Download May 2007

Thames PAG Meeting Thursday May 17th 2007
Anaesthesia and co-existing medical conditions…
Feedback from APA meeting
Philippa Evans, GOSH (Trainee representative to the APA Council)
Philippa presented ‘the bottom line’ from some of the Manchester APA presentations:
1. Postoperative Vomiting Guideline Group (Alison Carr, Plymouth)
a. Anxious, older children with a history of PONV, having tonsillectomy,
squint surgery or groin surgery, receiving volatile agents and morphine
(N2O not a problem) – are at more risk of PONV.
b. Combination therapy (ondansetron 0.1-0.15 mg/kg, max 8mg +
dexamethosone 0.15mg/kg, max 8mg) is effective.
c. Consider prophylactic treatment in high risk patients and to keep your day
case programme running smoothly! (NB POV is rarely a problem in
infancy).
2. Regional anaesthesia: new developments
a. Surface mapping techniques are useful when classic landmarks are
absent or difficult to define – the path of a superficial nerve or plexus can
be traced by stimulating the motor component transcutaneously – the
point of maximal motor response is used as the landmark.
b. Ultrasound is increasingly becoming the method of choice for nerve
localisation.
c. Equipment for continuous peripheral nerve blocks is now available for use
in children.
d. A paediatric regimen for intralipid administration in the case of local
anaesthetic toxicity has been defined (BLS/ALS + 1ml/kg intralipid over 1
minute, repeated at 3-5 minutes to a max of 3ml/kg: convert to an infusion
of 0.25ml/kg/hr).
IV ketorolac – who is using it?
Pauline Vine, Bromley
Pauline conducted a brief survey of use of ketorolac within the group – only 1 of 17 units
responding is using it routinely, mainly in orthopaedics – concerns remain in patients
undergoing tonsillectomy. The APA pain guidelines are awaited!
Surgery in children with sickle disease
David Rees, Consultant Paediatrician, Kings College Hospital
David reviewed the pathophysiology of SSD and discussed the perioperative
management of children presenting for surgery, including preoperative transfusion, the
benefits of which remain controversial.

Preoperative transfusion raises general concerns about the risks of unnecessary
transfusion, the difficulties in achieving an exchange transfusion in a child, the
possibility of hyperviscosity which may induce a sickle crisis, also a major
concern regarding alloimmunisation, such that future transfusion, for instance
during a sickle crisis, may be almost impossible.

Preoperative transfusion may reduce sickle related perioperative complications in
some patients.

The current policy at Kings is to exchange transfuse patients undergoing high
risk surgery (cardiac, neurosurgery, craniofacial) or who are high risk-patients
(frequent sickle crises, evidence of cerebrovascular disease, pulmonary disease,
low steady state haemoglobin).

Transcranial Doppler is used as a routine annual screening test to identify
children with cerebrovascular disease, and surgery is not undertaken until TCD
has been performed.

Children having moderate or low risk surgery, or who have phenotypically mild
disease are not transfused if their Hb is greater than 7g/dl, or given a top-up
transfusion to achieve Hb 9-10g/dl if their starting Hb is <7g/dl.

All blood transfused to sickle patients should be matched for extended Rhesus
and Kell, and should be sickle negative. Blood transfusion should be avoided in
patients with red cell antibodies; such patients should be discussed with blood
bank and all blood likely to be used electively crossmatched preoperatively.

There is no evidence for therapeutic benefit of blood transfusion in priapism, and
penile irrigation should not be delayed for transfusion, unless the patient is high
risk.

The Transfusion Alternatives Preoperatively in Sickle Disease Study
(TAPS) is an international multicentre study, funded by the National Blood
Transfusion Service and the MRC, which is aimed to identify if there is any
benefit to preoperative transfusion in patients with sickle disease. Patients will be
randomised to no preoperative transfusion or preoperative top-up/partial
exchange transfusion, and the primary outcome measure will be all complications
within 30 days of surgery. High risk patients/surgery will be excluded.
Surgery and immunisation in children
Jonathan Smith, GOSH
David Elliman, Consultant in Community Child Health, GOSH
Natasha Crowcroft Consultant Medical Epidemiologist Health Protection
Agency

Immunisation is one of the most important medical interventions for protecting
individuals and the community from infectious diseases.

Up to 20% of children are not immunised.

There are concerns regarding interactions between anaesthesia and
vaccination (increased incidence of adverse reactions, reduction in efficacy of
vaccination, diagnostic difficulty with respect to postoperative complications),
but these remain theoretical rather than of significant clinical importance

The guidelines from the Department of Health state that recent or imminent
surgery or imminent general anaesthesia are not contraindications to routine
immunisations, and should be adhered to.

The decision to proceed with surgery in the child who is unwell following
vaccination should remain at the discretion of the individual anaesthetist, as it
is the case with any unwell child.
Non-cardiac surgery in children with congenital cardiac disease
Andrea Kelleher, The Royal Brompton Hospital

About 5000 babies with congenital heart disease (CHD) are born every
year; survival from treatment or palliation is improving, and the number
of patients with adult CHD is expected to increase by 25% this
decade…

CHD is classified as severe in all patients with cyanosis, also some
acyanotic lesions – AVSD, large VSD/ASD, coarctation, severe aortic
or pulmonary stenosis.

Perioperative risk is increased with increasing severity of CHD.

Patients particularly at risk for perioperative complications are
neonates and infants with CHD (for both major and minor procedures),
all those with complex CHD, all those who are cyanosed, in heart
failure or generally unwell.

Patients with pulmonary hypertension, especially where the pressure in
the right ventricle exceeds systemic pressure, are at particularly high
risk from anaesthesia.

All at risk patients should be discussed with a cardiologist (and a
cardiac anaesthetist) preoperatively; consider whether to continue onsite or transfer to a specialist centre.

Some ‘top tips: seek advice before stopping aspirin or warfarin;
consider the merits of inhalational vs careful intravenous induction,
especially in patients with low cardiac output; IPPV is generally
preferable to spontaneous ventilation; beware of air embolism in
cyanosed patients; give endocarditis prophylaxis; pay careful attention
to fluid balance and formulate a clear plan for postoperative care – the
risks are highest within the first 24hours postoperatively.

In patients with high pulmonary blood flow, or where there is a balance
between the pulmonary blood flow and systemic blood flow,
uncontrolled oxygen therapy may be hazardous (it is the best
pulmonary vasodilator we have!)

Seek advice and aim to provide individualised care; maintain
normotension, the normal balance between systemic and pulmonary
circulations, and keep oxygen saturation within 10% of preoperative
values; avoid dehydration and use fluids judiciously.

Most CHD does not need major modification of the usual anaesthetic
technique – in complex cases communication is vital.
IAW Sept 2007