title: Acute response to intracisternal bupivacaine in patients with refractory pain of the head and neck.
abstract: Continuous intracisternal infusion of bupivacaine for the management of intractable pain of the head and neck is effective in controlling pain in this patient group. With the catheter tip being located at the height of the C1 vertebral body, autonomic regulatory information may also be influenced by the infusion of bupivacaine. By combining direct sampling of cerebrospinal fluid (CSF), via a percutaneously placed catheter in the cisterna magna, with a noradrenaline and adrenaline isotope dilution method for examining sympathetic and adrenal medullary activity, we were able to quantify the release of brain neurotransmitters and examine efferent sympathetic nervous outflow in patients following intracisternal administration of bupivacaine. Despite severe pain, sympathetic and adrenal medullary activities were well within normal range (4.2 +/- 0.6 and 0.7 +/- 0.2 nmol min(-1), respectively, mean +/-S.E.M.). Intracisternal bupivacaine administration caused an almost instantaneous elevation in mean arterial blood pressure, increasing by 17 +/- 7 mmHg after 10 min (P < 0.01). Heart rate increased in parallel (17 +/- 5 beats min(-1)), and these changes coincided with an increase in sympathetic nervous activity, peaking with an approximately 50% increase over resting level 10 min after injection (P < 0.01). CSF levels of GABA were reduced following bupivacaine (P < 0.05). CSF catecholamines and serotonin, and EEG, remained unaffected. These results show that acutely administered bupivacaine in the cisterna magna of chronic pain sufferers leads to an activation of the sympathetic nervous system. The results suggest that the haemodynamic consequences occur as a result of interference with the neuronal circuitry in the brainstem. Although these effects are transient, they warrant caution at the induction of intracisternal local anaesthesia.
authors.affiliation: Department of Clinical Physiology, Sahlgrenska Hospital, Göteborg, Sweden. gavin.lambert@baker.edu.au
authors.forename: Gavin
authors.initials: G
authors.lastname: Lambert
authors.forename: Mikael
authors.initials: M
authors.lastname: Elam
authors.forename: Peter
authors.initials: P
authors.lastname: Friberg
authors.forename: Christopher
authors.initials: C
authors.lastname: Lundborg
authors.forename: Sinsia
authors.initials: S
authors.lastname: Gao
authors.forename: Jonas
authors.initials: J
authors.lastname: Bergquist
authors.forename: Petre
authors.initials: P
authors.lastname: Nitescu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D015306:Biogenic Monoamines / Q000134:cerebrospinal fluid; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001933:Brain Stem / Q000502:physiology; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D002395:Catecholamines / Q000134:cerebrospinal fluid; D002404:Catheterization / Q000009:adverse effects / Q000379:methods; D002946:Cisterna Magna; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010148:Intractable Pain / Q000134:cerebrospinal fluid / Q000188:drug therapy* / Q000503:physiopathology*; D012701:Serotonin / Q000134:cerebrospinal fluid; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000134:cerebrospinal fluid
chemical_list: D000779:Anesthetics, Local; D015306:Biogenic Monoamines; D002395:Catecholamines; D012701:Serotonin; D005680:gamma-Aminobutyric Acid; D002045:Bupivacaine