Front Pediatr. 2014 Apr 2;2:24. doi: 10.3389/fped.2014.00024. eCollection 2014.
Acute severe bronchospasm is an emergency situation and sometimes these children may fail to respond to conventional treatment and deteriorate rapidly to respiratory failure requiring mechanical ventilation. We present a case of 2-year-old girl, who presented with severe bronchospasm resulting in respiratory failure not responding to conventional management including mechanical ventilation and was found to be H1N1 positive. She was treated with ketamine infusion, which led to prompt improvement in airway obstruction.
KEYWORDS: H1N1 infection; acute severe asthma; bronchospasm; ketamine; wheezing
BACKGROUND AND AIMS: Status asthmaticus is a common cause of morbidity and mortality. The addition of ketamine to the standard treatment regimen of severe asthma has shown to improve outcome and alleviate the need for mechanical ventilation. The purpose of this review is to determine the pulmonary effects of ketamine and to determine whether sufficient evidence exists to support its use for refractory status asthmaticus. DATA SOURCE: MEDLINE, EMBASE, Google Scholar, and Cochrane data bases (from their inception to Jan 2012) using key words "ketamine", "asthma", "bronchospasm", "bronchodilator", and "mechanical ventilation" were searched to identify the reports on the use of ketamine as a bronchodilator in acute severe asthma or status asthmaticus, and manual review of article bibliographies was done. Relevant databases were searched for the ongoing trials on use of ketamine as a bronchodilator. Outcome measures were analyzed using following clinical questions: Indication, dose and duration of ketamine use, main effects on respiratory mechanics, adverse effects, and mortality. RESULTS: Twenty reports illustrating the use of ketamine as a bronchodilator were identified. In total, 244 patients aged 5 months to 70 years received ketamine for bronchospasm. Twelve case reports, 3 double-blind randomized placebo-controlled trials, 2 prospective observational studies, 2 clinical evaluation study, and 1 retrospective chart review were retrieved. Most of the studies showed improved outcome with use of ketamine in acute severe asthma unresponsive to conventional treatment. Patients who received ketamine improved clinically, had lower oxygen requirements, and obviated the need for invasive ventilation. Mechanically-ventilated patients for severe bronchospasm showed reduction in peak inspiratory pressures, improved gas exchange, dynamic compliance and minute ventilation, and could be weaned off successfully following introduction of ketamine. CONCLUSION: In various studies, ketamine has been found to be a potential bronchodilator in severe asthma. However, a large prospective clinical trial is warranted before laying down any definitive recommendations on its use in status asthmaticus.
KEYWORDS: Bronchodilator; emergency department; intensive care unit; ketamine; status asthmaticus
OBJECTIVES: An increasing prevalence of pediatric asthma has led to increasing burdens of critical illness in children with severeacute asthma exacerbations, often leading to respiratory distress, progressive hypoxia, and respiratory failure. We review the definitions, epidemiology, pathophysiology, and clinical manifestations of severe acute asthma, with a view to developing an evidence-based, stepwise approach for escalating therapy in these patients. METHODS: Subject headings related to asthma, status asthmaticus, critical asthma, and drug therapy were used in a MEDLINE search (1980-2012), supplemented by a manual search of personal files, references cited in the reviewed articles, and treatment algorithms developed within Le Bonheur Children's Hospital. RESULTS: Patients with asthma require continuous monitoring of their cardiorespiratory status via noninvasive or invasive devices, with serial clinical examinations, objective scoring of asthma severity (using an objective pediatric asthma score), and appropriate diagnostic tests. All patients are treated with β-agonists, ipratropium, and steroids (intravenous preferable over oral preparations). Patients with worsening clinical status should be progressively treated with continuous β-agonists, intravenous magnesium, helium-oxygen mixtures, intravenous terbutaline and/or aminophylline, coupled with high-flow oxygen and non-invasive ventilation to limit the work of breathing, hypoxemia, and possibly hypercarbia. Sedation with low-dose ketamine (with or without benzodiazepines) infusions may allow better toleration of non-invasive ventilation and may also prepare the patient for tracheal intubation and mechanical ventilation, if indicated by a worsening clinical status. CONCLUSIONS: Severe asthma can be a devastating illness in children, but most patients can be managed by using serial objective assessments and the stepwise clinical approach outlined herein. Following multidisciplinary education and training, this approach was successfully implemented in a tertiary-care, metropolitan children's hospital.
KEYWORDS: asthma; child; critical care; infant; respiratory failure; status asthmaticus
BACKGROUND Asthma accounts for 0.4% of all deaths worldwide, a figure that increases annually. Ketamine induces bronchial smooth muscle relaxation, and increasing evidence suggests that its anti-inflammatory properties might protect against lung injury and ameliorate asthma. However, there is a lack of evidence of the usefulness and mechanism of ketamine in acute asthma exacerbation. This study aimed to analyze the therapeutic effects and mechanism of action of ketamine on acute ovalbumin (OVA)-induced murine asthma. MATERIAL AND METHODS In vivo, BALB/c mice with OVA-induced asthma were treated with or without ketamine (25 or 50 mg/mL). Serum, lung sections, and mononuclear cell suspensions from the lung were collected for histological, morphometric, immunofluorescence, microRNA, quantitative polymerase chain reaction, regulatory T cell identification, cytokine, and Western blotting analyses. In vitro, bronchial epithelial cells were cultured to analyze the effect and mechanism of ketamine on epithelial-mesenchymal transition (EMT) and transforming growth factor-β (TGF-β) signaling. RESULTS The inhalation of ketamine 25 or 50 mg/mL markedly suppressed OVA-induced airway hyper-responsiveness and airway inflammation, significantly increased the percentage of CD4+CD25+ T cells, and significantly decreased OVA-induced up-regulation of TGF-β1 and the EMT. MiR-106a was present at higher amounts in OVA-induced lung samples and was suppressed by ketamine treatment. The in vitro results showed that TGF-β1-induced EMT was suppressed by ketamine via miR-106a level regulation. CONCLUSIONS Ketamine ameliorates lung fibrosis in OVA-induced asthmatic mice by suppressing EMT and regulating miR-106a level, while ketamine inhalation might be a new therapeutic approach to the treatment of allergic asthma.