Management of the intoxicated patient

Management is based on three general principles, which involve the initial approach and laboratory and clinical tests, applied therapy, detection of complications, and damage limitation, these actions are summarized inFigure 1

Figure 1 Management of the intoxicated pediatric patient 

Emergency phase

The care of the intoxicated patient begins in the same place where the intoxication occurred. Whenever possible, it should be performed by personnel trained in pre-hospital emergency care or, otherwise, by physicians trained in the care of critical trauma patients. The following steps must be carried out⁸:

In this phase, if it were a chemical disaster, the evacuation and initial handling of possible victims should be carried out by special teams for handling hazardous materials (HAZMAT)¹³.

Life Support Phase

This phase of the management of the intoxicated pediatric patient is carried out both in the pre-hospital setting and in the emergency service, and its main objective is the stabilization of the patient.

General evaluation

This should be done in a period of 15 to 20 seconds to categorize if the patient presents any alteration at the level of appearance, breathing, or circulatory system that put the infant at imminent risk¹⁴, through the action “All in one look”, as proposed by the pediatric assessment triangle (PAT), and this action must be carried out upon arrival at the emergency room¹⁵. The presence of any of the items listed inFigure 2indicates that the corresponding side of the triangle is altered¹⁴.

Once the patient's health status has been categorized, the actions to follow are:

Figure 2 Pediatric assessment triangle 

Primary assessment

Once the PAT has been evaluated, and initial measures have been initiated, if necessary, the primary evaluation is carried out, which, as in most cases, is based on the acronym ABCDE^14,15, and dictates the priority order of care, and in this way, we systematize care without ignoring any weak point in the care chain. Each health team has established organizational systems, with defined tasks for each of the members, and a leader who coordinates and supervises the actions carried out. The actions of this process have been briefly summarized inFigure 3, with emphasis on patients with suspected intoxication.

Figure 3 The primary assessment of the intoxicated pediatric patient 

Secondary assessment

After performing a general evaluation and identifying the patient's potential risk events, and having stabilized the life-threatening conditions, we can proceed to the detailed history and physical examination. We must remember that this step must wait until we have completed the PAT and the ABCDDE, since skipping these steps delays the child's immediate care¹⁴. At this point, its essential function is to obtain a brief clinical history of the episode, a directed physical examination, and an initial diagnosis. An appropriate option is the use of the acronym SAMPLE for the questioning of the patient's history (Figure 4).

Figura 4 Approach to the secondary evaluation of the intoxicated pediatric patient 

A crucial point in the approach to the intoxicated pediatric patient is the physical examination since this can give us important data to substantiate or confirm our suspicion of a toxicological agent and thus carry out detailed care, for example:

Unlike adults, in whom sudden death is secondary to cardiac conduction disorders, pediatric patients must receive timely treatment and, if necessary, basic resuscitation maneuvers as soon as any PAT alteration is detected, before these states last longer and cause conditions that exponentially increase infant mortality^14,19,23.

Initial diagnosis of the intoxicated pediatric patient

During the stabilization process, if conditions allow, maneuvers can be started to establish the etiological diagnosis of the patient's probable intoxication.

The following methodology is a rapid approach during the life support phase, which is an immediate and effective diagnostic orientation by interrogating and exploring data that various toxic agents modify (pupils, alertness, perfusion, breathing, etc.). This process must be carried out during the critical phase of the approach to start a specific treatment as soon as possible and must always be complemented afterward through a deep questioning and the integration of syndromes that indicate toxicity (if there is). In addition to the SAMPLE; already used during the life support phase; The doctor should ask himself three important questions:

The approach to an intoxicated patient is sometimes so delicate and precise that it is almost a detective process, in which all the elements of the scene can guide us, but without a doubt, the clinic is mandatory in the process of identifying or suspecting the toxic agent^{12,17,24,26,27}, the main clinical manifestations of the main toxic agents inTable 1.

Tertiary assessment

As we have already seen, in most cases the diagnosis of intoxication is one of exclusion, which is why the use of paraclinical tests will be carried out according to the characteristics of the patient, clinical picture, organ failure, and the complications observed.

The initial approach should include Complete blood count, complete blood chemistry, serum electrolytes (including Ca, Mg, P), liver function tests (including ammonia), urinalysis, arterial and venous blood gases, toxicological profile, serum toxic levels (barbiturates, anticonvulsants, benzodiazepines, immunosuppressants, digitalis, etc.)^28,29. Toxicological analysis without clinical suspicion is of little use, since it can provide false positives derived from qualitative but not quantitative determination, increasing the costs of care and the use of resources unnecessarily³⁰, and likewise, the inability to quantify various toxic agents does not allow us to distinguish if they are at non-toxic levels. It has been observed that the measurement of serum or urinary levels does not affect the immediate management of the intoxicated patient³¹.

Upon admission, the anion gap should be measured (Na + K - (Cl ENT#091;mEq/LENT#093; + HCO3 + 12), since this can approach some toxicological conditions when it is high, related to the increase in acid concentrations (anions), a product of endogenous metabolism; such as the states of severe hypoxemia and Lactic acidosis; or exogenous; like certain toxins such as salicylates or methanol^32,33.

In certain intoxications; due to the high risk of cardiotoxicity, an electrocardiogram and cardiac enzymes should be requested, even an echocardiogram in cases of acute or rapid onset heart failure^26,34,35. In the presence of concomitant disorders and the appearance of the systemic inflammatory response, the determination of acute phase reactants should be performed; as part of the approach to a superimposed infectious process; such as erythrocyte sedimentation rate, C-reactive protein, Procalcitonin, and microbiological cultures³⁶. The use of imaging studies can guide us in some specific cases, such as the use of radiography (pneumonitis, aspiration, foreign bodies, heavy metals, capsules, iron, mercury, etc.), the use of ultrasound at the patient's bedside, as well as tomography are reserved according to the clinical context of the patients and according to the organic involvement that the patient presents^37-39.

Decontamination

This process is of vital importance since it is used to reduce the absorption of the toxic agent, and it can be: gastrointestinal, dermal, and ocular, although there is no respiratory decontamination; in case the toxin has been inhaled, the indication is to remove the patient from the contaminated environment and administer oxygen at high concentrations, and assess the use of bronchodilators or respiratory support therapies^24,40.

Ocular decontamination

The ocular tissue can participate in percutaneous absorption processes of fat-soluble products, and ionic chelation processes; that is why, if the entry route was that immediate ocular irrigation with saline solution or water should be performed for 15 to 20 minutes, without using other substances or medications for ophthalmic application^41,42.

Skin decontamination

The skin offers a very wide absorption surface, so if the contact with the toxin is through this route, actions must be taken to limit, and if possible, stop the absorption process. As in all processes, the priority is to prioritize the safety of personnel, so personal protective equipment must be used before starting this process. The initial point is to remove the contaminated clothing, then wash the patient's skin (shower, sponge, cloths), with special care in the areas of folds, under the nails and the scalp, this process must be carried out at least two times^17,40,43,45.

Digestive decontamination

This is the most frequent route of entry of toxic agents, however, these should only be carried out if the following criteria are met:

There are several options to reduce the absorption of the agent, and these are described in general terms below:

a) Provoked vomiting.

Currently in disuse because it has been observed that on many occasions it produces "double damage", increasing the risk of bronchial aspiration. If this has been caused, nothing should be administered orally for 60-120 minutes, and observation should be maintained for at least 4 hours.^17,24,42.

b) Gastric lavage.

Its use is debatable, and should only be considered when the amount of the toxicant was ingested in large quantities and during the first hour after ingestion, however, in some situations (toxins that delay gastric emptying, pylorospasm, prolonged release medications) time can be extended up to 6-12 hours. However, various schools and academies specializing in pediatric toxicology management are more restrictive in its use and maintain that its use is limited and that support and monitoring measures should be better provided, and in the case of having activated charcoal, this is preferred over gastric lavage^42,47-49.

c) Multiple-dose activated charcoal.

The mechanism of action of this is to act as an adsorbent since the toxic adheres to it due to its large adsorption surface; since one gram of activated charcoal has an adsorption surface of 1200 m2. Some studies have shown that this intervention has much better results than gastric lavage. Although activated charcoal is effective in the adsorption of various substances, the acronym PHAILS reminds us of substances with very little or almost no adsorption by this means: Pesticides, Hydrocarbons, Acids-Alkalis-Alcohols, Iron and other heavy metals, Lithium, and Solvents.

The established dose for the pediatric population is 1g/kg orally every 4 hours, maximum 4 doses (maximum 25 g in <14 years, and maximum 50 g in older), it can be diluted in water, but due to its unpleasant taste and consistency, in the pediatric population, it can be diluted in juices, cola drinks, flavored waters for better tolerance. The use of activated charcoal should always be accompanied by the use of a cathartic to prevent it from hardening and causing intestinal obstruction. It can be administered orally to tolerance, or by nasogastric tube. The use of activated charcoal is contraindicated in cases of not having a protected airway (patients with neurological deterioration), obstruction, risk of hemorrhage, intestinal perforation, and ingestion of caustics and hydrocarbons. ^{11,42,46,49,50}.

d) Cathartics or laxatives.

In some reports, it is suggested that the use of these aids in the faster elimination of the agent and/or the activated carbon-toxic complex from the gastrointestinal tract, however, it has not been observed that its use reduces the morbidity and mortality of these patients. Likewise, its use is extended to counteract constipation caused by activated carbon^51,52.

e) Bowel irrigation

Its use is reserved for very precise indications:

Polyethylene glycol 250-500 mL/hour may be used until clear stools are achieved. In school children and adolescents, the dose can be increased up to 1000-2000 ml/h. It should not be used if there is a respiratory compromise, an unprotected airway, hemodynamic instability, or gastrointestinal obstruction/perforation/bleeding^43,48,51.

Antidotes

Although the use of antidotes is important in the management of the intoxicated patient; especially in those cases that have a specific antidote; their use is often not so frequently because some of these antidotes are difficult to obtain, generally due to their high price, short expiration date, exceptional indications or because they are drugs imported from abroad.Table 2shows the main antidotes used in pediatrics and their dosage.

Criteria for needing to be managed by the Pediatric Intensive Care Unit

Although most cases of poisoning do not present with serious symptoms, some of the patients will have severe symptoms; life-threatening; that warrant evaluation by the Pediatric Intensive Care Unit (PICU), due to the complexity and continuous management of the patient, to reduce the risk of mortality from this condition. Various criteria must be considered that are essential for its acceptance or not by the PICU, which is shown in Table 3 ^{3,12,17,53,54}.