Hydrocarbons

w Organic compounds containing H and C w Derived from plants or from petroleum distillates w 3 basic types aliphatic aromatic halogenated w Petroleum distillates - produced from fractional distillation of crude petroleum w Terpenes - distillates of pinewood

Hydrocarbons w AAPCC lists HC’s as the 12th most common poison exposure w 66, 645 cases of HC exposure in 1997, as reported by the American Association of Poison Control Centers w 95% were unintentional, 60% were pediatric w more than 1/2 of all exposures occur in children under the age of 6 years w most exposures are accidental w 20 people died in 1997, most in children > 5yrs.

Hydrocarbons, cont. w Examples of petroleum distillates kerosene gasoline mineral spirits naphtha mineral seal oil diesel oil fuel oil

Hydrocarbons, cont. w Characteristics that determine toxicity w surface tension - cohesiveness of molecules on the surface of a liquid w volatility - tendency of a liquid to change into a gas or vapor w viscosity - resistance of a substance to flow over a surface, directly relates to the aspiration hazard low verses high viscosity

Hydrocarbons, cont. Mechanism of toxicity, cont. w major threat is danger of aspiration pneumonitis w vomiting increases the risk of aspiration w when aspirated, petroleum distillates : inhibit surfactant - causing alveolar collapse and resultant hypoxemia can displace O2 in alveoli - hypoxia cause bronchospasm and capillary damage cause hemorrhagic bronchitis cause pulmonary edema

Hydrocarbons, cont. Mechanism of toxicity, cont. w Systemic toxicity can occur after oral ingestion Most are lipophilic and attracted to the CNS - causing CNS depression Most cause direct mucosal irritation Certain volatile agents (toluene, benzene, butane and xylene) have a disinhibiting euphoric effect Can cause AV block, bradycardia

Hydrocarbons, cont. w Characteristics of poisoning: w Signs and symptoms of pulmonary involvement coughing, gasping and choking smell of gasoline to the breath rales and wheezing upon auscultation hemoptysis and pulmonary edema w Signs of CVS involvement: Dyspnea, syncope, sudden cardiac death (sens. myocardium to catecholamines)

Hydrocarbons, cont. w Signs and symptoms of GIT involvement irritation of oropharynx nausea and vomiting abdominal pain w Signs and symptoms of CNS involvement cerebral hypoxemia lethargy somnolence coma or seizures

Hydrocarbons, cont. w Management of poisoning w Keep patient calm w To induce vomiting or not to induce vomiting w Do not induce vomiting in patients who have ingested low viscosity petroleum distillate hydrocarbons ingestion as it increases the risk of aspiration pneumonitis w Do Maintain airway and support respiration

Hydrocarbons, cont. w Do induce vomiting in patients who have ingested: halogenated hydrocarbons insecticides turpentine aromatic hydrocarbons or ones which contain of heavy metals - must protect airway (endotracheal intubation)

Hydrocarbons, Terpenes w Unsaturated aliphatic cyclic hydrocarbons derived from plants w Includes pine oil, turpentine, and camphor oil w 1998 AAPCC reported 10,482 exposures to disinfectants containing pine oil, 1,064 to turpentine, 8,945 to camphor and 1,237 to camphor/methyl salicylate. w No fatalities were reported w Most exposures are accidental

Hydrocarbons, Terpenes w Mechanism of Action all terpenes are local irritants GIT signs and symptoms aspiration pulmonary toxicity coma seizures w Treatment: Careful attention to airway DO NOT induce vomiting because of initial risk of aspiration and risk of CNS depression or seizure