ARDS is divided into three separate phases: the exudate phase, the fibroproliferative phase, and the resolution phase. In the exudate phase, which occurs early in the onset of ARDS, the patient has early symptoms such as dyspnea and tachypnea. While the symptoms may not appear complex, the internal changes are already causing the alveoli to fill with fluid leading to atelectasis. The goal of treatment in this stage is to administer supplemental oxygen to correct or maintain the current saturation, provide supportive care, and treat any underlying etiology such as infection. The purpose of this is to prevent the condition from worsening and advancing to the next stage (Ignatavicius et al., 2018).
In the fibroproliferative phase, the patient experiences increasing lung injury that causes pulmonary hypertension and possible fibrosis of the injured lung tissue. The body will attempt to repair the damage and stop the inflammatory process. During this stage, a more significant portion of the lung is affected, which further impacts the process of gas exchange. It is during this phase that the patient may experience dysfunction in other organs, which is referred to as multiple organ dysfunction (MODS). Treatment in this phase is directed towards improving or maintaining oxygenation, continuing to deliver supportive care, as well as trying to prevent further complications (Ignatavicius et al., 2018).
The patient usually enters the resolution phase around 14 days after the initial symptoms began. Hopefully, the initial injury that caused the ARDS is resolving; if not, the patient may succumb to the disorder or develop a chronic disease as a result of the ARDS. The patient may or may not have fibrosis as well as other long-term effects (Ignatavicius et al., 2018).
The patient with ARDS needs supportive care and management of oxygenation during each phase. Some patients will need to be intubated and require mechanical ventilation. If the patient requires mechanical ventilation, they will need either positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP). The safest and best practice standards would indicate that this process should be provided using “open lung” and lung-protective ventilation strategies. These strategies recommend using low tidal volumes (6 ml/kg of body weight) (Ignatavicius et al., 2018).
When using PEEP, the recommendation is to start at 5 cm of water and increase as needed to keep oxygen saturation at an appropriate level. One of the goals during mechanical ventilation is to get the alveoli that are not functioning to participate in gas exchange by using a method of ventilation that is pressure-controlled versus volume-controlled. One potential disadvantage is that PEEP can result in a tension pneumothorax, so the nurse needs to assess lung sounds on an hourly basis and use suction to maintain a patent airway as often as needed. Diminished or absent breath sounds may indicate a tension pneumothorax. Other types of ventilation may be indicated in ARDS cases that are more moderate to severe such as airway pressure-release ventilation (APRV) or high-frequency oscillatory ventilation (HFOV) (Ignatavicius et al., 2018).
Patient positioning is helpful as it can help improve the lung condition, but researchers are not in agreement as to which position is best. The two positions that seem to be most helpful are the prone position and elevation of the head, or the fowler’s position. The prone position is frequently recommended as this shifts pressure off the dependent portions of the lung, allowing for better ventilation. As the patient is moved from a prone position to a Fowler’s position, there is a noted rise in arterial oxygenation compared to just supine positioning. This is felt to be attributed to an increase in lung volume redistribution as the patient moves from the prone to a Fowler’s position. In the prone position, the chest wall is less compliant, but the upright position allows for increased chest wall compliance and increased volume resulting in higher oxygen levels. When a patient is placed in a supine position, the dependent lung can be negatively affected by the weight of the other organs. Prone positing can be a difficult task to complete, but the use of specialized beds and a collaborative approach can assist with this (Aoyama et al., 2019; Ignatavicius et al., 2018).
Patients with ARDS will likely need antibiotics when an infection is suspected or has been definitively diagnosed. Healthcare providers may also order medications to help reduce the levels of inflammation. ARDS may be the result of a primary condition such as pancreatitis or other disorder, which will be treated with the appropriate medications. Some providers are using vitamins C and E as well as surfactant replacement drugs to assist in the treatment of ARDS. The patient may also need fluid and electrolyte therapy to maintain balance, but fluid resuscitation should be limited to limit edema. A more conservative approach to fluid infusion will often lead to a better response and quicker recovery. Some patients will also need diuretic therapy to assist with the level of edema or treat some cardiac disorders (Ignatavicius et al., 2018).
Other medications that could be indicated are proton pump inhibitors or histamine-2 receptor antagonists to help reduce gastric acid and the risk of a stress ulcer. If the patient has increased risk for a blood clot related to immobility, the patient may be started on anticoagulants. Muscle relaxants and/or antianxiety medications may be used for patients on ventilators to assist with muscle tension. This allows the ventilator to work against less resistance and makes the patient more comfortable and less anxious. Pain medications may be indicated for the treatment of pain and during various procedures that need to be performed (ALA, 2019b; Ignatavicius et al., 2018; NHLBI, 2019).
In a critically ill patient, nutrition can be a challenge. There should be a collaborative approach between the provider, dietary services, and nursing to maintain adequate nutrition. If the patient has a mild case of ARDS, oral intake could be possible with supplements as needed. In more critical cases, the patients will likely need enteral feedings or total parenteral nutrition. A discussion and decision will be made with the healthcare provider and the dietitian to maintain an appropriate diet that will assist in tissue support and repair. These patients could be on bed rest for several days or even weeks, so nutrition is essential to promote skin integrity and vital functions (Ignatavicius et al., 2018).
Additionally, physical and or occupational therapy should be included to assist in the care of these complex patients. Both disciplines evaluate the patient’s needs during the acute and recovery phases to prevent muscle wasting, loss of muscle strength, possible development of contractures as well as other concerns. Either physical or occupational therapy may assist with positioning to promote oxygenation and respiratory effort. Both specialty areas would work with the patient as they recover their strength and mobility as well as prepare for discharge (Ignatavicius et al., 2018; NHLBI, 2019).
Another type of treatment utilized in ARDS patients that are not responding to traditional ventilation and oxygenation methods would be extracorporeal membrane oxygenation (ECMO). Mainly, this is utilizing heart-lung bypass equipment to function for the patient like a lung that is external to the body. The ECMO helps to rid the body of excess carbon dioxide and to add oxygen to the patient’s bloodstream. ECMO is used when other methods are not successful, and often while the patient is awaiting a lung transplant (ALA, 2019b; Ignatavicius et al., 2018; NHLBI, 2019).