An Overview of Status Asthmaticus

Status asthmaticus is a severe asthma attack that comes on abruptly or lasts a very long time. In status asthmaticus, asthma symptoms continue on and respiratory function declines, despite standard treatments. In the United States, asthma affects approximately 7.7% of adults and 9.6% of children. Of these, between 3.9% and 4.3% have severe forms of asthma that place them at an increased risk for status asthmaticus.

Status asthmaticus can lead to respiratory failure, prolonged hospitalization, and even death. It signifies a medical emergency that requires immediate and aggressive treatment. In one study of the population in Denmark, around 1.5% of people hospitalized for status asthmaticus did not survive.

Despite advances in emergency treatment, status asthmaticus remains a serious concern. Each year, around 3,500 deaths are attributed to asthma in the United States. Everyone with or without asthma should be familiar with the common warning signs and symptoms.

Types of Status Asthmaticus

There are two types of SA:

• Slow-onset attack: This more common type may take a long time to unfold and usually results because of inadequate treatment. The person with this type of status asthmaticus will experience days or weeks of worsening symptoms, punctuated by moments of relief and ending in symptoms that cannot be reversed with medications in the home.
• Sudden-onset attack: The person experiencing this type of status asthmaticus has not experienced any worsening symptoms in the preceding weeks but is struck with sudden and severe bronchospasm, breathlessness, wheezing, and cough. This type of asthma attack is often brought on by a large exposure to trigger substances, such as pollen, dust, or food allergens.

Symptoms

Symptoms of status asthmaticus are not unlike those of asthma, but they're considerably more severe. The severe restriction of air coupled with the severity of bronchial spasms will typically manifest with some or all of the following symptoms:

• Difficulty breathing
• Profuse sweating
• Trouble speaking
• Extreme fatigue and weakness
• Abdominal, back, or neck muscle pain
• Panic
• Confusion
• Blue-tinted lips or skin (cyanosis)
• Loss of consciousness

In emergency situations, these symptoms are commonly referred to as "critical asthma syndrome" (CAS) and suggest that the child or adult is at an increased risk of death.

Causes

During a severe asthma attack, the way the body normally processes respiratory gases in the alveoli is impaired. This leads to lower oxygen levels and higher carbon dioxide levels in the blood, which, in extreme cases, can cause coma and death. Asthma also causes air to be trapped in the lungs, a condition that causes increased pressure in the chest. This can cause lung collapse and even cardiac arrest.

Risk Factors

With slow onset status asthmaticus, there are several warning signs which should alert you to call your healthcare provider or seek emergency treatment. These include:

• A decline in peak expiratory flow (PEF) of 20% or more using your peak flow meter
• The increased need of a rescue inhaler
• Nighttime awakenings due to your asthma
• Increasing shortness of breath despite the consistent use of asthma medications
• Using one or more canisters of a short-acting inhaler over the past month

Diagnosis

Status asthmaticus is typically diagnosed by symptoms and supported by various tests that measure respiration rate and blood oxygen levels. The common diagnostic signs of status asthmaticus include:

• Breathlessness at rest
• Inability to speak in sentences or not being able to speak at all
• Increased respiratory rate at rest (greater than 30 breaths per minute)
• Elevated pulse rate at rest (greater than 120 beats per minute)
• Agitation and irritability
• Low blood oxygen levels (hypoxemia followed by hypoxia)
• Reduced breathing capacity (as measured by peak flow meter)

Treatment

Status asthmaticus is always treated as a medical emergency. Standard treatment protocols in the emergency room include:

• Emergency oxygen therapy delivered by mask
• Short-acting beta-agonists (such as albuterol) via inhaler or nebulizer
• Corticosteroids (such as prednisone) given by mouth or intravenously (into a vein)
• Inhaled anticholinergic medications (such as Atrovent)
• Beta-agonists (such as terbutaline) injected under the skin
• Magnesium sulfate delivered intravenously
• Leukotriene modifiers (such as zafirlukast or zileuton) taken by mouth

Mechanical ventilation is generally considered a treatment of last resort due to the risk of lung trauma and an increased risk of death. Less than 1% of emergency room visits for asthma require mechanical ventilation.

As a final modality, extracorporeal membrane oxygenation (ECMO) has been effective in a few patients in which asthma would have been fatal even with mechanical ventilation. ECMO (extracorporeal membrane oxygenation) offers yet another last resort and final treatment modality for those for who all treatments including mechanical ventilation have failed.

It is now thought that ECMO should be considered as an early treatment for people with status asthmaticus who have poor gas exchange (the inadequate intake of oxygen and expiration of carbon dioxide) and are not responding to standard emergency interventions. ECMO offers a way of restoring gas exchange in the body while preventing lung injury related to mechanical ventilation.

A Word From Verywell

Many people with asthma do not realize how powerful their medications are and fail to tell their healthcare providers if the drugs no longer work as well as they used to. If no one intervenes to correct these shortcomings, you may find that it is harder to treat asthma in emergency situations.

To avoid potentially life-threatening emergencies, always keep your healthcare provider apprised of how well your drugs are working and how often you need a rescue inhaler.