 patient should be admitted to hospital for observation. NOTE High concentrations of ethanol are also found in perfumes, aftershaves, mouthwashes, a nd over-the-counter cough and cold remedies. POISONS1 431 Ethylene glycol General comments Ethylene glycol is the active ingredient in antifreeze and motor coolant fluids. Cases of ethylene glycol poisoning have also resulted from deliber- ate contamination of alcoholic drinks such as wine. Clinical features - Ataxia - Slurred speech - Nausea and vomiting - Convulsions - Drowsines s and coma. Later symptoms (after 12 hours) are predominantly cardiorespiratory, including arrhythmias, bronchopneumonia, and cerebral oedema. These are unlikely to be encountered in the pre-hospital environment. Management - Establish and maintain a patent airway - Treat complications symptomatically - Transfer to hospital URGENTLY for investigation and management. The diagnosis of ethylene glycol poisoning is often far from obvious. If it can be established with reasonable certai nty that the patient has taken ethylene glycol, and they are capable of taking it, ethanol (as whisky, gin, or vodka containing 40g/l ethanol) can be given my mouth. Ethanol \200 \230mops up \200\231 alcohol dehydrogenase, reducing the metabolism of ethylene glycol into toxic metabolites. CHAPTER 6 Poisoning and substance abuse 432 Fungi \200\224poisonous Examples - Amanita phalloides ( \200\230death cap \200\231 mushroom ) \200\224the most common cause of fatalities from eating mushrooms Gyrometra spp - Psilocybe spp. Clinical features A wide range of symptoms is possible. Early nausea, vomiting, and diarrhe a may occur. Other symptoms include profuse sweating, salivation, abdominal pain, hallucina tions, headache, flushing, and blurred vision. Management Early management is supportive, with urgent evacuation to hospital. Wherever pos sible, a sample of the ingested fungus (fungi) should accompany the patient to hospital. In travenous fluids may be commenced and an antiemetic given. POISONS1 433 Hypoglycaemic agents Examples Tolbutamide, chlorpropramide, gliclazide, glipizide, tolazami de, glibencla- mide. These are sulphonylureas; metformin (a biguanide) does not cause hypog lycaemia in overdose. Clinical features - Reduced conscious level or coma - Pupillary dilatation (not always pres ent) - Neurological abnormalities including upgoing plantars and hyper-reflexia Fits. Hypoglycaemia due to sulphonylurea overdose can be extremely prolonged and recurrent, even after treatment. Careful monitoring and repeated BM stix readings are, therefore, ess ential. Management - Establish and maintain a secure airway - 10% dextrose by slow IV injection (IV glucagon is an alternative, initial dose 1mg) Fits may respond to correction of hypolycaemia; otherwise use diazemuls 2.5mg every 30 seconds until control is achieved Urgent transfer to hospital. NOTE: glucagon is ineffective in patients with inadequate glycogen stores such as alcoholic s. CHAPTER 6 Poisoning and substance abuse 434 Insulin Clinical features - Reduced conscious level or coma - Pupillary dilatation (not alw ays present) - Neurological abnormalities including upgoing plantars and hyper-reflexia Fits. Management - Establish and maintain a secure airway - 50% dextrose (50ml initially) by slow iv injection ( iv glucagon is an alternative, initial dose 1mg) Fits may respond to correction of hypoglycaemia; otherwise use diazemuls 2.5mg every 30 seconds until control is achieved Urgent transfer to hospital. Depending on the insulin injected, repeated doses of glucose o r a dex- trose infusion may be necessary to prevent recurrence of symptoms. Regular monitoring of BM stix is essential POISONS1 435 Iron Clinical features For such a widely prescribed ( and self-prescribed ) medication, iro n can be remarkably toxic in overdose or poisoning. Accidental ingestion of iron supplement s is not uncommon in children. - Vomiting (or haematemesis) and diarrhea (may be black or g ray) - Abdominal pain - Lethargy, drowsiness, coma - Fits - Shock - Later symptoms (after a bout 12 hours) include shock, acidosis, jaundice, and renal failure. Management - Establishment and maintenance of a patent airway - Symptomatic treatment of co mplications - URGENT referral to hospital. Where possible, the remaining medication or its container should accompany the patient to hospital so that an estimate of the amount of ele mental iron ingested can be made. CHAPTER 6 Poisoning and substance abuse 436 Lithium Clinical features - Nausea, vomiting, and diarrhea - Tremor, hyperreflexia, agitati on - Fits - Coma. Non-specific ST depression and T wave inversion may be found on the ECG. Malignant arrhythmias are rare. Management Pre-hospital management is supportive. A patent airway should be estab- lished a nd maintained. If transfer to hospital is likely to be delayed or prolonged, an intravenous infusion should be commenced. ECG monitoring is essential. POISONS1 437 Mefenamic acid Mechanism of action Mefenamic acid is a non-steroidal anti-inflammatory drug . General features Prescribed for menorrhagia and dysmenorrhoea, as well as arthritides and r elated conditions, mefenamic acid (Ponstan ) is relatively commonly taken in overdose. Clinical features - Muscle twitching - Fits - Diarrhea and vomiting. Management - Establish and maintain a protected airway - Diazemuls for prolonged or recurre nt seizures - Urgent evacuation to hospital - Give activated charcoal if transfer is likely to be delayed or prolonged. CHAPTER 6 Poisoning and substance abuse 438 Methanol General comments Methanol is used in windshield washer fluids, as a component of m ethy- lated spirits (not in significant levels), as a fuel antifreeze additive, and as an i ndustrial solvent. Methanol poisoning may result from the consump- tion of contaminated or adulterated wines. Clinical features - Nausea, vomiting - Abdominal pain and diarrhea, rigid Headache - Dizziness - Breathlessness - Sweating - Convulsions (rare) - Cardiorespiratory abdomen Visual abnormalities (including blurred vision, flashing lights, and decreased visual acuity). May progress to blindness. Photophobia failure. Management - Establish and maintain a patent airway (use the recovery position if there is no possibility of cervical spine injury) Assist ventilation (where necessary) and administer high-flow oxygen - Diazemuls for fittin g - If the patient is well enough and hospital transfer is likely to be prolonged or delayed, oral ethanol can be given in the form of whisky, gin, or vodka (40% p roof). - Urgent transfer to hospital. POISONS1 439 Metoclopramide Clinical features Overdosage or poisoning with metoclopramide does not appea r to be a problem. A minority of patients, however, suffer acute dystonic reactions. These include chewing movements, spasms of torticollis, and oculogyric crisis. These movements ca nnot be controlled by the patient, who remains fully conscious throughout. Management The treatment of acute dystonia is procyclidine 5 \200\22310mg im (adult dose) o r benztropine 1 \200\2232mg im or iv (adult dose). If one of these is not available, the pa tient should be reassured and transferred to A&E for treatment. CHAPTER 6 Poisoning and substance abuse 440 Monoamine oxidase inhibitors (MAOIs) Examples - Phenelzine, tranylcypromine, isocarboxazid, moclobemide - The anti-parkinsonian agent, selegiline, and the chemotherapeutic agent, procarbazine, are also MAO inhibitors. Clinical features - Headache - Agitation - Hallucinations - Flushing - Sweating - Muscular rigidity - Tachycardia - Tachypnoea - Hypotension, bradycardia, Abnormal muscular movements (writhing, grimacing) Coma - Nystagmus - Hyperpyrexia - Hypertension. and asystole Symptoms may initially be entirely absent, even in very serious over- doses. Management - Scrupulous attention to ABC - Diazemuls for seizures, rigidity, and agitation - Conventional ALS protocols for dysrrhythmias (bretylium is contra-indicated and atropine and beta blockers should be avoided) Fluids iv for hypotension - Passive cooling measures for hyperpyrexia - Urgent transfer to hospital - Consider activated charcoal if transfer is likely to be delayed or prolonged POISONS1 441 Opiates See drugs of abuse, p.478. CHAPTER 6 Poisoning and substance abuse 442 Organophosphate insecticides (including carbamates) Examples There are many insecticides in these two groups. They are used exten- sively and are relatively common causes of poisonin g, either deliberate or accidental. Uses Agricultural and horticultural. Clinical features Mild poisoning - Anxiety and restlessness - Skin redness and erythema - N ausea, vomiting - Abdominal pain and diarrhea - Sweating - Hypersalivation - Bronchospasm/b ronchorrhoea - Miosis (not present in every case) - Dizziness - Headache. Moderate/severe poisoning - Reduced level of consciousness - Muscle fasciculation and weakn ess - Pulmonary oedema - Fitting - Cardiac dysrhythmias. Management - Remove patient from contaminated area - Remove contaminated clothing - Wash co ntaminated skin with soap and water - Establish and maintain a patent airway (suction for i ncreased secretions) High-flow oxygen - ECG and pulse oximetry - Atropine 2mg iv every 10 minutes (approximately ) until the patient feels better or tachycardia, dry flushed skin, dry mouth, and dilated p upils are evident Diazemuls for anxiety and fitting - URGENT evacuation to hospital. Rescuers must at all tim es ensure that they do not themselves become poisoned. POISONS1 443 Paracetamol General features In normal individuals, the minimum toxic dose of paracetamol i s in the region of 150mg/kg (90mg/kg in children). This level is considerably lower in chro nic alcohol abusers, malnourished patients, those on anticonvul- sants, and HIV patients. Clinical features There are no immediate features of paracetamol overdose. Nausea and vomit ing may occur within a few hours. The diagnosis is based on infor- mation from the patient or witnesses and the presence of circumstantial evidence such as empty pill bottles. Late complications include cerebral oedema, encephalopathy, hepa- torenal failure, serum electrolyte abnormalities, and rashes. The presence of a reduced conscious level or coma in the early stages of paracetamol overdo se suggests that a CNS depressant has also been taken. Compound analgesics such as co-codam ol (codeine and paraceta- mol), co-dydramol (dihydrocodeine and paracetamol), and co-proxam ol (codeine and dextropropoxyphene) are possible causes of this, although two entirely sepa rate medications may have been taken. Management The patient should be transferred to hospital for assessment of paracetamol leve ls and further management, including N-acetyl cysteine where appropriate. In extremely remote areas where transfer is likely to be very prolonged or delayed, each ca se should be discussed with the receiving hospital and consideration given to the administr ation of oral methionine (adult dose 2.5mg 4hrly to a total of 10mg). CHAPTER 6 Poisoning and substance abuse 444 Paraquat Examples Paraquat is a bipyridylium herbicide present in a wide range of commer- c ial weed control products of which the most frequently encountered is . Many proprietary herbicides are mixtures of herbi- probably Weedol cidal compounds and other substances such as petroleum distillates. Clinical features The clinical features depend on the portal of entry: Oral ingestion - Mucous membrane irritation - Nausea and vomiting - Abdominal pain and diar rhea. With increasing dose: - Shock (fluid loss and direct myocardial effect) - Pulmonary oedema - Oropharyngeal ulceration. The later effects of paraquat poisoning include renal necrosis, haemor- rhagic pulmonary oedema, ataxia, coma, and demyelination. Inhalational exposure - Sore throat - Huskiness of speech - Epistaxis. More serious symptom s are rare. Skin and eye contamination Blistering may occur but thorough decontamination should prevent systemic toxicity. Splashes into the eyes result in blepharospasm, lacrima- tion, and corn eal ulceration. Thorough lavage is essential. Management - Careful assessment and management of ABC - Symptomatic treatment of complicati ons - Administration of activated charcoal 50g (if carried) - URGENT evacuation to hospital . DO NOT GIVE OXYGEN IN PARAQUAT POISONING POISONS1 445 Pepper spray General comments Pepper spray is used as a personal protection system by membe rs of the police services. The active ingredient is capsaicin, extracted from chili peppers . Clinical features - Burning eyes and mucous membranes - Burning skin. Management - Remove from the contaminated area - Remove clothing - Irrigate the eyes (local anesthetic may be used) - Showering - Consider transfer to hospital. CHAPTER 6 Poisoning and substance abuse 446 Petroleum distillates and turpentine Examples Gasoline, diesel, paraffin, lighter fuel, tur pentine, turpentine substitute, furniture polish, kerosene, gasoline, glues, typewriter cor rection fluid. Clinical features Most patients are likely to be symptom free. However, symptoms may includ e: - Vomiting - Diarrhea (rare) - Cough/haemoptysis - Wheezing/ breathlessness - Decreased level of consciousness or coma (rare) - Fitting (rare). Management - Careful attention to ABC - High-flow oxygen - Symptomatic treatment of complic ations - Urgent evacuation to hospital. POISONS1 447 Phenothiazines and haloperidol/droperidol Examples - Chlorpromazine, promazine, promethazin e - Thioridazine - Haloperidol, droperidol - Fluphenazine, prochlorperazine, trifluoperazin e - Flupenthixol. General comments Members of this group of drugs are prescribed for a wide range of condi- t ions, the most common indication being as antipsychotics. Others are indicated in the treat ment of nausea, vomiting and motion sickness, and for their antihistamine properties. Clinical features - CNS depression (coma rare) - Hypotension - Hypo-/hyperthermia - Acute d ystonic reactions - Fitting - Cardiac arrhythmias/non-specific ECG changes. Management - Careful attention to ABC - Activated charcoal 50g (if carried) if patient is f ully conscious - Arrhythmias should be treated conventionally, but may be ineffective until hypoxia and acidosis are corrected Urgent transfer to hospital. The treatment of acute dystonia is procyclidine 5 \200\22310mg im (adult dose) or benztropine 1 \200\2232mg im or iv (adult dose). If one of these is not available, the patient should be reassured and transferred to A&E for treatment. CHAPTER 6 Poisoning and substance abuse 448 Phenytoin Clinical features - Nausea and vomiting - Dysarthria - Ataxia - Choreo-athetoid m ovements - Dizziness and nystagmus - Drowsiness and confusion - Coma (rare) - Fits. Management - Ensure a patent airway - Monitor ECG - Give activated charcoal 50g (if availab le) - Commence iv fluids if transfer times prolonged or transfer delayed - Urgent transfer to hospital. POISONS1 449 Plant toxins Examples - Cotoneaster - Dieffenbachia - Foxglove - Hemlock - Hogweed - Holly - Honeysuckle - Mistletoe - Yew. General approach to poisoning with plant toxins - Careful attention to ABC Establish and maintain a patent airway - iv access. Decontamination of dermal exposure with soap and water - Symptomatic treatment as required (see below) - Seek appropriate advice - Ensure that a sample of the plant accompanies the p atient to hospital. Cotoneaster Presentation The red berries of this garden shrub enclose seeds which contain c yano- genic glycosides. It is extremely unusual for sufficient to be taken to cause serious problems although abdominal pain, vomiting, and diarrhea may occur. Management No treatment is usually necessary. In the case of large ingestions, acti- vated charcoal should be given. Symptomatic treatment may be required. Dieffenbachia Presentation Dieffenbachia (and the related Monstera and Philodendron spp) ar e com- mon house plants. Their leaves contain oxalate crystals and cause intense burning pa in in the lips and mouth. Hypersalivation occurs and the tongue, lips, and oral mucosa swel l, often rendering speech difficult. Airway compromise is possible but rare. Management Symptomatic relief is possible with ice cubes, ice cream, or milk. Analge- sia s hould be given. Airway compromise may mandate intervention including orotracheal intubation . Foxglove Presentation Foxglove, oleander, and lilly of the valley all contain cardiac glyco sides. Symptoms of ingestion include nausea, vomiting, visual disturbance, changes in menta l state, and cardiac arrythmias. CHAPTER 6 Poisoning and substance abuse 450 Management Treatment is generally supportive. Cardiac monitoring is essential. Arrhythmias may respond to conventional therapy but digoxin-specific antibody treatment in hospital is also effective. Calcium is absolutely contraindicated. Hemlock Presentation Water hemlock and related species contain a number of dangerous toxins and ingestion of small amounts can be fatal. Symptoms include nausea, vomiting, abdominal pain, and sweating. Fits occur and death is secondary to status epilepticus and cardiac arr est. Very small quantities may result in fatal poisoning. Management Establishment and maintenance of a patent airway, activated charcoal if availabl e, control of fitting with diazemuls, and urgent transfer to hospital. Hogweed Presentation Giant hogweed sensitizes skin to ultraviolet light causing burning. Management Conventional management for superficial burns: analgesia, non-adherent dressing. Hospital or GP follow-up. Holly Presentation The red berries of holly are sometimes eaten by inquisitive children. Mo st will develop no problems with the quantities they are likely to eat. When symptoms occur , they are vomiting, abdominal pain, and diarrhea. Management None, usually. Symptomatic management when required. Honeysuckle Presentation The berries of this common plant are sometimes eaten by young chil dren. Symptoms are unusual but include vomiting and abdominal pain. Management No treatment is usually required. Symptomatic treatment may occasionally be nece ssary. Mistletoe Presentation Children rarely eat enough berries or leaves to cause problems. When they do, symptoms include vomiting, abdominal pain, diarrhea, and, rarely, bradycardia and circulatory failure. Muscle weakness also occurs. POISONS1 451 Management Children who have eaten more than three berries or leaves require admission to h ospital for observation. If there is any doubt, referral to hospital is appropriate. Activa ted charcoal may be given. Yew Presentation All parts of the yew are poisonous. Symptoms are rare but include vom- iti ng, abdominal pain, diarrhea, and rarely, fits, reduced conscious level, respiratory depres sion, tachy- and brady-dysrhythmias, hypotension, and cardiac arrest. Management Immediate transfer to hospital is essential. Treatment is symptomatic, with conv entional treatment for dysrhythmias. CHAPTER 6 Poisoning and substance abuse 452 Pulmonary irritants Chlorine is considered separately (see p.423). General comments A wide range of gasses act as pulmonary irritants, the majority associated with chemical processing. Examples include: acrolein, ammonia, formal- dehyde, hydrogen ch loride, hydrogen fluoride, hydrogen sulfide, and phosgene. In many cases, it will not be po ssible (at least in the early stages) to identify the agent involved. Clinical features Initial exposure results in rhinitis and conjunctivitis, followed by sinu sitis and laryngitis. Further exposure causes inflammation of lung tissue, even- tually lea ding to pulmonary oedema. Individual irritants will also produce a wide range of specific c linical problems. Symptoms of respiratory irritant poisoning include: Cough - Shortness of breath - Bronchospasm - Chest pain - Haemoptysis - Headache - Cardiac arrhythmias. Management - Ensure that the patient is away from the contaminated area - Remove contaminat ed clothing - Decontaminate with water - Establish and maintain a patent airway - Look for signs of thermal airway injury - Serial chest examinations - Administer high-flow oxygen - Consider salbutamol for bronchospasm - Monitor SaO2 and ECG - Transfer to hospital. POISONS1 453 Salicylates Examples - Aspirin - Decongestants - Cold, cough, and \200\230flu \200\231 rem edies - Musculoskeletal pain medications (including Benorylate Clinical features Salicyla tes stimulate the brain respiratory center, leading to respiratory alkalosis and compensato ry metabolic acidosis. Lactic acidosis follows. - Vomiting - Gastrointestinal irritation an d haematemesis - Tinnitus - Hyperpnoea - Lethargy. ). Severe poisoning - Fitting - Coma - Hyperthermia - Hypoglycaemia - Pulmonary oedema - Cardi orespiratory failure. Symptoms can begin within 1 to 2 hours following ingestion, but they may be significantly delayed. Symptoms of severe poisoning are unlikely to be seen in the p re-hospital environment. Management - Establish and maintain a patent airway - Support respiration if necessary - Co nventional management of complications such as fitting - Give activated charcoal (50g) if a vailable - Urgent transfer to hospital - If transfer to hospital is likely to be prolonged or delayed, commence cautious iv administration of crystalloid. CHAPTER 6 Poisoning and substance abuse 454 Serotonin uptake inhibitors \200\224selective serotonin inhibitors (SSRIs) Examples Citalop ram, fluoxetine, fluvoxamine, paroxetine, sertraline. General comments The SSRIs were introduced as a safer alternative to the tricyclic antide- pressants. Serious overdoses are, therefore, rare. Clinical features - Bradycardia - Nausea and vomiting - Tremor - Lethargy - Dizziness - Dep ressed conscious level - Fitting. Management - Careful attention to ABC - Activated charcoal (50g) if available - Monitor ECG - Transfer to hospital. POISONS1 455 Snake bite (see also adder bite) A wide range of snakes is held in zoos and by private indi viduals. In such cases, the type of snake may be known. Prolonged and hazardous attempts to capture the snake should be avoided and the patient transferred rapidly to hospital. IT IS possible to be bitten by a dead snake! Advice regarding management and provision, where ap propriate, of specific antivenom, can then be sought from the local poisons unit (see p.399 for telephone number) or tropical medicine unit. Management - Do not apply a tourniquet ( a bandage may be applied proximal to the bite, which is tight enough to occlude superficial veins only) Do not apply ice - Do not suck on the wound - Apply a splint to immobilize the bitten limb - Keep the patient calm and rested - Urgent transfer to hospital. CHAPTER 6 Poisoning and substance abuse 456 Tetracyclic antidepressants Examples Mianserin. Clinical features - Drowsiness - Hypo- or hypertension. Management - No specific pre-hospital management is required; attention should be paid to ABC management Activated charcoal 50g (if available) - Transfer to hospital for further management and psy chiatric assessment is appropriate. POISONS1 457 Theophyllines Examples - Theophylline - Aminophylline. Theophyllines are present in a wide range of cough and decongestant preparations. The majority of preparations are slow release and, as a result, symptoms of poisoning may not be apparent until more than 12 hours after ingestion. Clinical features - Nausea, vomiting - Diarrhea (rare) - Haematemesis - Restlessness, anxie ty, hyperactivity - Pupillary dilatation - Tremor - Hyperventilation - Tachycardia - Suprav entricular and ventricular arrhythmias including VF - Myoclonus, increased muscle tone, inv oluntary limb movements - Fitting. Management - Careful attention to ABC - Establish and maintain a patent airway - Support re spiration - Administer activated charcoal (50g adult dose) if available, repeated if transfer is delayed or prolonged Monitor ECG and SpO2 - Manage fitting with diazemuls or rapid sequence initiation of anaest he- sia if the skills are available Tachy-dysrhythmias respond to beta blockers (if available), otherwise follow conventional managment Urgent transfer to hospital. CHAPTER 6 Poisoning and substance abuse 458 Toiletries and cosmetics General comments Aftershaves, deodorants, make-up, perfumes, shamp oos, hair lacquer and remover, shaving cream, nail varnish (and remover), bath crystals. These preparations variously contain ethanol, other alcohols, waxes, lanolin, and an assort ment of chemical compounds. They are commonly consumed by children, fortunately in small qu antities. Non-toxic substances The following are relatively non-toxic and consumption of enough to ca use serious problems is unlikely: - Shampoo - Skin creams and lotions - Make-up and lipstic k - Shaving cream - Bubble bath. They may, however, cause nausea and vomiting. Substances containing ethanol Preparations containing ethanol, such as perfumes and aftersh ave, are not usually consumed in sufficient quantities to be of harm. Potentially toxic substances Nail varnish and its remover are potentially toxic. Management Transfer to hospital for assessment and observation in potentially serious cases . POISONS1 459 Tricyclic antidepressants Examples With sedative properties Amitriptyline, clomipramine, do thiepin, doxepin, mianserin, trimipramine Less sedative Imipramine, lofepramine, nortriptyline, amoxapine Clinical features Tricyclic antidepressant (TCA) overdose should always be considered poten tially life-threatening. Deterioration may be very rapid and within 1 hour of ingestion. - Dry flushed skin, dry mucous membranes - Urinary retention - Pupillary dilatation, blurred vision - Decreased bowel sounds - Altered mental state (including hallucinations and deliri um) - Altered conscious level, coma - Fitting - Arrhythmias Sinus tachycardia - i QRS duration - i PR interval - Heart block - SVT - VT (including tour sade de pointes) Hypotension. Management - Establish and maintain a patent airway - Support respiration as required - Est ablish intravenous access \200\224cautious iv fluids for hypotension - Monitor ECG and SpO2 - Give activated charcoal (50mg) if safe to do so - Avoid unnecessary stimulation (may pre cipitate fits) - iv diazepam for prolonged fitting (brief fits may resolve spontaneously) - Asymptomatic arrhythmias should be observed if perfusion is adequate and the BP is accepta ble. Serious symptomatic arrhythmias are best treated with sodium bicarbonate (1 \200\2233m mol/kg slow iv infusion) but this is unlikely to be available pre-hospital. If necessary, t hese arrhythmias can be treated with lignocaine Transfer to hospital urgently. CHAPTER 6 Poisoning and substance abuse 460 Venomous bites and stings See also: adder bite (p.409), snake bite (p.455) Jellyfish stings Presenting features - Pain - Paraesthesia - Paralysis - Pruritic rash - Anaphylactic react ions (rare) - Hypotension (rare). Management - Wash with salt water (or normal saline) or diluted (1:20) vinegar for 30 minutes Remove tentacle fragments carefully (use forceps or thick gloves \200\224 a single layer of surgical glove can be penetrated) Give analgesia - Do not rub the area or wash in fresh water. Sea urchins Presentation See a bove. Management - Analgesia - Prophylactic antibiotics - Immerse in hot water - Carefully remove spines (can be performed in hospital; retained spines are radio-opaque). Spider bites Presentation There are no toxic native spiders in the UK. Such species may occ asion- ally escape from private collections or bite keepers in zoos. Symptoms include (depe nding on the species): - Local pain - Muscle cramp - Sweating - Nausea - Diarrhea - Tachyca rdia - Hypertension - Anxiety. Management - Specific antisera may be available in specialist centers or zoos which keep toxic species Diazemuls will lower blood pressure, slow tachycardia, and calm the patient Morphine (or a similar opiate) should be given for pain - Monitor BP, ECG, and PaO2 - Trans fer to hospital. This page intentionally left blank CHAPTER 6 Poisoning and substance abuse 462 Substance abuse Substance abuse is becoming increasingly common and is a problem that every pre-hospital practitioner is likely to meet sooner or later. This section deals with the p resentation and management of commonly abused drugs. Some of the complications which are di scussed are fortu- nately rare, but may be fatal if incorrectly treated. Specific managemen t points are given, but this in no way lessens the importance of good sup- portive care and careful attention to ABC. It is important to remember that, in many cases, these substance s will have been taken in combina- tion, most often with alcohol. Drug abusers are probably everybody \200\231s least favorite patients. They are frequently aggressive, demanding, and almost never grateful. It is even more important, therefore, tha t personal prejudices are not allowed to interfere with management which must be of the hig hest standard for the protection of patient and clinician. Patients who are under the influ ence of drugs and other substances are at particularly high risk of further injury or harm and are owed a duty of care in this regard also. SUBSTANCE ABUSE1 463 Amphetamines Description Amphetamines and methamphetamine stimulate the sympathetic nervous system and block reuptake of catecholamines, dopamine, and serotonin. Methods of abuse Oral. Clinical features Effects occur within 1 hour and last 4 \200\2236 hours with smaller doses , up to 48 hours after larger. Sympathomimetic effects - Tachycardia, cardiac arrhythmias* (usually supraventricular) - Di lated pupils and blurred vision - Hypertension (may result in CVA*) - Pallor - Sweating, dr y mouth. Central effects - Agitation - Talkativeness - Drowsiness, coma* - Paranoia - Visual halluci nations - Convulsions.* A hyperpyrexial syndrome may also occur Immediate management - Intravenous access - Monitor ECG - Diazemuls for fitting, agitation, or psychosis (also reduces hypertension agitation and tachycardia) Activated charcoal can be given within 1 hour of oral ingestion if hospi- tal transfer is likely to be prolonged If transfer is likely to be prolonged or delayed, hyperthermia should be treated with cold intravenous fluids. Damp sponging should be carried out to reduce the core temperature. Transfer to hospital (SVT and hypertension can be treated after arrival, unless this is likely to be delayed). Hallucinating patients must not be left alone! Their behavior may put themselves and others at risk. severe poisoning. CHAPTER 6 Poisoning and substance abuse 464 Amyl nitrate Description Conventionally used in the management of cyanide poisoning. Methods of abuse Ingestion and inhalation. Clinical features - Headache - Nausea and vomiting - Sweating - Flushing - Chest tightness - Confusion - Fitting (rare) - Cyanosis may occur due to methaemoglobinaemia. Immediate management - No specific management is required - Monitor: pulse, BP, respiratory rate - Maintain a patent airway and administer oxygen 15l/min - Transfer to hospital. SUBSTANCE ABUSE1 465 Benzodiazepines Description Prescription drugs. Methods of abuse Oral ingestion. Clinical features - Drowsiness - Confusion - Mid position or dilated pupils - Ataxia (slurr ed speech) and nystagmus - Coma (rarely deep GCS <10) - Hypotension (usually mild) - Respir atory depression - Cardiorespiratory arrest (after iv use). Immediate management Supportive care for the patient with a reduced conscious level. Partic ular care should be paid to airway maintenance. Flumazenil is NOT licensed for the treatment of deliberate benzodi- azepine overdose. The c orrect pre-hospital management is supportive care pending arrival in hospital. Rarely, flum azenil treatment may be appropriate but it should be used with caution and complete reversa l should not be attempted. Flumazenil is ABSOLUTELY contraindicated in a patient with a history of convulsions or thos e who have also ingested tricyclic antidepressants in whom it may precipitate fits and vent ricular arrhythmias. Acute with- drawal may result from the use of flumazenil in those pati ents addicted to benzodiazepines Activated charcoal is not indicated. CHAPTER 6 Poisoning and substance abuse 466 Cannabis Description Psychoactive substances derived from the plant Cannabis sativa. Mari- juana refers to any part of the plant used for its pharmacological effects; hashish is drie d resin from the flowers. Common names include: grass, pot, hash, reefer ganja, bhang, and spliff. Methods of abuse - Dried, then smoked or eaten - Occasionally injected. Clinical features These will depend on the mood, personality of the individual, environ- me nt, and the amount consumed. After smoking, the onset of effects is 10 \200\22330 minutes; after ingestion, 1 \200\2233 hours. Duration of effects, 4 \200\2238 hours. Low dose - Euphoria - Altered perception - Relaxation - Drowsiness - Hypertension, tachycar dia - Slurred speech - Ataxia, lack of co-ordination - Appetite stimulation - Injected conj unctivae - Dilated pupils. High dose - Acute paranoid psychosis - Anxiety, panic attacks - Confusion - Hallucinations and distortions of time and space. Intravenous abuse may result in diarrhea, nausea, vomiti ng, and abdomi- nal pain, as well as hypotension and pulmonary oedema. Management of psycho tic features is discussed on p.484. Immediate management Supportive therapy and observation is usually all that is required. Di aze- muls may be used for sedation, if required. Hypotension responds to intravenous fluids . SUBSTANCE ABUSE1 467 Cocaine/crack cocaine Description - Cocaine is an alkaloid from the leaves of the coca bush from South America. Cocaine: cocaine hydrochloride is a white crystalline powder or colorless crystals Crack cocaine: crack cocaine ( \200\230crack \200\231) is cocaine separated from the hydrochloride base, and usually sold as \200\230rocks \200\231. Methods of abuse - Cocaine is \200\230snorted \200\231 (sniffed) or injected intravenously - Crack is smoked. Clinical features When cocaine is snorted, effects occur very rapidly and may last up to 90 minutes. Smoked crack produces its maximum effect in about 10 minutes and has begun to wea r off after about 15 \200\22320 minutes. Mild/moderate intoxication - Euphoria - Slurred speech and ataxia - Restlessness, tremor, a gitation, and aggression - Hallucinations - Pupillary dilatation - Nausea and vomiting - Pa llor, cold sweats - Tachycardia, tachypnoea, ventricular ectopics/arrhythmias, hypertension. Severe intoxication - Drowsiness and coma - Convulsions - Incontinence - Hyperreflexia - Ci rculatory and respiratory failure \200\224leading to hypotension, hypoxia, and arrhythmias Severe hypertension \200\224leading to stroke, intracerebral hemorrhage, and infarction Artery spasm \200\224leading to myocardial and intestinal ischaemia and AMI - Hyperthermia. A paranoid delusional state may occur with chronic usage. Psychotic reac- tions to individ ual doses may also occur. Hallucinations may also occur. Severe depression and aggression may follow the \200\230high \200\231 and may result in suicide attempts or violent behavior against others. Pneumothorax may be found as a result of valsalva maneuvers per- formed to increase the absorption of inhaled cocaine. CHAPTER 6 Poisoning and substance abuse 468 Immediate management The patient should be assessed in a quiet environment. - Monitor: ECG, pulse, BP - Establish and maintain a patent airway; ensure intravenous access - Diazemuls for fitting, agitation, or psychosis (also reduces hypertension agitation and tachycardia) Transfer to hospital. If transfer is likely to be prolonged or delayed, hyperthermia should be treated with tepid sponging. Cold intravenous fluids may be necessary. Activated charcoal can be given within one hour of oral ingestion if hospital transfer is likely to be prolonged. SUBSTANCE ABUSE1 469 Ecstasy Description Ecstasy (3,4 methylenedioxymetamphetamine, MDMA) is a derivative of amp hetamine. Methods of abuse Oral ingestion. Clinical features - Euphoria and increased sensuality - Dehydration - Hyperthermia - Agitat ion - Convulsions - Muscle spasm - Abdominal pain - Hypotension - Coma - Cerebral hemorrhag e and infarction - Cardiac arrhythmias. Effects of chronic use include anorexia, palpitatio n, jaw stiffness, teeth grinding, sweating, and insomnia Immediate management - Intravenous access - Monitor ECG - Diazemuls for fitting, agitation, or psychosis (also reduces hypertension agitation and tachycardia) Activated charcoal can be given within one hour of oral ingestion if hospital transfer is l ikely to be prolonged. If transfer is likely to be prolonged or delayed, hyperthermia shoul d be treated with damp sponging to reduce the core temperature. Cold intravenous fluids sho uld be considered. Transfer to hospital (SVT and hypertension can be treated after arrival, unless this is likely to be delayed). Note The common causes of death following ecstasy use appear to be arrhyth- mias (early) an d a hyperthermic neuroleptic malignant-like syndrome (late). CHAPTER 6 Poisoning and substance abuse 470 Gammahydroxybutyric acid Description GHB is sold (illegally) for body building and weight l oss. It is also used as a psychedelic agent. Methods of abuse Sold as a powder, GHB is dissolved in water and taken orally. Clinical features Symptoms are dose dependent and include: - Nausea - Diarrhea - Drowsiness , confusion, coma - Vertigo - Tremor - Extrapyramidal signs - Agitation - Bradycardia - Hyp otension - Cardiorespiratory depression (severe poisoning) - Fits. Immediate management - Monitor: BP, pulse, respiratory rate, and pulse oximetry - Check: BM stix - Diazemuls for fits - Atropine for bradycardia - Transfer to hospital. SUBSTANCE ABUSE1 471 Hallucinogenic fungi Description A wide range of fungi are ingested for their hallucinogeni c properties. The most common of these is Psilocybe semilanceata (liberty cap). Methods of abuse Oral ingestion. Clinical features Symptoms usually begin within 30 \200\22390 minutes following ingestion a nd include: - Nausea and vomiting - Abdominal pain - Dilated pupils - Hallucinations (visua l and auditory) - Agitation, tremor - Drowsiness - Depression. Immediate management - Evacuation to hospital - Diazemuls for sedation, if required. CHAPTER 6 Poisoning and substance abuse 472 Ketamine Description A dissociative anesthetic/analgesic. Methods of abuse - Commercial ketamine is injected intramuscularly or intravenously - Stree t ketamine is sniffed or smoked. Clinical features The onset of action is rapid and the psychological effects usually last l ess than one hour: - Euphoria - Psychological effects/confusion: Synaesthesia (experiencing a stimulus with the \200\230wrong \200\231 sense) - Out-of-body experiences - Depersonalization - Persistent repetition of acts or words Agitation - Aggression - Vomiting - Slurred speech - Blurred vision - Numbness - Dizziness and ataxia - Hypertension and tachycardia - Rarely, convulsions, cardiac and respiratory ar rest, raised intracranial pressure, and pulmonary oedema may occur. Emergence reactions may be profoundly unpleasant including vivid dreams, hypersensitivity t o light, and hallucinations. Immediate management - Monitor: pulse, BP, ECG, and pulse oximetry - The patient should be maintained wherever possible in a quiet dark environment to reduce emergence phenomena. Dia zemuls may be used for agitation and will also reduce emergence symptoms. Transfer to hospital. SUBSTANCE ABUSE1 473