Minerva anestesiologica
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Minerva anestesiologica · May 2003
Review[Prevention of hypotension in spinal anaesthesia carried out for caesarean section].
After describing the most commonly applied obstetric indications for caesarean section and the respective percentages reported in countries that are comparable with Italy in terms of health care standards, the clinical reasons and requirements on the basis of which it is considered that spinal anaesthesia is first choice compared to general anaesthesia in obstetrical surgery are outlined. This evidence is confirmed by the spinal anaesthesia/general anaesthesia ratio encountered in the major national and international Obstetric Hospitals. Maternal hypotension remains the most frequent and clinically important complication consequent on spinal anaesthesia in pregnant women at term. ⋯ It is pointed out that certain procedures have become part of standard practice but their effectiveness has not yet been confirmed while others are not only ineffective but also expose mother and foetus to potential complications. For others again the jury is still out on their real effectiveness. Finally, the techniques that are currently considered to be effective and shared by the majority of authors are described and these must therefore be included in the procedural protocols regarding spinal anaesthesia for caesarean section.
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Minerva anestesiologica · May 2003
Review Comparative StudyPost-operative epidural versus intravenous patient-controlled analgesia.
Patient-controlled analgesia techniques have opened a new dimension to individualize patient's need for analgesia, in the treatment of acute post-operative pain. These techniques can be used intravenously, in the epidural space, and into peripheral nerve sheets. There is a common consensus that intravenous patient-controlled analgesia should not have a continuous infusion while epidural patient-controlled analgesia (PCEA) should be programmed with a continuous infusion. ⋯ The continuous epidural infusion of opioids has the advantages of fewer fluctuations in cerebrospinal fluid concentrations of drug, but it is necessary to administer a loading bolus, to overcome the fact that it takes several hours to provide adequate analgesia. The advantages of epidural versus intravenous patient-controlled analgesia are represented by better analgesia and a reduced opioids requirement, while the advantages when compared to epidural continuous infusion are: increased efficiency, self-adjustment by the patient, higher patient satisfaction, less sedation, and lower opioids dosage. The clinical advantages of PCEA may outweigh the greater cost and invasiveness of this technique.
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Ketamine is an NMDA receptors antagonist, with a potent anaesthetic effect. NMDA receptors are involved in nociceptive modulation, in the wind-up phenomenon, in peripheral receptive fields expansion, in primary and secondary hyperalgesia, in neuronal plasticity. Ketamine effects are well-known: it produces a state of "dissociative anaesthesia", amnesia, and, at the same time, it mantains the respiratory drive effective and supports the sistemic arterial blood pressure. ⋯ The suggested doses are: Epidural or caudal route (as an ajuvant for local anaesthetic agents, in the treatment of postoperative pain): 0.5 mg/kg. Sedative/analgesic effect (for algesic procedures): 1-2 mg/kg i.v. Continuous infusion (intensive care unit): 0.5 mg/kg/h, with a range from 20-30 microg/kg/min to 80 microg/kg/min, depending on the age of the patient.
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Minerva anestesiologica · May 2003
ReviewPostanaesthetic shivering. Epidemiology, pathophysiology and approaches to prevention and management.
Postanaesthetic shivering is one of the leading causes of discomfort for patients recovering from general anesthesia. During EMG records, the distinguishing factor from shivering in fully awake patients is the existence of clonus similar to that recorded in patients with spinal cord transection. They coexist with the classic waxing and waning signals associated with cutaneous vasoconstriction (thermoregulatory shivering). ⋯ Prevention mainly entails preventing hypothermia by actively rewarming the patient. Postoperative skin surface rewarming is a way of obtaining the threshold shivering temperature while raising the skin temperature and improving the patient's comfort. However, it is less efficient than certain drugs such as meperidine, nefopam or tramadol, which act by reducing the shivering threshold temperature.