Differential diagnosis of acute intestinal infections

Principles of dosing and administration of heterologous serum

Specific therapy requires a clear understanding of the rules for handling antitoxic drugs. It is important to remember that the course dose is always determined exclusively by the severity of the clinical course and the dynamics of disease progression. It does not depend on the patient's body weight or age. Drugs are administered intramuscularly (IM) or intravenously (IV).

Depending on the clinical picture, the following administration regimens are distinguished:

• Mild course: a single administration of one therapeutic dose of the drug is prescribed.
• Severe course: the frequency of administration is increased to two to three times a day, administering one therapeutic dose each time. If an insufficient clinical effect is observed, administration is continued for three to four days. Note that further administration of the drug is considered inappropriate.
• Prophylactic purpose: the drug is administered at 1–2 thousand IU of each type intramuscularly once.

Since the drug contains foreign protein, administration is performed with mandatory testing of the patient's sensitivity to horse protein. In all cases, this procedure is performed only under the strict supervision of the attending physician.

Algorithm for testing and desensitization

Assessment of sensitivity to horse protein is carried out in stages to minimize the risk of developing severe allergic reactions.

Step 1. Intradermal test. First, the patient is given a test with diluted serum at a ratio of 1:100.

Tactics for a negative test:

1. The patient is injected with 0.1 ml of undiluted serum subcutaneously (SC).
2. The patient is observed for exactly 30 minutes.
3. In the complete absence of local or systemic reaction, the entire prescribed therapeutic dose is administered.

Tactics for a positive test (intradermal or subcutaneous): In this case, the serum is allowed to be administered only for absolute vital indications and strictly in an intensive care unit setting. To prevent anaphylaxis, the following measures are used:

• Specific desensitization according to Besredka: the diluted serum is administered subcutaneously at strict 20-minute intervals. Doses are gradually increased according to the schedule: 0.5 ml $\rightarrow$ 2 ml $\rightarrow$ 5 ml.
• Prophylactic anti-shock therapy: prednisolone at a dose of 240–360 mg IV in combination with antihistamines is mandatory.

Homologous preparations and nonspecific detoxification

An alternative to heterologous preparations is homologous (human) botulinum antitoxin. Its main advantage is that it is administered without preliminary skin testing, which significantly saves time. The drug is administered intravenously, once. Dosage depends on the type:

• type A — 450–500 IU;
• type B — 300–600 IU;
• type E — 250–500 IU.

Specific antitoxic botulinum fresh frozen donor plasma may also be included in the treatment regimen. Its dosage is 250–300 ml, administered 2–3 times a day.

In addition to specific therapy, comprehensive treatment includes powerful nonspecific detoxification:

• Performing siphon gastric and intestinal lavage.
• Mandatory administration of enterosorbents.
• Parenteral administration of polyionic solutions, glucose, and hemodez.
• Carrying out infusion therapy against the background of forced diuresis.

Use of extracorporeal methods

One of the key methods of intensive care is plasmapheresis. It is important to note that this procedure is indicated for absolutely all forms of botulism. However, maximum clinical efficacy is observed precisely in the early stages of disease development, while the toxin is circulating in the bloodstream.

The frequency of sessions and technical parameters of the procedure are always selected individually for each patient. The average number of sessions per treatment course directly depends on the severity of the pathological process:

• Mild form: 1–2 sessions are required.
• Moderate form: 3 to 5 sessions are prescribed.
• Severe form: 4 to 10 plasmapheresis sessions are performed.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Features of siphon gastric and intestinal lavage
• Specific desensitization according to Besredka
• Infusion therapy and forced diuresis
• Indications and parameters for plasmapheresis

Other topics in the "Acute Intestinal Infections" section

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