News & Research

Shivering is an unpleasant experience after spinal anesthesia. Shivering is defined as an
involuntary, repetitive activity of skeletal muscles. The mechanisms of shivering in patients
undergoing surgery are mainly intraoperative heat loss, increased sympathetic tone, pain, and
systemic release of pyrogens. Spinal anesthesia significantly impairs the thermoregulation
system by inhibiting tonic vasoconstriction, which plays a significant role in temperature
regulation. Spinal anesthesia also causes redistribution of core heat from the trunk (below
the block level) to the peripheral tissues. These two effects predispose patients to
hypothermia and shivering. The median incidence of shivering related to regional anesthesia
observed in a review of 21 studies is 55%. Shivering increases oxygen consumption, lactic
acidosis, carbon dioxide production, and metabolic rate by up to 400%. Therefore, shivering
may cause problems in patients with low cardiac and pulmonary reserves. The best way to avoid
these intraoperative and postoperative shivering-induced increases in hemodynamic and
metabolic demands is to prevent shivering in the first place. Although magnesium is among
several pharmacological agents used for the treatment of shivering, its effects on prevention
of shivering during central neuraxial blockade have not been evaluated to date. Henceforth,
the aim of this study was to evaluate the effect of magnesiume on shivering during spinal
anesthesia.

Aim:

to compare the efficacy of intravenous versus intrathecal magnesium sulphate for prevention
of post spinal shivering in adult patients undergoing elective lower limb orthopedic
surgeries.