Page 627 - ACCCN's Critical Care Nursing

604 S P E C I A LT Y P R A C T I C E I N C R I T I C A L C A R E

most cases water will be the safest and best available gluconate may be required. Continue to monitor for sys-
liquid. Provide skin or eye protection with a sterile temic effects of perforation or tissue injury. 135
dressing. 135
PETROLEUM DISTILLATES
For ingested acids, emesis or lavage should not be
attempted, as the substance will cause additional damage Petroleum distillates are common substances, and
114
when ejected from the stomach. A gastric tube may also account for 7% of all poisonings. Typical petroleum
cause structural damage by penetrating or irritating friable products are benzene, fuel oils, petrol, kerosene, lacquer
tissues. 135-137 Do not attempt to neutralise the acid, as this diluents, lubricating oil, mineral oil, naphthalene, paint
may result in a chemical reaction and generate heat thinners and petroleum spirits. Toxicity depends on:
as a byproduct, with potential further burning and route of exposure (ingestion or aspiration); volatility
damage. 135-137 Suctioning of oral secretions should be (ease with which the substance evaporates); viscosity
done carefully and with as much visualisation of tissues (density or thickness); amount ingested; and presence of
as possible. A patient may be given water or milk to irri- other toxins. 114
gate the upper gastrointestinal tract, although extreme Products with a low viscosity are more likely to be aspi-
care is required to ensure that the airway is adequately rated and can quickly spread over the lung surface. Sub-
protected because of risk of aspiration. 135 stances with low viscosity and high volatility (e.g. benzene,
kerosene, turpentine) are toxic in doses as low as 1 mL/
CORROSIVE ALKALIS kg, with death from doses of 10–250 mL. Mortality is

Alkalis produce tissue destruction on contact by interact- increased if an additional toxic substance is present, or if
ing with fats and proteins and producing necrotic tissue. accidental aspiration occurs. 114
Alkalis involved in toxic emergencies include many
substances found around the house, such as ammonia Assessment
(detergents, cleaning agents); cement and builder’s Aspiration causes a pneumonitis with low-grade fever,
lime; low-phosphate detergents; sodium carbonate tachypnoea, coughing, choking, gagging and pulmonary
(dishwasher detergent); and sodium hypochlorite oedema as a late effect. 114,136 Immediately assess the
(laundry bleaches). 137 patient’s respiratory tract for possible aspiration; cough-
Skin contact and ingestion are the most common types ing, cyanosis or hypoxia may indicate aspiration or
137
of injury from an alkali; ingestion is most immediately chemical pneumonitis. As petroleum distillates are fat
life-threatening. Erosion of the oesophagus and stomach solvents and rapidly cross the lipid cell membrane, nerve
occurs if ingested orally, and peritonitis or mediastinitis tissue is especially sensitive to injury. A patient may
may develop as sequelae. Late effects are similar to those exhibit local effects, such as depressed nerve conduction;
produced by acids. Oesophageal strictures due to scarring or varied central effects, such as feelings of wellbeing,
are common post-ingestion. About 25% of patients who headache, tinnitus, dizziness, visual disturbances, through
137
ingest a strong alkali will die from the initial insult, to respiratory depression, altered levels of consciousness,
136
while 98% will develop strictures. 135-137 convulsions and coma.
Assessment Management
In the awake and alert patient, the decision to treat is
The immediate response to ingestion is increased secre-
tions, pain, vomiting or haemoptysis. Signs of perforation based on the physical properties of the substance, the
include fever, respiratory difficulty or peritonitis. Alkalis likelihood of aspiration or other complications, and the
136,137
and skin contact produce a soap-like substance because amount consumed. When preventing absorption,
of the interaction with tissue fats, giving a slimy, soapy carefully consider gastric emptying, as neither induced
feeling. 135,137 vomiting nor gastric lavage are recommended. If the
patient is lethargic or unconscious, an endotracheal tube
Management is placed for adequate airway protection, 114,135-137 although
this heightens the risk of aspiration as hydrocarbons
Induced vomiting or gastric lavage should not be adhere to the tube and increase the risk of chemical
attempted, as the alkalis will be neutralised by stomach pneumonitis. 114,135-137
acid, and lavage tubes may cause further tissue
damage. 135,137 External contact with alkalis requires ORGANOPHOSPHATES
copious irrigation at the point of contact; continue irriga- Organophosphates are a large and diverse group of chem-
tion for at least 15 minutes; for the eye, irrigation can be icals used in domestic, industrial and agricultural settings
for up to 30 minutes. Cover all wounds after irrigation (e.g. insecticides, herbicides). 103,104,138 Organophosphates
with sterile dressings to reduce the risk of infection.
are absorbed through the skin, ingested or inhaled.
A patient is deemed ‘nil by mouth’ until inspection of the Although most patients become symptomatic soon after
mouth and throat to determine the amount and extent ingestional exposure, the onset and duration of action
of burns. 135 An oesophagoscopy identifies the degree of depends on the nature and type of compound, the degree
injury and enables direct irrigation of any affected areas and route of exposure, the mode of action of the com-
of mucosa. 135 Alkalis that contain phosphates may pound, lipid solubility, and rate of metabolic degrada-
produce a systemic hypocalcaemia, and IV calcium tion. 103,139,140 The primary effect of organophosphates is