Whole-bowel irrigation should not be used routinely in poisoned patients.

Whole-bowel irrigation is a method of gastric decontamination in the poisoned patient involving administration of large volumes of osmotically balanced polyethylene glycol-electrolyte solution to empty the gastrointestinal tract of ingested toxins before absorption, limiting systemic toxicity. While this approach may seem intuitive, and observational studies confirm it can lead to expulsion of tablets or packets in the rectal effluent, there is a lack of evidence correlating this with improved patient outcomes. Administration of whole-bowel irrigation is also challenging to the inexperienced physician and associated with adverse effects, which may be serious. Recommendations for whole-bowel irrigation are therefore limited to patients who have ingested modified-release preparations, those who have ingested pharmaceuticals not adsorbed by activated charcoal and for the removal of packages in "body packers". Until more robust evidence is available from high-quality prospective studies demonstrating efficacy, the use of whole-bowel irrigation should not be used routinely in poisoned patients.

Carbon monoxide exposures reported to the UK National Poisons Information Service: a 4-year study.

BACKGROUND: Unintentional carbon monoxide (CO) poisoning poses a public health challenge. The UK National Poisons Information Service (NPIS) provides advice to healthcare professionals via the online database, TOXBASE®, and a 24-hour telephone line. Our aim was to analyse all CO-related enquiries to the NPIS. METHODS: We analysed enquiries regarding unintentional CO exposure (1st July 2015-30th June 2019). Information on patient demographics, CO source and location, clinical features and poisoning severity was collected from telephone enquiries and TOXBASE accesses. RESULTS: 2970 unintentional non-fire-related CO exposures were reported. Exposures occurred commonly in the home (60%) with faulty boilers frequently implicated (27.4%). Although five fatalities were reported, 68.7% of patients experienced no or minor symptoms only (headache most frequently reported). Despite being the gold standard measurement, blood carboxyhaemoglobin concentration was only recorded in 25.6% patients, with no statistically significant correlation with severity. CONCLUSIONS: Unintentional CO exposures in the UK commonly occur in domestic settings and although are generally of low severity, fatalities continue to occur. Carboxyhaemoglobin measurement is important to confirm exposure but further work is required to assess its validity as a prognostic indicator in CO exposure. Public health policy should continue to focus on raising awareness of the dangers of CO.

Reduction of adverse effects from intravenous acetylcysteine treatment for paracetamol poisoning: a randomised controlled trial.

BACKGROUND: Paracetamol poisoning is common worldwide. It is treated with intravenous acetylcysteine, but the standard regimen is complex and associated with frequent adverse effects related to concentration, which can cause treatment interruption. We aimed to ascertain whether adverse effects could be reduced with either a shorter modified acetylcysteine schedule, antiemetic pretreatment, or both. METHODS: We undertook a double-blind, randomised factorial study at three UK hospitals, between Sept 6, 2010, and Dec 31, 2012. We randomly allocated patients with acute paracetamol overdose to either the standard intravenous acetylcysteine regimen (duration 20·25 h) or a shorter (12 h) modified protocol, with or without intravenous ondansetron pretreatment (4 mg). Masking was achieved by infusion of 5% dextrose (during acetylcysteine delivery) or saline (for antiemetic pretreatment). Randomisation was done via the internet and included a minimisation procedure by prognostic factors. The primary outcome was absence of vomiting, retching, or need for rescue antiemetic treatment at 2 h. Prespecified secondary outcomes included a greater than 50% increase in alanine aminotransferase activity over the admission value. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov (identifier NCT01050270). FINDINGS: Of 222 patients who underwent randomisation, 217 were assessable 2 h after the start of acetylcysteine treatment. Vomiting, retching, or need for rescue antiemetic treatment at 2 h was reported in 39 of 108 patients assigned to the shorter modified protocol compared with 71 of 109 allocated to the standard acetylcysteine regimen (adjusted odds ratio 0·26, 97·5% CI 0·13-0·52; p<0·0001), and in 45 of 109 patients who received ondansetron compared with 65 of 108 allocated placebo (0·41, 0·20-0·80; p=0·003). Severe anaphylactoid reactions were recorded in five patients assigned to the shorter modified acetylcysteine regimen versus 31 who were allocated to the standard protocol (adjusted common odds ratio 0·23, 97·5% CI 0·12-0·43; p<0·0001). The proportion of patients with a 50% increase in alanine aminotransferase activity did not differ between the standard (9/110) and shorter modified (13/112) regimens (adjusted odds ratio 0·60, 97·5% CI 0·20-1·83); however, the proportion was higher with ondansetron (16/111) than with placebo (6/111; 3·30, 1·01-10·72; p=0·024). INTERPRETATION: In patients with paracetamol poisoning, a 12 h modified acetylcysteine regimen resulted in less vomiting, fewer anaphylactoid reactions, and reduced need for treatment interruption. This study was not powered to detect non-inferiority of the shorter protocol versus the standard approach; therefore, further research is needed to confirm the efficacy of the 12 h modified acetylcysteine regimen. FUNDING: Chief Scientist Office of the Scottish Government.

Disproportionate effect on child admissions of the change in Medicines and Healthcare Products Regulatory Agency guidance for management of paracetamol poisoning: an analysis of hospital admissions for paracetamol overdose in England and Scotland.

OBJECTIVE: The aim of the present study was to assess the effects of the changes in the management of paracetamol overdose recommended by the UK Commission for Human Medicines on rates of hospital admission. METHODS: An interrupted time series analysis was carried out on data for hospital admissions for paracetamol poisoning for England between January 2010 and June 2014, and for Scotland between January 2010 and Sept. 2014. The main outcome measure was admissions to hospital with paracetamol poisoning (T39.1), as defined by first position coding in children and adults. RESULTS: The time series analysis (Jan 2010 to June 2014) showed that admission rates for paracetamol poisoning were steady from 2010 to the date of change (September 2012), with an estimated 269 [95% confidence interval (CI) 252.5, 285.5] child (0-14 years) and 3541 (95% CI 3454, 3628) adult admissions per month. In September 2013, 12 months after the change, there were an estimated additional 116 [37.3% (95% CI 17.2-67.4)] child and 426 [12.5% (95% CI 4.5-19.6)] adult admissions. Thus, in the year before the change (September 2011 to August 2012) there were 45,181 (3500 child and 41,681 adult) admissions, and in the year after (September 2012 to August 2013) there were 50,198 (4779 child and 45,419 adult) admissions. The overall proportion of child admissions was significantly greater after the change (Chi-square 32.486, P < 0.001), emphasizing the disproportionate effect in children. CONCLUSIONS: Changes to the management guidelines for paracetamol poisoning in September 2012 were rapidly implemented but have particularly increased paediatric hospital admissions for paracetamol poisoning. This impact in children, who are at low risk of mortality from paracetamol toxicity, appears excessive.

Effect of the UK's revised paracetamol poisoning management guidelines on admissions, adverse reactions and costs of treatment.

AIMS: In September 2012 the UK's Commission on Human Medicines (CHM) recommended changes in the management of paracetamol poisoning: use of a single '100 mg l(-1) ' nomogram treatment line, ceasing risk assessment, treating all staggered/uncertain ingestions and increasing the duration of the initial acetylcysteine (NAC) infusion from 15 to 60 min. We evaluated the effect of this on presentation, admission, treatment, adverse reactions and costs of paracetamol poisoning. METHODS: Data were prospectively collected from adult patients presenting to three large UK hospitals from 3 September 2011 to 3 September 2013 (year before and after change). Infusion duration effect on vomiting and anaphylactoid reactions was examined in one centre. A cost analysis from an NHS perspective was performed for 90 000 patients/annum with paracetamol overdose. RESULTS: There were increases in the numbers presenting to hospital (before 1703, after 1854; increase 8.9% [95% CI 1.9, 16.2], P = 0.011); admitted (1060/1703 [62.2%] vs. 1285/1854 [69.3%]; increase 7.1% [4.0, 10.2], P < 0.001) and proportion treated (626/1703 [36.8%] vs. 926/1854 [50.0%]; increase: 13.2% [95% CI 10.0, 16.4], P < 0.001). Increasing initial NAC infusion did not change the proportion of treated patients developing adverse reactions (15 min 87/323 [26.9%], 60 min 145/514 [28.2%]; increase: 1.3% [95% CI -4.9, 7.5], P = 0.682). Across the UK the estimated cost impact is £8.3 million (6.4 million-10.2 million) annually, with a cost-per-life saved of £17.4 million (13.4 million-21.5 million). CONCLUSIONS: The changes introduced by the CHM in September 2012 have increased the numbers of patients admitted to hospital and treated with acetylcysteine without reducing adverse reactions. A safety and cost-benefit review of the CHM guidance is warranted, including novel treatment protocols and biomarkers in the assessment of poisoning.

Medication errors involving intravenous paracetamol in children: experience from enquiries to the National Poisons Information Service.

INTRODUCTION: Children are at higher risk of medication errors due to the complexity of drug prescribing and administration in this patient group. Intravenous (IV) paracetamol overdose differs from overdose by ingestion as there is no enteral absorptive buffering. We provide the first national UK data focusing on paediatric IV paracetamol poisoning. METHODS: All telephone enquiries to the National Poisons Information Service between 2008 and 2021 regarding children less than 18 years old in the UK concerning IV paracetamol overdose were extracted from the UK Poisons Information Database (UKPID). Data were analysed using descriptive statistics. RESULTS: Enquiries were made concerning 266 children, mostly involving children under the age of 1 year (n=145; 54.5%). Acute and staggered overdoses were the most frequent types of exposure. Common error themes included 10-fold overdose in 45 cases (16.9%) and inadvertent concomitant oral and IV dosing in 64 cases (24.1%). A high proportion of cases were asymptomatic (87.1%), with many calls regarding overdoses below the treatable dose of 60 mg/kg (41.4%). Treatment with the antidote acetylcysteine was advised in 113 cases (42.5%). CONCLUSIONS: Inadvertent IV paracetamol overdose appears to occur more frequently in young children. A significant proportion were calculation errors which were often 10-fold errors. While these errors have the potential for causing serious harm, thankfully most cases were asymptomatic. Errors with IV paracetamol might be reduced by electronic prescribing support systems, better communication regarding administration and consideration of whether other routes are more appropriate.

Paediatric opioid poisoning in the UK: a retrospective analysis of clinical enquiries to the National Poisons Information Service.

OBJECTIVE: To evaluate a decade of reported paediatric opioid poisoning cases in the UK. METHODS: The National Poisons Information Service (NPIS) telephone enquiries database (UK Poisons Information Database) was searched for calls regarding opioid poisoning in children under 18 years from 2012 to 2021. The NPIS online clinical guidance database TOXBASE was searched for accesses relating to opioids for both adults and children. The Office of National Statistics provided paediatric data for hospital admissions and deaths in those aged under 20 years old due to opioids. RESULTS: The NPIS received 426 774 telephone enquiries from 2012 to 2021 from across the UK, 3600 in relation to opioid exposures regarding children under 18 years. Annual telephone enquiries regarding paediatric opiate poisoning reduced year on year, from around 450 to 300 calls/year. A rise in all age TOXBASE annual accesses relating to opioids from 71 642 in 2012 to 87 498 in 2021 was noted, a total of 838 455 during the study period. Hospital admissions from opioid poisoning remained consistent, with around 1500 admissions/year. Deaths were uncommon, but averaged 18 deaths annually. Co-codamol was the most reported substance to NPIS, with 1193 calls (36.5%), followed by codeine with 935 (26.1%). CONCLUSIONS: Opioid poisoning in children is not uncommon. There is a general downward trend in telephone enquiries to NPIS, but many childhood exposures may have been dealt with through consultations via TOXBASE, where accesses relating to opioids have increased. Unfortunately, children still die from opioid exposure each year in the UK and this figure has changed little during 2012-2021.

Measurement of renal function in patients with chronic kidney disease.

Chronic kidney disease affects millions of people worldwide and is associated with an increased morbidity and mortality as a result of kidney failure and cardiovascular disease. Accurate assessment of kidney function is important in the clinical setting as a screening tool and for monitoring disease progression and guiding prognosis. In clinical research, the development of new methods to measure kidney function accurately is important in the search for new therapeutic targets and the discovery of novel biomarkers to aid early identification of kidney injury. This review considers different methods for measuring kidney function and their contribution to the improvement of detection, monitoring and treatment of chronic kidney disease.

Histamine-induced vasodilatation in the human forearm vasculature.

AIM: To investigate the mechanism of action of intra-arterial histamine in the human forearm vasculature. METHODS: Three studies were conducted to assess changes in forearm blood flow (FBF) using venous occlusion plethysmography in response to intra-brachial histamine. First, the dose-response was investigated by assessing FBF throughout a dose-escalating histamine infusion. Next, histamine was infused at a constant dose to assess acute tolerance. Finally, a four way, double-blind, randomized, placebo-controlled crossover study was conducted to assess FBF response to histamine in the presence of H1 - and H2 -receptor antagonists. Flare and itch were assessed in all studies. RESULTS: Histamine caused a dose-dependent increase in FBF, greatest with the highest dose (30 nmol min(-1) ) infused [mean (SEM) infused arm vs. control: 26.8 (5.3) vs. 2.6 ml min(-1) 100 ml(-1) ; P < 0.0001]. Dose-dependent flare and itch were demonstrated. Acute tolerance was not observed, with an increased FBF persisting throughout the infusion period. H2 -receptor antagonism significantly reduced FBF (mean (95% CI) difference from placebo at 30 nmol min(-1) histamine: -11.9 ml min(-1) 100 ml(-1) (-4.0, -19.8), P < 0.0001) and flare (mean (95% CI) difference from placebo: -403.7 cm(2) (-231.4, 576.0), P < 0.0001). No reduction in FBF or flare was observed in response to the H1 -receptor antagonist. Itch was unaffected by the treatments. Histamine did not stimulate vascular release of tissue plasminogen activator or von Willebrand factor. CONCLUSION: Histamine causes dose-dependent vasodilatation, flare and itch in the human forearm. H2 -receptors are important in this process. Our results support further exploration of combined H1 - and H2 -receptor antagonist therapy in acute allergic syndromes.

Metformin-associated lactic acidosis reported to the United Kingdom National Poisons Information Service (NPIS) between 2010 and 2019: a ten-year retrospective analysis.

INTRODUCTION: Metformin toxicity following therapeutic use or overdose may result in metabolic acidosis with hyperlactatemia. This study aims to assess the relationship between serum lactate concentration, arterial pH, and ingested dose with severity of poisoning, and to identify if serum lactate concentration is a useful marker of severity in metformin toxicity. METHODS: A retrospective study of telephone enquiries relating to metformin exposures to the National Poisons Information Service between 2010 and 2019 from hospitals in the United Kingdom. RESULTS: Six-hundred and thirty-seven cases were identified; 117 involved metformin only and 520 involved metformin with other drugs. The majority of cases involved acute (87%) and intentional (69%) exposures. There was a statistically significant difference in doses between the Poisoning Severity Scores, as well as between intentional and unintentional or therapeutic error doses (P < 0.0001). The distribution of cases for each Poisoning Severity Score differed between the metformin only and metformin with other drugs cases (P < 0.0001). Lactic acidosis was reported in 232 cases. Serum lactate concentration and arterial pH differed across Poisoning Severity Scores. Arterial pH inversely correlated with ingested dose (r=-0.3, P = 0.003), and serum lactate concentration positively correlated with ingested dose (r = 0.37, P < 0.0001). Serum lactate concentration and arterial pH did not correlate with each other. Twenty-five deaths were recorded, all following intentional overdoses. DISCUSSION: The dataset focuses mostly on acute, intentional overdoses. Increasing ingested metformin dose, a higher serum lactate concentration and worsening arterial pH were all associated with an unfavourable Poisoning Severity Score in patients in both metformin only and metformin with other drugs groups. As serum lactate concentration did not correlate with arterial pH, it represents an independent marker of poisoning severity. CONCLUSIONS: Data from the present study suggest that serum lactate concentration can be used to assess severity of poisoning in patients who have reportedly ingested metformin.

Mechanisms for an effect of acetylcysteine on renal function after exposure to radio-graphic contrast material: study protocol.

BACKGROUND: Contrast-induced nephropathy is a common complication of contrast administration in patients with chronic kidney disease and diabetes. Its pathophysiology is not well understood; similarly the role of intravenous or oral acetylcysteine is unclear. Randomized controlled trials to date have been conducted without detailed knowledge of the effect of acetylcysteine on renal function. We are conducting a detailed mechanistic study of acetylcysteine on normal and impaired kidneys, both with and without contrast. This information would guide the choice of dose, route, and appropriate outcome measure for future clinical trials in patients with chronic kidney disease. METHODS/DESIGN: We designed a 4-part study. We have set up randomised controlled cross-over studies to assess the effect of intravenous (50 mg/kg/hr for 2 hrs before contrast exposure, then 20 mg/kg/hr for 5 hrs) or oral acetylcysteine (1200 mg twice daily for 2 days, starting the day before contrast exposure) on renal function in normal and diseased kidneys, and normal kidneys exposed to contrast. We have also set up a parallel-group randomized controlled trial to assess the effect of intravenous or oral acetylcysteine on patients with chronic kidney disease stage III undergoing elective coronary angiography. The primary outcome is change in renal blood flow; secondary outcomes include change in glomerular filtration rate, tubular function, urinary proteins, and oxidative balance. DISCUSSION: Contrast-induced nephropathy represents a significant source of hospital morbidity and mortality. Over the last ten years, acetylcysteine has been administered prior to contrast to reduce the risk of contrast-induced nephropathy. Randomized controlled trials, however, have not reliably demonstrated renoprotection; a recent large randomized controlled trial assessing a dose of oral acetylcysteine selected without mechanistic insight did not reduce the incidence of contrast-induced nephropathy. Our study should reveal the mechanism of effect of acetylcysteine on renal function and identify an appropriate route for future dose response studies and in time randomized controlled trials. TRIAL REGISTRATION: Clinical Trials.gov: NCT00558142; EudraCT: 2006-003509-18.

An integrated care pathway improves the management of paracetamol poisoning.

BACKGROUND: Paracetamol poisoning remains a major cause of morbidity and mortality. Clinical care of paracetamol poisoning depends on a range of patient variables and typically involves both medical and nursing care. An integrated care pathway (ICP) is a multidisciplinary management plan that incorporates guidelines and best practice to enhance care and documentation for a specific patient group. Paracetamol overdose is thus amenable to an ICP. AIM: To evaluate the introduction of an ICP on process of care of the paracetamol poisoned patient. METHODS: A retrospective case note review of consecutive patients admitted to the Royal Infirmary of Edinburgh following a paracetamol overdose was conducted. Data were collected for a 3-month period before and after introduction of the ICP to the emergency department and toxicology inpatient unit. RESULTS: The ICP was used in 77% of cases in the time period studied and was associated with improvements in initial documentation of patient assessment (pre-ICP vs post-ICP: 87/161 (54%) vs 101/113 (89%), p<0.0001) and appropriateness of blood sampling (146/161 (91%) vs 111/113 (98%), p=0.01), but no change in timely blood sampling (pre 124/161 (77%) vs post 93/113 (82%)). All aspects of intravenous acetylcysteine administration also significantly improved: administration of acetylcysteine if indicated (pre-ICP vs post-ICP: 57/71 (80%) vs 71/71 (100%), p<0.0001); acetylcysteine commenced in a timely fashion (33/71 (46%) vs 55/71 (77%), p=0.0002); and acetylcysteine correctly prescribed (44/58 (76%) vs 71/71 (100%), p<0.0001). CONCLUSIONS: Implementation of an ICP for paracetamol poisoning significantly improved patient management and helped to standardise inter-professional decision making in this challenging patient group. This is likely to improve patient outcome.

Potential cyanide poisoning reported to the UK national poisons information service: 2008-2019.

INTRODUCTION: Cyanide is a prevalent, lethal chemical. Possible sources of exposure include products of combustion, plant material, industry, chemical warfare and terrorism. METHODS: Retrospective review of UK Poisons Information Database of telephone enquiries to the National Poisons Information Service between 1st January 2008 and 31st December 2019 where cyanide poisoning was considered a possibility. Data extracted included demographics, exposure source, clinical features, Poisoning Severity Score, lactate concentration and antidotes given. RESULTS: A total of 1,252 cases of suspected cyanide poisoning were identified, 239 (19%) involved children under 10 years. The commonest sources of exposure were ingestion of plant material (437 cases; 35%) and smoke inhalation (399; 32%). Smoke inhalation caused the majority of severe and fatal cases (139; 71%). Clinical features associated with fatal outcomes were cardiac arrest (OR 36.4; 95% CI 14.4-92.2), hypotension (15.8; 7.0-35.9), coma (10.8; 5.6-21.0) and lactic acidosis (7.8; 4.1-14.8). 110 patients (9%) were given an antidote and 40 patients (3%) died.Lactate concentrations correlate with Poisoning Severity Score category (r = 0.6, p < 0.0001). Serum lactate <2.0 mmol/L was associated with Poisoning Severity Score None or Minor (sensitivity 76%; specificity 86%) and >11.0 mmol/L was associated with fatal outcome (sensitivity 74%; specificity 80%). 61 cases (5%) had severe carboxyhaemoglobin toxicity (COHb >30%). This was associated with a fatal outcome (OR 7.0; 95% CI 1.5-33.7) and there was positive correlation between carboxyhaemoglobin and Poisoning Severity Score, r = 0.57, p < 0.0001. CONCLUSIONS: Most cases of ingestion of plant material involved children under five years and resulted in no or mild symptoms. In adults smoke inhalation was associated with the most severe poisoning. The lactate cut-off values associated with each severity score calculated in this study are lower than the values used by NPIS on TOXBASE. Analytical conformation of cyanide exposure was unavailable in the majority of case, limiting the strength of these conclusions.

Bites by exotic snakes reported to the UK National Poisons Information Service 2009-2020.

Introduction: Snakebite is recognised as a neglected tropical disease and a cause of substantial morbidity and mortality. Whilst the most medically important snakes are typically native of Asia, Africa, Latin America and Oceania, the possibility of encountering these snakes is no longer limited by geography due to an increasing number of exotic (non-native) snakes being held in captivity.Methods: A retrospective review of snakebite enquiries to the UK National Poisons Information Service (NPIS) between 2009 and 2020. Enquiries about the European adder (Vipera berus) or where the identity of the snake was unknown were excluded.Results: There were 321 exotic snakebites in 300 patients involving 68 different species during this period. Ten patients were bitten on more than one occasion. The majority of patients (64.5%) were male. Most bites were inflicted by snakes of the family Colubridae (184/321, 57.3%); seventeen bites resulted in moderate symptoms (predominantly swelling of the bitten limb). There were 30 (9.3%) bites by Viperidae and 14 (4.3%) bites by Elapidae. All severe cases (n = 15) resulted from bites by either Viperidae (n = 10) or Elapidae (n = 5). Antivenom was given in 17 cases. One fatality was recorded.Conclusions: Despite their low incidence, exotic snakebites present a substantial challenge for UK healthcare professionals. Although rare, these bites typically occur in individuals (usually male) who keep snakes as part of their occupation or hobby and are therefore at risk of multiple bites. Bites can result in venom hypersensitisation and the risk of venom-induced anaphylaxis. Rapid access to expert clinical advice is available in the UK on a 24-hour basis through the National Poisons Information Service and is strongly recommended in all cases of exotic snakebite.

Acetylcysteine has No Mechanistic Effect in Patients at Risk of Contrast-Induced Nephropathy: A Failure of Academic Clinical Science.

Contrast-induced nephropathy (CIN) is a major complication of imaging in patients with chronic kidney disease (CKD). The publication of an academic randomized controlled trial (RCT; n = 83) reporting oral (N)-acetylcysteine (NAC) to reduce CIN led to > 70 clinical trials, 23 systematic reviews, and 2 large RCTs showing no benefit. However, no mechanistic studies were conducted to determine how NAC might work; proposed mechanisms included renal artery vasodilatation and antioxidant boosting. We evaluated the proposed mechanisms of NAC action in participants with healthy and diseased kidneys. Four substudies were performed. Two randomized, double-blind, placebo-controlled, three-period crossover studies (n = 8) assessed the effect of oral and intravenous (i.v.) NAC in healthy kidneys in the presence/absence of iso-osmolar contrast (iodixanol). A third crossover study in patients with CKD stage III (CKD3) (n = 8) assessed the effect of oral and i.v. NAC without contrast. A three-arm randomized, double-blind, placebo-controlled parallel-group study, recruiting patients with CKD3 (n = 66) undergoing coronary angiography, assessed the effect of oral and i.v. NAC in the presence of contrast. We recorded systemic (blood pressure and heart rate) and renal (renal blood flow (RBF) and glomerular filtration rate (GFR)) hemodynamics, and antioxidant status, plus biomarkers of renal injury in patients with CKD3 undergoing angiography. Primary outcome for all studies was RBF over 8 hours after the start of i.v. NAC/placebo. NAC at doses used in previous trials of renal prophylaxis was essentially undetectable in plasma after oral administration. In healthy volunteers, i.v. NAC, but not oral NAC, increased blood pressure (mean area under the curve (AUC) mean arterial pressure (MAP): mean difference 29 h⋅mmHg, P = 0.019 vs. placebo), heart rate (28 h⋅bpm, P < 0.001), and RBF (714 h⋅mL/min, 8.0% increase, P = 0.006). Renal vasodilatation also occurred in the presence of contrast (RBF 917 h⋅mL/min, 12% increase, P = 0.005). In patients with CKD3 without contrast, only a rise in heart rate (34 h⋅bpm, P = 0.010) and RBF (288 h⋅mL/min, 6.0% increase, P = 0.001) occurred with i.v. NAC, with no significant effect on blood pressure (MAP rise 26 h⋅mmHg, P = 0.156). Oral NAC showed no effect. In patients with CKD3 receiving contrast, i.v. NAC increased blood pressure (MAP rise 52 h⋅mmHg, P = 0.008) but had no effect on RBF (151 h⋅mL/min, 3.0% increase, P = 0.470), GFR (29 h⋅mL/min/1.73m², P = 0.122), or markers of renal injury. Neither i.v. nor oral NAC affected plasma antioxidant status. We found oral NAC to be poorly absorbed and have no reno-protective effects. Intravenous, not oral, NAC caused renal artery vasodilatation in healthy volunteers but offered no protection to patients with CKD3 at risk of CIN. These findings emphasize the importance of mechanistic clinical studies before progressing to RCTs for novel interventions. Thousands were recruited to academic clinical trials without the necessary mechanistic studies being performed to confirm the approach had any chance of working.

Impact of a focussed teaching programme on practical prescribing skills among final year medical students.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Medication errors, and particularly prescribing errors, are common in UK hospitals. Junior doctors make the majority of prescribing errors. Deficiencies in prescribing education and training have been closely linked to the high frequency of medication errors. WHAT THIS STUDY ADDS: Focussed prescribing teaching can lead to an improvement in prescribing ability. Prescribing confidence can be significantly improved through education. Education is insufficient alone in eradicating prescribing errors. AIM: To assess the impact of prescribing teaching on final year medical students. METHODS: Students randomly allocated to two hospitals completed a prescribing assessment. Prescribing teaching was delivered to the intervention group while no additional teaching was provided for the control group. All students then completed a second prescribing assessment. RESULTS: Teaching improved the assessment score: mean assessment 2 vs. 1, 70% vs. 62%, P= 0.007; allergy documentation: 98% vs. 74%, P= 0.0001; and confidence. However, 30% of prescriptions continued to include prescribing errors. CONCLUSION: Medical students make significant errors in prescribing. Teaching improves ability and confidence but is insufficient alone in eradicating errors.

Radiology for medical students: Do we teach enough? A national study.

OBJECTIVE: A recent study has shown that the averaged time tabled teaching for a medical student across 5 years in the UK was 4629 hours. Radiology has been demonstrated to be an excellent teaching source, yet the number of hours allocated to this has never been calculated.The aims of this study were to evaluate and quantify the hours allocated to radiology teaching in Scottish Medical Schools and to evaluate if they can fulfil requirements expected from other Clinical disciplines and the upcoming General Medical Council Medical Licensing Assessment (GMC MLA). METHODS: Data pertaining to timetabled teaching for Radiology in Scottish Universities were obtained from the authors of the Analysis of Teaching of Medical Schools (AToMS) survey. In addition, University Lead Clinician Teachers were surveyed on the radiological investigations and skills medical students should have at graduation. RESULTS: Medical students in Scottish Universities were allocated 59 h in Radiology (0.3%) out of a total 19,325 h of timetabled teaching. Hospital-based teaching was variable and ranged from 0 to 31 h. Almost half (15 of 31) of Clinician Teachers felt that there was insufficient radiology teaching in their specialty. Thirteen of 30 conditions included in the GMC MLA were listed by Clinician Teachers, while 23 others not listed by the GMC were considered important and cited by them. CONCLUSION: This study demonstrates that medical students do not receive enough radiology teaching. This needs to be addressed by Universities in collaboration with the NHS in an effort to bring up this up to line with other developed countries and prepare students for the GMC MLA. ADVANCES IN KNOWLEDGE: (1) There is insufficient time allocated in Medical Students' curriculum to Radiology.(2) Radiology teaching in medical schools fall short of University Lead Clinician Teachers' and GMC expectations of medical students at graduation.

Paradoxical refractory hypotension following adrenaline administration in a patient taking clozapine.

Clozapine is a potent antipsychotic commonly used for refractory schizophrenia. Adverse effects are well recognised including constipation, intestinal obstruction, agranulocytosis and cardiomyopathy. We present a case of paradoxical refractory hypotension following epinephrine administration in a patient taking clozapine. A psychiatric inpatient who had been taking clozapine for many years developed paralytic ileus and obstruction requiring surgical intervention. Following initiation of epinephrine administration intraoperatively he developed refractory hypotension which improved only when epinephrine was weaned off. This effect is likely due to uninterrupted ß2-agonist activity in the presence of clozapine-induced α-blockade. Clinicians need to have greater awareness of this serious interaction and avoid the use of epinephrine in patients taking clozapine.

Use of the online poisons information database TOXBASE and admissions rates for poisoned patients from emergency departments in England and Wales during 2008 to 2015.

BACKGROUND: The impact of poison information services on patient care in hospital, particularly decisions on whether to admit patients after initial attendance at an emergency department (ED), is unclear. In the United Kingdom, the vast majority of poisons information is provided by use of the online poisons information database, TOXBASE. We investigated the relationship between rates of hospital access to TOXBASE and rates of poisoning admissions from EDs in England and Wales to begin to address the interactions between use of poisons information and patient management as reflected by hospital activity. METHODS: Data were obtained on attendances and admissions due to poisoning for individual National Health Service (NHS) Trusts in both England and Wales, together with data on the overall number of accesses to TOXBASE for drugs (pharmaceuticals and drugs of abuse), from 2008 to 2015. Rates of TOXBASE access and admissions per poisoning attendance in London were clearly different to the rest of England and Wales; London was therefore analyzed separately. Negative binomial generalized additive models were fit, incorporating an interaction effect, for accesses, attendances and admissions to check for variability according to hospital size. Additional models were then fit to assess whether there was any variation in association of overall TOXBASE use with rates of admission for 6 key drug subgroups: antidepressants, paracetamol, antipsychotics, opioids (including all medicines, but excluding heroin), heroin and non-opioid drugs of abuse. RESULTS: Rates of TOXBASE use per Trust increased across the study period by 39.3% (95% confidence interval [CI] = 34.1%, 44.8%) in England and 76.9% (24.7%, 151.0%) in Wales, showing an increase in TOXBASE use which was substantially greater than the increase in poisoning attendances. Admission rates exhibited seasonality, with lower rates in January and February, increasing by 2.0% (1.0%, 3.1%) in England and 5.8% (5.5%, 5.9%) in Wales toward the middle of the year. The initial model fit indicated that the average proportion of poisoning patients admitted increased with both increasing attendances and increasing TOXBASE use (England and Wales overall, P < 0.0001; England and Wales excluding London, P < 0.0001; London, P < 0.0001). In England and Wales overall, and in London alone, increased TOXBASE access to non-opioid drugs of abuse advice was associated with a significant decrease in admissions (England and Wales, -0.15% [-0.29%, -0.01%] [P = 0.032]; London, -1.02% [-1.53%, -0.50%] [P < 0.0001]). In contrast, increased access to heroin advice was associated with a significant increase in admissions in London (+2.03% [+0.11%, +3.99%] [P = 0.034]). Increasing access to TOXBASE for paracetamol advice was associated with lower admissions in England and Wales (England and Wales, -0.11% [-0.23%, -0.01%] [P = 0.036]; England and Wales excluding London, -0.18% [-0.30%, -0.06%] [P = 0.001]) but higher admissions in London (+0.52% [+0.03%, +1.01%] [P = 0.035]). CONCLUSIONS: We have shown that greater overall use of TOXBASE by hospitals is associated with a higher proportion of poisoning attendances being admitted. Interestingly, looking at particular drug groups, we found significant associations in both directions between overall TOXBASE use and rates of admission for some drug groups. The current methodology is unable to determine whether such decisions might be appropriate or not. Mixed-methods research is now required to gain a better understanding of how provision of poisons information affects decisions within the ED.

A review of 4652 exposures to liquid laundry detergent capsules reported to the United Kingdom National Poisons Information Service 2008-2018.

Introduction: Liquid laundry detergent capsules contain concentrated liquid laundry detergent in a water-soluble polyvinyl alcohol membrane.Objective: To review 4652 exposures reported to the United Kingdom National Poisons Information Service (NPIS) and to assess the impact of regulatory changes on potential toxicity.Methods: Telephone enquiries to the NPIS and returned questionnaires for these products were analyzed for the period January 2008 to December 2018.Results: Data on 4652 exposures were reported by telephone or questionnaire, of which 95.4% involved children aged ≤5 years. Overall, 1738 of 4594 patients remained asymptomatic (Poisoning Severity Score [PSS] 0), 2729 developed minor (PSS 1) features, 107 suffered moderate features (PSS 2), 19 were graded as severe (PSS 3) and one died. Ingestion was involved in most exposures (n = 4175): vomiting occurred in 46.5%, coughing occurred in 4.3% and central nervous system depression in 3.2%. Nine (0.2%) children were intubated and ventilated. The eye was exposed in 646 cases: 371 (59.8%) suffered conjunctivitis or eye irritation and 21 (3.4%) had keratitis/corneal damage, which persisted in one patient for 9 d. The skin was involved in 364 cases; in 127 (35.5%) minor dermal features developed including erythema, irritation and rash. The most commonly reported features in the 127 cases with PSS ≥2 were vomiting (n = 75), stridor (n = 34), CNS depression (n = 22), keratitis/corneal damage (n = 21), coughing (n = 18), conjunctivitis (n = 13), hypersalivation (n = 12), foaming from the mouth (n = 11) and hypoxemia (n = 11). However, respiratory features (stridor, hypoxemia, bronchospasm, respiratory distress, dyspnea, pulmonary aspiration and tachypnea) were the reason for grading 56 of 127 cases as PSS ≥2.Conclusions: This large data set of 4652 exposures is reassuring in that 97.2% of exposures resulted in no or only minor features, only 107 patients suffered moderate features (PSS 2) and 19 severe (PSS 3) features; one patient died.