Prediction of postoperative pain after percutaneous nephrolithotomy: can preoperative experimental pain assessment identify patients at risk?

Postoperative pain remains a significant problem and the individual variance in postoperative pain is not fully understood. In recent years, there has been focus on identifying risk factors predicting patients with high postoperative pain intensity or consumption of analgesics, which may facilitate an improvement in rehabilitation. This study evaluates the relationship between preoperative experimental pain assessment and postoperative pain and opioid consumption. Forty-four patients with uni- or bilateral kidney stone disease scheduled for percutaneous nephrolithotomy were included. The preoperative pain thresholds were measured using electrical (single and 5 repeated) and pressure pain stimulation over the flank bilaterally (stone-side = operation side and control-side = non-operation side). Postoperative pain scores were recorded on a numerical rating scale and analgesic consumption was registered. The responses to repeated electrical stimuli (temporal summation) were preoperatively increased on the stone-side compared to the control-side (P = 0.016). Preoperative electrical pain thresholds from the control-side correlated inversely with postoperative opioid consumption (single stimuli: ρ = ?0.43, P < 0.01; repeated stimuli: ρ = ?0.45, P < 0.005). This correlation was more pronounced for the 22 patients with unilateral renal calculi (single stimuli: ρ = ?0.54, P < 0.02; repeated stimuli: ρ = ?0.58, P < 0.01). There were no other correlations between the preoperative sensory tests and postoperative pain or opioid consumption. This study showed a correlation between the preoperative electrical pain thresholds on the control-side and postoperative opioid consumption after percutaneous nephrolithotomy. Preoperative measurement of the electrical pain thresholds may, therefore, be useful as a screening tool to identify patients at high risk of postoperative pain.     

The Effect of a Combination of Diclofenac and Methadone Applied as Gel in a Human Experimental Pain Model – A Randomized,Placebo‐controlled Trial

Pain involves responses in which both peripheral and central mechanisms contribute to the generation of pain. Pre‐clinical laboratory data have supported that a topical formulation of combined diclofenac and methadone (Diclometh) may alleviate local pain, and potentially, the side effect profile should be low. We hypothesized that antiallodynic and antihyperalgesic effects of Diclometh could be demonstrated in a human experimental pain model and that Diclometh would be safe to administer. Thus, the aims were as follows: (i) to compare two doses of Diclometh versus placebo; and (ii) to assess the safety profile of Diclometh. The study was a crossover, randomized, double‐blind, placebo‐controlled comparison of two doses of Diclometh gel (0.1% and 0.2%) administered topically in healthy participants. Nerve growth factor (NGF) and capsaicin intradermal injections were used as human pain models. Pressure stimulation, contact heat stimulation, hyperalgesia (pinprick stimulation) and allodynia (brush stimulation) to mechanical stimulation were performed in the area where capsaicin and NGF were injected. Side effects were recorded on a four‐point Likert scale. Twenty‐one men completed the study (mean age 26.14 ± 5.3). Diclometh 0.2% reduced the capsaicin‐induced dynamic mechanical allodynia compared to placebo (primary end‐point, p = 0.03). No other primary or secondary end‐points were found significantly different (all p > 0.05). All side effects were reported as mild with no differences between treatments (p = 0.15). Indication of antiallodynic effect of Diclometh 0.2% was found. Additionally, it was demonstrated that Diclometh was safe to use.     

Impact of pharmaceutical care on adherence, hospitalisations and mortality in elderly patients

Background Elderly polypharmacy patients may be more at risk of not adhering to medication. If so, the underlying reasons may be more readily disclosed during private discussions with patients. Hence pharmaceutical care discussions at home might improve treatment adherence. Objective The aim of this study was to investigate the impact of pharmaceutical care on medication adherence, hospitalisation and mortality in elderly patients prescribed polypharmacy. Setting Pharmaceutical care discussed at home. Methods A randomised controlled trial with two arms; pharmaceutical care (n = 315) and controls (n = 315) was designed. It involved patients aged 65+ years living in Aarhus, Denmark who used five drugs or more without assistance. Pharmacists visited the pharmaceuticalcare patients at home, once only, and followed them during the subsequent year with three telephone calls. Non-adherence was measured by a pill-count. Patients were categorised as non-adherent if their mean adherence rate for all drugs consumed was <80 %. The impact of pharmaceutical care on non-adherence and hospitalisation was analysed by 2 × 2 tables, and mortality by Cox regression. Main outcome measure Medication adherence, hospitalisation and mortality. Results The final analyses included 517 patients (median age 74 years; females 52 %). Dropouts were more frequent for the pharmaceutical-care group than for controls. Pharmacists encountered drug-related problems amongst 72 % of pharmaceutical-care patients. Pharmaceutical-care patients (11 %) and control patients (10 %) were similarly nonadherent (Odds ratio 1.14; 95 % confidence interval 0.65–2.00), and similar with respect to hospitalisation frequency (30 vs. 28 %; Odds ratio 1.14; 95 % confidence interval 0.78–1.67) and mortality (7.5 vs. 5 %; Hazard ratio 1.41; 95 % confidence interval 0.71–2.82). Conclusions Pharmaceutical care given to our elderly polypharmacy patients made no significant impact on medication adherence, hospitalisation or mortality, when compared to comparable control patients.