Toxins สารพิษ

TOXINS
Miosis : C (cholinergic) O (opiod) P (pontine hge) S (sedative)
Mydriasis : A (Anti-histamine) A (A-depressant) A (A-cholinergic) S (sympathomimetics)
เหงื่อออก : S (sympathomimetics) O (organophosphate) A (ASA) P (PCP)

1. Opioid > Morphine, Heroine, Dextromethorphan
*Miosis, (BT, RR, PR, BP, reflex) hypovent, hypothermia, bradycardia, hypotension
*Hypoactive bowel sound (Ileus)
Mx: Naloxone
>> Apnea/cyanosis: 2 mg IV q 2-3 min
>> mild: 0.1 mg IV (dependent), 0.4 mg IB (non-dependent)

2. Cholinergic > Organophosphate, Carbamate, Physostigmine, Mushroom
*Miosis, 3killer Bs : Bronchospasm, bronchorrhea, bradycardia
*Hyperactive bowel sound
*SLUDGE — saliva, lacrimal, urine, defeces, diaphoresis, emesis
— Organophosphate : Irreversible, intermediate syndrome*, 2PAM (aging), slow > 48 hr
* prox. motor weakness 2-4 days after (fat redisribution)
— Carbamate : Reversible, Fast <48 hr
Mx: DEAD
Decon: NG lavage (<1hr), Activated charchoal 1 gm/kg (<4hr)
Diag: serum cholinesterase level, gastric content
Elimination: –
Antidote:
– Atropine 0.6 mg q 5 min X III [0.02-0.05 MG],
– 2PAM (organophosphate): Pralidoxime 1-2 gm IV then 500 mg/hr
[20-50 MK bolus, then 10-25 MK drip]

3. Anticholinergic > Atropine, Antihistamine, TCA
*Mydriasis, +++ Fever, tachy, HT, flushing, psychosis, DT, ชัก
*Hypoactive bowel sound (ileus), urinary retention
*** dry skin
vs
4. Sympathomimetic < Cocaine, Amphetamine, Caffeine, Theophylline
*Mydriasis, +++ Fever, tachy, HT, flushing, psychosis, DT, ชัก
*Hypoactive bowel sound (ileus), urinary retention
*** diaphoresis

5. Paracetamol Toxicity (APAP)
** >150 mg/kg
>>อาการ N/V, RUQ pain, liver enz, TB, jaundice, heptatic encep.
>>Serum paracetamol level at 4-24 hr (Rumack-Mattthew normogram)
EKG: terminal large R wave in aVR, sinus tachycardia
Mx:
<4hr: GI decon, 4-24 hr — serum APAP >4hr APAP level
(available >8 hr — give 1st dose AC ใน 8 hr)
>24hr: GI decon for unknown — serum APAP level + LFT + 1st dose AC
(APAP>10 mcg/mL + AST/ALT ขึ้น > treat AC)
Andidote: NAC (N-acetylcysteine)
goal: AST<1000, INR<2, Hepatic encep resolved
* IV NAC (AST>1000, INR>2, hepatic encep.)
150 MK x1hr, 50 MK x4hr, 100 MK x16hr (21hr)
* Oral NAC 140 MK for loading, 70 MK po q 4 hr x 17 doses

6. Corrosive ingestion
อาการ drooling (oropharyngeal), odynophagia/ dysphagia (esophageal), abd.pain/UGIH (stomach), dysphonia/ stridor/ res.distress (laryngotracheal), retrosternal chest pain (mediastinitis)
Mx:
– Airway: early intubation (stridor, dyspnea, OP obstruction)
– B/C: shock, peritoneal sign&mediastinitis, ตรวจตา/ผิว
– ห้ามทำ GI decon, no role of neutralization
– EGD; 4-6hr post-ingestion, ห้ามเกิน 48 นะจ้ะ
– skin: Hydrofluoric acid ให้ใช้ 2.5% calcium gluconate ทาจนกว่าจะหายปวด (10นาที)

7. EKG 12 leads
TCA toxicity: wide QRS (>100 msec), avR STE, RAD
—anticholinergic, GI decon+eliminate, NaHCO3 (QRS>100, hypotension, RAD in aVR >3mm, arrhythmia)
Digitalis toxicity: scoop pattern, Bidirectional VT ***


TOXICO MANAGEMENT

RESUS(ABCD)-RSI(toxidrome)-DEAD

Ix: CBC, BUN, Cr, Elyte, DTX, LFT, EKG, UA, UPT

1. D: Decontamination
Skin: remove, cleansing l Eye: NSS (no neutralize) l Inhaled : O2
GI:
*NG lavage : <1hr l ห้ามใน unpropected airway, corrosive, hydrocarbon, alcohol (จะเกิด chemical aspirate pneumonitis)
*Activated charcoal : 1gm/kg, <4hr l ห้ามใน risk of aspiration, ห้ามใช้ DRUGS (CHAMP)
— C: cyanide, camphor, caustic, H: hydrocarbon, A: alcohol, M: metal, mineral, P: potassium

2. E: Enhance Elimination
– Repeat activated charcoal 0.5-1 g/kg q 2-3 hr
– Urine alkalization (keep UpH >7) : ASA, TCA, Phenobarbitol
>>>> 7.5% NaHCO3 1-2 mEq/kg IV then 100-150 mEq + D5W drip
– Hemodialysis : Methanal, Ethylene glycal, Salicylate
ต้องละลายน้ำได้ดี low MW, low protein binding, small Vd

3. A: Antidote
– Naloxone, Flumazenil (BZD), NaHCO3 (TCAs), Calcium (CCBs)
– Atropine (Organophosphate, Carbamate), 2PAM-Pralidoxime (Organophosphate)