general management of toxicological cases
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general management of toxicological casesTRANSCRIPT
GENERAL GENERAL APPROACH TO APPROACH TO
ACUTELY ACUTELY POISONED PATIENTSPOISONED PATIENTS
GENERAL GENERAL APPROACH TO APPROACH TO
ACUTELY ACUTELY POISONED PATIENTSPOISONED PATIENTS
Prof. Enas El TaftazaniProf. Enas El Taftazani
Prof. of clinical toxicologyProf. of clinical toxicology
Objectives•To provide a systematic approach to
the resuscitation, work-up, diagnosis and treatment of the acutely poisoned patients.
Outline• Case based approach to:
– initial stabilization– History– Evaluation of the poisoned patient– Techniques to prevent absorption– Techniques to enhance elimination
Immediate Stabilization
• Airway with cervical spine control– Intubate…what do you want to use?
• Breathing– 100% O2 , ventilation
• Circulation– Insert new IVs– Draw bloods with IV start– Bolus 1-2L NS – Cardiac monitor
History
Personal history
History of present illness
Past historyFamily history
Toxicological History• Often incomplete, unreliable or
unobtainable
• Sources – Patient, friends, family, pill containers
• liver/renal disease, concurrent medications, previous overdoses, substance abuse
The 5W’s of toxicology• Who – pt’s age, weight, relation to others• What – name and dose of medication,
coingestants and amount ingested,pre-consultation treatment.
• When – time of ingestion, single vs. multiple ingestions
• Where – route of ingestion, geographical location
• Why – intentional vs. unintentional
Ask about :
Respiratory symptoms:Cough,chest pain,dyspnea,,sputum
GIT: N,V,diarhea,pain ch.ch. Of vomitus.
Neurological: weakness,rigidity,
CVS: palpitation ,chest pain,.dyspnea.
Urinary: urine retention,…
Examination • General :General : vital data-Pupil, conscious state• Pupil: miosis,mydriasis,• Consciousness:grading of
coma,agitation, hallucination.• Systemic examinationSystemic examination
Vital signs
Pulse
TemperatureBlood pressure
Respiratory rate
Pulse
Bradycardia:
Organophosphates,digoxin,opiate,barbiturates,B-blockers
Tachycardia:
Anticholinergics,
sympathomimetics
Irregular pulse: digoxin,TCA,sympathomimetics,CO
Blood pressure
Hypotension:
Decreased peripheral resistance
Hypovolemia
Decreased myocardial contractility
Hypertension:
Sympathomimetics
Scorpion
anticholinergics
Temperature
Hyperthermia
Salicylates
Sympathomimetics
Anticholinergics
Antidepressents
Hypothermia:
CO,oral hypoglycemics
Hypnotics
ethanol
Respiratory rate
Tachypnea:
Hypoxia
Acidosis
With dyspnea as irritant gas
Bradypnea :
CNS depression,neuromuscular blockade
Toxicologic Physical Exam
•CNS – level of arousal, GCS, pupils, behaviour, neurologic exam
•CVS – rate, rhythm•Resp – pattern, depth, wheezing•GI – bowel sounds, distention•Skin – color, temp, signs of trauma•Odors
Laboratory Investigations
• What lab tests should we order?
• What special tests are available?
Laboratory investigations (cont’d)
• General labs(routine): CBC,ECG,LFT, Electrolytes, BUN, Cr, glucose, ABG.
• Special laboratory investigation indicated in following cases– Intentional ingestion– Substance unknown– Potential for mod to severe toxicity
•Labs considered essential and available: –EtOH, acetaminophen, salicylate, digoxin,
Carbamazepine, phenobarb, phenytoin, Valproate, theophylline
–Methanol, Ethylene glycol, Isopropanol, Iron, Lithium
•Tox screen – does not contribute to patient management
Laboratory investigations (cont’d)
Additional Tests•ECG – TCA or other cardiotoxic drugs,
arrhythmias, ischemia
•Radiology –CXR – aspiration, noncardiogenic
pulmonary edema–Abdominal films useful in screening for
ingestions of radio-opaque materials–What substances are visible on AXR?
DECONTAMINATION• DERMAL:OPC,Carbolic acid. ( remove clothes,wash with soap & water
for 15 min,NO forceful rubbing)• EYE:wash conj. With running water or saline
for 20 min.• Inhalation:CO ,CN. 1.Remove to fresh air 2.Care of resp.• GIT
Gastrointestinal Decontamination
• Emesis.• Gastric lavage• Whole bowel irrigation • Activated charcoal• Cathartics
GIT emptying• Removal of poison from stomach
by emesis or g. lavage:• Causes of limitation of its use
nowadays: time factor, small dose, previous vomiting, presence of other methods (charcoal).
• Indications: high lethal dose, if other measures are applicable.
Ipecac• Emetic – both peripherally and central acting• >90% effective• Dose 30cc PO :adults, 15cc >2yrs, 10cc 6-
2yrs.• IF failed within 30 m,repeat,if not then GL..• Advantages over lavage:
– Safe – Efficient– Less traumatic
• Contraindications- Substance- Patient - Time passed
• Complications– Diarrhea, lethargy/drowsiness, prolonged
vomiting
Never Never Never
( Use Salty H2O???? )
Gastric Lavage• ContraindicationsAbsolute Corrosives, froth-forming
Relative Unprotected airway, comaConvulsions HydrocarbonsRisk of GI bleed or perforationTime factor (unless delayed)
• ComplicationsAspn pneumonia, laryngospasm, hypoxia, mechanical injury, fluid/electrolyte imbalances, bradycardia, hypertension
Activated Charcoal• 1g/kg PO or NG• Indications
– Nearly all suspected toxic ingestions except– May be considered more than 1 hour after
ingestion but insufficient data to support or exclude use
• Contraindications– Unprotected airway– When AC therapy may increase risk and
severity of aspiration– Corrosives (why??) , IO, hydrocarbons ,NOT
ADSORBED.• Complications
– GIT obstruction, constipation, adsorb medication
Drugs that don’t adsorb to AC
• PHAILS– Pesticides ???– Hydrocarbons, Heavy metals (Fe,Hg,Pb)– Acids/Alkalis/Alcohols– Iron– Lithium– Solvents– Gases
INDICATIONS OFMDAC
• Drugs remain in GIT:• SR-prep:theophylline• concretions:salicyl. Phenobarbit.• slowing GIT motility:antichol.• EHC:digoxine,dapson,TCA• Passive diffusion from bl to lower GI
lumen:theophylline.
Whole bowl irrigation
• A newer method for decontamination, well tolerated ,safe in pregnancy
Whole bowel irrigation• PEG via NG at 1-2 L/h (500cc/h in peds) until
effluent clear
• Indications– Potentially toxic ingestion of SR prep– Ingested packets of illicit drug (stuffers,
packers)– Substances not adsorbed by AC– Iron ingestions
Whole bowel Irrigation• Contraindications
– Bowel perforation or obstruction– GI bleed – Ileus– Unprotected airway– Hemodynamic instability– Intractable vomiting
• Complications– Nausea, vomiting, aspiration, cramps
TYPES OF CATHASIS• OSMOTIC:MgSO4(15-30g)in glass of
water.• IRRITANT:Castor oil(60-100ml)• Contraind.:GI Hge, IO,ileus,recent
bowel surgery,RF(Mg load)• Complications:dehydration &
elec.imb
Cathartics•Sorbitol, Mg citrate, Phosphosoda•May be an argument for adding to
initial dose of multiple dose activated charcoal
•No studies have demonstrated a benefit in clinical outcome with cathartics
Enhancing elimination
• Multiple dose activated charcoal • Diuresis • Alkalinization • Hemodialysis • Hemoperfusion
Alkalinization• Enhances elimination of weak
bases by ion trapping• Useful for:
– Salicylates, phenobarbital, myoglobin
• NaHCO3 1-2 mEq/kg IV • Aim for Urine pH 7-8• Must replace K
Hemodialysis
• Blood passed across membrane with countercurrent dialysate flow
• Toxins removed by diffusionProperties required:
– Molecular weight < 500 daltons– Low or saturable plasma protein binding– Low Vd (<1L/kg)
Hemoperfusion• Blood passed through cartridge
containing AC• Toxins removed by adsorptionProperties required:
– Low Vd <1L/kg– Low endogenous clearance <4cc/min/kg– Adsorbable to AC
Substances amenable to hemodialysis or hemperfusion• LET ME SAV P
– Lithium– Ethylene glycol– Theophylline
– MEthanol
– Salicylates– Atenolol– Valproic acid
– Potassium, paraquat
Complications of hemodialysis
• Bleeding at venous puncture site• hypotension• Bleeding due to systemic
anticoagulation• Infection• Air embolus
AntidotesIf after stabilization a toxin is identified, there may be a specific antidote
Antidotes (Cont’d)
antidote poison
acetylcysteine acetaminophen
Crotalid Antivenin
Crotalid snake bite
atropine Carbamate or organophosphate
Ca gluconate or Ca chloride
CCB or hydrogen fluoride
Cyanide kit cyanide
Deferoxamine Iron
Digoxine immune Fab
Digoxin, digitoxin
Dimercaprol (BAL)
Arsenic, mercury, lead
antidote poison
ethanol MeOH, et glycol
flumazenil BDZ
Fomepizole MeOH
glucagon Β-blocker, CCB
Methylene blue
methemoglobin
naloxone opioids
physostigmine anticholinergic
pralidoxime organophosphate
pyridoxine isoniazid
Sodium bicarbonate
TCA, cocaine, salicylates
Summary• Airway with cervical spine control• Breathing• Circulation• Drugs (coma cocktail),
Decontamination• Elimination• Find an antidote• General management
Thank You
Bradycardia• Propanolol (β-blockers),
phenylpropanolamine (-agonists)• Anticholinesterase drugs(OPC)• Clonidine, CCBs• Ethanol / alcohols• Digoxin, Darvon (opiates)
Tachycardia• Free base (cocaine/stimulants)• Anticholinergics, antihistamines • Sympathomimetics• Theophylline (methylxanthines)
Hypotension• Clonidine• Reserpine (antihypertensives)• Antidepressants• Sedative hypnotics • Heroin (opiates)
Hypertension• Cocaine• Theophylline, thyroid supplements
• Sympathomimetics• Caffeine• Anticholinergics, amphetamines• Nicotine
Hyperthermia• Neuroleptic malignant syndrome• Antihistamines• Salicylates, sympathomimetics,
serotonin syndrome• Anticholinergics, antidepressants
Hypothermia• Carbon monoxide• Opiates• Oral hypoglycemics/insulin• Liquor (EtOH)• Sedative hypnotics
Seizures• Organophosphates• Tricyclic antidepressants• INH, insulin• Sympathomimetics
• Camphor, cocaine• Amphetamines, anticholinergics• Methylxanthines• Phencyclidine• Benzodiazepine withdrawal, botanicals• Ethanol withdrawal• Lithium, lidocaine• Lead, lindane
PupilsMiosis
•Opiates/organophosphates•Phenothiazines,
pilocarpine, pontine bleed•Sedative hypnotics•Cholinergics/clonidine
Mydriasis•Antihistamines•Antidepressants•Anticholinergics•Sympathomimetics
Odors• Bitter almonds – cyanide• Fruity – DKA, isopropanol• Minty – methyl salicylates• Rotten eggs – sulfur dioxide, hydrogen
sulfide• Pears – chloral hydrate• Garlic – organophosphates, arsenic• Mothballs - camphor
Radiodense substances that may be visible on
AXR• CHIPES
– Chloral hydrate– Heavy metals– Iron– Phenothiazines– Enteric coated preps– Sustained release preps
• Drug Packets
Questions
??
CPRCPRCPRCPR
CPR•Position of the patient.•Artificial respiration (mouth to mouth breathing=rescue
breathing)•Ext. Chest compression with monitoring the carotid or
femoral pulse.•Rate: (2 resp. /15 beats if one rescuer) or
(1 resp. /5 beats if two rescuers)•IV line, Oxygen, intubation NaHCO3,•Adrenaline 1 mg /5min IV.•Ca chloride.•DC shock
SEQUENCE OF ACTION
•1-Ensure safety of rescuer and victim•2-Check the victim & see if he
responds:gently shake his shoulders & shout loudly:”Are you all right”?
•3-If he responds by answering or moving---check him & get assistance
•If he doesn’t respond:shout for help
•4-Check position,airway open then•LOOK for chest movements•LISTEN at his mouth for breath
sounds•FEEL for air on your cheek•(for no more than 10 sec to
determine if he is breathing normally)
• 5- If he is breathing: Turn him into recovery position Check for cont. breathing Send for help If not:ask for assistance - turn him on his back - tilt head, chin lift -pinch soft part of his nose -open his mouth a little but maintain chin lift -take a breath,place your lips around his mouth, make
good seal -blow ,watch his chest take about 2 sec - give him 2 rescue breaths (each makes his chest rise & fall)
•6-ASSESS CIRCULATION:
LOOK LISTEN & FEEL for normal
breathing,coughing or any movement
Check pulse(for no more than 10 sec)
•7-If no signs of circ.(START CHEST COMPRESSION)
•Combine rescue breathing & comp.•After 15 comp. tilt head,lift chin & give 2
effective breaths and so on in a ratio of 15:2
•Stop to recheck for signs of circ only if he makes a movement or takes a spont
breath;otherwise resuscitation should not be interrupted
CONTINUE UNTIL??•QUALIFIED help arrives &
takes over
•The victim shows signs of life
•YOU become exhausted
Notes On Tech. Of BLSRESCUE BREATHING:
• only slight resistance should be felt• each one should take about 2 seconds• Blowing too quickly will force air into the
stomach & inc. the risk of regurgitation• each should make the chest rise clearly•The rescuer should wait for the chest to fall
fully during exp(about 2-4 sec)
CHEST COMPRESSION:•The aim is to press down approx.4-5 cm &
apply enough pressure to achieve this•Pressure should be firm,controlled &
applied vertically(erratic or violent action is dangerous)
•You should not waste time to check the presence of pulse.
•The presence of dilated pupils is an unreliable sign & shouldn’t influence