Page 636 - ACCCN's Critical Care Nursing

Emergency Presentations 613

Aspiration may cause a rise in intracranial pressure (ICP). A 12-lead
Fresh water Salt water ECG identifies any arrhythmias (resulting from acidosis
and hypoxia rather than electrolyte abnormalities) and
the patient is managed conventionally (see Chapter
Bronchospasm Alveolar 11). 187 All patients require serial chest X-rays, as lung
Surfactant
Acute emphysema oedema fields often worsen in the first few hours. In clinically
significant submersions, the chest X-ray will typically
show bilateral infiltrates undifferentiated from other
V/Q-mismatch causes of pulmonary oedema.
Atelectasis
Compliance WOB MANAGEMENT

The condition of the patient, the environment and the
skill of the attending rescue personnel will influence pre-
hospital management of the postsubmersion patient, and
Hypoxia the adequacy of initial basic life support at the scene is
Acidosis the most important determinant of outcome. 188 The
Heimlich manoeuvre should not be performed in an
V/Q-mismatch, ventilation/perfusion mismatch; WOB, work of breathing.
attempt to remove aspirated water, as it is ineffective
FIGURE 22.2 Pathophysiology of respiratory failure due to fluid and likely to promote aspiration of gastric contents.
185
aspiration. Supplemental oxygen 100% is administered as soon
as possible. 188,189
For patients presenting to the ED in cardiac arrest, active
life. Other factors influencing the extent of injury include resuscitation measures continue (see Chapter 24),
water temperature and submersion time, stress during although the need for continued CPR is generally associ-
submersion, and coexisting cardiovascular and neuro- ated with a poor neurological outcome (submersions in
logical disease. 185,186,190 Prediction of death or persistent very cold water may have a better outcome). 188 The focus
vegetative state in the immediate period after near- of management for patients with spontaneous circulation
drowning is difficult. Patients awake or with only blunted includes respiratory support and the correction of
consciousness on presentation usually survive without hypoxia, neurological assessment and maintenance of
neurological sequelae. A third of patients admitted in optimal cerebral perfusion, cardiovascular support and
coma or after cardiopulmonary resuscitation will survive maintenance of haemodynamic stability, correction of
neurologically intact or with only minor deficits, while hypothermia and management of other associated
the remaining two-thirds of patients will either die or injuries.
remain in a vegetative state. 185
All patients require 100% supplemental oxygen via a
Hypothermia is a well-documented feature in submer- non-rebreathing mask initially. Patients without any
sion victims 185-189 (specific effects and management of respiratory symptoms should be observed for 6–12 hours,
hypothermia are covered later in this chapter). Incidents until there is a GCS >13, normal chest X-ray, no signs of
of submersion times of greater than 15 minutes where respiratory distress and a normal oxygen saturation on
victims recovered with a good neurological outcome all room air. 185-187 Alert patients unable to maintain adequate
occurred in very cold water (<10°C). While the exact oxygenation should be considered for CPAP or BiPAP
mechanisms in these outcomes is unclear, acute cold sub- prior to intubation (see Chapter 15).
mersion hypothermia may be protective against cerebral
insult by: very rapid cooling in victims with low levels of While cerebral oedema and intracranial hypertension is
subcutaneous fat who have aspirated a large amount of often seen in hypoxic neuronal injury, only general sup-
very cold water; induced muscle paralysis leading to portive measures are recommended as there is insuffi-
minimal struggling and very little oxygen depletion; and cient evidence to indicate that invasive ICP monitoring
the heart gradually slowing to asystole in the presence of and related management improve outcomes. 185-189 Any
profound hypothermia. 185-188 In these cases prolonged seizures should be promptly treated with appropriate
resuscitative efforts may be warranted, including active measures (see Chapter 17). Normocapnia is recom-
and aggressive re-warming interventions, that should not mended, although this needs to be balanced against any
be abandoned until the patient has been re-warmed to at permissive hypercapnia (cerebral vasodilation and
least 30°C. 187 increased ICP) for the management of any concomitant
ADS. Barbiturate-induced coma or corticosteroids are
190
ASSESSMENT not recommended as there is no evidence of improve-
189,190
Continuously monitor heart rate, BP and SaO 2 , and assess ment in outcome.
neurological status, including any seizure activity. Dete- Cardiovascular support may require a multifaceted
rioration is evident with a falling level of consciousness approach, initially by improving hypoxia and correcting
(LOC), a high alveolar–arterial (A–a) gradient, respira- circulating volume. Hypotensive patients require rapid
tory failure (PaCO 2 >45 mmHg) or worsening ABG volume expansion (crystalloid or colloid) and an indwell-
results. 187 Caution should be taken to avoid activities that ing catheter for hourly urine measurement. Patients with