The Influence of Neuroleptanalgesic Drugs on Cerebrospinal Fluid Pressure

Abstract

The effects of the neuroleptanalgesic drug combinations, droperidol 5 mg + phenoperidine 1.5 mg, and droperidol 5 mg + fentanyl 0.1 mg, on the cerebrospinal fluid (c.s.f.) pressure, have been studied in patients with normal c.s.f. pathways during controlled ventilation. The influence of droperidol 5 mg+fentanyl 0.1 mg on intracranial pressure has also been investigated in patients with intracranial space-occupying lesions. In patients with normal c.s.f. pathways, droperidol and phenoperidine produced only small alterations in c.s.f. pressure in either direction, while droperidol plus fentanyl resulted in falls in c.s.f. pressure in each case studied, with a significant decrease in overall mean c.s.f. pressure. Similarly, in patients with intracranial space-occupying lesions, droperidol plus fentanyl produced decreases in c.s.f. pressure in all but one of the cases studied. The striking difference between the effect on c.s.f. pressure of these drugs and of the volatile anaesthetic agents could be of importance to the clinical anaesthetist dealing with head injuries or working in a neurosurgical unit, when under conditions of controlled ventilation these drugs could be used as adjuvants to nitrous oxide-oxygen anaesthesia.

Physiology of Cerebral Blood Flow

“…Methoxyflurane resembles halothane in its cerebral metabolic effects (dose-dependent CMRo 2 decrease), and also increases CBF (Michenfelder and Theye, 1973). Administration of 1.5% methoxyflurane to patients with space-occupying lesions induces an ICP increase which could not be completely counteracted by moderate hyperventilation (Fitch et al, 1969b).…”

“…A significant ICP decrease in patients with normal c.s.f. pathways as well as with intracranial spaceoccupying lesions will be associated with neuroleptanaesthesia (Fitch et al, 1969a).…”

The Effect of Nitrous Oxide and Halothane Upon the Intracranial Pressure in Hypocapnic Patients With Intracranial Disorders

“…However, the combined effect of an increase in ICP and a reduction in arterial pressure from hyperventilation with halothane may contraindicate the use of this anaesthetic agent in some patients with intracranial diseases and a labile circulation. Other anaesthetics may be preferable if dangerous cardiac depression is suspected, for example fluroxene (Jorgensen and Henriksen, 1973), or neuroleptanalgesic drugs which seem to cause a reduction in ICP (Fitch et al, 1969).…”

“…The effects of many anaesthetics upon ICP has been investigated both experimentally and clinically. While the neuroleptanalgesia techniques seem to produce a decrease in ICP (Fitch et al, 1969) all volatile agents studied so far cause an increase in intracranial pressure, as a result of cerebral vasodilatation and an increase in cerebral blood volume. The resulting intracranial hypertension may be completely or partially counteracted by hyperventilation (Jennett, McDowall and Barker, 1967;Adams et al, 1972;Henriksen and Jorgensen, 1973;Jorgensen and Henriksen, 1973).…”

Neuroleptanesthesia: current status

“…66 In a study by Fitch and coworkers, 66 this combination resulted in decreased CSF pressure in all six patients with normal CSF pathways and in eight of nine patients with intracranial space-occupying lesions during normocapnia. This result, however, was not confirmed in a later study with Innovar (0.1 ml.kg-1), 67 which found no effect on CBF and CMRO 2 during normocapnia.…”