Is there a connection between the clinical response after an external fixation test or a subsequent lumbar fusion and the pre-test intervertebral kinematics?

STUDY DESIGN: Evaluation of a possible correlation of clinical symptoms of chronic low back pain (LBP) patients before and after application of external spinal fixation (ESF) with three-dimensional motion patterns. OBJECTIVE: To determine whether the intervertebral kinematics in chronic LBP patients correlate with pain relief after stabilization of the suspected painful segments. SUMMARY OF BACKGROUND DATA: Chronic LBP is a complex clinical entity with mechanical, biochemical, and psychosocial components. Although clinically controversial, ESF has been shown to reduce intervertebral motion, and thus, it provides a mechanism to investigate the mechanical aspect of LBP. METHODS: Thirty-four chronic LBP patients were tested with ESF of the suspected painful segments. The subjective pain relief experienced by the patients during the test and 2 years after spinal fusion surgery was determined, along with the Oswestry Disability Index. Before removal of ESF, the three-dimensional intervertebral kinematics of the painful segments (specifically range of motion, coupling patterns, and motion asymmetries) were analyzed with a precision optoelectronic camera system during active trunk motions. A series of linear correlations were performed between the clinical measures and the motion parameters. RESULTS: The subjective pain relief during the ESF test was nominally, but not significantly, associated with lateral bending asymmetry ( = 0.22) and "abnormal" axial rotation-lateral bending coupling ( = 0.13). The improvement in the Oswestry Disability Index both post-test and at 2 years after lumbar fusion surgery was significantly correlated with the extension range of motion ( = 0.049 and = 0.036, respectively) and the extension-to-flexion range of motion ratio ( = 0.035 and = 0.044, respectively). CONCLUSIONS: The "abnormal" motion patterns of chronic LBP patients did not correlate with subjective pain relief after ESF of the suspected symptomatic levels or with the midterm outcome of subsequent lumbar fusion surgery. The results suggest that preserved motion of the symptomatic segments before surgery is positively correlated with the clinical result of the subsequent spinal fusion in case of a positive ESF test result.

Patient-controlled analgesia (PCA) with codeine for postoperative pain relief in ten extensive metabolisers and one poor metaboliser of dextromethorphan.

Postoperative pain relief with codeine was evaluated in 11 women undergoing hysterectomy. Patient-controlled analgesia (PCA) was used to administer codeine. After the study the patients were phenotyped with respect to the O-demethylation of dextromethorphan (cytochrome P4502D6 polymorphism). Ten were extensive metabolisers and one a poor metaboliser. There was a nine-fold variation in the minimum plasma concentration of codeine consistent with pain relief (40-350 ng ml-1). Two patients did not experience any effect of codeine, one of whom was a poor metaboliser of dextromethorphan, confirmed by genotyping. In the other nine patients the effective dose of codeine varied from 4.8-25.3 mg h-1.

pain relief mediated by implantable drug delivery devices.

Various totally implantable drug delivery systems from single access ports to micropumps are now available for administration of repeated boluses, and continuous or programmable infusions. In this respect, emphasis is given to a relatively cheap, totally implantable system for self-administering intraspinal opiates in the treatment of cancer pain. The SECOR pump system, developed by Cordis, consists of a dual pump with refill port and safety valve. The volume of the pliable reservoir is 12 ml and refill is accomplished with a 25-G needle. The bolus delivered with each transcutaneous activation of the pumps is 0.1 ml. Clinical results demonstrated that this patient-controlled drug delivery system is safe and provides excellent pain relief associated with terminal cancer. A possible advantage of this drug delivery system over continuous infusion pumps is that patients can elect to have the morphine delivered only when they feel pain. Thus pain relief would be maximized and tolerance build-up would be minimized.

Postobstructive chronic pancreatitis: results with distal resection.

HYPOTHESIS: For most patients with chronic obstructive pancreatitis, distal pancreatectomy confers pain relief. DESIGN: Retrospective case series. Follow-up was complete in 80% of study subjects (mean follow-up, 6.7 years). SETTING: Tertiary care center. PATIENTS: Among 484 patients with chronic pancreatitis undergoing operation from 1976 to 1997, 40 with postobstructive chronic pancreatitis were identified. Criteria for selection included an isolated, dominant major pancreatic duct stricture or cutoff, changes of chronic pancreatitis in the distal pancreas, and ostensibly normal parenchyma without calcification in the proximal gland. The patients were reviewed with regard to operative procedure, postoperative course, and outcome. MAIN OUTCOME MEASURES: Outcome measures included degree of pain relief, morbidity and mortality of operation, survival, rates of endocrine and exocrine insufficiency, and ability to return to work and/or normal activities. RESULTS: All but 1 of the 40 patients had abdominal pain, and 20 (50%) had recurrent episodes of acute pancreatitis. Suspicion of malignancy was a concern in 16 patients (40%). Thirty-eight patients underwent distal pancreatectomy; 1 had a central resection and another a Roux-en-Y cystojejunostomy. There was no operative mortality, but significant morbidity occurred in 15%. Among 31 patients with preoperative pain in whom long-term follow-up was available, complete or significant pain relief was achieved in 25 (81%); 74% returned to normal social function, but about half had some element of pancreatic insufficiency. CONCLUSIONS: Distal pancreatectomy is a safe procedure and achieves pain relief and good quality of life in a large percentage of patients (80%) with presumed postobstructive chronic pancreatitis. However, some of these patients with chronic pancreatitis involving the entire gland have disease masquerading as postobstructive chronic pancreatitis secondary to an ostensibly isolated dominant pancreatic ductal stricture.