Intrathecal clonidine for postoperative analgesia in elderly patients: the influence of baricity on hemodynamic and analgesic effects.
Intrathecal (IT) clonidine is an effective analgesic, but it also produces hemodynamic depression and sedation which are likely to be related to IT clonidine's cephalad spread within the cerebrospinal fluid. We hypothesized that IT clonidine's side effects could be reduced without compromising the duration and quality of analgesia by injecting clonidine IT in a hyperbaric solution and elevating the patient's trunk. We prospectively randomized 30 elderly patients to receive IT 150 microg of either isobaric (ISO) or hyperbaric (HYPER) clonidine for postoperative analgesia after surgical repair of traumatic hip fracture. Hemodynamics, IV fluid administration, visual analog pain scores, sedation scores, and clonidine cerebrospinal fluid levels were recorded at fixed intervals. Patients in the ISO group required significantly more crystalloid fluid administration (median, 2500 mL; range, 1500-3000 mL) than those in the HYPER group (median, 1500; range, 500-3000 mL) to maintain adequate arterial blood pressure (P < 0.01). Also, the decrease in heart rate was significantly more pronounced in the ISO than in the HYPER group (P < 0.01). The duration of analgesia was significantly larger in the ISO (median, 400 min; range, 115-400 min) than in the HYPER (median, 265 min; range, 205-400 min) group (P < 0.05). Sedation scores did not differ between groups. We conclude that increasing the baricity of IT clonidine solution in the conditions of our experiment reduces hemodynamic side effects but also analgesia from IT administered clonidine.
*Department of Anesthesiology and General Intensive Care, University of Vienna, Vienna, Austria; †Department of Anesthesiology and Center for the Study of Pharmacologic Plasticity in the Presence of Pain, Wake Forest University School of Medicine, Winston-Salem, North Carolina; and ‡Department of Traumatology, University of Vienna, Vienna, Austria.
Amir
A
Baker
Walter
W
Klimscha
James C
JC
Eisenach
Xin-Hui
XH
Li
Eckart
E
Wildling
Wolfgang A
WA
Menth-Chiari
Astrid I
AI
Chiari
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003000:Clonidine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006620:Hip Fractures / Q000601:surgery; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D019637:Orthopedic Procedures; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000188:drug therapy* / Q000503:physiopathology*; D011312:Pressure; D011446:Prospective Studies
D000316:Adrenergic alpha-Agonists; D003000:Clonidine