CROUP

I. Definition = laryngeo-tracheo-bronchiolitis

II. Causes: parainfluenza, RSV; mostly Spring & Fall

III. Typical clinical presentation:

  1. URI x 2-3d beforehand, then us. 48-72h of:
  2. Fever
  3. Hoarseness
  4. Inspiratory stridor
  5. "Seal-like" cough

n.b. More rapid progression suggests

IV. Differential includes anaphylaxis, foreign body, diphtheria, and bacterial tracheitis, as well as epiglottitis

V. Treatment

  1. "Mist" (humidity)
    1. A traditional treatment for croup
    2. However, in a study in 140 children presenting to an ED with moderate-to-severe croup randomized to 30min of (100% O2 via blow by, which was the "placebo", 40% humidity with 40% oxygen via nebulizer, or 100% humidity with 40% oxygen via nebulizer), there were no sig. diffs. among the groups in severity scores, O2 sat, or RR at 30min; also no diff. in incidence of hospitalizations or eventual tx with steroids or epinephrine (JAMA 295:1274, 2006--JW)
  2. O2 if hypoxemic
  3. Inhaled Beta-agonists
  4. Consider epinephrine if stridorous
  5. Steroids (e.g. Dexamethasone 0.6mg/kg IM x1) may be beneficial
  1. Moderate-to-Severe croup
    1. 198 children 3mo-5yo presenting to an ER with croup and a "croup score" from 2-7 after 15min of "mist therapy" randomized to dexamethasone 0.6mg/kg PO and placebo neb, PO placebo and budesonide 2mg neb, or dex PO & budesonide neb. No sig. difference in mean change in croup score during ER visit, time in ER, return visits to ER, hospitalization, or sx at 1 week. Authors conclude that PO dex is best b/c it's cheapest and easies to give. (JAMA 279:1629, 1998; ref. for croup score is AJDC 132:484, 1978)
    2. 100 kids 4mo-10yo with croup not severe enough to admit randomized to usual care + placebo vs. usual care + dexamethasone 0.15mg/kg PO; no diff. in duration of sx but sig. reduction in need for return visits & subsequent need for hospitalization (BMJ 313:140, 1996-JW)
    3. 144 kids with "moderately severe" croup all got racemic epi then randomized to single dose of steroids: budesonide neb 4mg, dexamethasone IM 0.6mg/kd, or placebo. 71% in placebo group required hospitalization c/w 38% in budesonide group and 23% in dex group. Diff. between tx groups and placebo groups were sig. as were diff. between budesonide and dex groups (NEJM 339:553, 1998--JW)
    4. Oral dexamethasone (0.6mg/kg, max 8mg) ass'd with no diff. in sx or return visits to hospital c/w IM dexamethasone (same dose) at 48-72h in a randomized trial of 277 kids 3mo-12yo with moderate croup (Peds 106:1344, 2000--JW)
  2. Mild croup
    1. In a study of 264 children 6mo-6yo with mild croup randomized to dexamethasone 0.6mg/kg PO x 1 (max 10mg), dexamethasone neb 160ug x 1, vs. placebo, tx failure was seen in sig. fewer of the oral dex kids than the dex neb or placebo groups (4% vs. 16% and 14%, respectively).  Tx failure defined as need for additional steroids or racemic epi (Arch. Ped. Adol. Med. 155:1340, 2001--JW)
    2. 708 children with mild croup of < 72h duration randomized to dexamethasone 0.6mg/kg PO vs. placebo; over 7d, incidence of return visits was sig. lower in steroid group (7.3% vs. 15.3%) as were clinical scores on days 1 and 2 of follow-up (NEJM 351:1306, 2004--JW)
  3. A meta-analysis of 24 studyies of steroids in croup showed sig. reduction in sx with steroids c/w placebo at 6 and 12h but not at 24h; also, steroid recipients had no sig. diff. in hosp. rate but did have sig. briefer ER stays and, if admitted, sig. shorter inpatient stays. (BMJ 319:595, 1999--JW)