HYDROCARBON POISONING
Toxic
mechanism
Pharmacology
Classification
Symptoms
Investigation
Mng
Charcoal resistant
RS: aspiration, surfactant depletion, lipid peroxidation, free radicals  chemical pneumonitis, microaspiration
Metabolic: lipid peroxidation of mitochondria, interrupts oxidative phosphorylation
CV: sensitises myocardium to catecholamines  arrhythmia
NS: myelin toxicity  neuropsychiatric issues long term
INH absorption determined by concentration / duration of exposure / minute ventilation; volatile liquid (toxicity proportional to volatility); highly lipid
soluble  CNS and liver; HL 15-72hrs
Group I: high viscosity = low toxicity; petroleum jelly, diesel, grease, lubricating oil; no trt needed
Group II: low viscosity = high toxicity (1-2ml required for signficant toxicity); kerosene, lighter fluid, petrol, turps
Group III: vinyl chloride, trichloroethylene, carbon tetrachloride; high toxicity
Group IV: benzene, toluene, xylene, camphor, phenol, lindane, DDT, endosulfan; found in glues, polishes, cleaning liquids, inks, disinfectants; may be
absorbed through intact skin and lungs
Solvents: chloroform; thinners, cleaning fluid, glues
Acetone: nail polish removal, cleaning material
Terpines: pine oil, turps (violet odour), camphor, tea tree oil
Essential oils: nutmeg, eucalyptus oil, peppermint, pennyroyal oil, clover oil, absinthe; used in aromatherapy
RS: dry cough (may be evolving pneumonitis), NCPO, pleural effusions (5%); aspiration and chemical pneumonitis from solvents and terpines 
wheeze, SOB, decr sats, haemoptysis, pul oedema  worsens over 24-72hrs  resolves in 5-7/7  may have serious progression and restriction in pul
function for years
In phenol: resp arrest, NCPO
GU: RTA with toluene, petrol, phenol; ARF (may take days to develop)
CNS: similar to ETOH – rapid onset CNS depression, ataxia, euphoria, coma, seizures
In toluene: chronic myopathy, encephalopathy, tremor
In benzene / lindane: agitation, muscle spasms, ataxia, seizures
In camphor: strabismus, mydriasis
In eucalyptus oil: CNS depression and seizures within 1-2hrs after 10ml
In petrol sniffers: eurphoria and intoxication for 6hrs; chronic cerebellar dysfunction, encephalopathy, peri neuropathy
GI: V+D; haematemesis (toluene, benzene, turps); hepatic toxicity (may take days to develop; fulminant in chloroform)
CV: in severe toxicity  arrhythmias, hypotension; occurs early
In benzene / lindane: decr HR, VF, NCPO
In petrol: chronic cardiomyopathy
Skin: eye and skin irritation in benzene / lindane / camphor / mothballs
BM: incr WCC, aplastic anaemia
Met: in toluene  rhabdo ( RTA), decr K
CXR: changes may lag 6hrs; may take 2-4/52 to resolve
Decontamination: remove clothes, wash skin
Indications for gastric lavage: all patients <1hr with any grp III/IV, or >1ml/kg grp II
ETT before lavage in all patients
ABC: O2; reduce dose of adrenaline if needed; withhold inotropes if possible (hypersensitive myocardium); give 5mg IV metoprolol / 1mg IV
propanolol for arrhythmia; Abx only if evidence of sepsis
Dialysis: may be used in severe
Discharge: if asymptomatic and normal CXR at 6hrs
Admit if: any symptoms / abnormal CXR
Notes from: Dunn, Cameron, Tox Book