1. Identify the anatomy, pathophysiology, and significance of thoracotomy pain.

2. Describe advantages and disadvantages of thoracic epidural analgesia (TEA) for thoracotomy.

3. Review complications associated with TEA.

4. Achieve a reduction in anxiety, agitation, pain, and delirium during the perioperative period, without inducing respiratory depression or hemodynamic compromise.

5. Determine a means of assessing the level of anxiety, agitation, and pain while in the ICU.

The Role of Epidural Analgesia in Thoracic Surgery
Michael S. O’Connor, DO, MPH, Chair, Department of Cardiothoracic Anesthesia, Institute of Anesthesia, and Staff Anesthesiologist, Cleveland Clinic, Cleveland, OH

Anatomy of thoracotomy pain: complex; inflammation (in chest wall and pleura, insults intercostal nerve; in diaphragm, affects phrenic nerve; in lung, mediastinum, and pleura, affects vagus nerve); primary problem multiple insults to intercostal nerve (eg, rib retraction, type of thoracotomy, closure of thoracotomy)

Consequences of thoracotomy pain: lung volumes reduced by 50%; leads to ineffective cough, poor inspiration, small airway closure, and atelectasis; occasionally necessary to reintubate after thoracotomy in comorbid diseases; Bromage (1975) showed use of local anesthetic in epidural space blunts spinal reflexes and improves chest wall compliance

Preemptive analgesia: study found preemptive analgesia technique with intravenous (IV) narcotics did not have predictive value; patients who had long-term pain had significantly higher visual analog pain scores, both at rest and during exertion; meta-analysis by Ong (2005) looked at efficacy of preemptive analgesia for acute postoperative pain management; techniques that show possible efficacy include epidural analgesia, local anesthetic wound infiltration, and use of nonsteroidal anti-inflammatory drugs (NSAIDs); systemic opioids and N-methyl-D-aspartate (NMDA) receptor antagonists did not show preemptive analgesic benefit; Ochroch (2002) looked at long-term pain and activity during recovery from major thoracotomy using thoracic epidural analgesia (TEA); all patients received thoracic epidural (test dose of lidocaine, 1.5%, with epinephrine) before induction; one-half then received bolus of fentanyl and bupivacaine and were continued on infusion at 8 mL/hr; other half received saline; at time of rib approximation, all patients received bolus dose of bupivacaine and fentanyl, then continued on infusion for 72 hr; excellent pain relief seen in both groups; at 1 yr, rate of postthoracotomy pain 21%; helpful to use epidural as adjunct to general anesthesia

Optimal perioperative analgesic strategy: Block (2003) looked at efficacy of postoperative epidural analgesia; meta- analysis of 100 studies found epidural analgesia better than parenteral opioids at all time points, up to 4 days after surgery

Thoracic epidural analgesia: standard for thoracic surgery; useful in smaller procedures (eg, video-assisted thoracoscopic surgery) and high-risk patients; should be placed preoperatively; labor intensive (placement sometimes causes 20- to 40-min delay in operating room [OR])

Benefits of epidural anesthesia/analgesia vs general anesthesia

Cerebral: improved postoperative cognition and reduction in stroke (not statistically significant)

Cardiovascular: statistically significant changes include reduced myocardial infarction, improved graft patency, reduced blood loss, reduced transfusion requirement, and reduced incidence of deep venous thrombosis (DVT); meta- analysis by Rodgers (2000) looked at reduction of postoperative mortality and morbidity with epidural or spinal anesthesia; overall mortality reduced 30% with use of neuraxial blockade (primarily due to reduction in cardiac complications); TEA has advantage over spinal or lumbar epidural analgesia (blocks stress of sympathetic activation; improves blood flow to ischemic myocardium)

Pulmonary: reduced pulmonary infections, reduced pulmonary embolism, reduced respiratory depression, and reduced intubation time; meta-analysis by Ballantyne (1998) looking at comparative effects of postoperative analgesic therapies on pulmonary outcome found epidural opioids had advantages (improved analgesia; reduced incidence of atelectasis) over systemic opioids; also found advantages of epidural local anesthetics over systemic opioids (increased PaO2 ; decreased risk for infections; decreased incidence of pulmonary complications)

Surgical: in study by Rigg (2002), use of epidural technique associated with 3.6% reduction in incidence of death or major complication; however, not statistically significant

Complications of TEA: involve insertion of catheter (eg, dural puncture, paresthesias) and use of analgesic agents; concerns include epidural hematoma (paraplegia rare); some researchers argue safer to perform thoracic rather than lumbar epidural; other complications related to agents used in epidural space, including local anesthetics (eg, cardiovascular collapse) and opioids (eg, pruritus, nausea, and urinary retention; risk for respiratory depression low)

Epidural contraindications: patient refusal; sepsis/infection at insertion site; coagulopathies; taking antiplatelet drugs or low molecular weight heparin (eg, enoxaparin [Lovenox]); DVT prophylaxis makes postoperative surgical period safer; study from France of serious complications related to regional anesthesia found only 2 complications (seizure and meningitis) in >5000 epidurals; adjusted complications for spinal epidural significantly higher

Multimodal analgesic strategies: since there are multiple pathways for pain transmission, use as much pharmacology as possible to act at distinct mechanisms for modulating pain transmission; use effective analgesia throughout perioperative period; minimize side effects; strategies include intraoperative and patient-controlled epidural analgesia, NSAIDs and oral acetaminophen, intercostal nerve blocks, local anesthetic wound infiltration, paravertebral nerve blocks, IV patient-controlled analgesia (PCA), IV tramadol, ketamine, dextromethorphan, and gabapentin (eg, Neurontin)

Sedation and Agitation in the Intensive Care Unit (ICU)
Steven R. Insler, DO, Staff Cardiac Anesthesiologist and Critical Care Physician, Cleveland Clinic, Cleveland, OH

Anxiety: defined as feeling of apprehension and fear, characterized by physical symptoms, eg, palpitations, sweating, feelings of stress or distress; causes include inability to communicate, excessive stimulation from continuous noise and ambient light, sleep deprivation, inadequate analgesia, and feelings of terror from diagnosis that led to patient’s being admitted to ICU

Agitation: results from extreme anxiety; inability to relax or be still; associated with feeling tense, irritable, and easily annoyed; causes include extreme anxiety, delirium, adverse drug effects, pain, metabolic disturbance, and medication withdrawal

Target: depends on acute disease processes; supportive or therapeutic interventions may be required; situation always changing; goal to have calm, easily aroused patient who maintains normal sleep-awake cycle and is able to tolerate mechanical ventilation (MV)

Therapy: goal-directed; once objectives determined, state desired level of sedation and reevaluate patient on regular basis; regimen should be written with flexibility to alter titration to desired end point

Indirect sedation assessment: hinders continuity of care; limits accurate titration of sedative agents toward therapy goals; places patient at increased risk for over- or inadequate sedation based on assessment; potentially more difficult to wean patient from MV or to optimize respiratory function

Inadequate sedation: pain; facial grimacing; unexplained tachycardia; tachypnea; hypertension; diaphoresis; tearing

Excessive sedation: patient no longer in distress, but unable to communicate effectively; moribund; difficult to arouse; may lead to delayed recovery; only recommended during complete neuromuscular blockade or open chest cardiac procedure

Relieve pain first: start sedation only after providing adequate analgesia; although opioids produce sedating effects, they do not decrease awareness, provide amnesia, or cause sedation; sedative-amnestic agents produce amnesia and sedation; benzodiazepines and analgesics optimize patient comfort, but may also cause agitation and disorientation; unrelieved pain causes inadequate sleep, leading to exhaustion and, eg, agitation, tachycardia, hypertension, increased myocardial O2 consumption, hypercoagulability, immunosuppression, persistent catabolism

Pain assessment: patient self-report optimal; other options include verbal rating score, visual analog score, and numeric rating system; surrogate may be necessary to assess pain (≈73% accurate); Anesthesiology and Critical Care Medicine (ACCM) recommends that pain assessment and response to therapy be performed on regular basis using scale appropriate for patient population and that it be documented in systematic fashion; level of pain reported must (whenever possible) be considered current standard for assessment of pain and response to therapy; ACCM recommends use of numeric rating scale; inability to communicate necessitates assessment via subjective observation of pain-related behaviors and change after therapy

Pain therapy: goal to develop individualized therapeutic plan for each patient, which is then communicated to all caregivers to ensure consistent analgesia; common agents include fentanyl, hydromorphone (eg, Dilaudid), and morphine; scheduled dosing or infusion recommended for consistent pain relief; PCA may be used in proper patient; fentanyl preferred for rapid onset and effectiveness in infusion; fentanyl and hydromorphone for hemodynamic-renal instability; morphine and hydromorphone effective for intermittent therapy, due to longer duration; NSAIDs effective in appropriate patients

Assessing sedation and agitation: structured approach; close monitoring of each patient; goal to direct titration of medications; multidisciplinary team optimal; sedation scale key component; enhances accurate and consistent medicine titration, improves understanding and communication, and reduces incidence of excessive drug use; ideal sedation scale would provide data that are simple to compute and record, accurately describe degree of sedation/agitation in well-defined categories, guide titration of therapy, and have validity, reliability, and applicability in ICU

Sedation assessment: most patients not monitored by any type of scale that would be used to guide medication delivery; 2 types of scales subjective and objective; subjective—have demonstrated usefulness in critical care setting; no gold standard established; objective—technology-based; include electroencephalography (EEG), bispectral index (BIS) monitor, and auditory-evoked potentials; originally, depth-of-anesthesia monitors

Ramsey scale: originally described in 1974; widely used; visually identifies situations of agitation or sleep; some consider it to be measure of consciousness, not sedation; lacks clear discrimination and descriptors of levels; poor validity; good reliability and interobserver agreement; divided into 6 levels, from awake to comatose

Glasgow Coma Scale: modified in 1987 by Cook and Palma; score modified for MV (cough and spontaneous respiration added); other categories include eye opening, higher function, and rates of consciousness; good reproducibility, interobserver agreement, and validated for clinical use; speaker notes, “the problem I think is it’s very cumbersome”

Sedation-Agitation Scale: described in 1999 by Riker to look at agitated adult ICU patient; reliable, high interobserver agreement, and valid in assessing agitation and sedation; provides additional information by stratifying patients into 3 categories (agitated, calm, and sedated)

Motor Activity Assessment Scale (MAAS): valid and reliable sedation scale in patient not on MV; 7 categories describe patient behavior in response to stimuli; easy to use

Richmond Agitation-Sedation Scale (RASS): monitors sedation over time; good reliability and validity; excellent interobserver reliability; first scale validated for ability to detect changes in sedation status over time; correlates well with dose of sedative/analgesic medication; valid and reliable in patient not on MV; subdivides patients into sedated or unable to be aroused by verbal or physical stimulation; easy to perform and document; wide range of scores to describe agitated, sedated, and delirious behavior; focuses on level of arousal vs content of arousal (ie, delirium)

Objective assessment: typically used with deep levels of sedation and when neuromuscular blockade masking observable behavior; uses heart rate variability, lower esophageal sphincter contractility, EEG, and BIS

BIS: scale of 0 to 100; strong agreement between recall/hypnosis and BIS index in OR, but has limitations in ICU (muscle activity may artificially elevate score; more reproducible with neuromuscular blocking agent; subjective scales more reproducible during light sedation; studies ongoing to validate utility

Guidelines from ACCM: end point established and regularly redefined for each patient; regular assessment and response to therapy documented; use of validated assessment scale recommended; objective measures of sedation have not proven useful in ICU setting

Sedation therapy: combination of midazolam and diazepam should be used for rapid treatment of acute anxiety and agitation; propofol recommended for rapid awakening or neurologic evaluation; midazolam only for short-term use; lorazepam (eg, Ativan) recommended for long-term use; essential point—optimal dose of medication requires knowledge of desired and unwanted effects; requires observation, repeated assessment, titration of dosage, and recognition that sedation needs vary; daily interruption of sedative infusions can reduce many complications in ICU; however, never interrupt sedation in patient receiving neuromuscular blockade until agent discontinued and out of system

Delirium: affects ≤80% of ICU patients; fluctuating mental status, inattention, and disorganized thinking; associated with sleep-awake cycle; hastened by reversal of day-night cycle; usually seen in patients in ICU for prolonged time; assessment—determined via Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV), clinical history, and physical examination; confusion and assessment method (CAM) more likely employed in busy ICU; treatment—neuroleptic agents (eg, haloperidol, droperidol) given initially at dose of 1 to 2 mg, then doubled every 15 to 20 min; doses >400 mg reported; prolonged QT interval may occur; follow electrocardiography (ECG); associated with ventricular arrhythmia, torsades de pointes, and neuroleptic malignant syndrome; speaker has also used atypical antipsychotics (eg, risperidone); dexmedetomidine under investigation for use in ICU; nonpharmacologic strategies include environmental modification, relaxation, music therapy, and massage

Sleep: essential component of overall health program; sleep deprivation associated with cognitive dysfunction, confusion, and delirium; patients typically permitted 2 hr sleep per day in ICU; factors leading to sleep deprivation include underlying clinical condition, drugs administered, and environmental disturbances (eg, noise, lights); sleep therapy—produce environment that promotes sleep; multidisciplinary approach required; maintain day-night cycle; α2 -agonists closest to inducing hypnotic state resembling endogenous sleep