7. Status Asthmaticus

Question 1

Status Asthmaticus is

Answer 1

airway hyper-reactivity that produces severe airway narrowing that is refractory to aggressive bronchodilator therapy, which may result in respiratory failure. It can be Fatal: see figure 4-12

Question 2

Clinical Presentation of Status Asthmaticus

Answer 2

-Dyspnea, tachypnea
-cough, chest tightness
-accessory muscle use
-wheezing –>decreased breath sounds–>absent breath
sounds…ominous sign!
-V/Q mismatch
-Chest X-ray may have flattened diaphragm (sign of air trapping)
-tachycardia
-pulsus paradoxus >= 15mmHg (severe is > 18 mmHg)
-Anxiety –>decreased LOC
-May have elevated WBC, eosinophils
-Peak flow rate < 80% of predicted, <50% is severe
-History of previous intubations (higher mortality)
-ABG changes (table 4-11)

Question 3

ABG Progression in Status Asthmaticus (on Room Air)

Answer 3

Stage 1: Normal PaO2, respiratory alkalosis (decreased
PaCO2)
Stage 2: Mild hypoxemia, respiratory alkalosis
(decreased PaCO2)
Stage 3: Worsening hypoxemia, normalization of pH and
PaCO2
Stage 4: Severe hypoxemia, respiratory acidosis

Question 4

Management of Status Asthmaticus

Answer 4

-Measure presenting peak flow rate (PFR)
-Admit the pt to the hospital if the PFR is 50-70%
-Admit the pt to the ICU if the PFR is < 50%

-Bronchodilator: short-acting beta-2 agonists, e.g.
albuterol (Ventolin)

-Anticholinergics, e.g. ipratropium (Atrovent)

-Corticosterioids (systemic)

-O2, pulse oximetry

-Hydration to prevent thickened secretions

-Avoid sedation agents

-Intubation, mechanical ventilation if any of the following ominous signs occur:
-Respiratory acidosis
-Severe hypoxemia
-Silent Chest
-Change in the level of consciousness (LOC)

-If the pt is intubated and sedated on mechanical ventilation, avoid paralytics because paralytics combined with steroids increase incidences of neuropathy.

-Ventilator Mgmt

Question 5

Ventilator Management for Status asthmaticus

Answer 5

-Use low rate to increase exhalation time.

-Use low tidal volumes to prevent auto-PEEP

-Increase inspiration/expiration (I/E) ratio, often greater than 1:3-4, to allow time for optimal exhalation and to prevent auto-PEEP