DISCUSSION
Non-invasive ventilation has profoundly changed the approach to patients
with ARF over the last 20 years, reducing hospital stay and avoiding the
complications of IMV ¹⁴. The overall effectiveness of NIV use in
avoiding intubation was reported to range between 69% and 79% in
randomized studies ¹⁵. It was also reported that NIV had the potential
to reduce the length of hospitalization and associated costs for adults
with chronic obstructive pulmonary diseases and ARF ¹⁶.
For drowning patients with Szpilman scores of grades 3 and 4,
administering high-flow oxygen therapy and/or mechanical ventilation was
proposed ¹⁷. Despite the absence of recommendations for NIV use for
cases of drowning-related ARF, NIV was previously applied with safety
and efficacy for drowning patients ¹º. Similar to IMV, NIV provides
airway pressure to prevent atelectasis and support respiratory muscle
use while preventing hypoxemia. Its value might be based on the use of
positive end-expiratory pressure (PEEP) over oxygen supplementation in
the clinical course ¹º.
We could find very limited relevant data in the literature; to our
knowledge, there is only one study evaluating adults and a few case
reports of adults and children describing the use of NIV for drowning
patients ¹º´¹¹´¹⁸ˉ²º. Our study has the largest number of pediatric
cases to evaluate the efficacy of NIV treatment to date.
Michelet et al. evaluated adults with drowning-related ARF in intensive
care units and assessed the efficacy of ventilator strategies used. They
declared that their cases were grades 3 to 5 according to the Szpilman
classification, and of the 25 patients who underwent NIV treatment, 4
were intubated due to respiratory or neurological deterioration. They
reported similar neurological outcomes and correction of hypoxemia and
acidosis comparing patients treated with NIV versus IMV after drowning.
Furthermore, patients who were treated with NIV had a lower incidence of
infection and decreased length of intensive care unit and hospital stay
¹º.
In our study, all children were treated using BiPAP, and none of them
deteriorated to require IMV. The Szpilman classification was grade 3 or
4 for our cases. Our results demonstrate that NIV treatment was
associated with rapid improvement in the early phase of oxygenation.
Considering drowning-related ARF, which is characterized by profound but
reversible hypoxemia without relevant hypercapnia, early application of
NIV may aid in the hastening of clinical improvement.
Our decision to use NIV was made on the basis of confidence that its
early application could be a preventive treatment strategy, with the
reversible nature of drowning, for eligible patients without complete
loss of consciousness to reduce morbidity ¹º´²º. We preferred to use
BiPAP to reduce the respiratory workload for patients who were
tachypneic, whereas the application of PEEP was repeatedly suggested and
CPAP was used as frequently as BiPAP in pre-hospital settings ¹º.
However, the use of NIV for drowning patients with altered mental status
should be considered with a high index of caution because there may be
increased risk of vomiting and aspiration ⁹. The initial neurological
assessment appears to be of paramount importance to initially choose the
ventilator strategy. The occurrence of neurological deterioration is an
indication for IMV rather than NIV use. Gregorakos et al. evaluated
adults with drowning-related ARF in the emergency department and
concluded that IMV could be avoided in non-comatose patients ¹⁸. The
improvement of neurological status as well as the lower incidence of
hemodynamic instability could facilitate alternative treatment choices
such as NIV ¹⁴´¹⁵. At this point, the Szpilman score, which is first
based on neurological status and secondly on respiratory and hemodynamic
status, could guide the physician for the choice of ventilation
strategy.
Ruggeri et al. reported successful NIV use for a 45-year-old man who had
ARF secondary to drowning after an epileptic crisis ¹¹. Dottorini et al.
reported 13- and 19-year-old drowning patients without loss of
consciousness who presented with radiographic appearance of pulmonary
edema and were successfully treated with nasal CPAP therapy,
highlighting the importance of neurological status in the choice of
ventilation strategy ¹⁹. Çağlar et al. also reported 5-, 12-, and
13-year-old drowning patients with pulmonary edema who were successfully
treated with BiPAP therapy in the pediatric emergency department. The
Szpilman classification was grade 3 or 4 for these patients ²º.
We acknowledge the limitations related to the retrospective nature of
our study. Information was missing for some patients. Also, we only
evaluated the patients who underwent NIV treatment. If we had a control
group, we could have compared the hastening of clinical improvement,
morbidity, complications, and length of stay in the hospital for NIV
treatment.
We have reported a favorable clinical course of drowning patients who
underwent early use of NIV in a pediatric emergency department.
Management of drowning patients by NIV with close follow-up can be
successfully applied in selected cases. The choice of NIV appears to be
a valuable preventive ventilation strategy for reducing IMV and
implicitly reducing morbidity resulting from the complications of IMV.
Nevertheless, multicenter studies with larger case series are required
to determine the effectiveness of choices for ventilator strategy and to
reveal the benefits of early application of NIV for drowning patients in
pediatric emergency settings, and to help shape treatment guidelines.