Anesthesia for patients with chronic obstructive pulmonary disease

INTRODUCTION — Chronic obstructive pulmonary disease (COPD) and its subtypes (emphysema, chronic bronchitis, and chronic obstructive asthma) are important risk factors for postoperative pulmonary complications (eg, pneumonia, reintubation after initial extubation, and prolonged intubation >48 hours), resulting in increased length of hospital stay and mortality.

This topic will discuss anesthetic management of patients with COPD. Details regarding anesthetic management of patients with asthma are addressed in another topic. (See "Anesthesia for adult patients with asthma".)

Medical evaluation of preoperative pulmonary risk and perioperative strategies to reduce pulmonary complications are discussed separately.

●(See "Evaluation of perioperative pulmonary risk".)

●(See "Strategies to reduce postoperative pulmonary complications in adults".)

●(See "Overview of the management of postoperative pulmonary complications".)

PREANESTHESIA CONSULTATION — The goals of the preanesthesia consultation are to assess COPD severity and comorbidities that contribute to perioperative anesthetic risk, work with the patient's pulmonary specialist/primary care provider to optimize the patient's medical condition, develop an anesthetic care plan, and educate the patient regarding anesthetic care.

Risk factors for pulmonary complications — By definition, patients with COPD have airflow limitation (ie, a forced expiratory volume in one second/forced vital capacity [FEV₁/FVC] ratio less than 0.7 or less than the lower limit of normal) that does not reverse completely after administration of inhaled bronchodilators. The airflow limitation is caused by a variable combination of airway inflammation, scarring, and secretions. Some patients have destruction of lung parenchyma and the pulmonary capillary bed that decreases the available surface area for gas exchange and reduces tethering of the small airways. The end result is increased airflow resistance, hyperinflation due to air trapping, and decreased gas transfer, resulting in ventilation/perfusion (V/Q) mismatch, hypoxemia, and hypercapnia. With advanced COPD ventilatory responses to both hypoxia and hypercapnia may be blunted, and hypoxic pulmonary vasoconstriction attenuated. (See "Chronic obstructive pulmonary disease: Diagnosis and staging".)

Although COPD increases risk for pulmonary complications [1,2], there is no prohibitive level of pulmonary function that contraindicates surgery. The prospective benefit of a proposed surgical procedure is weighed against evaluated risk in an individual patient with COPD (table 1 and table 2 and algorithm 1). (See "Evaluation of perioperative pulmonary risk", section on 'Chronic obstructive pulmonary disease (COPD)' and "Evaluation of perioperative pulmonary risk", section on 'Estimating postoperative pulmonary risk'.)

Patient-related factors — Relative risk of COPD and other patient-related factors are discussed in a separate topic. (See "Evaluation of perioperative pulmonary risk", section on 'Patient-related risk factors'.)

Common risk factors and comorbidities that may impact operative risk include:

●Age – Most patients with COPD are older adults; advancing age has an independent effect on the risk of pulmonary complications (table 1) [3]. (See "Evaluation of perioperative pulmonary risk", section on 'Age' and "Anesthesia for the older adult", section on 'Respiratory system'.)

●Tobacco use – Ongoing cigarette smoking is an additional risk factor for pulmonary complications. (See "Smoking or vaping: Perioperative management", section on 'Rationale for smoking cessation' and "Evaluation of perioperative pulmonary risk", section on 'Smoking'.)

●Cardiovascular disease – Ischemic heart disease, dysrhythmias, heart failure, and/or pulmonary hypertension are common comorbidities in patients with COPD, as discussed separately [4-6]. (See "Management of the patient with COPD and cardiovascular disease" and "Arrhythmias in COPD" and "Evaluation of cardiac risk prior to noncardiac surgery".)

●Obstructive sleep apnea (OSA) – OSA is associated with increased risk for pulmonary and cardiac complications, and is common in patients with COPD (ie, overlap syndrome). (See "Sleep-related breathing disorders in COPD" and "Surgical risk and the preoperative evaluation and management of adults with obstructive sleep apnea" and "Intraoperative management of adults with obstructive sleep apnea".)

Procedure-related factors — Procedure-related factors increase risk of pulmonary complications. (See "Evaluation of perioperative pulmonary risk", section on 'Procedure-related risk factors'.)

●Surgical site – Functional residual capacity (FRC) is reduced during anesthesia and surgery, which can lead to early airway closure and atelectasis, worsening V/Q mismatch, hypoxemia, and respiratory failure (figure 1) [7]. Proximity of the surgical procedure to the diaphragm is the primary factor determining the degree of FRC reduction and the likelihood of postoperative respiratory failure [7-9]. Thus, complications are more likely in patients undergoing thoracic and upper abdominal surgery compared with procedures in the lower abdomen and other sites. (See "Evaluation of perioperative pulmonary risk", section on 'Surgical site'.)

●Surgical positioning – In general, supine, Trendelenburg, lithotomy, and lateral decubitus positioning reduces FRC and leads to atelectasis (figure 1) [10,11]. Notably, prone positioning in COPD patients does not negatively affect respiratory mechanics and may improve FRC, V/Q distribution, and oxygenation [12-14]. Also, compared with normal lungs, FRC may be less reduced in the supine position in patients with COPD because of airway closure prior to alveolar collapse [15].

●Duration of surgery – Surgical time longer than five hours has been associated with increased risk of postoperative pulmonary complications [16]. (See "Evaluation of perioperative pulmonary risk", section on 'Duration of surgery'.)

Anesthetic factors

●Sedative effects of anesthetic agents – Since COPD patients are highly sensitive to sedative and analgesic agents, use of these agents during monitored anesthesia care (MAC) can result in severe hypoventilation, with atelectasis, hypercapnia, and hypoxemia. Also in the immediate postoperative period, residual effects of anesthetic agents in the immediate postoperative period may lead to respiratory depression with hypoventilation, poor cough, and atelectasis. Thus, vigilant monitoring is necessary throughout the perioperative period.

●Airway manipulation – Laryngoscopy, intubation, and extubation can cause reflex-induced bronchoconstriction that may be severe. (See "Anesthesia for adult patients with asthma", section on 'Choice of anesthetic technique'.)

●General anesthesia – Use of the anesthesia breathing circuit may result in dried airway secretions, interference with surfactant production, slow mucociliary clearance, and increased permeability of the alveolar-capillary barrier [17].

●Controlled ventilation – Controlled ventilation may exacerbate hyperinflation in COPD patients when expiratory airflow limitation causes inspiration to occur prior to full exhalation of the previous breath (figure 2). This breath stacking leads to dynamic hyperinflation, which in turn can lead to increased positive end-expiratory pressure (PEEP), known as auto-PEEP [18]. The consequences of dynamic hyperinflation include worsening V/Q mismatch, hypoxemia, hypercapnia, barotrauma, and hypotension (due to impaired venous return) [19,20].

Measurement of auto-PEEP and management of dynamic hyperinflation are discussed elsewhere:

•(See 'Mechanical ventilation' below.)

•(See "Dynamic hyperinflation in patients with COPD".)

•(See "Invasive mechanical ventilation in acute respiratory failure complicating chronic obstructive pulmonary disease", section on 'Dynamic hyperinflation'.)

Preoperative assessment — Preoperative risk assessment is based on:

●History and physical examination – (See "Preoperative evaluation for anesthesia for noncardiac surgery", section on 'Medical history and review of systems' and "Preoperative evaluation for anesthesia for noncardiac surgery", section on 'Anesthesia directed physical examination'.)

●Laboratory tests – In selected patients using a high dose of beta-adrenergic agonists or systemic glucocorticoids, laboratory values may be obtained to check for abnormalities in electrolyte values and serum glucose. Also, preoperative anemia is investigated to rule out reversible causes before elective surgery (algorithm 2). Hemoglobin ≤10 g/dL has been associated with increased risk of postoperative pulmonary complications (odds ratio [OR] 3.0, 95% CI 1.4-6.5; (table 1)) [3]. (See "Evaluation of perioperative pulmonary risk", section on 'Preoperative risk assessment' and "Perioperative blood management: Strategies to minimize transfusions", section on 'Treatment of anemia'.)

●Pulmonary function tests (PFTs) – Formal assessment of PFTs, gas exchange (eg, ambulatory oximetry, six minute walk test), and less commonly, cardiopulmonary exercise testing is obtained (or reviewed) in patients with known or suspected COPD (eg, reduced exercise tolerance, COPD exacerbation in past year, cigarette smoking >20 years). A risk assessment tool can be helpful in quantifying risk (table 1 and table 2) and (calculator 1). (See "Evaluation of perioperative pulmonary risk", section on 'Preoperative risk assessment'.)

●Arterial blood gas (ABG) – Baseline ABG analysis may be helpful in selected patients (eg, those undergoing major surgery or procedures of long duration more than three hours, particularly if FEV₁ is <50 percent of the predicted value and in those with prior hypercapnia) [9,21]. Preoperative ABG results may be used to identify patients who will need more intense monitoring, oxygen therapy, noninvasive ventilation (NIV), or controlled mechanical ventilation in the immediate postoperative period. ABG values are also used to guide intraoperative and postoperative ventilator adjustments to maintain pressure of arterial carbon dioxide (PaCO₂) near baseline in a patient with preexisting hypercapnia. (See "Evaluation of perioperative pulmonary risk", section on 'Assessment of oxygenation and hypercapnia' and 'Management of postanesthesia care' below.)

●Risk assessment tools – Other risk assessment tools, such as the short physical performance battery that emphasizes the sit-to-stand test, have been used to predict COPD exacerbation, increased hospital length of stay, or readmission [22].

●Chest radiograph – Preoperative chest radiography (CXR) is not routinely indicated since findings rarely impact anesthetic care, but a CXR may be obtained in a patient with new lung auscultation findings, worsening respiratory symptoms, or exercise intolerance [6].

Preoperative interventions to optimize pulmonary function — Achieving optimal baseline level of pulmonary function is a major preoperative goal for patients with COPD. Interventions before the day of surgery include [23,24]:

●Refer patients with poorly controlled COPD for treatment – Before elective procedures, the patient's primary care clinician or pulmonologist is consulted for further treatment if the patient reports dyspnea at rest or with minimal exertion (unless this is previously known and unchanged), wheezing, copious sputum production, or evidence of active infection (eg, fever, purulent sputum), or if tachypnea, wheezing, or crackles are noted on examination. (See "Evaluation of perioperative pulmonary risk", section on 'Clinical evaluation'.)

Patients with a COPD exacerbation can benefit from (see "COPD exacerbations: Management") [25,26]:

•Intensification of their inhaled bronchodilator medications (eg, beta-adrenergic agonists and muscarinic antagonists [anticholinergic agents]).

•A brief course of systemic glucocorticoid therapy in some cases. However, even a brief course of systemic glucocorticoids may have some adverse effects (eg, hyperglycemia, upper gastrointestinal bleeding, psychiatric disorders). (See "Major adverse effects of systemic glucocorticoids".)

•Antibiotic therapy, if indicated.

We suggest postponing elective surgery in patients with signs and symptoms of exacerbation of chronic COPD or active upper respiratory infection [23]. Time needed to return to baseline after an exacerbation is variable, so the duration of postponement should be determined on an individual basis. (See "Evaluation of perioperative pulmonary risk", section on 'Upper respiratory infection'.)

●Encourage smoking cessation – Patients should be counseled about cessation of smoking and/or vaping (ie, with electronic cigarettes) during the preanesthesia consultation [27]. Optimal timing of cessation is unknown, but cessation for four to eight weeks prior to surgery likely has the benefit of decreased risk of postoperative pulmonary complications [28,29]. However, even cessation for as little as two days may have some benefit (eg, decreased carboxyhemoglobin levels, elimination of nicotine effects, and improved mucociliary clearance). (See "Smoking or vaping: Perioperative management", section on 'Helping perioperative patients quit smoking or vaping'.)

●Initiate preoperative incentive muscle training – Preoperative instruction regarding inspiratory muscle training (ie, deep breathing exercises or self-administered incentive spirometry) may reduce the incidence of postoperative complications and can be accomplished in the preoperative anesthesia clinic [30]. Although this strategy is time-intensive and potentially expensive, there are no risks [28,31]. (See "Strategies to reduce postoperative pulmonary complications in adults", section on 'Pulmonary prehabilitation'.)

PERIOPERATIVE MEDICATION MANAGEMENT

Inhaled bronchodilators and glucocorticoids — Guideline-based treatment of COPD with long-acting beta agonists (LABA), long-acting muscarinic antagonists (LAMA), and inhaled glucocorticoids may decrease postoperative pulmonary complications [16,32]. Each patient should be assessed to ensure that baseline therapy is adjusted optimally for the individual level of symptoms, risk of exacerbations, and response to therapy. (See "Stable COPD: Initial pharmacologic management", section on 'General principles'.)

Inhaled LABA and LAMA agents, as well as inhaled glucocorticoids, are continued in the perioperative period, including the usual dose on the morning of surgery, with resumption shortly after surgery [17,28,33]. Some patients may need additional doses of short-acting bronchodilators, including those who remain symptomatic with bronchospasm even after treatment with muscarinic antagonists.

For patients who require endotracheal intubation, particularly those with a history of asthma-like symptoms (ie, bronchoconstriction), we administer an inhaled, rapid-acting beta-agonist (eg, albuterol, either two to four puffs from a metered dose inhaler or a nebulizer treatment) within 30 minutes of intubation, and again during emergence from general anesthesia shortly before extubation. (See "Strategies to reduce postoperative pulmonary complications in adults", section on 'Chronic obstructive lung disease' and "Anesthesia for adult patients with asthma", section on 'Premedication' and 'Emergence' below.)

Stress-dose glucocorticoid coverage — Patients taking oral or high-dose inhaled (table 3) glucocorticoids are at risk for hypothalamic pituitary axis (HPA) suppression and adrenal insufficiency during anesthesia and surgery. The likelihood of HPA suppression is estimated based on the dose and duration of glucocorticoid therapy and is discussed separately. (See "The management of the surgical patient taking glucocorticoids" and "Major adverse effects of systemic glucocorticoids", section on 'Metabolic and endocrine effects'.)

For patients with a high likelihood of adrenal suppression, supplemental glucocorticoids are given in accordance with the magnitude of the anticipated stress of the procedure (table 4). Notably, the usual morning oral dose of glucocorticoid is always administered, regardless of whether additional glucocorticoid will be given just prior to the procedure. For patients taking high doses of inhaled glucocorticoids, the risk of symptomatic adrenal suppression or acute crisis appears to be very small, particularly if the daily dose is within the recommended range. (See "The management of the surgical patient taking glucocorticoids" and "Major side effects of inhaled glucocorticoids", section on 'Adrenal suppression'.)

Other chronically administered medications — The following medications are also notable for patients with COPD:

●Theophylline – Theophylline is discontinued on the evening prior to surgery [34]. (See "Perioperative medication management", section on 'Theophylline'.)

●Nicotine replacement therapy (NRT) – NRT should be continued. Overall, the likelihood that surgical patients can abstain from smoking is increased by use of NRT initiated or continued in the perioperative period. (See "Smoking or vaping: Perioperative management", section on 'Helping perioperative patients quit smoking or vaping'.)

Preoperative management of other chronically administered medications is discussed elsewhere. (See "Perioperative medication management".)

Premedication — Anxiety in the preoperative period can lead to increased respiratory rate, which may lead to lung hyperinflation (due to breath stacking) and worsening dyspnea in a COPD patient. Sedatives titrated in very small doses (eg, midazolam 0.25 to 0.5 mg) usually reduce anxiety without leading to respiratory depression. If tachypnea is primarily due to pain, a small dose of an opioid (eg, fentanyl 25 to 50 mcg) may be used for premedication instead of a sedative. Combinations of sedatives and opioids should be used with caution to avoid respiratory depression [35]. Monitoring (eg, pulse oximetry) is continuous during and after administration of any preoperative sedative or opioid so that respiratory depression can be immediately recognized and treated.

CHOICE OF ANESTHETIC TECHNIQUE — The choice of anesthetic technique (monitored anesthesia care [MAC], neuraxial anesthesia, peripheral nerve blocks, or general anesthesia) should be guided primarily by the requirements of the procedure, and by surgeon and patient preferences. Notably, bronchospasm may develop at any time in the perioperative period during any surgical procedure, regardless of which anesthetic technique is selected.

For most patients with COPD, we suggest MAC, neuraxial anesthesia, or another regional anesthetic technique (eg, peripheral nerve block) when appropriate for the planned procedure, to avoid airway stimulation due to laryngoscopy and endotracheal intubation or insertion of other airway devices.

However, general anesthesia is typically preferred for patients with more severe COPD (eg, baseline dyspnea with minimal exertion, inability to lie supine, persistent coughing) and for procedures of prolonged duration. Also, general anesthesia is necessary for performance of many surgical procedures (eg, abdominal laparoscopic procedures, thoracic procedures, or surgical incisions involving the head, neck, or multiple extremities), and for those who do not consent to a regional anesthetic technique.

INTRAOPERATIVE MANAGEMENT

Monitored anesthesia care — Monitored anesthesia care (MAC), with or without judicious sedation or a concomitant regional anesthetic technique, is often selected for patients with COPD undergoing minor procedures. (See "Monitored anesthesia care in adults".)

Since COPD patients are typically older, they may be particularly sensitive to the respiratory depressant effects of individual sedative or opioid agents and combinations of these agents. Therefore, small, incremental doses are administered as necessary, with continuous monitoring of oxygen saturation and end-tidal carbon dioxide (EtCO₂). (See "Monitored anesthesia care in adults", section on 'Drugs used for sedation and analgesia for monitored anesthesia care' and "Anesthesia for the older adult", section on 'Selection and dosing of anesthetic agents'.)

Oxygen saturation should be kept as close as possible to preoperative values during MAC techniques. If necessary, supplemental oxygen is administered to maintain saturation 88 to 92 percent. Administration of a high oxygen percentage in a spontaneously breathing COPD patient increases risk of CO₂ retention and may not enhance tissue oxygenation [36]. The resultant hypoventilation and interference with hypoxic pulmonary vasoconstriction leads to worsening ventilation/perfusion (V/Q) mismatch [36]. (See "The evaluation, diagnosis, and treatment of the adult patient with acute hypercapnic respiratory failure", section on 'Titration of oxygen' and "COPD exacerbations: Management", section on 'Oxygen therapy'.)

Neuraxial anesthesia — Use of neuraxial techniques (ie, spinal, epidural, and combined spinal-epidural) as the primary anesthetic for appropriate surgical procedures avoids airway manipulation as a potential cause of bronchospasm. Theoretical concerns include paralysis of accessory muscles of breathing with midthoracic or higher levels of neuraxial anesthesia, alteration of the ratio of parasympathetic to sympathetic tone due to sympathectomy (theoretically favoring an increase in bronchomotor tone), and arterial hypotension due to sympathectomy. However, these concerns have not been supported by clinical outcomes [37-46]. (See "Overview of neuraxial anesthesia".)

Neuraxial analgesic techniques (eg, epidural) may also be used (with or without intraoperative general anesthesia) to provide multimodal postoperative analgesia, particularly if a large thoracic or abdominal surgical incision is planned. Compared with general anesthesia alone with postoperative use of systemic opioid analgesia, neuraxial analgesia provides superior postoperative pain control and facilitates deep breathing and ambulation [46].

In a review of surgical patients with known COPD in the Surgical Care Improvement Project database, the investigators used propensity matching to compare general anesthesia (n = 2644 patients) with regional anesthesia (epidural, spinal, or peripheral nerve block; n = 2644 patients) [37]. Those receiving regional anesthesia had a lower incidence of postoperative pneumonia (2.3 versus 3.3 percent, difference of 1 percent, 95% CI 0.09-1.88), unplanned postoperative reintubation (1.8 versus 2.6 percent, difference of 0.8 percent, 95% CI 0.04-1.62), and prolonged intubation >48 hours (0.9 versus 2.1 percent, difference of 1.2 percent, 95% CI 0.51-1.84). Similarly, in a cohort study in 541 consecutive patients with known COPD who were undergoing major abdominal surgery, the investigators noted a reduction in pneumonia (11 versus 16 percent, odds ratio [OR] 0.6, 95% CI 0.3-0.9) and mortality (5 versus 9 percent, OR 0.6, 95% CI 0.3-1.2) in those receiving epidural anesthesia in addition to general anesthesia (n = 324), compared with general anesthesia alone (n = 217) [38]. In another study, propensity matching was used to ensure an equal incidence of COPD (24 percent) in 452 patients receiving neuraxial anesthesia and 904 receiving general anesthesia for lower extremity revascularization [47]. Less need for prolonged mechanical ventilation ≥48 hours was noted after neuraxial anesthesia (0.2 versus 2.4 percent). Several meta-analyses of unselected patients undergoing a variety of surgical procedures have reported a significantly lower incidence of respiratory complications when neuraxial anesthesia/analgesia was administered during the perioperative period compared with general anesthesia alone, as discussed elsewhere. (See "Strategies to reduce postoperative pulmonary complications in adults", section on 'Anesthetic technique'.)

Noninvasive ventilation (NIV) may be effective during neuraxial anesthesia to reverse hypoventilation induced by oversedation or inadvertent spread of local anesthetic to higher dermatomes [48]. Similarly, NIV may be employed to treat respiratory distress in the post-anesthesia care unit, and may decrease the need for reintubation in COPD patients. (See 'Management of postanesthesia care' below.)

Regional and peripheral nerve blocks — Regional or peripheral nerve blocks may be appropriate in patients with COPD if the surgical site is peripheral (eg, ophthalmic or extremity procedures) and the planned procedure is of short to moderate duration [37,43]. As with neuraxial anesthesia, airway manipulation is avoided. (See "Overview of peripheral nerve blocks".)

●Transverse abdominis plane block – Preoperative or postoperative transversus abdominus plane and/or rectus sheath blocks have also known to be helpful adjuncts for postoperative pain management [49]. (See "Abdominal nerve block techniques", section on 'Rectus sheath block' and "Transversus abdominis plane (TAP) blocks procedure guide".)

●Brachial plexus blocks – Some brachial plexus blocks for upper extremity surgery (eg, interscalene block, supraclavicular block) paralyze the ipsilateral hemidiaphragm by blocking the phrenic nerve, resulting in a 25 percent reduction of forced vital capacity (FVC) [50-52]. This effect may last for many hours, and may not be tolerated in patients with severe or symptomatic COPD (particularly if the larger right lung is affected). Use of an ultrasound-guided technique to facilitate more accurate delivery of smaller doses of local anesthetic may reduce the incidence of hemidiaphragmatic paralysis, but this adverse side effect cannot be predictably avoided [50]. (See "Upper extremity nerve blocks: Techniques".)

General anesthesia

Induction and airway management — A primary goal of anesthetic induction is to minimize the risk of a bronchoconstrictive response to airway manipulation, similar to induction in patients with asthma. This risk is lower with mask ventilation or insertion of a laryngeal mask airway (LMA) compared with endotracheal intubation, although LMAs have not been specifically studied in patients with COPD [53]. However, intubation is necessary for some patients due to procedure-related or patient-related factors. (See "Anesthesia for adult patients with asthma", section on 'Airway management' and "Airway management for induction of general anesthesia", section on 'Choice of airway device'.)

Most adults prefer intravenous (IV) induction of anesthesia because of the unpleasantly pungent odor of most potent volatile agents [54] (see "Induction of general anesthesia: Overview", section on 'Intravenous anesthetic induction'). Furthermore, IV induction is faster than inhalation induction. In COPD patients, inhalation induction can be further delayed due to ventilation/perfusion (V/Q) mismatch causing anesthetic tension differences between end-tidal gas and arterial blood uptake [55].

Either propofol or ketamine is suitable as the primary agent for IV induction of anesthesia in patients with COPD. Etomidate is less desirable since it increases airway resistance and is associated with adrenal gland dysfunction [56,57]. Details regarding choice of induction agent are discussed separately. (See "Anesthesia for adult patients with asthma", section on 'Induction of anesthesia' and "General anesthesia: Intravenous induction agents".)

If endotracheal intubation is planned, adjuvant medications, typically an opioid and/or lidocaine, as well as a neuromuscular blocking agent (NMBA) are administered together with the primary induction agent. (See "General anesthesia: Intravenous induction agents", section on 'Adjuvant agents'.)

When an inhalation induction technique is preferred, sevoflurane is typically selected since it has the most pronounced bronchodilatory properties of the available agents [19,58] (see "Induction of general anesthesia: Overview", section on 'Inhalation anesthetic induction'). Desflurane is avoided because its extreme pungency may increase secretions and cause coughing, laryngospasm, and/or bronchospasm during induction, particularly in current smokers, and it may increase airway resistance [58-60]. (See "Anesthesia for adult patients with asthma", section on 'Induction of anesthesia' and "Inhalation anesthetic agents: Clinical effects and uses", section on 'Induction of general anesthesia'.)

Maintenance of anesthesia — Similar to patients with asthma, we typically select a potent volatile inhalation agent with bronchodilatory properties (eg, sevoflurane, isoflurane) as the primary agent to maintain general anesthesia [19,58], supplemented with small doses of an opioid (eg, fentanyl) to deepen anesthesia or suppress the cough reflex. For some cases, total intravenous anesthesia (TIVA) may be preferred and is a reasonable alternative. For example, TIVA is useful for patients with large bullous emphysema to avoid the hypoxemia that may occur due to interference with hypoxic pulmonary vasoconstriction caused by volatile agents. In such cases, nitrous oxide (N₂O) is also avoided, as N₂O may cause bullae expansion and rupture as gas is trapped [61]. (See "Anesthesia for adult patients with asthma", section on 'Maintenance of anesthesia'.)

If necessary, a NMBA is administered to facilitate surgical exposure. We suggest using agents that do not release appreciable amounts of histamine, such as rocuronium, vecuronium, or cisatracurium, rather than atracurium or mivacurium. (See "Clinical use of neuromuscular blocking agents in anesthesia".)

Mechanical ventilation — Either a volume- or pressure-limited mode of ventilation can be used, but optimal tidal volume and positive end-expiratory pressure (PEEP) must be maintained.

Lung-protective ventilation for the patient with COPD should include the following (see "Mechanical ventilation during anesthesia in adults", section on 'Lung protective ventilation during anesthesia') [30]:

●Controlled ventilation with reduced tidal volume (6 to 8 mL/kg predicted body weight) (table 5 and table 6). Reducing tidal volume helps prevent air trapping and avoids high driving pressure and high plateau pressure (eg, >15 cm H₂O), thereby minimizing risk of barotrauma. However, reducing tidal volume may decrease minute ventilation, potentially causing hypercapnia and hypoxemia. This can be partially offset by a cautious increase in respiratory rate, as long as expiratory time remains adequate for complete exhalation.

●Reduced respiratory rate (8 to 10 breaths/minute [bpm]) with longer expiratory time (eg, inspiratory-to-expiratory [I:E] ratio of 1:3 to 1:4) to reduce air trapping. We typically do not exceed 10 bpm. Some degree of hypercapnia is acceptable in patients without any specific contraindication for hypercapnia (eg, elevated intracranial pressure), but adequate oxygenation and a pH ≥7.25 should be maintained. (See "Permissive hypercapnia during mechanical ventilation in adults".)

●Cautious use of PEEP, initially at 5 cmH₂O to keep the small airways open, with continuous monitoring for signs of hyperinflation. (See "Invasive mechanical ventilation in acute respiratory failure complicating chronic obstructive pulmonary disease", section on 'Dynamic hyperinflation'.)

●Maintenance of driving pressure ≤15 cmH₂O. At the initial settings for tidal volume and PEEP noted above, if driving pressure is >15 cm H₂O we increase PEEP cautiously in an attempt to recruit alveoli and improve compliance (algorithm 3). There is no absolute plateau pressure above or below which baro- or volutrauma does or does not occur but, in general, the higher this pressure, the greater the risk of barotrauma; plateau pressures above 35 cm H₂O carry the highest risk.

●Monitoring for a phenomenon known as breath-stacking (ie, dynamic hyperinflation, auto-PEEP, air-trapping), which may occur during mechanical ventilation of patients with COPD, and can cause high peak airway pressures or cause a sudden decrease in systemic blood pressure (figure 2) (see "Invasive mechanical ventilation in acute respiratory failure complicating chronic obstructive pulmonary disease", section on 'Dynamic hyperinflation'). Signs of breath-stacking include increasing peak airway pressure, decreasing exhaled volume, and hypotension. Failure of the flow tracing to return to baseline before the next breath on flow-volume loops also indicates persistent end-expiratory flow and likely auto-PEEP [62]. When breath stacking is suspected, transiently disconnecting (eg, <1 minute) the anesthesia circuit can be diagnostic and therapeutic. Auto-PEEP (also called intrinsic PEEP) improves immediately (typically in less than one minute) when the anesthesia mask is transiently lifted from the face, or the breathing circuit is transiently disconnected.

Dynamic hyperinflation is subsequently managed by administering bronchodilator medication, reducing minute ventilation (ie, reducing respiratory rate and tidal volume), and sometimes by increasing inspiratory flow to increase expiratory time. If auto-PEEP (intrinsic PEEP) persists, it may be helpful to cautiously add applied PEEP (also called extrinsic PEEP) at levels below 80 percent of the measured auto-PEEP; close observation is needed as worsening of dynamic hyperinflation may occur.

Notably, dynamic hyperinflation creates a risk for pneumothorax in COPD patients with subpleural bullae. Like dynamic hyperinflation, pneumothorax may present as sudden hypotension and worsening oxygenation. However, the hypotension does not resolve when the ventilator circuit is disconnected from the endotracheal tube. Emergency treatment of tension pneumothorax involves needle decompression followed by surgical chest tube placement. (See "Thoracostomy tubes and catheters: Indications and tube selection in adults and children", section on 'Tension pneumothorax'.)

●Adjusting fraction of inspired oxygen (FiO₂) to the lowest level required to target a pulse oxygen saturation of 88 to 92 percent.

Details regarding lung-protective mechanical ventilation in patients with COPD are available in other topics:

●(See "Mechanical ventilation during anesthesia in adults", section on 'Lung protective ventilation during anesthesia'.)

●(See "Anesthesia for adult patients with asthma", section on 'Controlled ventilation during anesthesia'.)

●(See "Invasive mechanical ventilation in acute respiratory failure complicating chronic obstructive pulmonary disease", section on 'Ventilator settings'.)

Emergence — Bronchoconstriction may develop as anesthetic depth is lightened at the end of the procedure. An aerosolized or nebulized bronchodilator may be administered prophylactically shortly before emergence if more than two hours have elapsed since the last dose. Patients with COPD may benefit from treatment with an aerosolized or nebulized bronchodilator shortly before emergence from general anesthesia if increases in airway pressure or resistance are observed. (See "Anesthesia for adult patients with asthma", section on 'Emergence from anesthesia'.)

End-tidal concentration of the inhalation agent is ideally brought to zero, although elimination of anesthetic agent by exhalation may be prolonged in COPD patients due to ventilation/perfusion (V/Q) mismatch and dead-space ventilation [20]. The arterial tension of carbon dioxide (PaCO₂) should be kept as close as possible to preoperative values during and after emergence.

Complete reversal of neuromuscular blockade at the conclusion of the surgical procedure is particularly important in patients with COPD [63-65] (see "Emergence from general anesthesia", section on 'Assess and reverse effects of neuromuscular blocking agents'). Residual neuromuscular blockade can cause upper airway obstruction, diaphragmatic dysfunction, and impaired mucociliary clearance leading to hypoventilation and pulmonary complications in the immediate postoperative period. (See "Clinical use of neuromuscular blocking agents in anesthesia", section on 'Reversal of neuromuscular block'.)

MANAGEMENT OF POSTANESTHESIA CARE — Management in the immediate postoperative period includes resumption of bronchodilator therapy (and inhaled glucocorticoids if part of baseline regimen) [17,28,33], use of incentive spirometry, and encouraging early ambulation. Pain control should be sufficient to facilitate deep breathing and mobilization, but hypoventilation should be avoided. Use of epidural opioids rather than with systemic opioids decreases risk of atelectasis and pulmonary infection [66]. (See "Strategies to reduce postoperative pulmonary complications in adults", section on 'Postoperative strategies' and "Epidural and combined spinal-epidural anesthesia: Techniques", section on 'Choice of epidural drugs'.)

Patients with COPD may develop bronchospasm or hypoventilation due to residual sedation caused by inhalation agents or opioids, or due to weakness caused by neuromuscular blocking agents (NMBAs) during the immediate postoperative period. Depressed ability to cough or breathe deeply due to somnolence, muscle weakness, pain, and/or opioid-induced respiratory depression can lead to retention of secretions, atelectasis, hypoxemia, and eventual development of bronchitis, pneumonia, and respiratory failure necessitating prolonged mechanical ventilation [17]. (See "Anesthesia for adult patients with asthma", section on 'Postoperative management' and "Respiratory problems in the post-anesthesia care unit (PACU)".)

Noninvasive ventilation (NIV) should be readily available in the post-anesthesia care unit to treat respiratory distress in COPD patients without contraindications: this may decrease the need for reintubation [67]. Reintubation, atelectasis, pneumonia, and prolonged controlled ventilation may be avoided by initiating NIV as soon as the patient has any signs or symptoms of respiratory distress, rather than waiting until there is definitive evidence of respiratory failure (table 7) [68-70]. High-flow nasal cannula (HFNC) oxygen may be helpful in patients at risk of acute hypoxemic respiratory failure post-extubation, although use in COPD patients has not been rigorously studied [71]. Details regarding initiation and management of NIV are discussed separately. (See "Noninvasive ventilation in adults with acute respiratory failure: Benefits and contraindications" and "Respiratory problems in the post-anesthesia care unit (PACU)".)

SPECIAL POPULATIONS

Laparoscopic surgery — Abdominal laparoscopic surgery is associated with less postoperative pain and does not reduce functional residual capacity (FRC) as much as open abdominal surgery [8]. However, laparoscopic surgery does not decrease the incidence of postoperative pulmonary complications in patients with COPD [16].

Absorption of the carbon dioxide (CO₂) gas used to create the pneumoperitoneum necessary for laparoscopic surgery may cause significant hypercapnia and respiratory acidosis, particularly in patients with COPD [72]. Treatment of hypercapnia with the usual compensatory adjustments of mechanical ventilation (eg, a faster respiratory rate) may not be possible due to the need for a prolonged expiratory time. In addition, pneumoperitoneum increases intraabdominal pressure, which may cause cephalad shift of the diaphragm, increased intrathoracic pressure, worsening V/Q mismatch, and hypoxemia. These changes are largely reversed after desufflation of the abdomen [72-74]. In some cases, intermittent desufflation and/or lower insufflation pressures may be necessary to minimize the adverse effects of pneumoperitoneum in some patients with severe COPD [13,72].

Pulmonary resection — Management of patients with pulmonary abnormalities (including COPD) during pulmonary resection is discussed in a separate topic. (See "Anesthesia for open pulmonary resection".)

Emergency surgery — Induction of anesthesia for emergency procedures requiring general anesthesia balances the need for rapid control of the airway with avoidance of bronchospasm during endotracheal intubation. Even in emergency surgery, there is usually time to administer preoperative inhaled bronchodilators. Details are discussed separately. (See "Anesthesia for adult patients with asthma", section on 'Emergency surgery'.)

Patients with increased intracranial pressure — Mechanical ventilation in patients with increased intracranial pressure (ICP) can be especially challenging since hyperventilation to decrease ICP may result in hyperinflation and barotrauma in a patient with COPD. Also, use of volatile anesthetics agents may decrease cerebral perfusion pressure (CPP) and further increase ICP. Anesthetic management strategies are discussed separately. (See "Anesthesia for adult patients with asthma", section on 'Asthmatic patients with increased intracranial pressure' and "Evaluation and management of elevated intracranial pressure in adults", section on 'Hyperventilation'.)

SUMMARY AND RECOMMENDATIONS

●Preanesthesia consultation and optimization – Preanesthesia consultation for patients with chronic obstructive pulmonary disease (COPD) includes assessment of whether pulmonary function is optimal. Elective surgery is postponed in patients with signs and symptoms of COPD exacerbation or active upper respiratory infection, with referral to primary care or pulmonary medicine. Typically, inhaled bronchodilators (eg, beta-adrenergic agonists and anticholinergic agents) and a brief course of systemic glucocorticoid therapy are prescribed, as well as antibiotics when indicated. The time needed for patients to return to baseline after a COPD exacerbation varies; thus, duration of postponement is individualized. (See 'Preanesthesia consultation' above.)

●Risk factors for pulmonary complications – Concerns regarding general anesthesia include bronchospasm due to mechanical stimulation of the airway during laryngoscopy, endotracheal intubation or extubation, airway suctioning, inhalation of cold anesthetic gases, or, rarely, pulmonary aspiration. Other concerns include dynamic hyperinflation due to breath stacking during controlled ventilation, atelectasis resulting from reduction in functional residual capacity (FRC), and residual sedation leading to hypoventilation. (See 'Anesthetic factors' above and 'Procedure-related factors' above.)

●Preoperative medication management – Inhaled beta-agonist and muscarinic antagonist bronchodilators, as well as inhaled glucocorticoids, are continued in the perioperative period, including the usual dose on the morning of surgery, with resumption shortly after surgery. For patients with a high likelihood of adrenal suppression, supplemental glucocorticoids are given in accordance with the magnitude of the anticipated stress of the procedure (table 4). Notably, the usual morning oral dose of glucocorticoid is always administered, regardless of whether additional glucocorticoid will be given just prior to the procedure. (See 'Perioperative medication management' above.)

●Choice of anesthetic technique – Requirements for the surgical procedure and patient preferences are the primary factors guiding selection of anesthetic technique. General anesthesia is necessary for performance of many surgical procedures (eg, abdominal laparoscopic procedures, thoracic procedures, or surgical incisions involving the head, neck, or multiple extremities), and is typically selected for procedures of long duration. Monitored anesthesia care (MAC), neuraxial anesthesia, or a peripheral nerve block is selected when appropriate for the planned procedure to avoid laryngoscopy and endotracheal intubation in patients with COPD. However, these techniques are not suitable for patients who do not consent or for those with extreme anxiety, severe dyspnea when lying flat, or chronic coughing if the surgeon requires absence of movement. (See 'Choice of anesthetic technique' above.)

●Neuraxial anesthesia – For consenting patients with COPD undergoing appropriate surgical procedures, we suggest a neuraxial anesthetic technique (Grade 2C), which provides superior perioperative analgesia and decreases the risk of pneumonia and respiratory failure. (See 'Neuraxial anesthesia' above.)

●Regional anesthesia – A peripheral nerve block may be appropriate if the surgical site is peripheral and the planned procedure is of short to moderate duration. However, some brachial plexus blocks for upper extremity surgery (eg, interscalene block, supraclavicular block) paralyze the ipsilateral diaphragm by blocking the phrenic nerve, an effect may last for many hours, and may not be tolerated in patients with severe or symptomatic COPD. (See 'Regional and peripheral nerve blocks' above.)

●Monitored anesthesia care – During MAC techniques, only small, incremental doses of anesthetic agents are administered as necessary. Oxygen saturation and end-tidal carbon dioxide (EtCO₂) are continuously monitored, and supplemental oxygen is administered to maintain saturation 88 to 92 percent if necessary. (See "Monitored anesthesia care in adults".)

●General anesthesia

•Induction – For general anesthesia, most adults prefer intravenous (IV) induction, which is faster than inhalation induction, particularly in COPD patients due to ventilation/perfusion (V/Q) mismatch; either propofol or ketamine is suitable. The risk of bronchoconstriction is lower with mask ventilation or insertion of a laryngeal mask airway (LMA) compared with endotracheal intubation. (See 'Induction and airway management' above.)

•Maintenance

-Agent selection – We typically select a potent volatile inhalation agent with bronchodilatory properties (eg, sevoflurane, isoflurane) as the primary agent for maintenance of anesthesia, supplemented with small doses of an opioid (eg, fentanyl) to deepen anesthesia or suppress the cough reflex. Total intravenous anesthesia (TIVA) is a reasonable alternative. (See 'Maintenance of anesthesia' above.)

-Management of ventilation – We employ lung-protective ventilation during general anesthesia (algorithm 3). Breath stacking (ie, dynamic hyperinflation, auto-positive end-expiratory pressure [PEEP]) may occur (figure 2), causing a sudden decrease in systemic blood pressure which improves immediately when the anesthesia breathing circuit is transiently disconnected. Tension pneumothorax due to rupture of subpleural bullae also causes sudden hypotension, but without resolution when the anesthesia circuit is disconnected. (See 'Mechanical ventilation' above and "Mechanical ventilation during anesthesia in adults", section on 'Lung protective ventilation during anesthesia'.)

•Emergence – Since bronchoconstriction may occur as anesthetic depth is lightened, an aerosolized or nebulized bronchodilator may be administered shortly before emergence if more than two hours have elapsed since the last dose. Complete reversal of neuromuscular blockade is particularly important to avoid upper airway obstruction, diaphragmatic dysfunction, and impaired mucociliary clearance leading to hypoventilation in the immediate postoperative period. (See 'Emergence' above.)

●Postanesthesia care – Management in the immediate postoperative period includes resumption of bronchodilator therapy (and inhaled glucocorticoids if part of baseline regimen), use of incentive spirometry, and early ambulation. Pain control should be sufficient to facilitate deep breathing and mobilization, but hypoventilation is avoided. Noninvasive ventilation (NIV) should be readily available to treat respiratory distress and potentially avoid reintubation in patients without contraindications (table 7). (See 'Management of postanesthesia care' above.)