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The role of analgesia and sedation in intensive care units (ICU) is ancillary to other intensive care strategies, nevertheless they permit that every other diagnostic and therapeutic procedure is safely performed by keeping the patient pain-free, anxiety-free and cooperative. Commonly used opioids in ICU include morphine, fentanyl, sufentanil and remifentanil. The choice among opioid drugs relies on their pharmacokinetics and their pharmacodynamic effects. Cardiovascular stability observed with fentanyl and sufentanil indicates their use in hemodynamically compromised patients. Short-acting remifentanil offers several advantages in patients requiring prolonged infusions. The organ-independent metabolism of this newer molecule may be valuable in patients with multiple organ failure. The main indications for opioid analgesia and sedation in ICU include: 1) Anxiety, pain and agitation: in turn, they can increase cardiac workload, myocardial oxygen consumption and rate of dysarrhythmias; 2) immediate postoperative period after major surgery; 3) short-term invasive procedures. Potential advantages offered by opioids in the ICU setting also include: a) Cardiac protection: in animal models, it has been observed that delta-opiate receptor stimulation confers a preconditioning-like protective effects against myocardial ischemia; b) Neuroprotection: recent studies suggest that mu- and kappa-opiate receptors are involved in ischemic preconditioning against seizures in the brain. During opioid therapy in the ICU, drug tolerance and withdrawal symptoms should be anticipated and the dose adjusted accordingly.

Background: The aim of this study was to evaluate the effects of remifentanil in comparison with those of fentanyl on the hemodynamic response to orotracheal intubation., Experimental Design: prospective comparative and randomized study., Setting: operating room in a neurosurgery department at University., Patients: 50 patients, ASA I or II with age ranging from 32 to 64 years were divided in two groups randomly., Interventions: 25 patients received fentanyl as single bolus dose of 2.0 micrograms/kg and atropine 0.01 mg/kg i.v. as premedication while the remainders received atropine 0.01 mg/kg i.v. and remifentanil 0.2 microgram/kg/min as infusion. All patients were induced with propofol 2.0 mg/kg and cisatracurium 0.15 mg/kg for muscle relaxation and were intubated 4 min after induction of anesthesia., Measurements: Heart rate, SAP, DAP, MAP and RPP were recorded at different times: baseline, induction, intubation, 1, 2, 3 and 4 min after intubation; ECG and pulsoximetry were monitored continuously. Statistical analysis was carried out using ANOVA for repeated measures and Bonferroni t-test a value of p < 0.05 was considered to be significant., Results: Significant increases in PAS were recorded, at intubation and at 1 min after in patients treated with fentanyl; in the remifentanil group significant decreases in SAP at induction and at 4 min after intubation were recorded. HR increased significantly at intubation and at 1, 2 and 3 min after in the fentanyl group. RPP showed a significant decrease at induction in the remifentanil group and significant increases at intubation and at 1, 2 and 3 min after in patients treated with fentanyl., Conclusion: In conclusion remifentanil was found to properly control the hemodynamic response to intubation in comparison with fentanyl.

Background: The aim of this study was to evaluate the effects of sufentanil in comparison with those of fentanyl during balanced anesthesia in patients undergoing neurosurgery., Experimental Design: prospective randomized study., Setting: operating room in a neurosurgery University department., Patients: 50 patients, ASA I and II with age ranging from 18 to 77 years were divided in two groups randomly., Interventions: 25 patients received sufentanil as single bolus dose of 0.2 microgram/kg i.v. as premedication and supplemental bolus doses of 0.15 microgram/kg during the maintenance of anesthesia while the remainders received fentanyl 2.0 micrograms/kg as premedication and supplemental boluses of 1.5 micrograms/kg. All patients were induced with propofol 2.5 mg/kg, were intubated after cisatracurium 0.15 mg/kg for muscle relaxation, then were ventilated with sevoflurane and O2:N2O (1:1)., Measurements: heart rate, SAP, DAP and MAP were recorded at different times and ECG, ETCO2 and pulsoximetry were monitored continuously. Furthermore postoperative analgesia by VAS, recovery time and inspiratory concentrations of the volatile anesthetic were evaluated. Statistical analysis was carried out using ANOVA for repeated measures and Bonferroni "t"-test; a value of p < 0.05 was considered to be significant., Results: Significant changes in MAP (at IOT and 1 and 2 min after IOT), in HR (at IOT) and in RPP (at IOT and 1, 2 and 3 min after IOT) were recorded in group F. Recovery time was shorter in group S than in group F and postoperative analgesia was more prolonged in group S. Inspiratory concentrations of volatile agent were lower in patients treated with sufentanil than in those treated with fentanyl., Conclusions: In patients treated with sufentanil a better cardiocirculatory stability was achieved with lower inspiratory concentrations of volatile agent and a well relaxed brain. Sufentanil can be considered a valid alternative to fentanyl as analgesic agent in balanced anesthesia for neurosurgery.

Remifentanil (R) is a novel short-acting mu-receptor opioid. R is in the same structural family as fentanyl and the other phenylpiperidines, but it differs from fentanyl because of its pharmacokinetic profile and its metabolism: R undergoes extrahepatic metabolism by blood and tissue nonspecific esterases. For these reasons the time required for decreases of any percentage plasmatic concentrations of R after termination of the infusion is independent of infusion duration. The pharmacokinetic profile of R is organ-independent and the dosing regimen must be regulated in elderly patients by reducing the bolus and infusion doses, and in obese subjects by calculating the intravenous dosages as a function of age and lean body mass. The placental transfer of R doesn't affect the newborn as recently described in literature but further and wider clinical experiences are needed for assessing the use of R in obstetric anesthesia. R causes either a reduction in the MAC of volatile anesthetics or a decrease in propofol requirements but it cannot be used as a sole anesthetic agent. R can be utilized to facilitate tracheal intubation without using muscle relaxants, to manage analgesia and sedation also in association with midazolam and/or propofol, furthermore as analgesic agent for monitored anesthesia care, for the critical patient in ICU and for the postoperative analgesia if a proper analgesic strategy had not been planned.

Background: To evaluate the efficacy of propofol as the sole anaesthetic agent for the anaesthetic management of the trigeminal rhizolysis., Experimental Design: retrospective study., Setting: operating room of the Neurosurgery Department at University., Patients: 200 patients were studied, 115 males and 85 females, with mean age of 62.8 +/- 3.6 years, ASA status I, II or III and with various underlying medical problems., Interventions: patients were premedicated with atropine 0.01 mg/kg i.v. 10 min before the induction of anaesthesia. The induction dose of P was titrated to the desired level in according to age and clinical conditions. After induction of anaesthesia the surgeon started the needle placement through the foramen ovale in the trigeminal cistern., Measurements: during both procedures the mean dose of P, induction and recovery times, side effects and complications and quality of anaesthesia were assessed. Statistical analysis of the data was carried out using ANOVA for repeated measures and Bonferroni "t"-test and a value of p < 0.05 was considered to be significant., Results: Anaesthesia was successfully induced after a mean dose of 1.9 mg/kg of P during PG and of 2.1 mg/kg during PR. A few side effects and short recovery time were recorded in all cases. P also provided an adequate cardiovascular stability during PG and PR., Conclusions: In conclusion, P can be considered suitable for this particular neurosurgical procedure requiring short period of anaesthesia and rapid recovery time in order to communicate with the neurosurgeon during the sensory testing.

Background: The aim of this study was to evaluate the effects of mivacurium on the cerebrospinal fluid pressure (CSFP) in patients requiring muscle relaxation to facilitate mechanical ventilation and on the intracranial pressure (ICP) in patients undergoing neurosurgery., Experimental Design: prospective study., Setting: ICU in a hospital and operating room in a neurosurgery department at University., Patients: 12 patients, GCS 6-7, with a mean age of 62.6 +/- 6.2 were studied in ICU and 10 patients, ASA I-II, with a mean age of 58.6 +/- 6.4 were studied in the operating room., Interventions: all patients received mivacurium as single bolus dose of 0.2 mg/kg i.v., Measurements: Heart rate, SAP, DAP and MAP were recorded at different times. In ICU CSFP was measured via a catheter in lumbar subarachnoid space and in operating room ICP was measured via an intraventricular catheter. CPP was evaluated as the difference between MAP and ICP. Statistical analysis was carried out using ANOVA for repeated measures and Bonferroni "t"-test and a value of p < 0.05 was considered to be significant., Results: Mivacurium was found not to influence or to increase ICP or CSFP. No significant changes in cardiocirculatory parameters were recorded in all patients., Conclusions: In conclusion, mivacurium can be considered a suitable and manageable neuromuscular blocking drug in the management of patients with intracranial pathology.

A new experimental trial to investigate the usefulness of early therapeutic measures in case of acute I.V.D. has been performed, on the basis of a previous already reported experience. A combined treatment consisting of hemodilution and revascularization starting 16 hours after the onset of cerebral ischemia was tested. The study was performed in a population of 20 New Zealand male rabbits in which an acute cerebral ischemia was achieved by means of extracranial ligation of both common carotid artery and of one vertebral artery. The animals were divided into two groups. 1st group: no treatment; 2nd group: revascularization + hemodilution. Better results were observed in treated group considering either CBF rates or histological changes.