Reinforced LMAs for paediatric tonsillectomy

Lesley Aitken

April 2008

Day-case tonsillectomy in Epsom

• 98% Day-case discharge rate

• Benefits– cost – effective– Less pressure on inpatient beds– Less psychological trauma for parents and

children

Anaesthesia 2006, 61, 116 - 122

Epsom children’s ENT day-case anaesthesia protocol

• Clear fluids up to 2hrs pre-op• EMLA or ametop• Propofol induction• IV ondansetron• Oxygen/air/sevoflurane• rLMA in children aged 3 or older• Spontaneous ventilation• IV dexamethasone• PR diclofenac• PR paracetamol• IM codeine• IV crystalloids 10ml/kg

Continued (Post-op)

• Free fluids and food on demand

• Nursing observations for 6hrs post-op

• Post-op consultant-led ward round

• Nurse-led discharge 6hrs post-op

Theoretical advantages of LMA

• Avoids neuromuscular blockade• Minimises pharyngeal & laryngeal trauma• No endobronchial/oesophageal intubation• Less airway soiling• Avoids extubation risks

– Deep– Awake– Airway protection until awake

Evidence

• Canadian paeds study (1993)

• English adult & paeds study (1993)

• Meta-analysis (1996)

UK practice

• Clarke et al, BJA 99 (3): 425-8 (2007)

Airway management

<3yrs 3-16 Adult

ETT 87% 79% 73%

Reusable LMA 0.6 0.6 1

Single-use LMA 1 2 7

Reusable flexi LMA 6 9 6

Single use flexi LMA 6 9 8

Ninewells?

• Prospective survey of LMA use

• 3 critical stages:– 1. Insertion– 2. Opening of BD gag– 3. recovery

Methods

• Simple form

• All NW paeds anaesthetists with regular ENT lists

• May 2007 – January 2008

• 64 patients

Age

0

1

2

3

4

5

6

7

8

9

3 4 5 6 7 8 9 10 11 12 13 14

Age

n

Weight

0

5

10

15

20

25

30

35

10 to 15 15 to 20 20 to 30 30+

Weight in Kg

LMA size

0

5

10

15

20

25

30

2 2.5 3 4

Number of insertion attempts

0

10

20

30

40

50

60

1 2 3+

Quality of fit

GoodOKPoor

57

6 1

Tolerance of Boyle-Davis Gag

GoodOK Poor

56

2 3

Reposition after BD gag insertion?

yesno

5

58

Reposition success?

• 2 successfully repositioned

• 3 converted to ETT

Conversion to ETT

1. Airway not acceptable with BD gag open

2. Suboptimal fit (? Better with smaller LMA) and “chunky” child

3. LMA obstructed completely with BD gag

Overall airway quality

GoodOKPoor

56

5 2

Recovery

• All smooth

Problems

1. Unsatisfactory fit – 2

2. Airway compromised by BD gag – 3

3. LMA dislodged during surgery - 3

Problems (1)

• Age 6

• 43kg

• LMA maybe too big

• “chunky” child

Problems (2)

• Age 13

• 65kg

• Lots of insertion attempts

• LMA never fitted well

Problems (3,4,5)

• Ages 4-6

• 15-20kg

• Obstruction of LMA with BD gag

Problems (6+7)

• Ages 7+8

• 27-28kg

• LMA dislodged when BD gag removed

Problems (8)

• Age 9

• 40kg

• LMA good for tonsillectomy

• Dislodged at end during tooth removal

Insertion

Recovery

Wake-up

Airway protection

Controversy

• Prions

• Training issues

• Cost

Recipe for success

• Communication

• Adequate depth of anaesthesia

• Use correct LMA size

• BD gag blade size can influence success

Conclusions

• Good evidence that LMA is safe alternative

• BD gag problem area

• Majority still use ETT

• Controversy still exists

Epsom children’s ENT day-case anaesthesia protocol

• Clear fluids up to 2hrs pre-op• EMLA or ametop• Propofol induction• IV ondansetron• Oxygen/air/sevoflurane• rLMA in children aged 3 or older• Spontaneous ventilation• IV dexamethasone• PR diclofenac• PR paracetamol• IM codeine• IV crystalloids 10ml/kg