Anesthesia Student Survival Guide.pdf - Index of

78 ● AnesthesiA student survivAl Guide
Table 7.4 Commonly used antiemetics. a
ondansetron (Zofran) 4 mg iv, may repeat x 1 (0.1mg/kg up to 4mg in children)
dolasetron (Anzemet) 12.5 mg iv, may repeat × 1
Granisetron (Kytril) 0.5–1 mg iv
Promethazine (Phenergan) 12.5–25 mg iv, may repeat × 1
dexamethasone (decadron) 4–8 mg iv, best given early during intraoperative period
droperidol (inapsine) b 0.625 mg iv, may repeat q 10 min × 3
a All dosages for adults unless noted.
b Must monitor ECG for 2 h post administration.
Droperidol blocks the transmission of dopamine, serotonin, and GABA.
Though an extremely effective antiemetic, it is typically reserved for refractory
nausea and vomiting due to concerns about QT prolongation, and the
consequent need to monitor the cardiac rhythm of patients after treatment.
Droperidol also possesses sedative properties, and was once popular as a
premedication prior to surgery.
Scopolamine is an anticholinergic drug which is often administered
preoperatively via a transdermal patch (lasts up to 3 days). Patients should be
counseled to wash their hands after the removal of a scopolamine patch, as
inadvertent rubbing of the eyes may lead to prolonged pupillary dilation.
Commonly used antiemetics and their dosages are outlined in Table 7.4.
Antihypertensives
A full discussion of all antihypertensive agents is beyond the scope of
this text, but it is worth noting that many patients require blood pressure
reduction perioperatively. As with many anesthetic agents, favored antihypertensives
tend to be available intravenously and have short (or at least
consistent) durations of action.
Beta blockers such as metoprolol or labetelol are easy to dose, and have
been shown in studies to positively affect outcomes in patients with preexisting
coronary artery disease. Esmolol is a pure b1 receptor antagonist that is
commonly used intraoperatively, because of its extremely quick onset and short
duration of action. Calcium channel blockers can be administered as boluses
or precisely titrated as drips, and are frequently used for tight control of blood