Airway Pressure (Paw)

1. Place the airway pressure gauge as close as possible to the patient to avoid errors due to leaks in the inspiratory limb.

2. Check the high pressure alarm and disconnection alarm. 3. Set the tidal volume, respiratory rate (see page 2.19) and always record the Paw as a base line value, so that subsequent changes can be compared. (During IPPV, airway pressure rises to 15-20 mmHg in inspiration).

INCREASE OF AIRWAY PRESSURE (>25 mm Hg)

Causes • Airway obstruction : ETT small, obstructed, endobronchial or bronchospasm • Reduced compliance : pneumothorax, pulmonary oedema, pulmonary collapse, head low position, increased intra abdominal pressure, obesity • Excessive tidal volumes and flow rates

Management I. Hand ventilate to confirm and exclude problems in the ventilator. 2. Check heart rate, pulse volume, Sp02, ETC02• 3. Check chest expansion and auscultate the lungs. 4. Check ETT for kinking or obstruction by passing a catheter, and check for cuff herniation by releasing the cuff.

5. If there is no patient problem, suspect and exclude the machine, and inflate with oxygen or room air via a self inflating bag.

6. If ventilation is still not possible, suspect the ETT. ("when in doubt, take it out") Detection of life threatening causes

1. No chest expansion (unilateral or bilateral) • Bronchospasm (rhonchi, silent chest) • Misplacement (oesophageal, endobronchial) • ETT obstruction

2. High Paw combined with low pulse volume and low Sp02 • Pulmonary oedema I aspiration • Tension pneumothorax • Anaphylaxis with bronchospasm

DECREASE OF AIRWAY PRESSURE

Major decreases : Disconnection of the tube connecting the patient to the ventilator Minor decreases : Disconnection of fresh gas flow (circle or Bain circuits, leaks in the circuit (partial disconnection or deflaton of cuff)