1 Lecture Outline 10/14/2011 Clinical Toxicology –Management of poisons Unconscious patient Conscious patient –1) Establish the Vital signs »(CV, ACLS & Toxic ACLS), »respiration (Doxapram), »CNS (Naloxone, Flumazenil, Diazepam) –2) Clinical evaluation –3) Determine the cause for the symptoms –4) Removal of unabsorbed portion of the poison

2 Clinical Toxicology 10/14/2011 Clinical toxicology * Branch of medical science that dealing with poisoning resulted from the exposure or intake of xienobiotics and also involved the chemical and physical means used to counteracting the adverse effects induced by such chemicals The place or site with the greatest potential for poisoning is HOME MD in Hospital ER, Poison Control Centers, who are experience in emergency medicine + poison management) They bring the information from all areas (almost instant) Deals with detection/identification of poison in Human –Concerns with treating patients who have been poisoned  Managing  Identify  Prevention/treatment

3 Clinical Toxicology Management of Poisons: Patient is either Unconscious OR conscious Unconscious Patient: *Determine vital signs -No respiration, no pulse  CPR -Respiration and pulse are adequate  - Do not induced emesis - Do not give any fluid orally - Administered Naloxone i.v., (if available) Transport to clinical facilities, if not already done

4 Clinical Toxicology Conscious and alert Patient: 1) Establish and stabilize adequate vital signs of Patient 2) Clinical evaluation 3) Determine the cause for the symptoms 4) Removal of unabsorbed or the remaining portion of poison from the site of exposure

5 Clinical Toxicology Conscious and alert Patient : 1) Establish and stabilize adequate vital signs of Patient. –Most crucial & life saving –Three major vital signs should be closely monitored: » CV (HR, BP) – Avoid arrhythmias, arrest or fibrillations »Respiration »CNS – Avoid coma/convulsion

6 Clinical Toxicology Emergency stabilization of patient: Cardiovascular –Administer CPR, maintain BP by using IV fluids (this would be the best option) – Prevent arrhythmias – This is a major symptom of poisoning, especially with Tricycle Antidepressants (block NE reuptake with anticholinergic properties) – Give IV sodium Bicarbonate (NaHCO3), this may reverse an early arrhythmia – The next agent of choice would be Lidocaine (IV injection) – Procainamide should be avoided due to its excessive cardiac depressant effect

7 Advanced Cardiac Life Support (ACLS) Cardiovascular * ACLS established by the American Heart Association (AHA) & American College of Cardiology (ACC) * Used in all CV emergency * Try to maintain vital signs CV & Pulmonary.  3 Approaches 1. Electric intervention 2. Mechanical - Cardiopulmonary Resuscitation (CPR) - Cardiac massage -Artificial Respiration 3. Drugs

8 Toxic ACLS – modified procedure for poisoning * In poisonings, resuscitation may exceed min * #1 rule-keep the number of drugs administered to a poisoned patient to a minimum * As a last resort, Doxapram may be used ( mg/kg IV) to Stimulates respiration * Use 95% O2 and 5% CO2 in the majority of poisoned patients * In patients poisoned by CO - DON’T USE: 95% O2 & 5% CO2 - CO has 250x more affinity to hemoglobin than O2 - Use hyperbaric pressure (under 3atm – 3 x 76mmHg) - O2 under pressure will help displace the CO from hemoglobin - If no hyperbaric chamber is available, USE 100% O2

9 Clinical Toxicology Respiration * Endotrachial intubation – unstable Pt. * Sometimes suck mucus out to make sure lungs are clear * Na Bicarbonate in case of Arrhythmias. – if does not work give Lidocaine OR Bretylium (It blocks the release of NE from nerve terminals +acts by blocking K + channels) * Stimulate Respiration  Can use Doxapram (acts on the CNS to stimulate the breathing muscles, improving respiration) – Analeptic & other CNS stimulant after surgery for respiration * Artificial (O2 tank) or Tracheostomy for blocked airway

10 Clinical Toxicology CNS * Avoid coma/Convulsion * Give IV glucose to a max of 50g, this will reverse a hypoglycemic coma * Give 0.8mg of Naloxone OR Naltrexone (Pure antagonist), this will reverse an overdose of opioids (Must give an increased dose of Naloxone) * Give Flumazenil- A benzodiazepine (BZP)- antagonist (often used as antidote for BZP overdose) * Avoid excessive sound, light, and handling of the patient * Administer Diazepam (agent of choice), mg/kg, iv, ( as anticonvulsant and to control seizures)

11 Conscious and alert Patient: 1) Establish and stabilize adequate vital signs of Patient 2) Clinical evaluation 3) Determine the cause for the symptoms 4) Removal of unabsorbed or the remaining portion of poison from the site of exposure

12 Clinical Toxicology Conscious and alert Patient: 2) Clinical evaluation * Based on the vital signs evaluation, determine extend of toxicity (i.e., any changes in HR, BP Respiration rate), * Determine the clinical state (lab test) by measuring (Oxygen, Carbon dioxide, pH Na, K, various enzymes, BUN, glucose, in blood)

13 2) Clinical evaluation ID the poison Activity of Pt. before incidence occur Sx patient exhibits may lead to the ID of the poison Pt. History directly/indirectly (look at clinical history, ask the patient directly or the relatives about meds, depression, etc.) Consult poison control center Confirmation by blood (10ml), Urine (100ml) and gastric aspirate/gastric fluid (50ml) analysis (to assess the amount of exposure = determine poison quantity) The blood test also reveals the changes in blood chemistry that may need to be corrected (electrolyte imbalance, BUN, oxygen, carbon dioxide) Do liver enzymes analysis

14 Conscious and alert Patient: 1) Establish and stabilize adequate vital signs of Patient 2) Clinical evaluation 3) Determine the cause for the symptoms 4) Removal of unabsorbed or the remaining portion of poison from the site of exposure

15 3) Determine the cause for the symptoms Hypothermia: Don’t tell much CNS depression & coma – caused by many factors so non indicative (more general) Hyperthermia: could indicate salicylates (ASA) overdose –↑ doses uncouple oxidative phosphorylation –ATP formation ↓ & energy is converted to heat - Hyperthermia –Could also be caused by Nitro compounds - Nitrophenols or anticholinergic agents like Atropine –Atropine may causes ↑ body temperature with confusion –Over dose (OD) of antihistamines (anticholinergic side effects) (Dry as a bone, red as a beet) –Some house hold insecticide/pesticide (chlorpyrifos = Durasban)

16 3) Determine the cause for the symptoms Pupil size: –Mydriasis, Dilated Pupil (Not diagnostic, seen in coma or severe CNS depression, so it is non indicative –Miosis, Constriction, Pinpoint, it may indicate over dose of: Opiates like Morphine/Heroin – Narcotics Phenothiazines Cholinergics like-agents Cholinesterase Inhibitors (absorbs quickly )  Ach Organo Phosphate compounds Sarin & Taiban – Gas (Lacrimation, salivation, ↑ bronchial constriction) –Breath, Bitter Almond & Silver Polish – CN- exposure –Garlic – Arsenic Poison –Fruity Due to acetone due to Hyperglycemia if diabetic Pt., Sniffing Glue, Organic Solutes –Rotten Egg – sulfur, Parathion & Malathion

17 Conscious and alert Patient : 1) Establish and stabilize adequate vital signs of Patient 2) Clinical evaluation 3) Determine the cause for the symptoms 4) Removal of unabsorbed or the remaining portion of poison from the site of exposure

18 4) Removal of unabsorbed portion of poison Depends on the route of exposure & type of Poison : –Injection, inhalation, dermal, eye, PO (ingestion) Gastric emptying –Emesis and agents-induced emesis –Gastric Lavage –Adsorption of poison –Cathartics –Neutralization –Antidotes (dispositional, pharmacological & physiological antidotes) Enhance elimination (Diuresis, changing urine pH) Artificial/Mechanical removal

19 Clinical Toxicology 3) Determine the cause for the symptoms * The lab analysis will determine or identify the poison, or what was ingested (i.e., the kind of poison) * Determine the amount (mg or ml) and time (how long ago) of exposure of the substance ingested * Also identify the rout of exposure

20 Clinical Toxicology 4)Removal of unabsorbed or the remaining portion of poison from the site of exposure * If the exposure was external (dermal), then wash skin thoroughly, (eye) then continuous water irrigation * If toxicity resulted from PO or ingested materials, then Gastric lavage (Pumping), or induced emesis (save vomitus for lab analysis), or diuresis