Postoperative airway and pulmonary complications in adults: Management following initial stabilization

INTRODUCTION — Respiratory problems are common in the postoperative setting due to a wide array of etiologies (table 1). Appropriate diagnosis and timely management are critical for a good prognosis.

This topic discusses management of postoperative pulmonary and airway complications that require ongoing treatment after initial stabilization.

Diagnostic evaluation and urgent management of serious life-threatening causes of postoperative respiratory compromise are discussed in a separate topic. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

Strategies to prevent postoperative pulmonary complications are also reviewed separately. (See "Strategies to reduce postoperative pulmonary complications in adults".)

EPIDEMIOLOGY AND RISK FACTORS — The reported incidence of postoperative pulmonary complications ranges from 5 to 83 percent, depending on the patient population, type of surgery performed, criteria used to define a complication, and hospital setting that was studied [1,2].

Postoperative respiratory failure accounts for more than 20 percent of all patients receiving ventilatory support [3,4]. Respiratory failure requiring unplanned reintubation in the postoperative period is associated with high morbidity (leading to longer hospital stays) and increase in 30-day mortality [5-7]. The incidence of unanticipated reintubation in the first 72 hours is low in general (<1 percent) but higher in older patients (up to 3 percent) and associated with an increased likelihood of death [5-7]. Reintubation is most likely within the first six hours after extubation following surgery [7].

Several patient-, procedure-, and anesthesia-related factors contribute to the development of pulmonary complications in the postoperative period. Preoperative evaluation tools are available to quantify this risk (table 2 and table 3). Knowledge of these risks can inform the evaluation of postoperative patients with pulmonary complications. Details regarding preoperative risk assessment and risk factors for individual etiologies are provided separately. (See "Evaluation of perioperative pulmonary risk" and "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Etiologies and their risk factors'.)

IMMEDIATE, POTENTIALLY LIFE-THREATENING EMERGENCIES — Common respiratory problems that present more frequently in the immediate postoperative period can be life-threatening if not urgently treated (table 1). These include hypoventilation due to residual anesthetic effects, conditions that cause upper airway obstruction (eg, laryngospasm, pharyngeal muscle weakness, upper airway edema, copious secretions, mucous plugging, aspiration, cervical hematoma), and several lower airway conditions (bronchospasm, cardiogenic or noncardiogenic pulmonary edema, tension pneumothorax, and pulmonary embolism). These conditions are discussed in the linked sections below.

Hypoventilation due to residual anesthetic effects — (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

Acute upper airway obstruction — (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

Lower airway conditions — (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

EARLY POSTOPERATIVE COMPLICATIONS (HOURS TO DAYS)

Lower airway and parenchymal/vascular disorders — Most postoperative pulmonary complications requiring management after the immediate postoperative period involve the lower airways, pulmonary parenchyma, or pulmonary vasculature (table 1).

Bronchospasm — Management of bronchospasm in the postoperative setting is the same as management in other settings (bronchodilators and treatment of the cause). (See "Acute exacerbations of asthma in adults: Emergency department and inpatient management" and "COPD exacerbations: Management".)

Specific to the postoperative patient, the underlying cause may be secretions or an allergic reaction to intraoperative medications. Short-acting inhaled beta-2-agonist bronchodilators (eg, albuterol) are considered first-line pharmacotherapy. The decision about whether to use an inhaled beta-2-agonist alone (first-line agent) or to add ipratropium bromide is made on a case-by-case basis, depending upon the severity of bronchospasm. Dosing is provided in the table (table 4).

Patients who do not improve after one or two doses of inhaled bronchodilators may benefit from other measures, which are discussed separately (table 5). (See "Perioperative anaphylaxis: Clinical manifestations, etiology, and management", section on 'Management' and "Acute exacerbations of asthma in adults: Emergency department and inpatient management".)

Atelectasis

●Initial measures – Atelectasis is best prevented with adequate analgesia, incentive spirometry, and mobilization to facilitate deep breathing and expectoration. It cannot be prevented using bronchoscopy as a tool to remove secretions.

When mild to moderate hypoxemia is thought to be due to atelectasis (eg, patient requires low-flow oxygen up to 6 L/minute), treatment is supportive and involves the same preventive measures of adequate analgesia, incentive spirometry, and mobilization [8]. Oral suctioning is suitable for patients who have copious secretions but are able to expectorate adequately while nasotracheal suctioning may be needed in patients who have difficulty expectorating.

●Additional treatment – If initial measures fail, our approach is the following:

•Minimal secretions – If secretions are not abundant, noninvasive ventilation (NIV) techniques may be trialed.

Limited data support some benefit of NIV in this population. In a study of 209 patients with hypoxemia due to postoperative atelectasis following elective major abdominal surgery, compared with supplemental oxygen, continuous positive airway pressure (CPAP) decreased the incidence of endotracheal intubation (1 versus 10 percent), pneumonia (2 versus 10 percent), infection (3 versus 10 percent), and sepsis (2 versus 9 percent) [9]. However, the trial was unblinded and terminated early due to benefit. In addition, these findings have not been universal [10,11].

The value and practical application of NIV for patients with hypoxemic respiratory failure are discussed separately. (See "Noninvasive ventilation in adults with acute respiratory failure: Benefits and contraindications" and "Noninvasive ventilation in adults with acute respiratory failure: Practical aspects of initiation".)

•Abundant secretions – In patients with abundant secretions (eg, >30 mL/day), pulmonary toilet alone (eg, suctioning, chest physical therapy) may be effective without the need for NIV.

-Pulmonary toilet – Suctioning and chest physiotherapy are relatively low risk, inexpensive interventions. Data to support their use is based upon clinical experience and indirect evidence from patients with lung diseases characterized by abundant secretions (eg, cystic fibrosis, bronchiectasis). (See "Cystic fibrosis: Overview of the treatment of lung disease", section on 'Chest physiotherapy'.)

-Bronchoscopy – Bronchoscopy is rarely needed for secretion removal in patients with worsening hypoxemia due to acute mucus plugging. We believe that flexible bronchoscopy should not be performed routinely before or instead of suctioning and chest physical therapy but may have a role in patients who are unresponsive to such therapies. This approach is supported by several studies reporting that routine bronchoscopy has little benefit when compared with standard therapy (eg, chest physical therapy, oxygen) [12-18].

In theory, patients without air bronchograms may benefit more from bronchoscopy than those with air bronchograms. Air bronchograms indicate airways that are free of secretions. Thus, it is possible that the lack of effect among patients with air bronchograms in studies obscured a beneficial effect among patients without air bronchograms.

-No or limited role of NIV and mucolytics – NIV and the mucolytic N-acetylcysteine do not have a role in the routine management of patients with abundant respiratory secretions. Inability to clear secretions is a contraindication to NIV because the patient-device interface tends to impede adequate expectoration (table 6). Although frequently administered in those with abundant secretions, N-acetylcysteine has not been studied as a therapy for postoperative atelectasis. However, it seems unlikely that it would be beneficial given its lack of effect in preventing postoperative atelectasis [19-21].

Pneumonia — Antibiotic therapy for the management of postoperative pneumonia is discussed separately. (See "Treatment of hospital-acquired and ventilator-associated pneumonia in adults".)

Factors specific to antibiotic selection to empirically treat postoperative pneumonia include the following:

●The most common pathogens in this population are gram-negative bacilli (eg, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter species) and Staphylococcus aureus. Haemophilus influenzae and Streptococcus pneumoniae are also common [22].

●Postoperative pneumonia is often polymicrobial in origin. The most frequent bacterial combinations appear to be Enterobacteriaceae plus either Staphylococcus aureus or Streptococci species [22].

●Victims of trauma are particularly susceptible to pneumonia caused by Haemophilus influenzae, Streptococcus pneumoniae, or Staphylococcus aureus. Neurosurgical patients, especially those requiring mechanical ventilation, are also at increased risk for pneumonia due to Staphylococcus aureus.

●Anaerobic coverage may be considered following thoracoabdominal surgery, although its value is uncertain. Antimicrobial coverage of aerobic bacteria should be continued if anaerobic coverage is added.

Pulmonary embolism — Venous thromboembolism (VTE) is common in the postoperative setting. Prevention and management strategies for postoperative VTE include anticoagulation, provided there is no contraindication. A discussion with the surgeon regarding the bleeding risk is prudent before initiating prophylactic or therapeutic anticoagulant therapy. (See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients" and "Prevention of venous thromboembolism (VTE) in adults with non-major extremity orthopedic injury with or without surgical repair".)

Further details regarding the management of VTE are provided separately. (See "Treatment, prognosis, and follow-up of acute pulmonary embolism in adults" and "Overview of the treatment of proximal and distal lower extremity deep vein thrombosis (DVT)".)

Nonvenous embolic phenomena are more rare and are discussed separately:

●(See "Air embolism", section on 'Surgery and trauma'.)

●(See "Fat embolism syndrome", section on 'Epidemiology and etiology'.)

●(See "Amniotic fluid embolism", section on 'Risk factors'.)

Pulmonary edema — Postoperative pulmonary edema may be cardiogenic or noncardiogenic.

●Cardiogenic pulmonary edema – Patients with cardiogenic pulmonary edema are generally treated with diuretics, but occasionally inotropic and ventilatory support is needed (table 7). Further details regarding the management of cardiogenic pulmonary edema are provided separately. (See "Perioperative management of heart failure in patients undergoing noncardiac surgery", section on 'Postoperative management' and "Treatment of acute decompensated heart failure: Specific therapies".)

●Noncardiogenic pulmonary edema – Treatment of noncardiogenic pulmonary edema is supportive with administration of supplemental O₂, as well as diuretics, if indicated. A trial of NIV (typically CPAP) is reasonable but reintubation may be necessary if oxygenation is severely impaired. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Lower airway pulmonary parenchymal/vascular emergencies' and "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Noninvasive ventilation'.)

●Other causes – If fluid overload is suspected due to the excessive perioperative fluid administration, a diuretic is typically administered. If abdominal compartment syndrome due to fluid overload is present, treatment is prudent, as reviewed separately. (See "Abdominal compartment syndrome in adults".)

Pleural effusion — Most postoperative pleural effusions are small and resolve spontaneously within a few days without requiring intervention. Thoracentesis may be necessary to manage some atypical or infected pleural effusions.

Evaluation of postoperative pleural effusions is similar to that in other settings. Further details are available in separate topics. (See "Diagnostic evaluation of the hemodynamically stable adult with a pleural effusion" and "Evaluation and management of pleural effusions following cardiac surgery".)

Subphrenic abscess is a complication of surgery that may induce pleural effusions; however, effusions associated with a subphrenic abscess are distinct from the usual postoperative pleural effusion in that they usually become apparent about 10 days after surgery and are typically associated with signs and symptoms of systemic infection [23]. (See "Management and prognosis of parapneumonic pleural effusion and empyema in adults".)

Aspiration (chemical) pneumonitis — Risk factors for aspiration are listed in the table (table 8). (See "Aspiration pneumonia in adults", section on 'Predisposing conditions'.)

Witnessed postoperative aspiration is treated with lateral head positioning (assuming integrity of the cervical spine) and suctioning of the oropharynx [24]. Patients with chemical pneumonitis are generally treated supportively with supplemental oxygenation and bronchodilators for bronchospasm. If severe, noninvasive or mechanical ventilatory support with positive end-expiratory pressure may be necessary.

We do not empirically treat suspected chemical pneumonitis with antibiotics unless bacterial pneumonia occurs as a complication of aspiration. Glucocorticoids are also not routinely administered.

Following the aspiration event, patients are monitored for the next 24 hours for the development of coughing, diffuse crackles on lung auscultation, bronchospasm (treated with bronchodilators), or signs of inadequate oxygenation or bacterial superinfection [25].

Further details regarding management of aspiration are provided elsewhere. (See "Aspiration pneumonia in adults".)

Pneumothorax — Immediate decompression is indicated for tension pneumothorax. A small-bore chest catheter is inserted if equipment and personnel are immediately available; otherwise, needle thoracostomy should be emergently performed, followed by chest tube placement as soon as possible. (See "Initial evaluation and management of penetrating thoracic trauma in adults", section on 'Role of needle/finger chest decompression' and "Thoracostomy tubes and catheters: Placement techniques and complications", section on 'Techniques'.)

The management of non-life-threatening pneumothorax is provided separately. (See "Treatment of secondary spontaneous pneumothorax in adults", section on 'Other pneumothorax types'.)

Upper airway disorders — Rapid diagnosis and urgent management of laryngospasm, pharyngeal muscle weakness, upper airway edema, copious secretions, or foreign body aspiration causing acute upper airway obstruction in the immediate postoperative period are discussed separately. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Acute upper airway obstruction' and "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Ensure a patent upper airway and adequate ventilation'.)

Some upper airway pathologies do not rapidly resolve such that ongoing management is necessary, as discussed in the sections below (table 1).

Oropharyngeal collapse due to obstructive sleep apnea — Worsening obstruction in patients with obstructive sleep apnea is typically managed with PAP, provided there are no contraindications (table 6). Further details are provided separately. (See "Postoperative management of adults with obstructive sleep apnea".)

Upper airway edema — If significant postoperative upper airway edema is present, extubation may be avoided or reintubation may be necessary. Subsequent therapy is directed at the suspected etiology including the following:

●Management of anaphylaxis and angioedema are discussed separately (table 5 and algorithm 1). If anaphylaxis or angioedema symptoms are mild, treatment with parenteral antihistamines and corticosteroids as well as IV and nebulized epinephrine may avoid the need for reintubation. (See "Perioperative anaphylaxis: Clinical manifestations, etiology, and management" and "An overview of angioedema: Clinical features, diagnosis, and management", section on 'Angioedema in or near the airway'.)

●If fluid overload is suspected to be a contributing cause, we administer a diuretic and discontinue fluids.

●Patients with significant upper airway edema may remain intubated in a critical care setting to allow time for resolution. Treatment with corticosteroids similar to that described in critically ill patients who fail extubation due to airway edema is appropriate. Further details of typical protocols are provided separately. (See "Extubation management in the adult intensive care unit", section on 'Glucocorticoids'.)

●Rarely, inhaled heliox is needed to reduce turbulent flow in large airways. (See "Physiology and clinical use of heliox", section on 'Use in adults'.)

Cervical hematoma — Most cervical hematomas are mild and can be treated conservatively, with local compression and monitoring for signs of airway compromise (eg, in the post-anesthesia care unit or intensive care unit). Emergency management of a rapidly expanding hematoma requires intubation and reoperation. Various approaches have been described depending on the speed of expansion and presence of airway compromise and are discussed separately. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Ensure a patent upper airway and adequate ventilation'.)

Rare upper airway disorders

Unilateral vocal cord paralysis — When diagnostic laryngoscopy reveals unilateral vocal cord paralysis, management is supportive since the condition is typically temporary and resolves spontaneously over a period of days to months unless frank nerve transection has occurred. Further details are provided separately. (See "Complications of airway management in adults", section on 'Vocal cord injury' and "Hoarseness in adults", section on 'Bilateral vocal fold paralysis'.)

Arytenoid dislocation — (See "Complications of airway management in adults", section on 'Injuries of the larynx and vocal cords'.)

Temporomandibular joint dislocation — (See "Complications of airway management in adults", section on 'Temporomandibular joint dislocation'.)

Tracheal laceration or rupture — Tracheal laceration or rupture is generally treated with surgical repair, although a small proportion may be treated conservatively (eg, minor laceration). Clinical features and management of tracheal injuries are provided in detail separately. (See "Identification and management of tracheobronchial injuries due to blunt or penetrating trauma".)

Hypoventilation due to postoperative administration of opioids or sedatives — Following supportive airway maneuvers (eg, chin lift or jaw thrust), patients may be treated with NIV (if mental status allows (table 6)) or invasive ventilation (if needed).

Occasionally, agent reversal is used when there is a desire to avoid reintubation, there are contraindications to NIV, or respiratory or near-respiratory arrest occurs. One of the challenges of reversal agents is that they have a short half-life and may result in a false sense of security that respiratory depression is curtailed. Thus, they are often reserved for true emergencies, such as impending or actual respiratory arrest.

●Opioids – If opioid overdose is determined to be the most likely cause of heavy sedation and persistent bradypnea, low doses of IV naloxone 40 mcg may be administered (table 9). In most patients, titration of low-dose naloxone will safely reverse opioid effects while preserving some analgesia. Higher doses may result in sudden reversal of analgesic effects and result in extreme discomfort and a sympathetic surge associated with hypertension, tachycardia, myocardial ischemia, and/or flash (noncardiogenic) pulmonary edema [26]. (See "Acute opioid intoxication in adults", section on 'Management'.)

●Benzodiazepines – Oversedation caused by benzodiazepines is uncommon in the perioperative setting. In rare cases, when benzodiazepine is suspected to be contributing to hypoventilation, IV flumazenil (0.2 mg) may be administered (table 9). (See "Benzodiazepine poisoning", section on 'Role of antidote (flumazenil)'.)

LATE POSTOPERATIVE CONDITIONS (WEEKS TO MONTHS)

Tracheal stenosis — Tracheal stenosis may be treated by surgical repair or local bronchoscopic techniques if surgery is not feasible. Details regarding the management of tracheal stenosis are provided separately. (See "Management of non-life-threatening, nonmalignant subglottic and tracheal stenosis in adults", section on 'Traumatic'.)

Obstructive pneumonia — Obstructive pneumonia due to a foreign body is generally treated by removal of the foreign body and treatment of the pneumonia with antibiotics that include anerobic coverage. (See "Airway foreign bodies in adults", section on 'Management' and "Lung abscess in adults", section on 'Treatment'.)

Unilateral diaphragmatic paralysis — Unilateral diaphragmatic paralysis often does not require treatment unless the patient becomes symptomatic. Management is discussed in detail separately. (See "Diagnosis and management of nontraumatic unilateral diaphragmatic paralysis (complete or partial) in adults", section on 'Treatment and prognosis'.)

POSTOPERATIVE RESPIRATORY FAILURE — Management of postoperative respiratory failure is discussed separately. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Provide supplemental oxygen and respiratory support'.)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Atelectasis (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Epidemiology – The reported incidence of postoperative pulmonary complications ranges from 5 to 83 percent. Prompt management is potentially lifesaving. (See 'Epidemiology and risk factors' above and "Evaluation of perioperative pulmonary risk".)

●Immediate potentially life-threatening emergencies – Common immediate postoperative life-threatening emergencies include the following (table 1) and are discussed in detail separately:

•Hypoventilation due to residual anesthetic effects – (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

•Acute upper airway obstruction (eg, laryngospasm, pharyngeal muscle weakness, upper airway edema, copious secretions, mucous plugging, aspiration, cervical hematoma) – (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

•Lower airway conditions (eg, bronchospasm, cardiogenic or noncardiogenic pulmonary edema, tension pneumothorax, and pulmonary embolism) – (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization".)

●Early postoperative complications (hours to days) – Most postoperative pulmonary complications requiring management after the immediate postoperative period involve the lower airways, pulmonary parenchyma, or pulmonary vasculature (table 1). Management is similar to other settings and is largely discussed in the following linked topics:

•Bronchospasm (table 4) – (See 'Bronchospasm' above and "Acute exacerbations of asthma in adults: Emergency department and inpatient management" and "COPD exacerbations: Management".)

•Pneumonia – (See 'Pneumonia' above and "Treatment of hospital-acquired and ventilator-associated pneumonia in adults".)

•Pulmonary embolism – (See 'Pulmonary embolism' above and "Prevention of venous thromboembolism (VTE) in adults with non-major extremity orthopedic injury with or without surgical repair" and "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients".)

•Pulmonary edema (including noncardiogenic pulmonary edema and fluid overload for which therapy is supportive) – (See 'Pulmonary edema' above and "Perioperative management of heart failure in patients undergoing noncardiac surgery", section on 'Postoperative management' and "Treatment of acute decompensated heart failure: Specific therapies".)

•Pleural effusion – (See 'Pleural effusion' above and "Diagnostic evaluation of the hemodynamically stable adult with a pleural effusion" and "Evaluation and management of pleural effusions following cardiac surgery".)

•Aspiration (table 8) – (See 'Aspiration (chemical) pneumonitis' above and "Aspiration pneumonia in adults".)

•Pneumothorax – (See 'Pneumothorax' above and "Treatment of secondary spontaneous pneumothorax in adults" and "Initial evaluation and management of penetrating thoracic trauma in adults", section on 'Role of needle/finger chest decompression'.)

•Atelectasis – Initial prevention and treatment of mild to moderate hypoxemia due to atelectasis is supportive. This includes adequate analgesia, incentive spirometry, and mobilization to facilitate deep breathing and expectoration. Oral, and less commonly, nasotracheal suctioning may be needed for patients who have copious secretions or need help expectorating.

If initial measures fail, the following approach is reasonable:

-For patients with minimal secretions and postoperative atelectasis, we suggest a trial of noninvasive ventilation (Grade 2C). Limited data suggest that noninvasive ventilation (NIV) may reduce rates of endotracheal intubation and infection.

-For patients with abundant respiratory secretions causing postoperative atelectasis (eg, >30 mL/day), we suggest frequent suctioning and chest physiotherapy (Grade 2C). These are low-risk and inexpensive interventions supported by indirect evidence from patients with cystic fibrosis/bronchiectasis. Bronchoscopy should be reserved for patients who are unresponsive to suctioning and chest physiotherapy. NIV and the mucolytic N-acetylcysteine have a limited role in this population.

•Upper airway disorders – The initial emergency management and stabilization of upper airway disorders is discussed separately. (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Acute upper airway obstruction' and "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Ensure a patent upper airway and adequate ventilation'.)

Subsequent management of specific etiologies is discussed in the linked sections below:

-Oropharyngeal collapse due to obstructive sleep apnea – (See 'Oropharyngeal collapse due to obstructive sleep apnea' above and "Postoperative management of adults with obstructive sleep apnea".)

-Upper airway edema (table 5 and algorithm 1) – (See 'Upper airway edema' above and "Perioperative anaphylaxis: Clinical manifestations, etiology, and management" and "An overview of angioedema: Clinical features, diagnosis, and management", section on 'Angioedema in or near the airway' and "Extubation management in the adult intensive care unit", section on 'Patients at risk' and "Physiology and clinical use of heliox".)

-Cervical hematoma – (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Ensure a patent upper airway and adequate ventilation'.)

-Unilateral vocal cord paralysis – (See "Complications of airway management in adults", section on 'Vocal cord injury' and "Hoarseness in adults", section on 'Bilateral vocal fold paralysis'.)

-Arytenoid dislocation, temporomandibular joint dislocation, tracheal laceration – (See "Complications of airway management in adults", section on 'Injuries of the larynx and vocal cords'.)

•Medication-related hypoventilation (table 9) – (See 'Hypoventilation due to postoperative administration of opioids or sedatives' above and "Acute opioid intoxication in adults", section on 'Management' and "Benzodiazepine poisoning", section on 'Role of antidote (flumazenil)'.)

●Late postoperative conditions (week to months) – Postoperative conditions that present later include the following:

•Tracheal stenosis – (See "Management of non-life-threatening, nonmalignant subglottic and tracheal stenosis in adults", section on 'Traumatic'.)

•Foreign body obstructive pneumonia – (See "Airway foreign bodies in adults", section on 'Management' and "Lung abscess in adults", section on 'Treatment'.)

•Unilateral diaphragmatic paralysis – (See "Diagnosis and management of nontraumatic unilateral diaphragmatic paralysis (complete or partial) in adults", section on 'Treatment and prognosis'.)

●Postoperative respiratory failure – (See "Postoperative airway and pulmonary complications in adults: Etiologies and initial assessment and stabilization", section on 'Provide supplemental oxygen and respiratory support'.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Michael Johnson, MD, who contributed to earlier versions of this topic review.