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REVIEW ARTICLE

S149

0021-7557/03/79-Supl.2/S149



Jornal de Pediatria

Copyright 

©

 

2003 by Sociedade Brasileira de Pediatria



1. Assistant Professor, Clinical Pediatrics and Emergency Medicine, State

University of New York at Buffallo. The Children’s Hospital of Buffalo.

2. MD, Intensive Care Unit, Children’s Hospital, Buffalo, NY.

3. Fellow in Pediatric Intensive Care, The Children’s Hospital of Buffalo,

Buffalo, NY, USA.

Abstract

Objective: To review the current support and treatment strategies of the acute respiratory distress

syndrome.



Sources of data: Original data from our research laboratory and from representative scientific articles

on acute respiratory distress syndrome and acute lung Injury searched through Medline.



Summary of the findings: Despite advances in the understanding of the pathogenesis of acute

respiratory distress syndrome, this syndrome still results in significant morbidity and mortality. Mechanical

ventilation, the main therapeutic modality for acute respiratory distress syndrome, is no longer considered

simply a support modality, but a therapy capable of influencing the course of the disease. New ventilation

strategies, such as high-frequency oscillatory ventilation appear to be promising. This text reviews the

current knowledge of acute respiratory distress syndrome management, including conventional and non-

conventional ventilation, the use of surfactant, nitric oxide, modulators of inflammation, extracorporeal

membrane oxygenation and prone position.



Conclusions: The last decade was marked by significant advances, such as the concept of protective

ventilation for acute respiratory distress syndrome. The benefit of alternative strategies, such as high-

frequency oscillatory ventilation, the use of surfactant and immunomodulators continue to be the target of

study.


J Pediatr (Rio J) 2003;79(Suppl 2):S149-S60: Acute respiratory distress syndrome, mechanical

ventilation, high-frequency ventilation, surfactant, nitric oxide.



Management of the acute respiratory distress syndrome

Alexandre T. Rotta,

1

 Cláudia L. Kunrath,

2

 Budi Wiryawan

3

Introduction

Acute respiratory distress syndrome (ARDS) is an entity

marked by a significant inflammatory response to a local

(pulmonary) or remote (systemic) insult which invariably

results in hypoxemia and marked alterations to pulmonary

mechanics. By definition four clinical criteria must be met

to establish a diagnosis of ARDS

1

: 1) Acute disease onset,



2) bilateral pulmonary infiltrates on chest x-ray, 3) pulmonary

capillary wedge pressure < 18 mmHg or absence of clinical

evidence of left atrial hypertension, and 4) ratio between

arterial oxygen partial pressure (PaO

2

) and the fraction of



inspired oxygen (FiO

2

) < 200. Patients that meet criteria 1



to 3, but exhibit a PaO

2

 / FiO



2

 ratio >200 and < 300 are

defined as having Acute Lung Injury (ALI), a process

physiopathologically similar to ARDS but of lesser clinical

severity. Based on the above criteria, it is estimated that



S150

  

Jornal de Pediatria - Vol.79, Supl.2, 2003

ARDS has an incidence of 13.5 cases per 100,000 people

and that ALI affects 17.9 of every 100,000 people.

2

 Despite


significant advances in general intensive care therapies, the

dramatic alterations that are characteristic of ARDS are

associated with an elevated mortality, varying between

35% and 71%.

3-5

Despite having first been described several decades



ago

6

 and being a significant causer of morbidity and mortality



in pediatric intensive care units all over the world, ARDS

has no specific pharmacological treatment. However,

advances in the understanding of the pathogenesis and

pathophysiology of ARDS over the years have resulted in

the development of a series of support therapies capable of

having an impact on the outcome of patients affected by this

pathology (Table 1).

resources and a large capacity for integration among

participating centers. The availability of clinical data specific

to the pediatric ARDS population is even more limited due

to the almost non-existence of controlled studies in this

population. This being the case, many of the strategies

employed for the management of pediatric ARDS and their

indications have been adapted or inferred from studies of

adult patients.

ARDS treatment strategies

Control of the causative factor

While ARDS has no specific treatment, many of the

factors causing and perpetuating the disease process can be

treated or controlled. For example, patients with

hypovolemic shock should be quickly identified and treated

with rapid volumetric replacement, in order to minimize the

impact on the evolution and maintenance of ARDS.

Similarly, patients with infectious acute abdomen should be

treated with antibiotics and early surgical intervention when

indicated. Patients with septic shock or pneumonia that

evolve to ARDS should be promptly treated with

intravascular expansion and antibiotics, since the treatment

of the infectious factor and hemodynamic control are

fundamental to the success of managing the subsequent

pulmonary pathology.

Controlled oxygen exposure

By definition, patients with ARDS exhibit significant

hypoxemia (PaO

2

/FiO



2

 < 200).


1

 For this reason, oxygen is

indicated for the management of the initial phase of the

acute respiratory insufficiency. Severe hypoxemia in patients

with ARDS is due to the intrapulmonary shunt, in which

unventilated lung zones that result from edema, atelectasis

or consolidation continue to receive blood supply, despite

being incapable of participating in its oxygenation. Oxygen

therapy, via mask, tent or non-invasive ventilation apparatus

is capable of producing symptomatic improvement during

the initial phase of acute respiratory failure. However, the

rapid natural progression of ARDS with diminishing

pulmonary compliance, increased exertion of respiratory

muscles and subsequent exhaustion means that oxygen

therapy only has value as a temporary symptom relief

measure until mechanical ventilation is introduced. The

great majority of patients that meet diagnostic criteria for

ARDS cannot be managed exclusively with oxygen therapy,

and will require mechanical ventilation. The health care

professional who understands the pathophysiologic process

of ARDS should recognize that a patient that meets diagnostic

criteria and requires an accelerated escalation in oxygen

therapy will need mechanical ventilation. Oxygen therapy

should not delay the institution of ventilatory support, since

intubation and initiation of mechanical ventilation for ARDS

should be an elective decision made before the patient

develops full-blown respiratory failure.

Table 1 -

Therapeutic Strategies in ARDS

Control of the causative factor (sepsis, shock, etc.)

Mechanical Ventilation

Controlled oxygen exposure



Avoidance of volutrauma (using reduced tidal volumes)

Avoidance of atelectrauma (using adequate PEEP)



Careful fluid administration

Optimization of hemodynamics and tissue oxygen delivery

Non-conventional ventilation

High-frequency ventilation



Ventilação não invasive

Liquid ventilation



Drug-based therapies

Surfactant



Nitric oxide

Corticosteroids and other anti-inflammatory agents



Extracorporeal membrane oxygenation (ECMO)

Position therapy (proning)

Prevention and early diagnosis of intercurrent infections

Analgesia and sedation

Nutritional support

Psychological support (patient and family)

Acute respiratory distress syndrome – Rotta AT 

et alii


Despite having been successful in an experimental

laboratory environment, many of the methods available for

the management of ARDS have not been shown effective or

have not yet been properly tested in clinical practice. This

is primarily due to the fact that patients with ARDS form an

extremely heterogeneous population, who needs to be

evaluated in studies of large samples, requiring significant




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