Increasing severity of status asthmaticus in an urban medical intensive care unit

Abstract

BACKGROUND:Life‐threatening status asthmaticus (SA) requiring intensive care is a major concern given the rising prevalence of asthma. We examined episodes of SA requiring admission to the medical intensive care unit (MICU) of an urban hospital center.METHODOLOGY:The charts of patients admitted to the MICU of an urban hospital center with a diagnosis of SA during the 5‐year period 2002–2006 were reviewed retrospectively. These results were compared with those of a previously published experience at our institution from 1995 to 1999.RESULTS:The medical records of 84 MICU admissions for SA were reviewed. There were 61 women (5 pregnant). The mean age was 44 years. Use of cigarettes or illicit drugs was found in 51% and 30%, respectively. Mechanical ventilation (MV) was required in 76% of admissions. Noninvasive ventilation was used in 10 patients. Neuromuscular blockade (NMB) was needed in 9% of admissions. The highest average PaCO2 during the first 24 hours was 67 mm Hg. Median duration of MV was 4.4 days. Six patients died, 3 of whom sustained prehospital cardiac arrest. Compared with the patients in the preceding 5‐year period, the more recent patients had greater use of illicit drug and cigarettes. Patients presented with more severe asthma, as reflected by a higher PaCO2 and an increased duration of MV.CONCLUSIONS:During the recent 5‐year period, we found a trend toward increasing severity of SA, as indicated by the degree of respiratory acidosis, need for NMB, and longer duration of MV. Access to medical care and cigarette and illicit drug use remain potential targets of primary intervention. Journal of Hospital Medicine 2008;3:206–211. © 2008 Society of Hospital Medicine.

Hospitalization rate and 30-day mortality among patients with status asthmaticus in Denmark: a 16-year nationwide population-based cohort study

“…Our 30-day mortality finding could possibly be explained by the restriction to first-time status asthmaticus hospitalizations, since the risk of further admissions and poor prognosis is increased by readmission,7 and by the encompassing of all patients hospitalized with status asthmaticus, and not only patients admitted to an ICU or both patients hospitalized with asthma and status asthmaticus 1,7,8,14,15,18,19,21,23,26…”

“…However, comparisons among studies are complicated by the restriction to ICU patients or different age groups in some studies 7,8,14,15,18–23,25,26…”

“…We identified 19 studies on status asthmaticus hospitalizations and prognosis using the definition of status asthmaticus provided above 1,3,5,7–9,14–26. These studies were restricted to either adult or pediatric study populations1,7–9,14–20,22–26 or were limited to a few hospitals or intensive care units (ICUs),7,8,14,15,18,21,23,25,26 reducing generalizability. Furthermore, 14 studies included readmissions,1,7,8,14–16,18–21,23–26 which may affect estimates of hospitalization rates and prognosis due to the increased risk of further admissions and worsened prognosis 7.…”

Mechanical Ventilation for Severe Asthma

“…24 In a second study, the highest Pa co 2 on the fi rst day of mechanical ventilation averaged 67 mm Hg and exceeded 100 mm Hg in 12% of cases. 36 Th e term "permissive" hypercapnia may not be entirely accurate when applied to severe asthma. Since hypercapnia is a consequence of increased dead space ventilation caused by alveolar overdistension, attempts to lower Pa co 2 by increasing minute ventilation will result in more hyperinfl ation and further increase in physiologic dead space.…”

Is there a role for therapeutic bronchoscopy in acute severe asthma?

“…This patients are at risk of profound hypoxemia, hemodynamic collapse and death. [ 9 10 11 ] The National Asthma Education and Prevention Program guidelines suggest that “permissive hypercapnia” or “controlled hypoventilation” should be utilized to reduce the risk of barotrauma. [ 12 ] If neuromuscular blockade is attained during the bronchoscopy it will reduce patient-ventilator asynchronies, but there is a potential risk of induced myopathy.…”