Total thyroidectomy is recommended as a line of
management of thyroid cancer in many cases. Our aim was to
compare postoperative analgesic effect of local ketamine 1 mg/kg
instilled in the wound to that of intramuscular (IM) ketamine and
placebo after total thyroidectomy.
Methods: A total of 90 patients aged 18 to 60 years, American
Society of Anesthesiologists (ASA) class I to II, with a body weight
of 50 to 90 kg, scheduled for total thyroidectomy were enrolled
after ethics committee approval in this prospective, randomized,
double-blind, controlled study and divided randomly into 3 groups
to receive treatment after hemostasis. Group (I) received 1 mg/kg
ketamine in a total volume of 10mL normal saline instilled in the
wound. Group (II) received 1 mg/kg of IM ketamine. Group (III)
received 10mL of normal saline instilled in the wound. Total
amount of morphine consumption, first request of analgesia, and
side effects were recorded. Visual analog scale at rest and movement
and hemodynamics were assessed immediately, 1, 2, 4, 6, 12,
and 24 hours postoperatively.
Results: Total morphine consumption was reduced and first request
of analgesia was delayed in group I compared with that in groups II
and III, and in group II compared with that in group III
(P=0.000). Visual analog scale at rest and movement were
decreased immediately postoperatively in groups I and II in comparison
with their values in group III; group II had higher sedation
scores.
Conclusions: Local wound ketamine instillation provided superior
postoperative analgesia with lower incidence of side effects in
comparison with IM ketamine and placebo following total
thyroidectomy.