Gastric contents, aspiration

Strategies to Minimize Aspiration of Gastric Contents during Enteral Nutrition... 

At blood levels from 0.4g%-0.6g% (86.8 to 130.2 mmol/L) alcoholic coma often occurs, accompanied by decreased respiration, blood pressure, and body temperature Blood levels between 0.6 g% and 0.8 g% (130.2 to 173.6 mmol/L) are often fatal resulting from respiratory arrest, aspiration of gastric contents, or airway obstruction due to flaccid tongue... 

Pneumonia owing to aspiration of oral contents is caused by a variety of anaerobes (Bacteroides spp., Fusobacterium spp., Prevotella spp., and anaerobic gram-positive cocci), as well as Streptococcus spp. M. catarrhalis and Eikenella corrodens may be involved, but much less frequently.14,15 When gastric contents are aspirated, then enteric gram-negative bacilli and Staphylococcus aureus are more commonly the pathogens.15... 

Aspiration of the oropharyngeal or gastric contents may lead to aspiration pneumonia or chemical (acid) pneumonitis. Risk factors for aspiration include... 

Seizures induced by local anesthetics are usually treated with intravenous anesthetic drugs (eg, thiopental 1-2 mg/kg, propofol 0.5-1 mg/kg, midazolam 0.03-0.06 mg/kg). The muscular manifestations of a seizure can be blocked using a short-acting neuromuscular relaxant drug (eg, succinylcholine, 0.25-0.5 mg/kg IV). It should be emphasized that succinylcholine does not alter the CNS manifestations of local anesthetic-induced seizure activity. Rapid tracheal intubation can prevent pulmonary aspiration of gastric contents and facilitate hyperventilation. 

In heavily muscled patients, the fasciculations associated with succinylcholine may cause an increase in intragastric pressure ranging from 5 to 40 cm H20, increasing the risk for regurgitation and aspiration of gastric contents. This complication is more... 

An understanding of common mechanisms of death due to poisoning can help prepare the care-giver to treat patients effectively. Many toxins depress the central nervous system (CNS), resulting in obtundation or coma. Comatose patients frequently lose their airway protective reflexes and their respiratory drive. Thus, they may die as a result of airway obstruction by the flaccid tongue, aspiration of gastric contents into the tracheobronchial tree, or respiratory arrest. These are the most common causes of death due to overdoses of narcotics and sedative-hypnotic drugs (eg, barbiturates and alcohol). 

Patients with ethanol or sedative-hypnotic overdose may be euphoric and rowdy ("drunk") or in a state of stupor or coma ("dead drunk"). Comatose patients often have depressed respiratory drive. Depression of protective airway reflexes may result in aspiration of gastric contents. Hypothermia may be present because of environmental exposure and depressed shivering. Ethanol blood levels greater than 300 mg/dL usually cause deep coma, but regular users are often tolerant to the effects of ethanol and may be ambulatory despite even higher levels. Patients with GHB overdose are often deeply comatose for 3-4 hours and then awaken fully in a matter of minutes. 

If the patient is comatose or in a state of stupor or delirium, emesis may cause aspiration of the gastric contents. 

Therapeutic uses Because of its rapid onset and short duration of action, succinylcholine is useful when rapid endotracheal intubation is required during the induction of anesthesia (a rapid action is essential if aspiration of gastric contents is to be avoided during intubation). It is also employed during electroconvulsive shock treatment. 

Usually intravenous pre-oxygenation followed by a small dose of an opioid, e.g., fentanyl or alfentanil to provide analgesia and sedation, followed by propofol or, less commonly, thiopental or etomidate to induce anaesthesia. Airway patency is maintained with an oral airway and face-mask, a laryngeal mask airway (LMA), or a tracheal tube. Insertion of a tracheal tube usually requires paralysis with a neuromuscular blocker and is undertaken if there is a risk of pulmonary aspiration from regurgitated gastric contents or from blood. 

An 80-year-old woman with dementia accidentally took about 200 ml of chlorhexidine gluconate 5%. She aspirated her gastric contents and despite intensive treatment died of acute respiratory distress syndrome 12 hours later. The serum concentration of chlorhexidine gluconate was markedly high (25 pg/ml). 

The authors concluded that aspiration of contrast material can be life-threatening and that administration of oral contrast media after trauma can increase the risk of aspiration of gastric contents (74). 

Because of the risk of pulmonary aspiration due to respiratory arrest, seizures, or vomiting, emergency department staff should not induce emesis. Instead, if the patient is alert and has not received charcoal previously, the patient should receive a slurry of activated charcoal. Gastric lavage, if administered within 30 min or less after ingestion, may be helpful. Staff attending to patients should consider gastric contents hazardous, and should dispose them appropriately (9). 

The total volumes of both aspirates were measured and samples were collected for lipase, pH, PEG and lipid analysis. The single lumen gastric tube was used to administer the meal and to collect gastric samples every 15 minutes as well as the total residual gastric contents at the end of the experiment. 

Aspiration pneumonitis—The inflammation of lung tissue caused by the aspiration of fluids and gastric contents that often leads to dyspnea, pulmonary edema, secondary infections and adult respiratory distress s5mdrome. Hydrocarbon pneumonitis is caused by the pulmonary aspiration of hydrocarbons such as kerosene and gasoline. 

Pulmonary aspiration—The inhalation of fluids and gastric contents into the lungs that may cause aspiration pneumonitis. 

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