Hypotension fentanyl

Morphine has certain undesirable side effects. Among these are respiratory depression, nausea, and vomiting, depression of the cough reflex, cardiovascular depression and hypotension, smooth muscle contraction (constipation), and histamine release (93). Morphine s onset of action, duration, and low therapeutic indices have prompted a search for a more effective opiate iv anesthetic. Extreme simplification of the complex morphine molecule has resulted in anilido —piperidines, the fentanyl class of extremely potent opiate iv anesthetics (118,119). 

Epidural analgesia is frequently used for lower extremity procedures and pain (e.g., knee surgery, labor pain, and some abdominal procedures). Intermittent bolus or continuous infusion of preservative-free opioids (morphine, hydromorphone, or fentanyl) and local anesthetics (bupivacaine) may be used for epidural analgesia. Opiates given by this route may cause pruritus that is relieved by naloxone. Adverse effects including respiratory depression, hypotension, and urinary retention may occur. When epidural routes are used in narcotic-dependent patients, systemic analgesics must also be used to prevent withdrawal since the opioid is not absorbed and remains in the epidural space. Doses of opioids used in epidural analgesia are 10 times less than intravenous doses, and intrathecal doses are 10 times less than epidural doses (i.e., 10 mg of IV morphine is equivalent to 1 mg epidural morphine and 0.1 mg of intrathecally administered morphine).45... 

Uses HTN, stable or unstable angina Action CCB relaxes coronary vascular smooth muscle Dose 2.5-10 mg/d PO -1- w/ h atic impair Caution [C, ] Disp Tabs SE Peripheral edema, HA, palpitations, flushing Interactions t Effect of hypotension M7 antih5rpCTtensives, fentanyl, nitrates, quinidine, EtOH, grapefruit juice t risk of neurotox W/Li -1- effects W/ NSAIDs EMS Concurrent EtOH and... 

Tranquilizer, sedation, antiemetic Dose Adults. N Initial max 2.5 mg IV/EM, may repeat 1.25 mg based on response Premed 2.5-10 mg IV, 30-60 min preop Peds. Premed 0.1-0.15 mg/kg/dose Caution [C, ] Contra Component sensitivity Disp Inj SE Drowsiness, i BP, occasional tach extrapyramidal Rxns, T QT interval, arrhythmias Interactions T Effects W/ CNS depressants, fentanyl, EtOH T hypotension W/ antihypertensives, nitrates EMS Monitor ECG, may T QT interval epi may cause paradoxical hypotension, do not use fentanyl may cause HTN, do not use if possible use caution w/ analgesics and opioids may T CNS depression monitor for S/Sxs of extrapyramidal Rxns which can be treated w/ Benadryl concurrent EtOH use can T CNS depression OD May cause T of nl SEs symptomatic and supportive... 

CCB Dose 10-60 mg/d PO 4- start doses w/ elderly or hepatic impair Caution [C, ] Disp Tabs SE Edema, HA, flushing Interactions T Effects W/ antihypertensives, cimetidine, nitrates, EtOH, high-fat foods 4- effects W/ phenytoin, St. John s wort EMS T Adverse effects w/ grapefruit juice and EtOH use fentanyl and nitro w/ caution T risk of photosensitivity Rxn OD May cause hypotension, tach, and CV collapse calcium salts can be given as antidote... 

An exception to the relatively safe use of high-potency agents has been noted in the combination of droperidol with the narcotic fentanyl, which can cause marked hypotension (27). 

Several adverse effects have been reported with the combined use of fentanyl and midazolam, including chest wall rigidity, making ventilation with a bag and mask impossible (SEDA-16, 79). In neonates, hypotension can occur (SEDA-16, 80), and respiratory arrest in a child and sudden cardiac arrest have been reported (SEDA-16, 80). However, in one study there were no cardiac electrophy-siological effects of midazolam combined with fentanyl in subjects undergoing cardiac electrophysiological studies (SEDA-18, 80). 

PROCARBAZINE ANALGESICS-OPIOIDS Unpredictable reactions may occur associated with hypotension and respiratory depression when procarbazine is co-administered with alfentanil, fentanyl, sufentanil or morphine Opioids cause hypotension due to arterial and venous vasodilatation, negative inotropic effects and a vagally induced bradycardia. Procarbazine can cause postural hypotension. Also attributed to an accumulation of serotonin due to inhibition of MAO Recommended that a small test dose (one-quarter of the usual dose) be administered in initially to assess the response... 

Hypotension has occurred in neonates given midazolam and fentanyl... 

Intrathecal blockade with 0.5% isobaric bupivacaine 10 mg has been compared with 0.5% isobaric bupivacaine 5 mg combined with fentanyl 25 micrograms (diluted to 2 ml with isotonic saline) in 32 patients undergoing elective cesarean section (177). The bupivacaine + fentanyl combination was associated with significantly less hypotension than bupivacaine alone (31 versus 94%) and a near 10-fold reduction in the mean ephedrine requirement (2.8 versus 23.8 mg). There were also significant differences in the incidence of nausea (31 versus 69%) and the median time to peak block (8 versus 10 minutes) with bupivacaine plus fentanyl. The authors advised further large-scale studies to quantify the minimum dose of bupivacaine plus fentanyl for single-dose spinal anesthesia. 

When an opioid is used as the sole agent by the epidural or intrathecal route, the results are disappointing, because of unwanted adverse effects, such as pruritus, nausea, vomiting, respiratory depression, and effects on the neonate, caused by significant systemic absorption (SEDA-17, 85). Hypotension and changes in fetal heart rate are not uncommon (SEDA-21, 91). Combinations of opioids (alfentanil, fentanyl, morphine, sufentanil) with local anesthetics (for example bupivacaine) have therefore been suggested to yield better results (SEDA-18, 83). 

Cardiovascular adverse effects are minimal with pancuronium. Ganglion blockade does not occur. Shght dose-dependent rises in heart rate, blood pressure, and cardiac output are common (5), but are often masked by the actions of other co-administered agents, such as fentanyl or halothane, which cause bradycardia or hypotension. These adverse effects of pancuronium are thus often beneficial and can be deliberately harnessed. Several mechanisms contribute vagal blockade via selective blockade of cardiac muscarinic receptors (6), release of noradrenaline from adrenergic nerve endings (7), increased blood catecholamine concentrations (8), inhibition of neuronal catecholamine reuptake (9-11), and direct effects on myocardial contractility (12). These have been reviewed (13-15). 

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