Language difficulties in outpatients and their impact on a chronic pain unit in Northwest Switzerland

Many foreign patients attending our pain clinic are unable to understand one of the four Swiss national languages and are also unable to speak English. Therefore, communication with these patients can be very difficult or even impossible. Consequently, diagnosis and treatment may also prove difficult. Recognizing that language barriers can have deleterious effects, the use of an interpreter is at times the only way to communicate, however, the financial responsibility becomes that of the health care provider

The myotonias and susceptibility to malignant hyperthermia

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle in which volatile anesthetics trigger a sustained increase in intramyoplasmic Ca(2+) via release from sarcoplasmic reticulum and, possibly, entry from the extracellular milieu that leads to hypermetabolism, muscle rigidity, rhabdomyolysis, and death. Myotonias are a class of myopathies that result from gene mutations in various channels involved in skeletal muscle excitation-contraction coupling and sarcolemmal excitability, and unusual DNA sequence repeats that result in the inability of many proteins, including skeletal muscle channels that affect excitability, to undergo proper splicing. The suggestion has often been made that myotonic patients have an increased risk of developing MH. In this article, we review the physiology of muscle excitability and excitation-contraction coupling, the pathophysiology of MH and the myotonias, and review the clinical literature upon which the claims of MH susceptibility are based. We conclude that patients with these myopathies have a risk of developing MH that is equivalent to that of the general population with one potential exception, hypokalemic periodic paralysis. Despite the fact that there are no clinical reports of MH developing in patients with hypokalemic periodic paralysis, for theoretical reasons we cannot be as certain in estimating their risk of developing MH, even though we believe it is low

Association between intra-operative fentanyl dosing and postoperative nausea/vomiting and pain A prospective cohort study

BACKGROUND Postoperative nausea and/or vomiting (PONV) is one of the anaesthesia-related effects most dreaded by patients and may delay hospital discharge. Although scores and risk factors are established, many were developed before contemporary anaesthesia regimens and without focussing on modifiable anaesthesia-related variables. OBJECTIVE To examine whether, in association with a contemporary anaesthesia regimen, there is an association between intra-operative fentanyl dose and PONV, and, second, postoperative pain within the first 24 h. DESIGN Prospective, observational cohort. SETTING Single-centre university hospital. PATIENTS Inclusion criteria were opioid-naive patients without chronic pain and with a simplified Apfel score at least 2 undergoing abdominal, gynaecological or otorhinolaryngological inpatient surgery. INTERVENTION None. MAIN OUTCOME MEASURE With logistic regression, we examined three models of increasing complexity exploring the relationship between PONV and fentanyl dosing: Model 1, simplified Apfel score + intra-operative fentanyl; Model 2, Model 1 + pre-emptive antiemetic prophylaxis; Model 3, Model 2 + postoperative morphine. Model 1 was the primary analysis. Second, we explored whether or not postoperative pain scores were associated with intra-operative fentanyl dosing. RESULTS From the 363 patients, 163 (45%) experienced PONV, despite the use of total intravenous anaesthesia with propofol in more than 80% of the cohort, and some 66% of patients receiving additional antiemetic agents. After adjusting for the simplified Apfel score, higher intra-operative fentanyl dose was associated with PONV: odds ratio per mu g h(-1), 1.006 [95% confidence interval (CI) 1.002 to 1.010]. Including intra-operative fentanyl in the simplified Apfel score also increased the area under the receiver operator characteristics curve [0.601 (95% CI 0.555 to 0.662) vs. 0.651 (95% CI 0.594 to 0.707); P = 0.016]. Finally, a higher intra-operative fentanyl dose was associated with higher 24 h pain scores (P = 0.001) and a trend towards higher 24 h morphine requirements (P = 0.055). CONCLUSION Even when using propofol and antiemetic agents, PONV within the first 24 h remained higher than expected. Intra-operative fentanyl, a modifiable risk factor, is associated with the incidence of PONV and postoperative pain

Serious complications associated with external intrathecal catheters used in cancer pain patients : a systematic review and meta-analysis

BACKGROUND: Potential risks of intrathecal catheters in cancer patients include infection, bleeding, and neurologic injury. METHODS: A systematic review and a pooled analysis of observational studies were performed. Articles reporting on adverse events (infections, bleeding, granuloma, and death) associated with intrathecal catheters and external pumps in cancer patients were identified. Electronic searches of PubMed, MEDLINE, and EMBASE were conducted. Observations from different studies were pooled using a generalized mixed-effect model. Model estimates and their standard errors (SEs) were used for calculating 95% confidence intervals (CIs) on the overall proportion. RESULTS: The analysis identified 10 articles, including a total of 821 patients. Twenty catheter-related infections were identified. Of these, 10 were superficial and 10 were deep infections, with rates of 2.3% (95% CI, 0.8-6.1) and 1.4% (95% CI, 0.5-3.8), respectively. Furthermore, the authors calculated that every 71st patient had a deep infection after an average catheter duration of 54 days. The risk of bleeding was found to be 0.9% (95% CI, 0-2.0), and for neurologic injury 0.4% (95% CI, 0-1.0). The infection rates are comparable to other intrathecal catheter techniques. CONCLUSIONS: Serious complications are rare in both hospitalized and homebound patients with intrathecal catheters. This analysis supports the reasoning that the potential benefit of intrathecal catheters in the treatment of severe cancer pain is likely to outweigh the potential for serious complications associated with this technique. Therefore, an external intrathecal catheter can be considered an effective and low-cost solution for the control of pain in such patients

Tropisetron blocks analgesic action of acetaminophen : a human pain model study

Because the mechanism underlying the analgesic action of acetaminophen remains unclear, we investigated the possible interaction of acetaminophen with central serotonergic pathways. The effects of acetaminophen, tropisetron, the combination of both drugs, and saline on pain perception and central sensitization in healthy volunteers were compared. Sixteen healthy volunteers were included in this randomized, double-blind, placebo-controlled crossover study. Intracutaneous electrical stimulation (46.1 ± 19.1 mA) induced acute pain (numeric rating scale, 6 of 10) and stable areas of hyperalgesia and allodynia. Pain intensities and areas of hyperalgesia and allodynia were regularly assessed before, during, and after a 15-min infusion of acetaminophen, tropisetron, the combination of both drugs, and saline. Acetaminophen concentrations were measured to rule out any pharmacokinetic interaction. Both acetaminophen and tropisetron led to decreased pain ratings as compared to saline. However, when acetaminophen and tropisetron were administered simultaneously, the pain ratings were not affected. There was no significant difference in the evolution of the hyperalgesic and allodynic areas during the study period between the study groups (P = .06 and P = .33, respectively). Acetaminophen serum levels were not significantly different when associated with tropisetron (P = .063), although we observed a trend toward lower acetaminophen concentrations when both drugs were concurrently administered. In summary, while the combination of acetaminophen and tropisetron showed no analgesic action, each drug administered alone led to decreased pain ratings as compared to saline. In an electrically evoked human pain model, the combination of acetaminophen with tropisetron was free of any analgesic potential. However, when administered on its own, both acetaminophen and tropisetron were mildly analgesic

Analgesic and antihyperalgesic properties of propofol in a human pain model

Propofol (Disoprivan, AstraZeneca AG, Zug, Switzerland) has long been considered to be nonanalgesic. However, accumulating evidence shows that propofol possesses modulatory action on pain processing and perception. In this study, the authors investigated the modulatory effects of propofol and a formulation similar to the solvent of propofol (10% Intralipid; Fresenius Kabi, Stans, Switzerland) on pain perception and central sensitization in healthy volunteers