Spinal Anaesthetic Clinical Trial
Official title:
Granisteron Versus Ondansetron for Prophylaxis Against Post-Spinal Anesthesia Shivering: a Randomized Controlled Study
3. Scientific committee approval (Was it scientifically approved by the department?) Yes
Date of approval: Sunday ,1ST September,2019
Background and Rationale:
Regional anesthesia is commonly associated with intraoperative shivering which reaches
40-60%. Spinal anesthesia contributes in impairment of thermoregulation, and predisposes
patients to hypothermia, which reduces the threshold for shivering and vasoconstriction.
Other mechanisms responsible for shivering include increased sympathetic tone, pain, and
systemic release of pyrogens. Shivering causes increase in metabolic activity, oxygen
consumption, intracranial, and intraocular pressure. Shivering is also responsible for
increasing cardiac output, peripheral resistance, carbon dioxide production, and lactic
acidosis. Furthermore, shivering interferes with electrocardiogram (ECG) and pulse oximetry.
1 Post anaesthetic shivering is one of the most frequent problems in the early recovery phase
following general anaesthesia. It was considered as the sixth most important problem of
current clinical anaesthesiology among 33 low morbidity clinical outcomes. Previous studies
have found that shivering occurs up to 60% of patients in the postoperative period and varies
according to sex, age, drugs used for anaesthesia and the duration for the surgery.2 Since
shivering is a response to hypothermia, body temperature should be maintained within
36.5-37.5°C, however, shivering may be also seen in normothermic patients undergoing regional
anesthesia. A number of factors responsible for developing of hypothermia in regional
anesthesia including age, level of sensory block, temperature of the operating room and
infusion solution.3 Perioperative hypothermia and shivering can be prevented by physical
methods like surface warming or pharmacologically by drugs such as pethidine, tramadol,
clonidine, doxapram, opioids, neostigmine, magnesium sulfate and ketamine.4 Pethidine is the
most commonly used drug for post spinal anesthesia shivering. The disadvantage of pethidine
is that it can cause respiratory depression in the presence of previously administered
opioids or anaesthetics. Moreover, hypotension, nausea and vomiting are also important side
effect of pethidine.5 Pethidine, which is considered as a time-tested drug for control of
shivering, can have adverse effects such as respiratory depression, nausea, and vomiting.
which begs to investigate the efficacy of other drugs.6 5-HT antagonists had been effectively
introduced for management of perioperative shivering by inhibiting thermoregulatory response
by central mechanism. Ondansetron is a 5-HT antagonist which had been effectively used in
treatment of postoperative shivering.7 Granisteron, a new generation of 5-HT antagonists, had
been also reported effective in the prevention of Postoperative shivering.9-10 No data are
available about the comparison of both drugs, ondansetron and granisteron, for prophylaxis
against post-spinal shivering The aim of the investigator's study is to compare the efficacy
of granisteron to ondansetron for prevention of intra- and post spinal anaesthesia shivering.
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