Outcome of status asthmaticus at a pediatric intensive care unit in Hong Kong.

OBJECTIVES: To characterize the clinical course and outcome of children with status asthmaticus (SA) admitted to a pediatric intensive care unit (PICU) METHODS: All patients with SA who were admitted to a PICU from January 2003 to December 2018 were reviewed. Polymerase chain reaction (PCR) studies on nasopharyngeal aspirate for respiratory pathogens were performed from 2014 to 2018. RESULTS: Sixty-seven SA admissions constituted 2.4% of total PICU admissions (n = 2788). Fifteen (22.4%) children required noninvasive ventilation (NIV), while 7 children (10%) required invasive mechanical ventilation. Nonadherence to prior asthma therapy was common. PCR was positive for enterorvirus/rhinovirus in 84% (16 out of 19) and for any virus in 95% of nasopharyngeal aspirate (NPA) samples of patients between 2014 and 2018. Over the 16-year period, increased utilization of ipratropium bromide, magnesium sulfate and NIV was noted (P < .05). Patients who required invasive mechanical ventilation had significantly higher heart rate, lower pH and longer PICU length of stay (LOS) when compared to nonintubated children (P < .05). There was no mortality, gender difference, or seasonal characteristics in these SA admissions. Median LOS in PICU was 2 days (interquartile range 1-3 days). CONCLUSIONS: SA accounts for a small proportion of PICU admissions. LOS was short and prognosis generally good. Nonadherence to prior asthma therapy was common. The most common trigger is enterovirus/rhinovirus for children with severe asthma requiring PICU admission. A trend of increase in usage of ipratropium, magnesium sulfate and NIV was observed. Primary prevention and early treatment of exacerbation are the most important step in managing children with asthma. Regular follow-up to ensure compliance together with annual vaccination could possibly avoid PICU admissions.

Influenza A triggered status asthmaticus requiring emergency ECMO.

We describe a case of acute respiratory failure due to severe pneumonia triggered by the influenza A virus, rapidly evolving into a refractory status asthmaticus requiring emergent ECMO assistance, in order to facilitate the clinical management of patients suffering from this rare but life-threatening condition. This case report demonstrates that infection with influenza A virus can present with severe pneumonia and status asthmaticus refractory to medical and ventilatory treatment. When medical treatment and mechanical ventilation fail, extracorporeal membrane oxygenation therapy should not be delayed as it will avoid injury resulting from inadequate mechanical ventilation and lung hyperinflation.

[Rhinovirus and acute respiratory infections in hospitalized children. Retrospective study 1998-2000]. / Rhinovirus et infections respiratoires aiguës de l'enfant hospitalisé. Etude rétrospective de 1998 à 2000.

OBJECTIVES: Rhinoviruses are the most common aetiological agents of colds, but the frequency and the severity of other locations of the infection are not well known. This study describes the clinical aspects and the severity of rhinovirus infections in hospitalised children. METHODS: Isolation in culture and a RT-PCR were performed for the detection of rhinovirus in nasal aspirates from hospitalised children from September 1998 to October 2000. A group of 211 children found to be positive for rhinovirus was studied. RESULTS: Rhinovirus-infected children suffered from the following clinical syndromes: 60 (28.4%) upper airway infections, 81 (38.4%) bronchiolitis, 25 (11.9%) pneumonias and 12 (4.7%) acute attacks of asthma. Clinical symptoms were wheezing (32%), ronchi (37%) and 29% of children presented with acute distress respiratory syndrome; 40% of the available chest X-Ray were abnormal. Eight children were hospitalised in the intensive care unit and two children died. Twenty-five children (10.9%) had a nosocomial infection; a dual infection was observed in 19 cases (9%) with the following viruses: RSV (3), influenza (2) parainfluenza (8), adenovirus (2), enterovirus (4); 19 (9%) children had a secondary bacterial infection. Rhinoviruses were detected in nasal aspirates in 112 cases (53%) according to the culture and in the rhinovirus culture-negative samples in 99 cases (47%) according to the RT-PCR assay. CONCLUSION: After eliminating cases of bacterial or viral dual infections, the clinical aspects of rhinovirus infections in children are the following: upper respiratory tract infections (25.6%), bronchiolitis ou bronchitis (25.6%), pneumonia (6.2%), acute attack of asthma (5.7%). The virological diagnosis according to culture is mainly improved by molecular techniques.

Respiratory viruses and asthma.

Viral infections have become increasingly recognized as a significant cause of asthma exacerbations, mainly because of improved viral detection techniques. Unfortunately, the ability to specifically treat viral infections and to limit the asthma morbidity associated with these agents has not kept pace with diagnostic technology. This article focuses on current concepts of the epidemiology of viruses in asthma exacerbations, investigations studying the physiologic and immunologic consequences of viral infection, and potential therapies to minimize virally-induced airway hyperresponsiveness. To impact this significant health problem, researchers must definitively ascertain the mechanisms by which viruses induce airway reactivity and must develop rational, safe approaches to prevent the consequences of viral infection in the patient with asthma.

Asthma and natural colds. Inflammatory indices in induced sputum: a feasibility study.

We examined the feasibility of using induced sputum to evaluate the airway inflammatory response to natural acute respiratory virus infections. We recruited eight asthmatics and nine healthy subjects on Day 4 of a cold. Viral infection was confirmed in six of the asthmatics (influenza A or B) and six of the healthy subjects (influenza A, rhinovirus, adenovirus, respiratory syncytial virus, and coronavirus). In the subjects with confirmed virus infection, five of the asthmatics had an objective exacerbation of asthma during the cold. Their sputum on Day 4 showed a high median total cell count of 19.7 x 10(6) cells/ml with a modest neutrophilia (58. 5%) and high levels of interleukin-8 (IL-8) (16,000 pg/ml), eosinophilic cationic protein (ECP) (1,880 microgram/L) and very high levels of fibrinogen (250 mg/L). In contrast, the proportion (1.3%) and absolute number of eosinophils was low. IL-2 levels were within the normal range, whereas IL-5 and interferon gamma were under the limit of detection of the assays. In the healthy subjects with a confirmed virus infection the sputum findings were qualitatively similar but significantly less prominent. Sputum IL-8 on Day 4 was strongly correlated with neutrophils (rs = 0.8, p < 0.001). This correlation was also significant when each group was analyzed separately. On Day 21 there was a fall in the absolute number of neutrophils and in ECP and fibrinogen levels in both groups. Similar results were found in the two asthmatic and three healthy subjects with a cold of comparable severity but in whom viral infection was not confirmed. We conclude that induced sputum examination can be used to study the effects of natural colds and influenza on the airways of the lungs. The results also suggest that natural colds, on Day 4, cause neutrophilic lower airway inflammation that is greater in asthmatics than in healthy subjects. The greater inflammatory response in asthmatics may be due to the changes associated with trivial eosinophilia or to the different viruses involved.