The post gives the general scheme of management of a patient coming into the emergency with status asthmaticus..the text gives only a general outline of the principles, the treatment modalities may be different in different parts of the world.the text is also meant to help medicos preparing for the board exam to write answers to the questions asked about the topic..

Introduction

Status Asthmatics(severe acute asthma)is the condition in which the attack of bronchial asthma is not relieved even on treatment with adrenaline and aminophylline.

Status Asthmaticus

  1. All patients with asthma have the potential to develop STATUS ASTHMATICUS.
  2. Severe at the onset or progresses rapidly despite routine therapy
  3. May result in ventilatory failure and death

Precipitating factors

  1. An acute respiratory infection
  2. Abrupt omission of corticosteriods therapy
  3. Drugs(NSAIDS) or inhaled allergens
  4. Acute emotional stress

Clinical Presentation

Indicators of Severe Asthma

Long duration of symptoms

Progression despite optimal outpatient therapy

Dyspnea precluding sleep

Dyspnea precluding speech

Accessory muscle use

Tachycardia > 120 BPM

Tachypnea > 35 breaths/min

Pulsus paradoxicus > 15 mmHg

FEV1 < 1 L/min

PEFR < 120 L/min

Rising or elevated PaCO2

Assessment of Severity
of Illness


STAGE 1 Can the patient be treated in OPD?

STAGE 2 Does the patient need admission to the hospital?

STAGE 3 Does the patient need admission to a critical care unit?

STAGE 4 Does the patient need intubation and mechanical ventilation?

Life Threatening Asthma

  1. Silent chest
  2. Cyanosis
  3. Poor respiratory effort
  4. Bradycardia or hypotension
  5. Exhaustion, confusion or coma
  6. PEF < 33% of best predicted
  7. Normal or high paCO2 ( >36 mmHg)
  8. Severe hypoxemia despite oxygen(< 60 mmHg)
  9. Low pH

Bronchodilator Therapy for
Status Asthmaticus

  1. Salbutamol and Ipatropium 0.5% by nebulization q15-20min,it is nebulised with oxygen in severe cases.
  2. Epinephrine (1:1000) 0.3ml s.c. if needed.
  3. Methylprednisolone 60-125mg iv q6h or prednisone 40mg orally q6h
  4. Theophylline 5mg/kg i.v. over 30min loading dose followed by 0.4mg/kg/h

Indications for Mechanical Ventilation

  1. Respiratory rate > 40 breaths/min
  2. Climbing pulsus paradoxus
  3. Falling pulsus paradoxus in the exhausted patient
  4. Altered sensorium
  5. Inability to speak
  6. Patient’s subjective sense of exhaustion
  7. Complicating barotrauma
  8. Unresolving lactic acidosis
  9. Diaphoresis in the recumbent position
  10. Silent chest despite respiratory effort
  11. Elevation of PaCO2 with progressive signs and symptoms

Management of the Patient on a Ventilator

  1. The patient should be fully sedated and muscles relaxed
  2. Small tidal volume (4-8ml/kg)
  3. Fast inspiratory flow to reduce inspiratory time (Ti<1sec or flow 80-100L/min)
  4. Ppeak < 55 cmH2O, Pplateau < 35cmH2O
  5. Keep PaO2 60-100mmHg

Liberation from Mechanical Ventilation

  1. It will require 24-48hs of aggressive bronchodilator and anti-inflammatory therapy until airway pressure fall.
  2. As airway pressure fall and PaCO2 normalize , sedatives, muscle relaxants and bicarbonates should be withheld.
  3. Change to spontaneous breathing mode
  4. Assess respiratory muscle strength
  5. Quick extubation à E-T tube itself may induce bronchospasm

REHYDRATION THERAPY

  • Oral or parentral administration of 5% glucose – saline.It also makes the bronchial secretions less tenacious.
  • Correction of acidosis by IV sodium bicarbonate