The burden of musculoskeletal pain and the role of topical non-steroidal anti-inflammatory drugs (NSAIDs) in its treatment. Ten underpinning statements from a global pain faculty

This document presents the conclusions of a detailed discussion on the role of topical NSAIDs during a round table Global Pain Faculty meeting held in Amsterdam in 2019 and subsequent discussions online. The aim of this evidence-based document is to describe the impact of musculoskeletal pain both in terms of the large numbers of sufferers and its economic impact. The document considers the place of topical therapies alongside other pharmacological and non-pharmacological treatments and presents the evidence for the benefits and harms of topical NSAIDS including indicators of efficacy for three main topical NSAIDs- diclofenac, ibuprofen and ketoprofen - based on almost 15,000 participants in randomized controlled trials for acute and chronic musculoskeletal pain. These topical NSAIDs have the largest body of evidence. For acute pain, numbers needed to treat to achieve at least 50% reduction in pain are as follows with 95% confidence intervals in brackets: Diclofenac emulgel 1.8(1.5-2.1) (5170 participants), Ibuprofen gel 2.7 (1.7-4.2) (436 participants), Ketoprofen gel 2.2 (1.7-2.8) (683 participants). For chronic pain, the NNTs are Diclofenac any formulation 9.5(7-14) (5995 participants). Ketoprofen 6.9(5.5-9.3) (2573 participants). Randomized controlled trial evidence suggests that adverse events for active topical NSAIDs are similar to placebo. Finally the gaps in knowledge are considered with suggestions on how further research might help. The global pain faculty was brought together by GSK under an unrestricted educational grant.

Severe Toxicity to the New Psychoactive Substances 3-Hydroxyphencyclidine and N-Ethylhexedrone: an Analytically Confirmed Case Report

INTRODUCTION

3-Hydroxyphencyclidine (3-HO-PCP) is a new psychoactive substance (NPS) and a hydroxy derivative of phencyclidine (PCP), and N-ethylhexedrone (Hexen) is a synthetic cathinone. We describe an analytically confirmed case of acute toxicity related to the use of both 3-hydroxyphencyclidine and N-ethylhexedrone.

CASE REPORT

A 56-year-old male was brought to the Emergency Department by ambulance with hyperthermia (39.9 °C), sinus tachycardia (150 beats per minute), reduced consciousness, ocular clonus, and vertical nystagmus. He was treated with cooled intravenous (IV) fluids and IV benzodiazepines. Following 1 hour of treatment, his temperature fell to 37.7 °C, he developed rhabdomyolysis (creatine kinase peaked at 5999 IU (normal range < 229 IU)): he was managed with supportive measures and was discharged after 25 hours. The patient admitted regular use of Hexen and recent use of 3-HO-PCP. Analysis of urine and serum identified 3-hydroxyphencyclidine and metabolites, N-ethylhexedrone and metabolites, and clephedrone and metabolites.

DISCUSSION

This is a case of analytically confirmed toxicity to 3-HO-PCP and N-ethylhexedrone. The acute toxicity reported in this patient is consistent with the use of 3-HO-PCP, but there were sympathomimetic and serotonergic features potentially consistent with the cathinone N-ethylhexedrone. The description of the acute toxicity of NPS, such as these, is vital to aid medical toxicologists and emergency medicine physicians treating patients who use them.

A cloud on the horizon-a survey into the use of electronic vaping devices for recreational drug and new psychoactive substance (NPS) administration

BACKGROUND

There is limited published scientific data on vaping recreational drugs other than cannabis. A recent review suggested that 15% of people vaping cannabis have also vaped a synthetic cannabinoid receptor agonist (SCRA) and identified over 300 Internet reports of e-liquid manufacture of recreational drugs and/or new psychoactive substances (NPS).

AIM

To determine the prevalence of use of electronic vaping devices for recreational drug and NPS delivery in the UK.

DESIGN

A voluntary online survey using a convenience sample of UK adult participants (aged 16 years old and over) identified by a market research company.

METHODS

Data was collected regarding demographics, smoking history, electronic vaping device history and recreational drug/NPS use and route of administration.

RESULTS

There were 2501 respondents. The mean (±SD) age was 46.2 ± 16.8 years old. The commonest lifetime recreational drug used was Cannabis (818, 32.7%). The majority of respondents had smoked (1545, 61.8%) with 731 (29.2%) being current smokers. The most commonly used SCRA product was 'Spice Gold' (173, 6.9%) and SCRA compound was ADB-CHMICA (48, 1.9%). 861 (34.4%) had used an electronic vaping device; 340 (13.6%) having used them for recreational drug administration; 236 (9.4%) reporting current use. The commonest lifetime recreational drug to be vaped was cannabis (155, 65.7%), with electronic cigarettes (230, 48.2%) being the commonest reported route of SCRA compound administration.

CONCLUSION

9.4% of respondents currently use electronic vaping devices for recreational drug administration with 6.2% reporting lifetime cannabis vaping use. Further larger scale studies are required to help inform the appropriate treatment and primary prevention strategies.

Adverse Drug Reactions in the Intensive Care Unit

Adverse drug reactions (ADRs) are undesirable effects of medications used in normal doses [1]. ADRs can occur during treatment in an intensive care unit (ICU) or result in ICU admissions. A meta-analysis of 4139 studies suggests the incidence of ADRs among hospitalized patients is 17% [2]. Because of underreporting and misdiagnosis, the incidence of ADRs may be much higher and has been reported to be as high as 36% [3]. Critically ill patients are at especially high risk because of medical complexity, numerous high-alert medications, complex and often challenging drug dosing and medication regimens, and opportunity for error related to the distractions of the ICU environment [4]. Table 1 summarizes the ADRs included in this chapter.

Toxicant-Induced Hepatic Injury

The sudden failure of a previously healthy and functioning liver is a dramatic and devastating event. Acute liver failure is the common final pathway of a multitude of conditions and insults, all of which result in massive hepatic necrosis or loss of normal hepatic function. The ensuing multiorgan system failure frequently has a fatal outcome, with mortality rates in most series ranging from approximately 55% to 95% [1]. Acute liver failure (ALF, previously often referred to as fulminant hepatic failure (FHF)) knows no age boundaries, with many cases occurring in those younger than 30 years. Short of excellent intensive care unit (ICU) support and liver transplantation in selected cases, few viable treatment options are available. Over the past few decades, however, survival has been improved by anticipation, recognition, and early treatment of associated complications, as well as the application of prognostic criteria for early identification of patients requiring liver transplantation (along with improvement in the techniques and science of transplantation itself). The etiology of ALF varies from country to country and the incidence change over time. Paracetamol (acetaminophen) has now replaced viral hepatitis as the leading cause of ALF [2]. In a study from London including 310 patients with ALF in the period 1994–2004, 42% of the cases were caused by paracetamol [3], whereas this was only the cause in 2% of 267 patients in Spain from 1992 to 2000 [4]. However, less than 10% of all liver transplants are performed in patients with ALF [5, 6].

Sparkle lamp ingestion: a rare cause of death

A 51-year-old man was brought to the emergency department after he had drunk 200 mL of fluid from a decorative sparkle lamp. His calcium level was 4.99 mmol/L with a blood gas pH of 7.21. His calcium levels were corrected and his acidosis improved, but his stay in the intensive care department was complicated on day 10 by upper gastrointestinal hemorrhage because of caustic erosions in his stomach. Ten days after admission, he had an emergency right hemicolectomy during which residual luminescent particles were found to have eroded through his cecal mucosa. He eventually died 15 days after admission because of disseminated intravascular coagulopathy and refractory septic shock. This case demonstrates the potential for fatal toxicity associated with ingestion of a common household item.

A modified low-cost colorimetric method for paracetamol (acetaminophen) measurement in plasma

BACKGROUND

Despite a significant increase in the number of patients with paracetamol poisoning in the developing world, plasma paracetamol assays are not widely available. The purpose of this study was to assess a low-cost modified colorimetric paracetamol assay that has the potential to be performed in small laboratories with restricted resources.

METHODS

The paracetamol assay used in this study was based on the Glynn and Kendal colorimetric method with a few modifications to decrease the production of nitrous gas and thereby reduce infrastructure costs. Preliminary validation studies were performed using spiked aqueous samples with known concentrations of paracetamol. Subsequently, the results from the colorimetric method for 114 stored clinical samples from patients with paracetamol poisoning were compared with those from the current gold-standard high-performance liquid chromatography method. A prospective survey, assessing the clinical use of the paracetamol assay, was performed on all patients with paracetamol poisoning attending the Peradeniya General Hospital, Sri Lanka, over a 10-month period.

RESULTS

The recovery study showed an excellent correlation (r(2) > 0.998) for paracetamol concentrations from 25 to 400 mg/L. The final yellow color was stable for at least 10 min at room temperature. There was also excellent correlation with the high-performance liquid chromatography method (r(2) = 0.9758). In the clinical cohort study, use of the antidote N-acetylcysteine was avoided in over a third of patients who had the plasma paracetamol concentration measured. The cost of consumables used per assay was $0.50 (US).

CONCLUSIONS

This colorimetric paracetamol assay is reliable and accurate and can be performed rapidly, easily, and economically. Use of this assay in resource-poor clinical settings has the potential to have a significant clinical and economic impact on the management of paracetamol poisoning.

Paracetamol (acetaminophen) pack size restrictions and poisoning severity: time trends in enquiries to a UK poisons centre

BACKGROUND AND OBJECTIVE

In September 1998, legislation was introduced in the United Kingdom to limit paracetamol pack sizes to 16 tablets of 500 mg at general sales outlets and 32 tablets of 500 mg at pharmacies. The effect of the regulations on severity of paracetamol poisoning is unclear. The aim of this study was to describe trends in the severity of paracetamol poisoning and to assess the impact of the 1998 Regulations on the enquiries to a UK poisons centre.

METHODS

We extracted data about the age, sex and number of tablets or capsules of paracetamol ingested by patients notified to Guy's and St Thomas' Poisons Unit (London, UK) between 1996 and 2004.

RESULTS AND DISCUSSION

During the study period, there were approximately 140 000 patients with suspected paracetamol poisoning, accounting for around 11% of all patients reported to the poisons unit. The median number of tablets fell from 25 to 20 for males and 20 to 16 for females after 1998. There was also a reduction in the proportion of patients who ingested 17-32 tablets (from 36% to 30%) and 33-100 tablets (from 25% to 19%).

CONCLUSION

Following the 1998 Regulations there was a decline in the severity, but not frequency, of paracetamol poisoning cases reported to Guy's and St Thomas' Poisons Unit. It is unclear whether the decline in severity was a direct consequence of the regulations.

Prolonged clinical effects in modified-release amitriptyline poisoning

BACKGROUND

Tricyclic antidepressant poisoning is often associated with significant cardiovascular and central nervous system toxicity. Effective treatment includes the use of appropriate gastric decontamination techniques, the administration of sodium bicarbonate, and meticulous supportive care. Tricylcic antidepressant toxicity typically lasts 24-48 hours following a significant overdose.

CASE REPORT

We describe a case of tricyclic antidepressant poisoning where significant clinical toxicity (QRS prolongation, metabolic acidosis) was observed for up to 4 days following ingestion of a modified-release preparation of amitriptyline. Successful patient recovery was associated with the use of multidose activated charcoal and repeated administration of intravenous sodium bicarbonate.

CONCLUSIONS

Clinicians should be aware of the potential for prolonged tricyclic toxicity in patients who have ingested modified-release amitriptyline in overdose. Gastric decontamination techniques such as multidose activated charcoal and whole bowel irrigation should be considered where there is evidence of ongoing tricyclic antidepressant absorption or clinical toxicity following ingestion of a modified-release preparation. These interventions may be indicated for prolonged periods (greater than 36 hours) post ingestion.

Doctors and Nurses Estimation of the Weight of Patients: A Preventable Source of Systematic Error

BACKGROUND

Although accurate determination of body weight is important in the management of the poisoned patient, many patients have their weight estimated rather than formally measured.

OBJECTIVE

To determine how good medical staff are at estimating patients*** body weights.

METHODS

Medical staff were asked to estimate the weight of six patients on a poisons ward. Estimated and actual patient weights were statistically compared.

RESULTS

Medical staff produced a large range of estimated weights for all patients. Patient weight was incorrectly estimated by greater than 10% in 61% of individual estimations. There was poor statistical correlation between actual and estimated weight.

CONCLUSIONS

All patients administered medication based on body weight and those treated following an overdose of any substance should have formal body weight determined as part of their standard management.

Primary liposarcoma of the omentum: a case report and review of the literature

A case of round cell liposarcoma of omentum in a 45-year-old man is reported. The patient presented with abdominal pain, swelling and fever of 4-month duration. Abdominal ultrasonography and computed tomogram confirmed the presence of an abdominal mass, but the omental origin of the tumour was revealed only on laparotomy. In addition to the main tumour mass, multiple nodules were present in the omentum. The tumour was excised with omentum. Histopathology of the tumour revealed a round cell liposarcoma. The patient expired 9 months after operation. Eight other cases of liposarcoma of omentum reported in English literature are reviewed.

Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Intravenous bolus or infusion of naloxone in opioid overdose

A short cut review was carried out to establish whether intravenous boluses of naloxone are better than intravenous infusion in opioid overdose. Altogether 188 papers were found using the reported search, of which one presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of this best paper is tabulated. A clinical bottom line is stated.

Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Intravenous or intramuscular/subcutaneous naloxone in opioid overdose

A short cut review was carried out to establish whether intramuscular/subcutaneous naloxone is better than intravenous naloxone in opioid overdose. Altogether 185 papers were found using the reported search, of which two presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. A clinical bottom line is stated.

Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Discharge of patients who have taken an overdose of opioids

A short cut review was carried out to establish whether patients with no recurrence of symptoms one hour after receiving naloxone for an opioid overdose can safely be discharged. Altogether 195 papers were found using the reported search, of which five presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. A clinical bottom line is stated.

Case report: Survival after deliberate strychnine self-poisoning, with toxicokinetic data

INTRODUCTION

Strychnine poisoning is uncommon, and in most severe cases, the patient dies before reaching hospital. The management of strychnine poisoning is well documented, although there are few data on the kinetics of elimination of strychnine after overdose.

CASE REPORT

A 42-year-old man presented shortly after ingestion of an unknown quantity of strychnine powder. After a respiratory arrest, with intensive supportive management requiring admission to an intensive care unit, he survived. Eight serum samples were taken over the first 5 days and analysed subsequently for strychnine concentrations.

RESULTS

The initial concentration at 1.5 hours after ingestion was 4.73 mg/l, falling to 0.38 mg/l at 74 hours postingestion. Serum concentrations followed a monoexponential elimination curve with a calculated elimination half-life of 12 hours.

DISCUSSION AND CONCLUSION

Strychnine poisoning presents with classical features, and with early diagnosis and supportive management, the patient can survive. The initial serum concentration of 4.73 mg/l is the highest reported concentration in a patient who has survived. Previous reports of the elimination half-life have suggested it is between 10 and 16 hours, which conforms to the elimination data in our case.

How feasible is it to conform to the European guidelines on administration of activated charcoal within one hour of an overdose?

OBJECTIVES

The European and American position statement on the use of activated charcoal recommends its administration within an hour of ingestion of a charcoal binding poison. But in reality, this time limit is difficult to follow for the majority of poisoned patients. This study aimed to examine the treatment of acutely poisoned patients with activated charcoal in an accident and emergency (A&E) department.

METHODS

63 patients who had taken potentially serious overdoses and required hospital admission from a London teaching hospital A&E department were identified over a six month period. The patients' case notes were analysed for age, sex, substances taken, and the timing of their management within the A&E department.

RESULTS

Median time of arrival after overdose was 136 minutes, and only 15 patients presented within an hour. Ten of these 15 patients were given activated charcoal, and only four of the 10 received it within the one hour limit. Sixteen patients received charcoal outside the time limit. Subanalysis of the individual cases given charcoal shows that triaging is fast (median five minutes), but a significant time delay occurs after this before charcoal is administered (median 21 minutes).

CONCLUSIONS

These results are likely to be exaggerated in rural hospitals and demonstrate the difficulty of adhering to the recommended guidelines, unless activated charcoal can be safely administered to appropriate patients in the prehospital environment.

Agenesis of gallbladder in symptomatic patients

Three women and one man among 771 patients, who underwent laparotomy with diagnosis of symptomatic gallbladder disease over a period of 5 years, were found to have agenesis of the gallbladder. Preoperative ultrasonography suggested cholelithiasis in all the four patients; three patients with jaundice had choledocholithiasis in addition. The absence of gallbladder was established by meticulous operative exploration and carefully repeated ultrasonography in postoperative period. The patients having choledocholithiasis underwent choledocholithotomy, while the fourth patient had no definitive procedure. One patient expired on 17th postoperative day following biliary leak, septicemia and liver failure. Another two patients were well and symptom free, while the fourth patient remained symptomatic. Awareness of the possibility of agenesis of gallbladder may allow the surgeon to attempt confirmation of diagnosis by non-operative methods and avoid surgical exploration in specific instances.