Asthma Flashcards
How does pregnancy affect the respiratory system?
Compensated respiratory alkalosis, incr in O2 demand, decreased FRC and TLC, respiratory rate remains unchanged
Ddx: FEV1
What is mild intermittent asthma?
FEV1>80%, well-controlled, less than 2 episodes/week. Use SABA like albuterol
What is mild persistent asthma?
> 2 episodes/week but NOT daily. FEV1>80%, use low dose steroids: pulmicort (budesonide), flovent (fluticasone) and prn albuterol
What is moderate persistent asthma?
daily sx, nocturnal sx>1/week. Limitations in nl activity. 60-80%. Medium low dose steroids (incr puffs, use 3-6 puffs), LABA (salmeterol)
What is severe persistent asthma?
continuous sx. Limits activity. Peak <65%. High dose steroids (solumedrol) and oral steroids.
When would you discharge patient home after asthma exacerbation?
If peak expiratory flow >70%, 60 min after last tx w/ no distress
What are indications for ICU admission and intubation?
- signs of respiratory distress
- Inability to maintain O2>92% despite HFNC, PO2<60, PCO2>45, pH<7.35, RR >30-40, maternal exhaustion, AMS.
- If recently received oral steroids, need IV hydrocortisone q8 to avoid adrenal crisis.
How do you counsel on asthma in pregnancy?
Depends on asthma severity. Mild=good outcomes. severe/poorly controlled: incr prematurity, need for CS, FGR, maternal morbidity.
What are effects of pregnancy on asthma?
Mild asthma: exacerbation of 12%, hospitalization 2%
Moderate asthma: exacerbation 25% and hospitalization 7%
Severe asthma: 51% and hospitalization 26%
Symptoms variable during pregnancy, can improve or stay the same
suboptimal control associated with incr maternal/fetal risk. Incr risk low birth weight and prematurity.
How do you diagnose asthma?
Sx: wheezing, chest cough, SOB, triggers (allergens, exercise, infections), wheezing on auscultation supports diagnosis.
Formal ddx: spirometry demonstrating airway obstruction that is partially reversible (>12% incr in FEV1 after bronchodilator). If clinically seems like asthma but can’t demonstrate reversible airway obstruction, can do trial of asthma therapy. If positive response, it’s asthma.
Differential diagnosis of respiratory sx during pregnancy?
Dyspnea of pregnancy, GERD, chronic cough from postnatal drip, bronchitis.
Dyspnea of pregnancy vs. asthma: DOP has lack of cough, wheezing, airway obstruction
How to assess pts with asthma during pregnancy?
Routine eval of pulmonary function. Spirometry preferable. Worsening sx evaluated w/ peak flow measurements. Identify prior hospitizatlions, iCU admissions, intubations, oral corticsteroid requirements. And effect of prior pregnancy on asthma control.
What is rescue therapy for asthma during pregnancy?
albuterol=1st choice. Short acting B2 agonist.
- mechanism of action: bronchial smooth muscle relaxation and inhibiting immediate hypersensitivity mediator release, particularly from mast cells
- Up to 2 treatments at 20 min interval. Counsel on use: when have exacerbation of sx (cough, chest tightness, dyspnea, wheezing).
What is add-on controller therapy? When is it added?
LABA (long-acting B2 agonist): when not controlled with use of medium-dose inhaled corticosteroids. Salmeterol and Formoterol.
How do you manage asthma?
Mild intermittent: albuterol as needed
Mild persistent: albuterol prn + ICS (Preferred ICS=budesonide. alternative is cromolyn, leukotriene-R antagonist or theophylline- bronchodilator)
Mod persistent: ICS + LABA (Salmeterol or Formeterol)
Severe persistent: high-dose ICS + LABA (salmeterol) + oral corticosteroid. Alternative: high dose iCS + theophylline + oral corticosteroid.
