2.3. Surgery and perioperative setting
There was a single specialist surgeon and specialist anaesthetist for
both groups and the surgical technique did not differ between the study
groups. The surgeon was blinded to the fasting status of the patients.
No sedative premedication was administered, and the patients underwent
inhalational induction with sevoflurane. Fentanyl 1mg/kg was used for
anaesthesia induction, and the patients were not paralyzed for
endotracheal intubation. In addition, the patients received
Dexamethasone 0.1 mg/kg, Paracetamol 12.5mg/kg, Clonidine 1mcg/kg and
intravenous antibiotics. The fluid deficit was calculated using the
Holliday–Segar formula(100ml/kg/day for the first 10kg of weight,
50ml/kg/day for the next 10kg and 20ml/kg/day for the weight over 20kg).
Intravenous fluid(Lactated Ringers) was given as a bolus
intraoperatively to correct for the calculated fluid deficit.
Anaesthesia was maintained with 1—2 MAC of sevoflurane in air,
depending on the required level of anaesthesia.
During the surgery, preemptive analgesia-administration of local
anaesthetic was given prior to excision of tonsils. Bupivicaine with
epinephrine 0.25% or Ropivacaine 1% was administered to the lesser
palatine nerves at the junction of the hard and soft palate. During the
operation, the specialist surgeon focused on minimal tissue damage to
key areas – anterior and posterior tonsillar pillars, the uvula, the
underlying constrictor muscles, the posterior oropharyngeal mucosa, the
buccal and labial tissues and the tongue.
The adenoids were removed under direct vision with a nasally introduced
zero-degree telescope, using an appropriate sized Barnhill adenoid
curette technique, along with or without the suction diathermy at
settings of Cutting Blend 30 and Coagulation Spray 30. Complete
haemostasis was achieved with temporary nasopharyngeal gauze swabs
and/or the use of diathermy with these settings.
To remove the palatine tonsils, the diathermy device generally used the
following parameters “cutting blend” setting of 10; “coagulation
spray” setting of 7; and bipolar coagulation standard setting of 6. To
avoid injury to remaining tonsillar area tissues, the surgeon aimed to
perform firm tonsil tissue retraction to allow precise dissection of the
palatine tonsils from the underlying mucosal surfaces of the anterior
and posterior pillars which carry the neuronal fibres of the lesser
palatine nerve and the branches of the glossopharyngeal nerve fibres
respectively.
Prophylactic control of bleeding points were performed at the tonsillar
branch of the facial artery, the tonsillar branches of the ascending
pharyngeal artery, the dorsal branch of the lingual artery and the
descending palatine artery.
The surgeon minimised additional soft tissue trauma by taking care to
minimise blunt dissection of the underlying constrictor muscles,
circumvent the use of catheters for retraction of the soft palate and
avoided finger palpation of the adenoid bed. The surgeon utilised
telescopic identification through the nose to ensure good adenoidal
clearance without causing velopharyngeal incompetence or leaving
substantial residual adenoid tissue at the posterior nasal choana. The
operated area would then be checked to ensure no significant residual
clots or retained swabs, and the surgical count with the scrub nurse
would be performed.
At the end of surgery, the child was extubated when spontaneous
respiration was regular and adequate. After extubation, the child was
transferred to the postanaesthesia care unit(PACU) for continuous
monitoring of vital signs and assessment of pain, as well as nausea and
vomiting. No patients had postoperative intravenous fluids routinely
given, but were encouraged to return to normal oral intake of fluids and
food. The patients were transferred to the ward when they were fully
awake and their cardiovascular and respiratory status was stable.