Status
Unconscious Pt without gag reflex
Ineffective ventilation with BVM / Oxysaver and airway Mx (OP/NP)
>10 minutes assisted ventilation required
Unable to intubate / difficult intubation
Contraindications
- Intact gag reflex or resistance to insertion - Strong jaw tone + trismus - Suspected epiglottitis or upper airway obstruction
Consider
Precautions - Inability to prepare the Pt in the “sniffing position” - Pts who require high airway pressures, e.g. advanced pregnancy, morbid obesity, decreased pulmonary compliance (stiff lungs due to pulmonary fibrosis) or increased airway resistance (severe asthma) - Significant volume of vomit in airway
Side Effects - Correct placement of the LMA does not prevent passive regurgitation or gastric distension

LMA Sizes and Cuff Inflation
LMA Size	Patient Weight	Inflation Portex™(Metro)	Inflation Unique™(Rural)
SIZE 3	30 - 50kg (small adult)	25 MLS	20 MLS
SIZE 4	50 - 70kg (normal adult)	35 MLS	30 MLS
SIZE 5T	70kg + (up to 140kgs) (larger adult)	55 MLS	40 MLS

Special Note

The LMA provides improved airway and ventilation Mx compared with a facemask and OPA. The LMA does not protect against aspiration, although studies have shown it to be as low as 3.5% with an LMA compared to 12.4% with a Bag Valve Mask (BVM). The LMA should therefore not be regarded as the equivalent of endotracheal intubation.

The LMA forms a low pressure seal around the posterior perimeter of the larynx and when correctly inserted is seated superior to the oesophageal sphincter thus enabling positive pressure ventilation via BVM or closed circuit resuscitator. Unconscious Pts who accept an OPA are generally suitable for insertion of an LMA.

Pt with morbid obesity have a naturally increased work of breathing and during assisted or intermittent positive pressure ventilation require higher pressures to inflate the lungs. They also have a higher incidence of hiatus hernia resulting in an increased likelihood of passive regurgitation of stomach contents.

General Care

If insertion fails and ventilation is difficult or inadequate, check position of LMA cuff using a laryngoscope. If minor adjustment fails to correct the problem, remove the LMA inflated. Immediately insert an OPA/NPA and ventilate the Pt using a BVM.

Only one attempt may be made to reinsert LMA. If insertion fails on the 2nd attempt, do not delay returning to BVM using an OPA/NPA

Do not over inflate cuff.

The LMA may be used for the unconscious APO Pt. However, gentle assisted ventilation should be provided using a closed circuit resuscitator.

The LMA may be inserted in left or right lateral positions or if entrapped, in a sitting position. Pts may be managed in the lateral position when the LMA has been correctly inserted and taped in situ, using Transpore or Sleek, however, in general, it is recommended that Pts be Mx supine and carefully observed for aspiration.

If the conscious state of the Pt improves and there is an attempt to reject the LMA, remove the LMA with the cuff inflated.