Intensive Care of Acute Poisoning - A. V. Hovenko 2010

Methods of Detoxification Therapy
Methods of Stimulation of Natural Detoxification
Gastrointestinal Decontamination

If poison enters the body orally, The Stomach must be emptied as quickly as possible. This is achieved by inducing vomiting or performing gastric lavage using a tube. Vomiting can be induced reflexively by irritating the posterior wall of the Pharynx and the ROOT of the Tongue, or by applying pressure to the epigastric region.

Gastric lavage via mechanical induction of vomiting (the so-called "restaurant method") is used only as an exception when tube lavage is not feasible. In comatose patients, tube gastric lavage is performed only after endotracheal intubation using a cuffed tube.

In cases of poisoning with narcotic agents and organophosphates, gastric lavage should be repeated every 4-6 hours. This Procedure is necessary because toxic substances re-enter the stomach from the intestine due to the regurgitation of chyme and Bile containing toxins and un-metabolized substances (such as morphine, glutethimide, leponex, etc.).

Gastric lavage is crucial at the pre-hospital stage, as it helps reduce the concentration of toxic substances in the Blood. However, the decision to perform gastric lavage must be individualized based on the specific clinical situation. In the presence of subjective or objective difficulties (such as the lack of a tube or intubation kit, or severe psychomotor agitation in the patient), if rapid hospitalization in a specialized department is feasible (within 30 minutes), it is advisable to hospitalize the patient first and perform gastric lavage in an inpatient Setting.

In practice, gastric lavage is sometimes omitted on the grounds that too much time has elapsed since ingestion. However, autopsy findings frequently reveal significant amounts of poison in the intestines even 2-3 days post-poisoning, demonstrating that refusing gastric lavage is unjustified.

In severe poisonings involving highly toxic agents (organophosphates, chlorinated Hydrocarbons, etc.), tube gastric lavage must be repeated every 3-4 hours until the stomach is completely cleared of toxins. The efficacy of the lavage can be assessed through sequential laboratory Analysis of the washout fluid.

Complications of gastric lavage. Unskilled performance of gastric lavage can lead to a range of complications, particularly in patients in a comatose state with suppressed natural Reflexes and decreased muscular tone of the Esophagus and stomach. The most dangerous complications include:

- aspiration of washout fluid;

- traumatic ruptures of the mucosa of the pharynx, esophagus, and stomach;

- tongue trauma complicated by bleeding and blood aspiration.

Technique of gastric lavage. The best way to prevent

complications during gastric lavage is strict adherence to the correct procedural protocol.

1. Before inserting the tube, the Oral Cavity must be thoroughly cleaned.

2. In patients with an hypersensitive gag reflex, the administration of atropine is indicated.

3. If the patient is unconscious, preliminary endotracheal intubation with a cuffed tube must be performed.

4. The patient should lie on their left side with the HEAD of the bed lowered at a 15° angle.

5. The size of the tube must correspond to the patient's physical parameters.

6. Forceful or rough insertion of the tube is strictly unacceptable, especially if the patient is resisting or agitated due to the effects of the poison or the environment.

7. Prior to insertion, the tube should be lubricated with petrolatum and then carefully advanced into the patient's stomach.

8. The first portion of the gastric contents, measuring 100-150 ml, is collected for toxicological analysis.

9. Next, flushing fluid (plain room-Temperature Water or isotonic sodium chloride solution) is introduced through the tube into the stomach in a single dose of 5-7 ml/kg of the patient's body weight per cycle.

10. After introducing the fluid, the open end of the tube is lowered below the level of the stomach to observe the outflow of fluid, or it is aspirated using a Janet syringe.

11. The total volume of washing fluid should be 10-15% of the patient's body weight. A strict balance between the volume of fluid introduced and recovered must be maintained, with a discrepancy not exceeding 1% of the patient's body weight.

12. Upon completion of the lavage, before removing the tube, an appropriate antidote or enterosorbent—or activated charcoal at a dose of 1-2 g/kg in their absence—is introduced into the stomach and left for 5-10 minutes. Afterward, the gastric contents are completely aspirated, as certain toxins can undergo desorption.

13. Repeated administration of activated charcoal (every 30 minutes) is indicated in poisonings with substances such as indomethacin, cardiac Glycosides, tricyclic antidepressants, and glutethimide. This intervention is necessary to interrupt the enterohepatic Circulation of toxins that are excreted in the bile and reabsorbed in the intestines. Administering other medications concurrently with activated charcoal is not recommended, as they may be adsorbed and mutually inactivate one another.

Most common errors during gastric lavage.

1. The patient is in a sitting position, which promotes the movement of fluid into the intestines under METABOLISM/18.html">The Influence of gravity.

2. A large volume of fluid administered at once causes the pylorus to open, pushing the fluid and the poison remaining in the stomach into the intestines, where the most intensive absorption of toxins occurs.

3. Failure to monitor the balance of administered and eliminated fluid, along with an excessive accumulation of fluid in the patient's body, can lead to water intoxication (hypotonic hyperhydration), particularly in children.

4. Widespread use of concentrated potassium permanganate solutions for gastric lavage is unjustified and even hazardous, as it can cause chemical Burns of the stomach. Pale pink potassium permanganate solutions are indicated for gastric lavage only in acute poisonings with Alkaloids or benzene.

5. Despite the intravenous route of administration in opiate overdoses, patients still require gastric lavage, since opium alkaloids are secreted by the gastric mucosa and are capable of reabsorption.

Bowel cleansing. Given that saline laxatives take 6–12 hours or more to act, their use in acute poisonings is impractical.

In cases of poisoning with fat-soluble substances, liquid paraffin (petrolatum) is used instead of vegetable oils. It is not absorbed in the intestines and actively binds such toxins (e.g., dichloroethane). It is administered at a dose of 1–2 mL/kg of the patient's body weight.

The Use of magnesium sulfate in doses exceeding 30 g in psychotropic drug poisonings exerts a toxic effect, leading to bradycardia, hypotension, and respiratory depression.

In recent years, oral administration of special high-molecular-weight solutions, such as Fortrans (France) or polyethylene glycol (USA), has been used for bowel lavage as a method of accelerated body detoxification.

Other Methods to stimulate intestinal peristalsis include cleansing enemas, as well as pharmacological and electrical stimulation.

The detoxifying effect of a cleansing enema is limited by the time required for toxic substances to pass from the Small Intestine into the Large Intestine. Therefore, applying this method too early in the first few hours after poisoning generally does not yield the desired result.

The most reliable method for cleansing the intestines of toxic substances is intestinal lavage via tubing and the administration of specialized solutions.

The therapeutic efficacy of this method lies in its ability to directly cleanse the small intestine where, in cases of delayed gastric lavage (2–3 hours after ingestion), a significant amount of poison is deposited and continues to enter the bloodstream.

Technique of intestinal lavage.

1. A dual-channel silicone tube (up to 2 m in length) with an inserted metal stylet is introduced into the stomach through the Nose.

2. Under gastroscopic guidance, the tube is advanced 30–60 cm distal to the Treitz ligament, after which the stylet is removed.

3. A specialized salt solution, ionic-equivalent to chyme (Table 4.1), is infused through the perfusion channel port located at the distal end of the tube.

4. The solution, warmed to 40 °C, is administered at a rate of 100 mL/min.

Class="center">Table 4.1 COMPOSITION OF THE salt solution for intestinal lavage

5. After 10–20 minutes, washout fluid begins to flow out through the aspiration channel and must be removed using an electric suction device, along with intestinal contents.

6. After 0.5–1.5 hours, bowel contents are discharged through the rectal drainage tube, accompanied by an increase in diuresis.

7. Toxic substances are detected in the washout fluids flowing from the aspiration channel of the tube and the rectal drainage.

8. Complete intestinal clearance is indicated by the absence of toxic substances in the final portions of the washout fluid.

9. Complete intestinal lavage requires the administration of 500 mL of solution per 1 kg of the patient's body weight (totaling 25–30 L). An improvement in the patient's clinical status is observed after the perfusion of the first 10–15 L, which is due to a decrease in the concentration of toxic substances in the blood.

Intestinal lavage does not impose an additional burden on The Cardiovascular system; therefore, it can be used even in cases of Exotoxic Shock and in elderly patients with unstable hemodynamics.

Possible complications include The Development of hyperhydration symptoms with uncontrolled fluid administration, as well as trauma to the mucous membrane of the stomach or duodenum resulting from rough manipulation during the insertion of the tube from the stomach into the intestine.