Drowning: symptoms, signs, initial assessment, diagnosis, severity. Relevance of the Orlowski score

By Cristiano Antonino On May 17, 2023

Drowning or ‘drowning syndrome’ in medicine refers to a form of acute asphyxia due to an external mechanical cause caused by the occupation of the pulmonary alveolar space by water or other liquid introduced through the upper airways, which are completely submerged in such liquid

If the asphyxia is prolonged for a long time, usually several minutes, ‘death by drowning’ occurs, i.e. death due to suffocation by immersion, generally linked to acute hypoxia and acute failure of the right ventricle of the heart.

In some non-fatal cases, drowning can be successfully treated with specific resuscitation manoeuvres.

IMPORTANT: If a loved one has been the victim of drowning and you have no idea what to do, first contact emergency services immediately by calling the Single Emergency Number.

This and other articles are intended to deepen a topic, and to know what to say to a Emergency Number Centre Operator.

Clinical aspects of drowning

The initial assessment of drowning victims should be as rapid as possible and aimed at determining the state of consciousness, pulse characteristics and respiratory rate.

Information gathered from eyewitnesses may also be very helpful in assessing the severity of the patient’s condition.

If possible, certain facts should be determined, including:

how long, approximately, the patient was immersed in the liquid,
the characteristics of the liquid in which the accident occurred (salt or fresh water, hot or cold, etc.),
the possible presence of vital signs at the time of first aid,
the approximate time elapsed before cardiopulmonary resuscitation (CPR) manoeuvres were started, and whether these were carried out immediately after the patient was pulled out of the water
how long CPR had to be continued before vital signs reappeared,
if possible the precise temperature of the water,
the subject’s age and general condition prior to the accident (e.g. does the subject suffer from lung or heart disease?)
any other circumstances that may be related to the incident (e.g. accident while diving or other, ingestion of alcohol or drugs, etc.).

Drowning: anamnesis and objective test must be very rapid

The vital signs of drowning victims can be very variable, which is why the information in the list above is relevant.

Patients may present in complete cardiac arrest or with respiratory activity and a peripheral pulse within normal limits.

Body temperature is variable and depends on the temperature of the water in which the accident occurred, the subject’s body surface area and the duration of the dive.

Hypothermia is common when the patient has been in cold water and may improve survival.

In such cases, rewarming should be done with caution.

The cardiac effects of a failed drowning usually consist of bradycardia, possibly followed by asystole.

The neurological damage resulting from hypoxia and the drugs administered during resuscitation lead to mydriasis, with depressed or absent pupillary reflex to light.

The head and neck should be carefully inspected for signs of trauma, resulting, for example, from a plunge into shallow water.

If an injury to the spine is suspected, it is necessary to immobilise the patient before transport to avoid possible further damage, in some cases irreversible and disabling, such as that leading to paralysis.

Auscultation of the thorax may demonstrate the presence of wheezes, due to bronchospasm or aspiration of foreign material and/or tele-expiratory rales, associated with atelectasis or pulmonary oedema.

The finding of accessory lung noises (such as coarse ralesalesales) suggests the aspiration of foreign matter and the risk of pneumonia and ARDS.

The extremities of these patients are often cold on thermoprinting, due to hypothermia and peripheral vessel constriction.

The slowing of the peripheral circulation leads to a lengthening of the capillary reperfusion time.

Arterial haemogas analysis (ABG) often reveals hypoxaemia, especially if aspiration has occurred, and metabolic acidosis.

The severity of metabolic acidosis generally correlates with the severity of tissue hypoxia.

Haemoglobin and serum electrolyte concentrations and haematocrit values may decrease if large amounts of fresh water are swallowed or aspirated, which passes into the circulation and induces blood dilution.

Initial assessment and prognosis in cases of drowning

Several point systems have been developed for the assessment of drowning victims, but none of them can predict clinical prognosis with 100% accuracy.

Three commonly used systems are:

the Glasgow Coma Scale (GCS),
the Orlowski score,
the post-submission neurological classification of Modell and Conn.

Glasgow Coma Scale

The Glasgow Coma Scale has three parameters, for each of which the patient’s best response is determined and given a numerical value (see table below).

Eye opening:

Absent
In response to painful stimuli
In response to verbal stimuli
Spontaneous

Best verbal response:

None
Incomprehensible
Inappropriate
Confused
Oriented

Best motor response

None
Extension (decerebrated)
Flexion (decorticated)
Localisation of painful stimulus
Command response

The Glasgow scale score is determined by assessing the patient’s best response in each category.

The numerical values for the observed behaviours are added together and provide an overall score.

An overall score of 3 is the lowest possible and indicates the worst possible condition; a score of 7 or less indicates that the patient is in a coma and a score of 14 the maintenance of full consciousness.

Prognosis is based on the GCS value obtained at the time of the initial clinical test.

Drowning victims with an initial GCS score of 4 or less have an 80 per cent probability of death or permanent neurological damage.

Patients with a GCS score of 6 or higher, on the other hand, are at low risk of death or permanent neurological injury.

Orlowski score

The Orlowski score is based on the presence of unfavourable prognostic factors in relation to the patient’s recovery.

Unfavourable prognostic factors of the Orlowski score

age equal to or less than 3 years;
estimated dive time greater than 5 minutes;
resuscitation manoeuvres not performed within the first 10 minutes;
patient arrived in the emergency department in a comatose state;
arterial pH equal to or less than 7.10 on haemogasanalysis.

The Orlowski score is given according to the number of unfavourable prognostic factors, listed here, found in the drowning victim.

Lower scores are associated with a better prognosis.

Those with two or fewer of these factors have a 90 per cent probability of making a full recovery while, in those with three or more, this probability is less than 5 per cent.

Modell and Conn’s post-submergence neurological classification

In 1980, Conn and Modell and their collaborators independently published a postresuscitation neurological classification based on the patient’s initial level of consciousness. Conn et al., unlike Modell, proposed a further subdivision within the ‘coma’ group.

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Category A. Awake

Awake, conscious and oriented patient

Category B. Dulling

Dulling of consciousness, patient is lethargic but can be awakened, purposeful response to painful stimuli

Patient cannot be awakened, responding abnormally to painful stimuli.

Category C. Comatose

C1 Decerebrate-type flexion to painful stimuli

C2 Decerebrate-type extension to painful stimuli

C3 Flaccid or absent response to painful stimuli

Prognosis is determined according to category, and is excellent for patients in categories A and B.

Within category C, the prognosis worsens as the coma becomes deeper.

In a retrospective study, all patients assigned at admission to category A survived without complications.

90% of the patients in category B survived without any sequelae, but 10% died.

Of the patients in category C, 55% recovered completely, but 34% died and 10% suffered permanent neurological injuries.

The severity of a drowning is divided into four degrees

Grade 1: the victim has not inhaled fluids, ventilates well, has good cerebral oxygenation, has no disturbance of consciousness, reports well-being;

2nd degree: the victim has inhaled liquids to a slight extent, crackling rales and/or bronchospasm are detectable, but ventilation is adequate, consciousness is intact, the patient displays anxiety;

3rd degree: the victim has inhaled discrete amounts of liquids, presents rales, bronchospasm and respiratory distress, develops cerebral hypoxia with symptoms ranging from disorientation to aggression, to a soporific state, cardiac arrhythmias are present;

4th degree: the victim inhaled so much liquid or remained in a hypoxic state until cardiac arrest and death.

IMPORTANT: the most serious symptoms of drowning occur when the amount of water inhaled exceeds 10 ml per kilogram of body weight, i.e. half a litre of water for a person weighing 50 kilograms or 1 litre if he weighs 100 kilograms: if the amount of water is less, symptoms are generally moderate and transient.

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