Approach to postoperative respiratory distress: Clinical sciences

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Introduction0:00–1:02

Postoperative respiratory distress can occur after any operation due to issues with the airway and lung parenchyma itself, or from respiratory muscle dysfunction.
It can be life-threatening if left untreated. Although there are many different causes, the life-threatening conditions you must first identify are tension pneumothorax, acute respiratory distress syndrome or ARDS, upper airway obstruction, and pulmonary embolism.
Other urgent causes include atelectasis, pneumonia, pleural effusion, pulmonary edema, aspiration pneumonitis, and bronchospasm.
Keep in mind that any cause of postoperative respiratory distress can become life-threatening if not managed appropriately, and any of these complications require immediate intervention.Your first step in assessing a patient with postoperative respiratory distress is to evaluate their ABCDE.

Unstable patient1:02–2:09

If you determine that the patient is unstable, initiate acute management immediately. First, stabilize the airway.
Keep in mind that some patients might require intubation or even a surgical airway like a cricothyroidotomy. Next, provide supplemental oxygen and support with mechanical ventilation, obtain IV access, and monitor their vitals.
Once these important steps are done, you should perform a focused history and physical exam to quickly assess for life-threatening conditions.
Here’s a clinical pearl! Regardless of the cause, many patients will have similar signs and symptoms, such as dyspnea, tachypnea, increased work of breathing, and hypoxemia.
So if you see any of these in a postoperative patient, make sure to act quickly!Alright, let’s first talk about tension pneumothorax.

Tension pneumothorax2:09–2:47

If the patient required high airway pressure or a central line placement, or if they had a difficult airway, and on the exam you find absent lung sounds, unequal breath sounds, hyperresonance to percussion, and tracheal deviation, you can make your diagnosis of tension pneumothorax.
Remember, tension pneumothorax is a clinical diagnosis, so you should go directly to treatment such as needle decompression or tube thoracostomy.
Okay, let's go back to history and physical exam to go over ARDS. History might reveal a severe inflammatory state like sepsis or a high-risk operation such as oncologic resection for cancer.

ARDS2:47–3:52

The physical exam typically reveals crackles and severe hypoxemia. In this case, you should think about ARDS.
Your next step is to obtain an arterial blood gas, or ABG, and a chest x-ray. The ABG will show hypoxemia, and either a respiratory acidosis or alkalosis, depending on how sick the patient is.
The chest x-ray will show severe bilateral lung infiltrates. These findings indicate ARDS, so you’ll need to provide positive pressure by intubating the patient, which recruits more alveoli and improves gas exchange.Next, let’s go over upper airway obstruction.

Upper airway obstruction3:52–4:41

Your patient may have a history of difficult intubation, obesity, obstructive sleep apnea, anaphylaxis, or postoperative soft tissue swelling or hematoma.
Also, surgeries involving the thyroid and parathyroid can cause damage to the recurrent laryngeal nerve and cause vocal cord paralysis and laryngospasm.
Here, you need to examine their neck and oropharynx quickly. If you see angioedema of the tongue, oropharyngeal swelling, and face or neck swelling, and hear stridor due to laryngeal swelling, you can make your diagnosis of upper airway obstruction.

Pulmonary embolism4:41–5:42

Let’s move on to our last life-threatening condition, pulmonary embolism. Your patient may have a history of hypercoagulopathy, which can be due to an underlying condition like malignancy or recent operations.
Physical exam will show signs of respiratory collapse, including hypoxemia and hyperventilation, due to V/Q mismatch. You may also see hemodynamic collapse due to pulmonary hypertension, resulting in symptoms like cyanosis, tachycardia, arrhythmias, and, if severe enough, hypotension.
If any of these findings are present, consider pulmonary embolism. Your next step is to order a CT angiogram of the chest to visualize any filling defects in the pulmonary arteries, which will confirm your diagnosis.

Stable patient5:42–6:32

Alright, now let’s talk about stable patients. Even if on initial assessment the patient is stable, you should always move to quickly determine the etiology of postoperative respiratory distress, as even the urgent causes can progress to life-threatening conditions if not managed appropriately.
Your first step in assessing a stable patient is to obtain a focused history and physical exam. Additionally, consider an ABG, which is not always needed to make your diagnosis, but may help this workup.
You might also consider other labs, like a CBC, depending on the situation. Finally, in all patients, obtain a chest x-ray.

Atelectasis6:32–7:52

The most common cause of postoperative respiratory distress is atelectasis. Let’s say you have a recent postoperative patient who reports a cough with or without sputum, and dyspnea.
On exam, you’ll see decreased chest expansion and shallow breathing, as well as decreased breath sounds and crackles on auscultation.
ABG will often show hypoxemia, while the chest x-ray will show increased opacification, displacement of lung fissures, narrowing of intercostal spaces, or elevation of hemidiaphragm on the affected side.
If you see these findings, you can diagnose atelectasis. Here’s a clinical pearl!
Atelectasis is due to poor lung expansion following surgery, which occurs because of pain, immobility, and drowsiness following anesthesia.
That’s why incentive spirometry is used to prevent and treat atelectasis in nearly all postoperative patients. Incentive spirometry helps to expand the lungs during inspiration and encourages deep breathing and coughing, which in turn helps mobilize and clear up the mucus in the airway.
Moving on, another cause can be pneumonia. Some patients present with fever on postoperative day five or later, as well as pleuritic chest pain or a productive cough.

Pneumonia7:52–8:39

On exam, you might find decreased breath sounds, as well as rales, crackles, or rhonchi on auscultation. ABG shows hypoxemia, hypercapnia, and respiratory acidosis, while CBC shows leukocytosis with left shift.
Finally, a chest x-ray reveals a pulmonary consolidation or an infiltrate. At this point, you can diagnose pneumonia.Postoperative respiratory distress might also be associated with pleural effusion.

Pleural effusion8:39–9:32

Let’s say your patient had cardiothoracic surgery or has a history of heart failure, liver disease, kidney failure or malignancy.
On exam, you should look out for sharp inspiratory chest pain, dullness to percussion, decreased breath sounds, and bibasilar crackles on auscultation.
The ABG may show hypoxemia, while an x-ray shows blunting of the costophrenic angle and a dependent fluid opacity. If the x-ray findings are not clear, you can alternatively perform a bedside ultrasound to visualize anechoic fluid above the diaphragm.
If you see these findings, you should think of pleural effusion. Okay, next, let’s consider pulmonary edema.

Pulmonary edema9:32–11:02

Think of a patient who has a history of one of the following, aggressive fluid resuscitation, mass transfusion, chest trauma, a cardiothoracic surgery, postextubation upper airway obstruction, congestive heart failure, renal failure, or pre-eclampsia.
On a physical exam, you can expect to find increased work of breathing, dullness to percussion, decreased breath sounds, and crackles on auscultation.
ABG will show hypoxemia, hypercapnia, and respiratory acidosis. Chest x-ray will reveal diffuse pulmonary infiltrates, confirming your diagnosis of pulmonary edema.
You should keep a close eye on these patients. While you may start with non-invasive ventilation and aggressive diuresis, these patients may ultimately progress to respiratory failure and require intubation.Here’s a clinical pearl!
Pulmonary edema related to heart failure can mimic signs and symptoms of ARDS, so be sure to rule this out, especially because the treatment differs.
With pulmonary edema, you will use diuretics, which will not work in ARDS!Next, let’s talk about aspiration pneumonitis.

Aspiration pneumonitis11:02–12:21

Your postoperative patient might report post-extubation dysphagia, choking, dry cough, and fever. The patient will also likely have vomiting, which is often witnessed in the hospital setting.
On exam, you find mildly decreased breath sounds and crackles on auscultation. Suctioning may reveal stomach contents.
ABG reveals hypoxemia, and chest x-ray shows patchy infiltrates in one or both lungs, which are typically most severe in the lower lobes.
With this clinical picture, you can make your diagnosis of aspiration pneumonitis, which occurs when inhaled liquids or food irritate the lungs and cause inflammation.
Often, postoperative patients are especially vulnerable to aspiration, because they might be immobilized on a spine board with a neck brace or intoxicated, or because of issues with gastrointestinal emptying, such as with bowel obstruction or achalasia.
If the patient continues to aspirate, pneumonitis can develop into aspiration pneumonia.Okay, let’s go back one last time to go over bronchospasm.

Bronchospasm12:21–13:28

Your patient may have a history of chronic lung disease, like COPD, and may have undergone a bronchoscopy, and might report chest tightness.
You may also learn that, during the surgery, the patient required high airway pressures with low tidal volume on the ventilation, but despite this, they were still difficult to oxygenate and had an elevated end tidal CO2.
Postoperatively, on exam, you might find wheezing, decreased tidal volume, and prolonged expiratory time. The ABG will likely be normal, but sometimes may show hypercapnia.
Similarly, the chest x-ray can be normal or show lung hyperinflation with displacement of the diaphragm. With these findings, we are talking about bronchospasm, which is usually due to an adverse response to anesthesia or to airway manipulation.

Review13:28–14:22

Alright, as a quick recap… Postoperative respiratory distress is a common complication that can be life-threatening. Your first step is ABCDE to assess and secure the airway before initiating your diagnostic workup.
If the patient is unstable, the four life-threatening causes that you need to quickly identify are tension pneumothorax, ARDS, upper airway obstruction, and pulmonary embolism.
If your patient is stable, you should also consider urgent causes, like atelectasis, pneumonia, pleural effusion, pulmonary edema, aspiration pneumonitis, and bronchospasm.
All of these diagnoses require immediate interventions, and can become life-threatening if not managed appropriately.