INTRODUCTION

Asthma is a syndrome that includes several clinical phenotypes that share similar clinical manifestations, but probably different etiologies. Classically, it is defined as a chronic inflammatory disease of the airways, involving different cells and mediators of inflammation, conditioned in part by genetic factors, with bronchial hyperresponsiveness and variable airflow obstruction, totally or partially reversible, either by drug action or spontaneously¹.

Asthma is a heterogeneous disease, generally characterized by chronic inflammation of the airways. It is defined by a history of respiratory symptoms, such as wheezing, shortness of breath, chest tightness, and cough, which vary over time and in intensity, along with variable expiratory airflow limitation. Airflow limitation may later become persistent².

Several asthma-related risk factors for death have been identified, such as history of previous intubation, ICU stay, multiple emergency room visits in the previous year, beta-agonist drug abuse, respiratory tract infections, aeroallergen sensitivity, old age, respiratory tract infections, systemic glucocorticoid dependence³.

In Peru, up to epidemiological week 08 - 2023, 7530 episodes of bronchial obstructive syndrome/asthma have been reported in the country. In 2022, during the same period, 5808 episodes were reported in Peru, and the cumulative incidence rate (CIR) was 21.95 cases per 10,000 inhabitants⁴.

Asthmatic exacerbation accounts for approximately 10% of emergency department visits. Life-threatening asthma, near-fatal asthma, asthmaticus or status asmaticus are known as asthmatic exacerbations leading to cardiorespiratory arrest, orotracheal intubation and mechanical ventilation, admission to an intensive care unit (ICU), hypercapnia or acidosis. Of the exacerbated asthmatics who will be hospitalized, 2.4% presented the first situation and 6.3% the second in the EAGLE study. Patients requiring life support had an in-hospital mortality of 2.5%. The following are predictors of life-threatening asthma: history of sudden exacerbations; previous intubation and ventilation for asthma; previous admission to the ICU for asthma; two or more hospitalizations in the last year for asthma; three or more visits to the emergency room for asthma in the last year; use of more than 2 salbutamol canisters in one month; recent abandonment of systemic corticosteroid treatment; poor perception of dyspnea; low socioeconomic status; use of illicit substances: cocaine, heroin⁵.

Classically, two types of exacerbations have been identified: type 1, with inflammatory predominance, slow onset and slow response to treatment, which represents 90% of crises, and type 2, with bronchial spasm predominance and rapid response to treatment, which represents 10% of cases⁵.

In addition, seizures can be mild, moderate, severe or near-fatal.

Objectively, we identify patients as life-threatening because they present with agonal respiration or apnea, absence of speech, bradypnea or apnea, bradycardia or cardiac arrest, hypotension, paradoxical pulse, paradoxical thoracoabdominal movement, auscultatory silence, impaired level of consciousness or coma, pulse oximetry less than 90%, hypoxemia and hypercapnia⁵.

The initial evaluation of the patient will respect the ABC of any emergency, identifying and assisting in order of priority the difficulty to defend the airway, the assistance of ventilation and oxygenation and circulatory support⁵.

Regarding airway instrumentation in apneic patients, with impaired level of consciousness or hypercapnic acidosis, if rapid sequence intubation is required, the use of propofol or ketamine is preferred, while atracurium and morphine are discouraged due to histamine release, which could enhance bronchospasm⁵.

Patients requiring mechanical ventilatory support are those who present to the emergency department in apnea, with impaired level of consciousness, hypoxemia and hypercapnia or who do not respond to initial treatment. The goal of ventilation is to reverse hypoxemia, stabilize hemodynamics, prevent and reverse air trapping and mechanical ventilation-induced damage.⁵

DESCRIPTION OF THE CLINICAL CASE

Male patient, 23 years old, with incomplete high school, born and coming from Lima-Peru, currently a student; he presents asthma since he was 5 years old with irregular salbutamol inhaler treatment; allergic rhinitis since he was 5 years old with symptomatic treatment; Asperger syndrome; as an important antecedent, he presented severe asthmatic crisis in December 2022, hospitalized for 28 days at the Santa Rosa Hospital in the Intensive Care Unit in mechanical ventilation and tracheostomy for prolonged intubation (more than 21 days). In addition, he presented psychiatric post-traumatic syndrome in treatment for 5 months.

Patient 5 days before admission presented "flu-like process" characterized by rhinorrhea, cough and general malaise, with symptomatic treatment; 1 day before admission he presented shortness of breath despite the use of salbutamol inhaler with no apparent improvement; the day of admission patient with increased respiratory distress and decreased oxygen saturation going directly to the trauma shock unit.

BP: 155/100 mmHg HR: 130 min FR: 30 x min T°: 37.2 °C Sat O2: 87%.

On examination, decreased vesicular murmur in both lung fields with diffuse wheezing; rhythmic, tachycardic heart sounds of regular intensity, no murmurs; Glasgow Coma Scale: 15, no meningeal signs or focalization.

DIAGNOSIS AND INITIAL MANAGEMENT: severe asthmatic crisis. Oxygen therapy; Nebulization with SABA/SAMA, intravenous and inhalation corticotherapy, intravenous magnesium sulfate.

EVOLUTION AND TREATMENT: 40 minutes after admission to the trauma shock unit, the patient was evaluated with arterial blood gas examination interpreted as respiratory acidosis and hypoxemia; also vital functions: BP: 160/100 mmHg HR: 155 x min FR: 32 x1min Sat O2; 81% (FiO2 0.40) with final diagnosis of ALMOST FATAL ASTHMA and orotracheal intubation is decided under rapid sequence using ketamine at a dose of 2 mg/kg and mechanical ventilation (continuous pressure controlled mechanical ventilation: PC-CMV). Poor respiratory mechanics, respiratory acidosis (pCO2: 64), previous history of severe asthmatic crisis with orotracheal intubation and long-stay ICU (Figure 1 and Table 3).

Figure 1: Chest X-ray, taken in emergency. 3a. Preserved radiotranslucent lung fields. Orotracheal tube in D3. 3b. Lung fields show left basal alveolar radio opacity. Central venous catheter projected in left subclavian vein. 

Patient is transferred to the intensive care unit to continue management of critically ill patient on mechanical ventilation with diagnostics:

Daily evolution of the arterial blood gas test showing pCO2 correction on the second day and correction of the acid-base disorder on admission (Table 4).

Hemogram showing leukocytosis with left deviation on the second day (abstinence 9%) related to the respiratory infectious picture associated with probable aspiration pneumonia (Table 5 and Figure 2).

Figure 2: Chest X-ray in ICU. There is evidence of accentuation of the pulmonary interstitium, with confluent posterobasal alveolar opacities predominantly on the right and bilateral hilar reinforcement. 

The mainstays of treatment were antibiotic therapy (Ceftriaxone/Clindamycin), intravenous and inhalation corticotherapy, short-acting beta agonists (SABA), short-acting antimuscarinics (SAMA), magnesium sulfate, aminophylline, sedoanalgesia and neuromuscular blocking agents (vecuronium).

Patient with favorable evolution, on the fourth day is extubated and on the sixth day goes to the medical hospital for 3 days, discharged on the ninth day of emergency admission.

DISCUSSION

Near-fatal asthma defines a subset of patients with asthma who are at increased risk of death from their disease. Studies show that deaths from asthma attacks typically occur in patients who present with poorly controlled asthma and whose condition gradually deteriorates over days or weeks before presenting with a fatal or near-fatal asthma episode.

Despite advances in treatment, asthma continues to be a disease of high prevalence and incidence worldwide. Approximately 2 to 4% of hospitalized patients with critical asthma syndrome develop acute ventilatory failure requiring mechanical ventilation, among which mortality ranges from 6.5% to 10.5%⁶.

Infections, especially viral infections, are also a risk factor as an important trigger for near-fatal asthma. Viral nucleic acids have been detected in up to 55% of patients, and patients with asthma and lower respiratory infection tend to have more severe and prolonged symptoms. There is progressive airway obstruction, with mucus plugs, loss of respiratory epithelium, mucous gland hyperplasia and submucosal eosinophilia (late phase). These patients have frequent use of bronchodilators and little use of inhaled steroids with a higher risk of reaching an asthmatic state⁶.

The signs and symptoms evidenced in the patient were progressive respiratory distress with decreased oxygen saturation (87%), rescue treatment for severe asthmatic crisis was started on admission with oxygen therapy, corticotherapy, SABA (nebulization) and SAMA (inhalation), magnesium sulfate 2g EV. After 20 minutes the patient was clinically reevaluated, tachypnea and low oxygen saturation persisted (81%), silent thorax and arterial gas analysis (pH: 7.21, pCO2: 64, pO2: 58, PaO2/FiO2: 148) with a diagnosis of ALMOST FATAL ASTHMA and orotracheal intubation is decided by rapid intubation sequence with the use of ketamine at a dose of 2 mg/kg, for its bronchodilator effect as it relaxes the bronchial smooth muscle and mechanical ventilation with PC-CMV mode (continuous pressure controlled mandatory ventilation). Among the poor prognostic factors that make us suspect and predict the possible use of mechanical ventilation is the patient's history of mechanical ventilation for a similar asthmatic crisis, associated with the lack of adherence to treatment (he only used the medication during exacerbations) and the post traumatic psychiatric syndrome disorder associated with a history of Asperger's syndrome; Apart from insufficient oxygenation and ventilation, the expected clinical evolution of the patient was clinical deterioration and the need for intubation and mechanical ventilation (PC-CMV).

The decisions made upon admission to the emergency room regarding intubation and early mechanical ventilation may have influenced the patient's prompt recovery and discharge at 9 days, in contrast to the previous similar situation.

It is important to know the history of emergency admission, adherence or not to the treatment received, precipitating risk factors and clinical factors to decide on orotracheal intubation in this type of patient, since early intervention improves morbidity and mortality (superinfections, prolonged stay).

CONCLUSION

Despite advances in treatment, asthma continues to be a disease of high prevalence and incidence globally; asthmatic crises are an important percentage of emergency care; knowing, diagnosing and treating this pathology in a timely and appropriate manner is very important for the patient's prognosis.

Patients with near-fatal asthma have an increased risk of death from their disease, related to the complication of the disease.

The signs and symptoms evidenced in the patient were progressive respiratory distress with decreased oxygen saturation (87%), which did not respond to initial rescue treatment; persisting low oxygen saturation (81%), at physical examination silent chest and arterial gas analysis examination pH: 7.21, pCO2: 64, pO2: 58, PaO2/FiO2: 148; with diagnosis of ALMOST FATAL ASTHMA and orotracheal intubation is decided by rapid intubation sequence.

The favorable response of the patient from his emergency admission, transfer to the intensive care unit and discharge was determined by a rapid response to the emergency admission and the treatment followed in the ICU.