Lack of cholinergic features in healthcare workers caring for a patient with organophosphate poisoning.

INTRODUCTION: Controversy exists with regard to risk of secondary exposure of health care workers caring for patients who have ingested an organophosphate insecticide. We aim to report clinical effects of staff members caring for an organophosphate poisoned patient. INCIDENT: A 76-year-old male presented to the Emergency Department exhibiting a cholinergic toxidrome requiring atropine, intubation and mechanical ventilation. METHODS: We undertook a retrospective chart review of any Emergency Department presentations for medical assessment in relation to the incident and conducted telephone interviews of any healthcare workers who did not present but were deemed to be closely involved with patient care. We collected data including age, gender, symptoms reported and plasma cholinesterase activity measurement. RESULTS: We collected data from 13 individuals, of whom nine presented for medical assessment, including the patient's spouse. Five additional staff members were interviewed, having been identified via Emergency Department rostering documentation. The 13 healthcare workers comprised five nurses, four paramedics and four doctors. Dizziness and nausea were reported in two and the patient's spouse reported one episode of vomiting. Of the nine patients who had plasma cholinesterase activity measured, none were below the laboratory reference range, including those who experienced symptoms. CONCLUSIONS: We found no clinical nor biochemical evidence of toxicity in healthcare workers caring for a critically ill patient with organophosphate ingestion. These findings are consistent with previously published guidelines advocating standard/Level D personal protective equipment. We believe that emergency departments should not be closed as a safety measure.

Reality of clonidine poisoning in children and adolescents.

AIM: We aimed to describe the severity of clonidine poisonings in a paediatric population referred to a tertiary toxicology service. METHODS: We undertook a retrospective review of all presentations of clonidine poisoning in children or adolescents reported to a tertiary toxicology service from March 2014 to February 2020. Cases were divided into young children (0-6 years), older children (7-11 years) and adolescents (12-17 years). We report clinical effects: bradycardia, hypotension and abnormal Glasgow coma score (GCS), based on standard paediatric observation charts, interventions, length of emergency department stay, proportion admitted to a medical ward or paediatric intensive care unit. RESULTS: We identified 111 clonidine poisonings, 41 young children, 9 older children and 61 adolescents. There were more females in the adolescent group and slightly more males in the younger age groups. The median dose ingested was 13 mcg/kg (interquartile range: 7-38 mcg/kg), which varied across ages. Clonidine alone was ingested in 78 cases (70%) and co-ingestion was more common in adolescents (24/61; 39%). Thirty-seven patients (33%) were admitted and 23 (21%) were admitted to paediatric intensive care unit. Median length of emergency department stay was 16.4 h, longer for adolescents. At least one abnormal observation occurred in 101 of 111 (91%) cases: 76 of 106 (72%) bradycardia, 76 of 110 (69%) hypotension and 4 of 99 (4%) GCS < 9. Thirteen (12%) had severe bradycardia, more common in young children and 23 (21%) had severe hypotension, more common in adolescents. For 27 children (0-11 years) ingesting 5-10 mcg/kg, 3 (11%) had severe bradycardia or severe hypotension and 1 received naloxone (4%). No cases ingesting <5 mcg/kg developed moderate/severe bradycardia or hypotension. Four cases received naloxone with no significant change, two patients got atropine with a transient response. One patient was intubated to facilitate safe inter-hospital transfer. CONCLUSION: Paediatric clonidine poisoning commonly results in bradycardia, hypotension and decreased GCS, but rarely severe or requiring major interventions. Children ingesting <5 mcg/kg do not require admission.

Case series profile of olanzapine post-injection delirium/sedation syndrome.

Olanzapine pamoate is an intramuscular depot injection for the treatment of schizophrenia. Approximately 1.4% of patients develop a serious adverse event called post-injection delirium/sedation syndrome (PDSS), characterised by drowsiness, anticholinergic and extrapyramidal symptoms. The objective is to investigate olanzapine PDSS presentations including clinical features and treatment approach. This is a retrospective review of olanzapine PDSS patients from three toxicology units and the NSW Poisons Information Centre between 2017 and 2022. Adult patients were included if they had intramuscular olanzapine then developed PDSS criteria. Clinical symptoms, treatment, timing and length of symptoms were extracted into a preformatted Excel database. There were 18 patients included in the series, with a median age of 49 years (interquartile range [IQR]: 38-58) and male predominance (89%). Median onset time post injection was 30 min (IQR: 11-38). PDSS symptoms predominate with drowsiness, confusion and dysarthria. Median length of symptoms was 24 h (IQR: 20-54). Most common treatment included supportive care without any pharmacological intervention (n = 10), benzodiazepine (n = 4) and benztropine (n = 3). In one case, bromocriptine and physostigmine followed by oral rivastigmine were given to manage antidopaminergic and anticholinergic symptoms respectively. This proposed treatment combination could potentially alleviate some of the symptoms but needs further studies to validate the findings. In conclusion, this case series supports the characterisation of PDSS symptomology predominantly being anticholinergic with similar onset (<1 h) and duration (<72 h). Bromocriptine is proposed to manage PDSS if patients develop severe dopamine blockade and physostigmine followed by rivastigmine for anticholinergic delirium.

Factors associated with paediatric and adolescent Emergency Department presentations involving acute behavioural disturbance events.

AIM: Studies reporting factors associated with paediatric/adolescent acute behavioural disturbance (ABD) in the Emergency Department (ED) are lacking. The aim of this study is to describe paediatric/adolescent ED presentations involving ABD events. METHODS: A retrospective chart review of presentations involving ABD events, identified via hospital security log, to a tertiary referral paediatric ED during the 2017 calendar year. Data reported included: cause of presentation, use of sedation/physical restraint, ED/inpatient length of stay (LOS) and time requiring security staff presence. RESULTS: From 280 reported ABD episodes 26 were excluded leaving 254 events involving 150 patients across 233 presentations of whom 38 (25.3%) presented on multiple occasions. Median age was 14 years (interquartile range (IQR): 13-16), 132/233 (56.7%) were female, 167/233 (71.7%) primary mental health complaints, 30/233 (12.9%) deliberate self-harm, 18/233 (7.7%) deliberate self-poisoning, 11/233 (4.7%) acute intoxication and 7/233 (3.0%) other. Transport to hospital involved police and ambulance in 124/233 (53.2%), ambulance only 71/233 (30.5%), police only 16/233 (6.9%), relative or carer 20/233 (8.6%), with self-presentation in 2/233 (0.9%). Sedation or physical restraint was used in 81/233 (34.8%), both 38/233 (16.3%), restraint only 26/233 (11.2%) and sedation only 17/234 (7.3%). Intra-muscular droperidol accounted for 57/96 (59.4%) sedations, IM/IV benzodiazepines 15/96 (15.6%), IM/IV ketamine 5/96 (5.2%) and 19/96 (19.8%) other. Discharge from ED occurred in 171/233 (73.1%) with median ED LOS 5.1 h (IQR: 3.5-7.7) and median hospital LOS 92.4 h (IQR: 47.5-273.4) for those admitted. The Mental Health Act was utilised in 183/233 (78.5%) presentations. Median security staff time requirement per presentation was 2.4 h (IQR: 1.0-3.9). CONCLUSIONS: Paediatric/adolescent ED presentations involving ABD are primarily due to mental health complaints. Less than half require the use of sedation/physical restraint. Time requiring security staff involvement is a significant resource consumption.

Paediatric poisoning presentations reported to a regional toxicology service in Australia.

AIM: The aim of this study is to describe the epidemiology and health-care utilisation of paediatric emergency department (ED) presentations due to poisoning. METHODS: A retrospective review of all ED presentations of paediatric poisoning cases (<18 years) reported to a tertiary toxicology service from 2015 to 2016 was conducted. Cases were classified into three age groups: pre-school (0-6 years), primary school (7-11 years) and adolescent (12-17 years). Outcomes included patient transfer, length of ED stay (LOS) and proportion admitted to a medical ward, mental health unit or intensive care unit (ICU). RESULTS: From 764 consultations over a 2-year period, 87 were excluded as non-ED presentations. From these, there were 194 (29%; 47% female) pre-school aged, 34 (5%; 41% female) primary school aged and 449 (66%; 77% female) adolescent presentations. Deliberate self-poisoning was most common in 394 of 449 (88%) adolescents. Accidental exposures accounted for 159 (82%) of pre-school presentations and natural toxins occurred in all three age groups. Paracetamol, selective serotonin reuptake inhibitors, antipsychotics and ibuprofen were the most common toxins. Discharge from ED occurred in 147 of 194 (76%) pre-school, 24 of 34 (71%) primary school and 223 of 449 (50%) adolescent presentations. Of the 449 adolescents, 137 (31%) were admitted medically (median LOS 19.9 h), 19 were admitted to ICU (median LOS 71 h) and 70 (16%) admitted to mental health (median LOS 122 h). Five pre-school aged children were admitted to ICU. CONCLUSIONS: Adolescent deliberate self-poisoning has a significant impact on hospital resources, with mental health problems requiring extended length of stay. There were fewer pre-school accidental poisoning consultations, which were mainly discharged from ED.

Use of a tablet-based application for clinical handover and data collection.

Context: Inpatient toxicology services undertake remote as well as inpatient management of poisoned patients. The aim of this study is to describe the introduction of a tablet-based electronic data collection tool allowing data to be captured on inpatient and remote consultations.Methods: Retrospective review of all cases entered in the database from 1 March 2014 to 28 February 2016. Data collected included demographics (age, sex), clinical details (exposure category), presentation facility and disposition.Results: The database included 3616 cases: 59 (1.6%) were excluded due to inadequate details, 122 (3.4%) had no electronic medical record available, 1985 (54.9%) presented to the inpatient unit facility and 1450 (40.1%) were external consultations. Of these 1450, 223 (6.2%) were paediatric (aged less than 12 years), 395 (10.9%) adolescent (12-17 years) and 832 (23.0%) adults (18 years and over). The proportion of paediatric cases (median age 2 y; 45.7% females) with pharmaceutical ingestions was 122 (54.7%; 95% confidence intervals (CIs): 48.2-61.1) compared with 345 (87.3%; 95% CI: 83.7-90.3) in adolescents (median age 15 y; 79.5% females). Of the adult presentations, 659 (18.2%) were metropolitan/regional facility presentations and 173 (4.8%) rural facilities with 125 (3.4%) adults subsequently transferred to the inpatient facility. Median age was 38 years (interquartile range (IQR) 35-52) with 338 (51.4%) females in the metropolitan group and 37 years (IQR 26-48) with 51 (30.5%) females in the rural group. There were more bites and stings in the rural group, 41 (23.7%; 95% CI: 18.0-30.6) versus 54 (8.2%; 95% CI: 6.3-10.5), more recreational substance exposures 27 (15.6%; 95% CI: 11.0-21.8) versus 40 (6.1%; 95% CI: 4.5-8.2) and less pharmaceutical exposures 93 (53.8%; 95% CI: 46.3-61.0) versus 462 (70.1%; 95% CI: 66.5-73.5).Conclusions: The tablet based database provided useful information on populations of poisoned patients not accessible previously. It demonstrated important differences in the types of patients presenting to rural versus metropolitan hospitals.

Low-dose ketamine provides poor analgesia for pain in redback spider envenoming.

Redback spider envenoming causes severe pain lasting several days. A recent clinical trial found that antivenom is not effective. We investigated ketamine for pain in redback spider envenoming. Ten adult patients with severe pain from redback spider envenoming were administered 15 mg intravenous ketamine after standard analgesia, then up to 4 oral doses of ketamine 25- 50 mg. Three patients had a clinically significant improvement in pain compared to baseline after intravenous ketamine. Five patients had a minimal decrease in pain and 2 had no improvement. Eight patients received oral ketamine: 4 doses in 5 and 2 doses in 3. At 24 h, 3/6 patients assessed had clinically significant improvement in pain and 4/5 patients assessed at 48 h, had clinically significant improvement in pain. Six patients reported side effects, including dissociation (4) and hallucinations (2). Five patients required rescue opioids and 2 were readmitted to hospital. We found that ketamine provided no additional pain relief in redback spider envenoming, compared to standard analgesia, and resulted in unacceptable adverse effects.

Impact of an emergency short stay unit on emergency department performance of poisoned patients.

OBJECTIVES: This was a before and after study which sought to assess the impact of opening an ED short stay unit (ESSU) on the ED performance of poisoned patients. METHODS: Data was collected from two groups of adult patients presenting to an ED with a tertiary referral inpatient Toxicology unit from the 2009 and 2012 calendar years, to assess the impact of the ESSU. The toxicology unit clinical database and hospital electronic medical records were interrogated for demographic, clinical and hospital flow details of presentations. The primary outcome was ED length of stay (LOS). Other outcomes included proportion of patients remaining in ED for their admission, 28day re-presentations and hospital LOS. RESULTS: During 2009, 795 patients met inclusion criteria, and during 2012, 762. The median LOS in ED was reduced from 8.5 h (IQR: 4.7-14 h) to 2.7 h (IQR: 1.6-4.6; p<0.0001). The proportion of patients remaining in ED for their entire hospital stay was reduced from 515/795 (65%) to 56/762 (7.3%) [Absolute difference: 57%; 95% CI: 53 to 62%; p<0.0001]. Total hospital LOS increased from 14.5 h (IQR: 8.4-21.8 h) to 16.7 h (IQR: 11.5-23; p<0.0001), but there was a decrease in re-presentations with self-poisoning within 28days from 6.9% in 2009 to 4.5% in 2012 (p<0.038). There was no difference between disposition destination or toxins causing exposure between the two groups. CONCLUSIONS: The ESSU led to a significant improvement in ED performance of poisoned patients. It also potentially assisted in reducing ED overcrowding.

Ketamine as Rescue Treatment for Difficult-to-Sedate Severe Acute Behavioral Disturbance in the Emergency Department.

STUDY OBJECTIVE: We investigate the effectiveness and safety of ketamine to sedate patients with severe acute behavioral disturbance who have failed previous attempts at sedation. METHODS: This was a prospective study of patients given ketamine for sedation who had failed previous sedation attempts. Patients with severe acute behavioral disturbance requiring parenteral sedation were treated with a standardized sedation protocol including droperidol. Demographics, drug dose, observations, and adverse effects were recorded. The primary outcome was the number of patients who failed to sedate within 120 minutes of ketamine administration or requiring further sedation within 1 hour. RESULTS: Forty-nine patients from 2 hospitals were administered rescue ketamine during 27 months; median age was 37 years (range 20-82 years); 28 were men. Police were involved with 20 patients. Previous sedation included droperidol (10 mg; 1), droperidol (10+10 mg; 33), droperidol (10+10+5 mg; 1), droperidol (10+10+10 mg; 11), and combinations of droperidol and benzodiazepines (2) and midazolam alone (1). The median dose of ketamine was 300 mg (range 50 to 500 mg). Five patients (10%; 95% confidence interval 4% to 23%) were not sedated within 120 minutes or required additional sedation within 1 hour. Four of 5 patients received 200 mg or less. Median time to sedation postketamine was 20 minutes (interquartile range 10 to 30 minutes; 2 to 500 minutes). Three patients (6%) had adverse effects, 2 had vomiting, and a third had a transient oxygen desaturation to 90% after ketamine that responded to oxygen. CONCLUSION: Ketamine appeared effective and did not cause obvious harm in this small sample and is a potential option for patients who have failed previous attempts at sedation. A dose of 4 to 5 mg/kg is suggested, and doses less than 200 mg are associated with treatment failure.

A prospective observational study of a novel 2-phase infusion protocol for the administration of acetylcysteine in paracetamol poisoning.

CONTEXT: The current 3-phase acetylcysteine infusion for paracetamol poisoning delivers half the dose over 15-60 min and frequently results in adverse reactions. OBJECTIVE: We aimed to determine adverse reaction frequency with a modified 2-phase infusion protocol with a longer initial infusion. MATERIALS AND METHODS: A prospective observational study of a modified 2-phase acetylcysteine protocol was undertaken at two hospitals. Acetylcysteine was commenced on admission and ceased if paracetamol concentrations were low-risk (below the nomogram line). The first infusion was 200 mg/kg over 4-9 h based on ingestion time or 4 h for staggered/chronic ingestions. The second infusion was 100 mg/kg over 16 h. Pre-defined outcomes were frequency of adverse reactions (systemic hypersensitivity reactions or gastrointestinal); proportion with alanine transaminase (ALT) > 1000 U/L or abnormal ALT. RESULTS: 654 paracetamol poisonings were treated with the new protocol; median age 29 y (15-98 y); 453 females; 576 acute and 78 staggered/chronic ingestions. In 420 (64%) acetylcysteine was stopped for low-risk paracetamol concentrations. An adverse reaction occurred in 229/654 admissions (35%; 95% CI: 31-39%): 173 (26.5%; 95% CI: 23-30%) only gastrointestinal, 50 (8%; 95% CI: 6-10%) skin only systemic hypersensitivity reactions; and three severe anaphylaxis (0.5%; 95% CI: 0.1-1.5%; all hypotension). Adverse reactions occurred in 111/231 (48%) receiving full treatment compared to 116/420 (28%) in whom the infusion was stopped early (absolute difference 20%; 95% CI: 13-28%; p < 0.0001). In 200 overdoses < 10 g, one had toxic paracetamol concentrations, but 53 developed reactions. Sixteen patients had an ALT > 1000 U/L and 24 an abnormal ALT attributable to paracetamol; all but one had treatment commenced >12 h post-ingestion. CONCLUSION: A 2-phase acetylcysteine infusion protocol results in a fewer reactions in patients with toxic paracetamol concentrations, but is not justified in patients with low-risk paracetamol concentrations.

Sodium azide ingestion and secondary contamination risk in healthcare workers.

This study reports the follow-up of healthcare staff directly involved in managing a fatal sodium azide ingestion. Clinical staff directly involved with the case were contacted by telephone or in person. Data collected were age, sex, time in contact with the patient, time off work following the incident and whether or not this was because of physical complications of exposure. Ten individuals had close contact with the case. Of these, five were men, median age was 39 years (range 22-52); four described being in close contact for greater than 60 min, three for 15-60 min and three for 5-15 min. Absence from work occurred in two cases for 1 day and several weeks, neither attributed to the physical effects of exposure. Our data do not support close contact with a sodium azide ingestion case as posing a high risk of significant postexposure complications in emergency service workers.

Clinical features of serum sickness after Australian snake antivenom.

Serum sickness is a delayed immune reaction in which the immune system responds to a protein in antiserum as a potentially harmful substance and mounts an IgG-mediated antibody response. A 32 year-old female patient had systemic envenoming following a bite by a red-bellied black snake (Pseudechis porphyriacus). She was treated with Tiger snake antivenom and recovered over 24 h and did not develop myotoxicity. She then presented with local pain, itching and swelling, which was partially treated with antihistamines. Eleven days after the bite she presented again with symptoms of worsening serum sickness including rash on the upper legs, joint and muscle pain in arms, ankles and knees, and nausea. The patient was prescribed five days of prednisone 50 mg/day, antihistamine 10 mg/day and analgesia 1000 mg/day and improved over 2 days. She had no further problems on follow up at 4 months. This case highlights that serum sickness can cause significant effects after the treatment of snake envenoming. It develops 5-14 days after antivenom administration and has characteristic clinical and laboratory features. Severe cases of serum sickness can result in morbidity but it appears to respond well to corticosteroid treatment.

Acute behavioural disturbance associated with phenibut purchased via an internet supplier.

CONTEXT: Toxicity from recreational substances marketed for other purposes is a well-documented clinical entity. We present two cases of phenibut toxicity procured via the internet. CASE DETAILS: A 20-year-old female presented to the emergency department (ED) having used phenibut the prior day. The main finding was a decreased level of consciousness, however when roused she became delirious. Supportive care only was required with no specific intervention. The patient made a full recovery over a 24-hour period and admitted to use of phenibut purchased online. Plasma phenibut concentration was 29.7 µg/ml. A 38-year-old male presented to ED with an agitated delirium. The prior evening he had used tetrahydrocannabinol or THC, alcohol and phenibut, the latter purchased via the internet. His behavioural state had a suboptimal response to parenteral sedation. He was subsequently intubated for airway protection in the context of ongoing sedation to optimally manage his behavioural state. Post extubation the next morning he admitted using phenibut. Plasma phenibut concentration was 36.5 µg/ml. DISCUSSION: Altered mental status was the predominant manifestation of phenibut toxicity in these cases. Clinicians to be aware of how phenibut toxicity may present as the internet has widened access to such substances.

The Safety and Effectiveness of Droperidol for Sedation of Acute Behavioral Disturbance in the Emergency Department.

STUDY OBJECTIVE: We investigate the safety and effectiveness of droperidol for sedation of acute behavioral disturbance in the emergency department (ED). METHODS: This was a prospective observational study in 6 EDs (August 2009 to April 2013). Adult patients requiring parenteral sedation for acute behavioral disturbance received droperidol 10 mg. If this did not sedate the patient within 15 minutes, further sedation was allowed but droperidol 10 mg was recommended as part of a sedation protocol. The primary outcome was the proportion of patients with an abnormal QT interval, defined by the at-risk line on the QT nomogram. Secondary outcomes were effectiveness determined by the time to sedation measured on the Sedation Assessment Tool, use of additional sedation, adverse events, and injury to staff or patients. RESULTS: There were 1,009 patients with an ECG performed within 2 hours of droperidol administration, with a median dose of 10 mg (interquartile range [IQR]10 to 17.5 mg). Thirteen of the 1,009 patients had an abnormal QT (1.3%; 95% confidence interval 0.7% to 2.3%), but 7 of these had another cause attributed for prolonged QT (methadone, escitalopram, amiodarone, or preexisting). In 1,403 patients sedated with a median total dose of droperidol of 10 mg (IQR 10 to 20 mg), the median time to sedation was 20 minutes (IQR 10 to 30 minutes) and 97% were sedated within 120 minutes. Additional sedation was required for 435 patients (31.0%; 95% confidence interval 28.6% to 33.5%). Adverse events occurred in 70 patients (5%) and oversedation without complications in 109 (8%), the latter more common for patients receiving benzodiazepines as additional sedation (16/109 [15%]). There were no cases of torsades de pointes. Injuries occurred in 34 staff members and 4 patients. CONCLUSION: The study supports the use of high-dose droperidol as a safe sedating agent for patients with acute behavioral disturbance in the ED. There is no evidence of increased risk for QT prolongation with the doses used in this study.

2-Methyl-4-chlorophenoxyacetic acid and bromoxynil herbicide death.

CASE REPORT: We report a fatal case of a 37 year old gentleman who ingested a MCPA/bromoxynil co-formulation herbicide. Although clinically well on initial examination, our patient declined dramatically over his 18 h admission with increasing CO2 production, hyperthermia and metabolic derangement to eventually die from cardiac asystole 20 h post ingestion. Two hours after ingestion the MCPA concentration was 83.9 µg/mL and bromoxynil concentration was 137 µg/mL. DISCUSSION: The patients' mechanism of death appeared to be uncoupling of oxidative phosphorylation, excess CO2 production and hyperthermia. There is limited knowledge on the acute toxicity of these herbicides, in particular bromoxynil, and this case highlights the relentless progression of severe toxicity in humans.

Intralipid therapy does not improve level of consciousness in overdoses with sedating drugs: a case series.

OBJECTIVE: To assess the effect of intralipid emulsion therapy (ILE) in sedating drugs presenting to an urban emergency department. METHODS: Following the introduction of a clinical protocol for the use of ILE a retrospective chart review was undertaken, which describes the use of ILE in treating sedating drug overdose in a facility with a tertiary referral level clinical toxicology unit. Demographic data as well as details of drug ingested, physiological parameters and disposition were extracted from the medical record. RESULTS: Over a 7 month period nine cases were treated with intralipid, of which two were male and the median age was 33 years (17-52 years). Endotracheal intubation was required in seven cases and of the other two, one required a nasopharyngeal airway for several hours while being observed in a critical care area. One patient was managed in the intensive care unit without intubation. The median duration of ventilation in the seven patients was 31 h (22-82 h), and median length of stay for all nine cases was 63 h (24-133 h). CONCLUSION: This study does not support any clinically significant effect of intralipid in sedating drug overdose.