Pulmonary Disorders II

Inhaled anticholinergic agents selectively bind to the muscarinic receptors on smooth muscle cells in

the airways and thereby reduce bronchoconstriction.

a SABA in moderate to severe exacerbations to promote additional bronchodilation through a different

pathway.

Adding ipratropium to inhaled albuterol compared with using albuterol alone in patients with severe

asthma improved the response; however, outcomes with this combination in status asthmaticus or

consisting of inhaled short-acting anticholinergics and a SABA compared with a SABA alone has

reduced hospitalization rates in severe asthma exacerbations. However, combination therapy may

increase the risk of adverse drug events, including agitation and palpitations (Cochrane Database Syst

Rev 2017;1:CD001284).

Adverse effects include headache, flushed skin, blurred vision, tachycardia, palpitations, and urinary

retention.

Corticosteroids decrease airway obstruction during an asthma exacerbation by decreasing inflammation,

increasing the number of β2-receptors and increasing their responsiveness to β-agonists, reducing

airway edema, and suppressing certain proinflammatory cytokines (Respir Med 2004;98:275-84).

Typically, there is a 6–8-hour delay in the response to corticosteroids in status asthmaticus or life

threatening asthma; therefore, administration should be considered early in the course (within 1 hour

of presentation) (Cochrane Database Syst Rev 2001;1:CD002178).

Oral prednisone is considered as effective as parenteral corticosteroids in most patients; however, it

may not be as effective in critically ill patients with impaired gastric absorption.

GINA guidelines recommend prednisone 1 mg/kg/day up to a maximum of prednisone 50 mg daily for

5–7 days for treatment of exacerbations.

Other guidelines recommend longer courses and higher doses for life threatening asthma

exacerbations based on the same evidence used by GINA.

For corticosteroid courses less than 2 weeks (GINA 2024), tapering is not necessary, especially if

patients are concurrently using an inhaled corticosteroid.

Inhaled corticosteroids can be initiated any time in the treatment of an asthma exacerbation. It is not

recommended to replace systemic steroids with inhaled corticosteroids (Respir Care 2018;63:783-96).

Ketamine is a phencyclidine derivative that has bronchodilatory properties that reduce airway resistance

2013;17:154-61). Ketamine may be used for as an induction for rapid sequence induction or sedation for

MV (Chest 2022;162:747-56).

who have life-threatening exacerbations and are unresponsive to conventional therapies after 1 hour

(GINA 2024).

Magnesium is thought to cause bronchodilation by inhibiting calcium channels on smooth muscle,

leading to relaxation.

In addition, magnesium may have anti-inflammatory properties that interfere with the activation

and release of neutrophils in patients with asthma.