Patho/ Background: Asthma flare-ups have two stages: early and late. They start when IgE antibodies produced by certain cells react to triggers such as pollen, dust, animals and many more. These antibodies attach to cells, causing the release of substances like histamines. This release tightens the airways making it harder to breathe. Certain immune cells play a crucial role in producing interleukins that communicate and sustain inflammation. These interleukins support the survival of specific cells and involve remodeling of the tissue. In the later phrase, various cells act in the lungs, causing breathing difficulties. Mast cells play a key role in transporting late-phrase reactants to inflamed areas. Recognizing these processes is essential for effective therapy, especially considering the impact on breathing. Interestingly, people with thicker airways tend to have longer-lasting issues. Inflammation and narrowing of the airways lead to breathing difficulties:
Air trapping
Lung hyperinflation
Increased RR to compensate for increased pulmonary dead space
Large negative inspiratory pressures --> increased afterload on LV causing a decrease in cardiac output (pulsus paradoxes)
Gas exchange abnormality (V/Q mismatch)
Between 2020-2023, there were about 250-340 cases reported annually for asthma in the PICU.
Inhaled short-acting beta-agonists (SABAs) have a rapid onset of action. These bronchodialtors work by relieving smooth muscle constriciton and relaxing the airway. Atrovent also provides smooth muscle relaxation in combination with albuerol. These therapies are administered up to 3 times back to back or at 20-30 minute intervals.
Systemic corticosteroids
Decrease airway inflammation
Early administration has been shown to decrease hospital admission rates (administer ASAP)
Continuous albuterol
Magnesium
It is thought that magnesium relaxes the smooth muscle, but the exact mechanism of action is unknown.
PICU:
Take note of prior ICU admissions for status asthmatics
Increased CO2 can cause mental status changes/ fatigue
Child may feel sense of impending doom
Oxygen: Assist with correcting VQ mismatch
Fluids: Increased insensible losses
Medications:
Inhaled beta agonists
Corticosteroids: decrease inflammation and mucous production
IV Beta Agonists: terbutaline
Anticholinergics: Bronchodilator without inhibition of mucous clearance, use in conjunction with beta agonists and steroids