion
Sinusitis treatment
- Augmentin and cefzil
- Saline nasal spray or saline nasal irrigation
- short term nasal corticosteroids (beclomethasone)
- intranasal cromolyn sodium
Bronchitis
- URI of large airways and manifests as cough that persists 10-20 days
- Etiology: usually caused by virus and abx therapy not indicated
- Can lead to pneumonia, women who’s s/s worsen or persist should be reevaluated
- Treatment: supportive care and symptom management
Asthma
- Chronic inflammatory airway disease characterized by increased reactions of airway inflammation and bronchoconstriction to multiple stimuli such as allergens, irritants, stress, physical exertion
- Most common lung disease in pregnancy, prevalence 4-8%
- For pregnant women with asthma, 1/3 improve, 1/3 stay the same, 1/3 worsen
Asthma s/s
- wheezing
- coughing, esp that worsens at night
- chest tightness
- SOB
Asthma maternal & fetal complications
- Well controlled asthma not associated with significant risk to mother or fetus
- Magnitude of perinatal risk r/t severity of maternal asthma
Uncontrolled asthma --> Maternal complications -HTN -Preeclampsia -PTL/PTB -Death (rarely)
Fetal complications:
- Stillbirth
- Fetal growth restriction
- Prematurity
- LBW
Asthma evaluation
Differential dx:
- Physiologic dyspnea of pregnancy (but does not have coughing at night, wheezing, chest tightness, or airway obstruction)
- Reactive airway disease
- URI
- Pneumonia
- GERD
- Obtain history of triggers
- Symptom characteristics
- Meds used currently or in the past for s/s relief
- For women with moderate to severe asthma, evaluate respiratory function at time of initial prenatal visit and periodically throughout pregnancy.
- Test peak expiratory flow rate (PEFR) with peak flow meter. Establish baseline when asymptomatic, “personal best” peak flow does not change d/t pregnancy
- People with moderate to severe disease should test peak flow BID
Asthma management
Main goal: prevent hypoxic episodes in mother, which can cause oxygen deprivation in fetus
- Avoid triggers
- Monitor lung function
- Assess severity
- Pharmacologic therapy * vast majority of asthma meds are safe to use in pregnancy and breastfeeding*
- -> then monitor lung function, assess severity, repeat.
- Consider serial growth US and NST’s for pregnant people with moderate to severe asthma during pregnancy
- With intermittent and well-controlled disease, no additional surveillance necessary
Asthma pharmacologic tx
Rescue therapy
- SABA: albuterol, 1-2 inhalations q4-6hrs PRN
- all people with asthma should have albuterol inhaler with them don’t hesitate to refill for people
- Prednisone/other steroids can be rescue therapy
Long term control meds
-Inhaled corticosteroids (ICS) in low, medium, high doses– i.e. budesonide* preferred in pregnancy.
Other ICS: fluticasone, mometasone, triamcinolone, flunisolide,
-Long acting bronchodilators
-Cromolyn, theophylline, leukotriene modifiers
Asthma step-wise treatment
Step 1: mild-intermittent asthma
-short-acting inhaled beta-agonist: albuterol
Step 2: mild-persistent asthma
-daily low-dose inhaled corticosteroid: Budesonide
Step 3: Moderate intermittent asthma
- Daily low-dose ICS + long-acting beta2 agonist PRN
- Medium dose ICS
Step 4: Severe persistent asthma
-Increase ICS and addition of oral corticosteroids considered
Pneumonia Management
Dx:
- CXR
- Flu swab
- ABGs
- Sputum for gram stain and culture
Management: treatment setting by clinical condition, hospital admission generally recommended
Bacterial pneumonia treatment:
- empirical antibiotics– macrolide + beta-lactam
- AVOID quinolones (levofloxacin, gatifloxacin, moxifloxacin)
- If MRSA pneumonia, vanco or linezolid
Viral pneumonia treatment:
- Flu: treat w/ antivirals
- Varicella pneumonia: acyclovir IV, ICU admit
- PJP (HIV+): Bactrim +/- steroids, ART
Pneumonia maternal and fetal risks
Maternal risks:
-no increased prevalence, but increased ICU, intubation and mortality with pregnancy
Fetal risks:
- PPROM
- fetal compromise
Pneumonia prevention
- Pneumococcal vaccine indicated for heart, kidney, liver, lung (including asthma), HIV, cancer, diabetes, smoking, s/p splenectomy, and more
- Probably safe, but not routinely given in pregnancy
Pneumonia causes, s/s
- Etiology: usually bacterial, many causative organisms. Most common pathogens – 1. streptococcus pneumoniae, 2. haemophilus influenzae
- Can occur independently or may follow viruses such as influenza, bronchitis, common cold, varicella, PJP (opportunistic infection in HIV)
- S/s: fever, productive cough, pleuritic chest pain, dyspnea, shaking/chills
Tuberculosis etiology, risk factors
Etiology: mycobacterium tuberculosis
Risk factors: -Born outside of US -elderly -poverty -immunocompromised crowded living quarters (group home, prison)
- Infection is often contained and remains dormant for long periods of time
- Can subsequently cause clinical disease
- Poor pregnancy outcomes w/ untreated active disease, minimal risk with latent disease
TB s/s
- Cough
- minimal sputum
- low grade fever
- hemoptysis
- weight loss
TB testing
Screen everyone at risk: -health care workers -known contact -foreign born PLHIV -working/living in homeless shelter -people w/ substance abuse disorders -detainees and prisoners
Testing:
- PPD
- Interferon-gamma release assays: quantiferon-TB gold or T-SPOT.TB
- if +, eval for active TB with thorough PE and CXR after 1st tri
TB treatment
Latent infection:
- Usually defer tx to postpartum
- Exceptions: new infection, PLHIV
Active infection:
- 4 drug regimen for 2 months (bactericidal phase)
- 4 month isoniazid and rifampin (continuation phase)
- All are compatible with BF
- Treatment is long! Pt needs support
Pulmonary Embolism S/S
- Chest pain
- SOB
- Feeling of apprehension
- Hemoptysis
- Unexplained tachycardia
Risk factors for PE
-Thrombophilia
-Previous thromboembolism
-Obesity
-Parity
-Smoking
-SCD
-Heart disease
-Systemic lupus
Varicose veins
-Immobility
-ART
-Hyperemesis gravidarum
Preeclampsia
Multiple gestation
Postpartum period
PE Dx
Differential dx:
- MI
- Anxiety/panic attack
- Asthma attack
- CHF
- Pneumonia
Dx:
- EKG
- CXR
- V/Q
- CTPA
PE treatment
Low-molecular weight heparin –
Enoxaparin (lovenox): 1 mg/kg SQ BID
