RCPs play an important role in monitoring patients undergoing procedural sedation and analgesia through maximal use of noninvasive technology, understanding medications, and working directly with physicians.

f02a.jpg (9204 bytes)In the past 10 years, there has been a revolution in the use of sedation and analgesia for procedures performed outside the confines of the operating room (OR).1 With the introduction of shorter-acting sedatives for sedation and opioids for pain control, specific reversal agents for both opioids and benzodiazepines, and the availability of noninvasive monitoring equipment, procedural sedation can now be safely administered in many health care settings.2 This article will describe the current status of procedural sedation and the practical aspects of sedation administration, review indications and medications for sedation, and explore the role of the respiratory care professional in this emerging field.

Definitions for Levels of Sedation
Many professional organizations have published sedation guidelines, the most prominent being the American Academy of Pediatrics (AAP),5 the American College of Emergency Physicians (ACEP),6 the American Society of Anesthesiologists (ASA),7 and the American Academy of Pediatric Dentistry (AAPD).8 Standards and guidelines set for procedural sedation should be consistent throughout the institution, regardless of where the sedation is administered.9 A patient receiving sedation in the emergency department should benefit from the same standard of care as a patient receiving sedation in the radiology department or gastroenterology unit. This means not only having the same monitoring equipment and access to emergency equipment, but also that clinicians assisting physicians with the procedure should have equivalent training. For this article, we will refer to the ASA guidelines since the administration of sedation with or without analgesia will trigger the use of anesthesia standards from the Joint Commission on Accreditation of Healthcare Organizations (JCAHO).10 In fact, JCAHO will be using the ASA guidelines as it develops new standards for procedural sedation during the year 2000.10

In 1999, the ASA revised and updated its guidelines to include a definition of the continuum of sedation that occurs when sedative and analgesic medications are administered.7 From lightest to deepest sedation, the levels are:
• minimum sedation/anxiolysis. In this state, the patient can respond to verbal commands and may have some cognitive impairment, but there is no effect on cardiopulmonary status;
• moderate sedation/analgesia. There is a depression of consciousness, but patients in this state can respond appropriately to verbal commands, either alone or in conjunction with light tactile stimulation. The patient is able to maintain an airway independently, ventilation is adequate, and cardiovascular function is usually unaffected by drugs administered;
• deep sedation/analgesia. Patients in this state are not easily awakened, but they respond purposefully (they do not simply withdraw) after repeated or painful stimulation. These patients may require assistance maintaining an airway and adequate ventilation, but normal cardiovascular status is usually sustained as long as ventilation is appropriate; and
• general anesthesia. In this state, patients experience a loss of consciousness, usually requiring ventilatory assistance, and possibly needing support of cardiovascular function.

These revised definitions replace the popular but misused term “conscious sedation,” as this level of sedation (as defined by the AAP in 1985) is insufficient for most painful procedures, especially in children. According to the ASA guidelines, most procedural sedation falls within the level of moderate sedation/analgesia although very painful procedures may require deep sedation/analgesia. However, what makes procedural sedation tricky is that it is impossible to predict with certainty how an individual patient will respond to each medication administered. A patient may end up at a level deeper than was initially intended. Therefore, clinicians participating in procedural sedation must be expert at rapid identification of cardiopulmonary complications and able to skillfully intervene to minimize any risk to the patient.

The indications for procedural sedation can vary from patient to patient, based on anxiety level and pain associated with the procedure.11 For example, one person who requires repair of a laceration near the eye may become very anxious because he or she can see the needle coming toward the eye. To keep the patient still and allow the physician to achieve the best outcome of the repair, the patient may need procedural sedation. A different patient may not experience the same level of anxiety, and therefore may not require significant sedation for the physician to perform successfully. Another variable is patient age. A young child may require procedural sedation in order to lie still for a medical imaging study that an adult handles with ease.

• Major dental procedures
• Flexible fiberoptic laryngoscopy and bronchoscopy
• Laceration repair in children
• Bone marrow aspiration
• Burn debridement/major abrasion cleaning (“road rash”)
• Cardiac catheterization
• Cardioversion (elective)
• Endoscopy
• Fracture reduction/dislocation reduction
• Interventional radiology procedures
• Thoracentesis
• Thoracotomy/chest tube placement
• Diagnostic imaging in children (MRI, CT)
• Central catheter placement
Table 1. Selected indications for procedural sedation.1

Table 1 lists procedures that typically require procedural sedation. But, rather than simply relying on a list to determine whether procedural sedation is indicated,12 the clinician is better served by considering the goals of procedural sedation and determining if a particular patient requires pharmacological intervention to meet the following goals during a procedure.13
• patient safety;
• minimizing pain and anxiety associated with a procedure;
• minimizing the patient’s motion during a procedure;
• maximizing the chance of success of a procedure; and
• returning the patient to a presedation state as quickly as possible.

Individualized care is important when determining if a patient requires procedural sedation. The patient might need an antianxiety drug, pain medicine, immobilization, simple reassurance, or a combination of these interventions. Young children will typically need pharmacological intervention more often than adults will.

The physician typically does a targeted history and physical examination before deciding to use procedural sedation. This will include an assessment of medical conditions, allergies, previous experiences with sedative and analgesic medicines or general anesthesia, cardiopulmonary assessment, and a careful assessment of the airway for any conditions that could make obstruction more likely with sedation, or make intubation difficult. Time of last oral intake is important, as it helps determine the risk of vomiting. In some cases, the procedure can be delayed to allow the stomach to empty before sedation is administered. Verbal consent should be obtained prior to the sedation.14 If the RCP is administering the medications, it is his or her responsibility to see that the assessment has been done and the consent obtained by talking with the physician and the patient (or parent or guardian) before any medication is administered that will alter the patient’s consciousness.

Safety equipment must be assembled before any medication is administered. Table 2 lists the minimal equipment needed at the bedside when procedural sedation is administered.3

• Bag-valve-mask devices of various sizes
• Oxygen source, with ready access to tank backup
• Oxygen tubing, nasal cannula, nonrebreather mask
• Oral airways, various sizes
• Suction source with Yankauer tip and suction catheters
• Intravenous supplies, fluid administration and flushing intermittent infusion device (saline lock)
• Adequate supplies of medications, especially reversal agents, so the RCP does not have to leave the patient to get additional medications
• Crash cart with defibrillator and airway management supplies (laryngoscope, endotracheal tube, etc) if not at the bedside, immediately available.
Table 2. Equipment for procedural sedation.

Monitoring Personnel
The first element of ensuring a good outcome during procedural sedation is assembling a skilled clinical team that works well together. The physician is one team member; the other may be another physician, registered nurse, trained monitoring specialist, or RCP. Traditionally, procedural sedation has been administered by a physician and a registered nurse. The physician typically assesses the patient for appropriateness for procedural sedation, orders the medications and oversees their administration, and then performs the procedure. The registered nurse is responsible for continuous patient monitoring throughout the procedure and during recovery. Since the primary physician will be focusing on the procedure to be performed, the teammate must be expert at monitoring the patient’s cardiopulmonary status, promptly detecting changes that may indicate a deterioration in the patient’s condition, and intervening appropriately to maximize patient safety. In addition, state laws (usually state practice acts) must be consulted to assure that the clinical teammate is legally permitted to administer intravenous medications used during procedural sedation. There must be continual communication between the physician and the clinical partner about the patient’s condition, whether additional medication is indicated, and the level of sedation and analgesia achieved at any given time.

The RCP assisting the physician should be particularly alert for the most frequent complications that occur with procedural sedation and know how to intervene immediately if any of these is detected1:
• respiratory depression/hypoventilation (can occur with all opioids and sedatives, and a synergistic effect can occur when the drugs are used in combination);
• apnea;
• partial or total airway obstruction (secondary to loss of upper airway musculature tone or relaxed tongue flopping back and occluding the posterior pharynx);
• emesis (can occur with all procedural sedation medications).

Patients are at the highest risk for developing complications during the 5 to 10 minutes following intravenous medication administration and right after the procedure is finished, when the patient’s body is no longer stimulated by the activity associated with the procedure.1

There are two elements of patient monitoring during procedural sedation—looking at the patient and watching patient monitors. The RCP should have a direct view of the patient’s face, mouth, and chest wall motion. If possible, the team should work together to position sterile drapes (if used) to maximize the visualization of the patient.

In addition to continuous monitoring, the RCP will document the medications administered, the patient response, the interventions performed, and vital signs. He or she will be the first to intervene if the patient develops any of the complications noted above. The RCP should have no other patient care responsibilities except focusing on the patient undergoing the procedure. Respiratory rate, blood pressure, and heart rate should be measured and recorded, at minimum, before the procedure starts, after a drug is given, when the procedure ends, and during the recovery period.1 Oxygen saturation and level of consciousness should also be routinely documented. In many settings, these parameters are continuously monitored and recorded on special flow sheets every 5 minutes. The time interval for recording vital signs will vary according to the level of sedation.3 In any case, the RCP should follow established policies and procedures in the setting in which the procedural sedation is being administered.

Pulse Oximetry
Continuous pulse oximetry monitoring (oxygen saturation and heart rate) with both visual and audible alarms is mandatory during procedural sedation.1,5,8 If the pulse oximetry probe is placed on the finger, it should be on the arm with the IV, opposite the blood pressure cuff. During blood pressure cuff inflation, arterial flow is interrupted, and pulse oximetry readings will be lost during that time; any IV infusion will stop as well.

The clinician responsible for patient monitoring must thoroughly understand the operation of pulse oximetry and how to interpret the values. Many clinicians erroneously believe that pulse oximetry reflects a patient’s ventilatory status when, in reality, it only measures oxygenation. Fortunately, RCPs have a thorough education in operation and interpretation of pulse oximetry, so this error is less likely to be made by an RCP monitoring a patient receiving procedural sedation. A patient’s ventilation may be depressed even with normal SpO2 values, particularly if the patient is receiving supplemental oxygen during procedural sedation. According to the ASA, the literature supports the use of supplemental oxygen during sedation/analgesia to reduce the risk of hypoxemia, but it emphasizes that this practice will delay the detection of apnea by pulse oximetry.14 This is one reason that direct observation of the patient and frequent measurements of respiratory rate are so important. However, the best way to assess patient ventilation is with capnography.

Capnography is the only direct, noninvasive way to measure a patient’s ventilatory status. Sidestream capnographs, configured for use in nonintubated, spontaneously breathing patients (using a nasal cannula for sampling), can measure end-tidal CO2 and respiratory rate on a breath-to-breath basis. Since 1989, capnography has been the standard of care for continuously monitoring patients under general anesthesia in the OR.15 In 1999, the ASA revised the standards for basic anesthetic monitoring to state that all patients undergoing general anesthesia must have continuous capnography monitoring.16 As a result, a uniform standard now applies to all anesthesia care (intubated and nonintubated patients, in and out of the OR) when the patient is under general anesthesia. The mandatory use of capnography applies whenever drugs are administered that interfere with protective airway reflexes, such as when deep sedation/analgesia is administered. For example, even though moderate sedation/analgesia is the typical level of procedural sedation, it is insufficient for a closed reduction of a displaced and severely angulated fracture of both bones in the forearm of a child; in such a case, deep sedation/analgesia is usually required.

Since the late 1980s, the JCAHO standards have consistently stated that when anesthetic agents capable of interfering with airway integrity are given outside of the OR, the same standards for level of care and monitoring must be used as in the OR. In clinical practice it is often difficult to differentiate deep sedation/analgesia from general anesthesia once the patient is unconscious. It may be difficult to assess whether the patient’s protective airway reflexes are still functioning. The JCAHO and the AAP clearly state, “Deep sedation and general anesthesia are virtually inseparable for the purposes of monitoring.”5,9 Just as capnography is mandated for use in the OR in this clinical situation, it is now also required outside the OR when a similar level of sedation/analgesia is achieved. The new ASA standards in conjunction with JCAHO and AAP guidelines mandate the use of capnography for patients who are deeply sedated (deep sedation/analgesia) or rendered unconscious during procedural sedation.

Improvements in capnography technology mean that this monitoring is easy to use and reliable. Historical problems with accuracy during sidestream sampling via nasal cannula in children have recently been solved by new low-flow technology.17 A sidestream capnograph with nasal cannula can be placed on the patient prior to medication administration to establish a baseline. Readings from the capnograph can be displayed in both digital and waveform configurations, and a knowledgeable clinician watching the capnogram can immediately identify changes in waveform that could indicate hypoventilation due to oversedation, or loss of the waveform indicating apnea. Capnography has been clearly shown to provide the earliest warning of respiratory depression and apnea, long before changes in pulse oximetry occur.18-20

Because RCPs are knowledgeable and experienced with exhaled CO2 monitoring, they are the ideal health care professionals to advocate the use of capnography as a routine part of monitoring patients undergoing procedural sedation. The RCP is also the ideal clinician to teach registered nurses and physicians involved in procedural sedation about the importance and value of capnography.

Expanding the Role of the RCP
Since the critical aspect of patient care during procedural sedation is monitoring cardiopulmonary status and intervening if complications occur, there is no reason a skilled RCP should not be the person responsible for patient monitoring and assisting with interventions if sedation levels inadvertently compromise the patient’s airway or ventilation. RCPs’ background and experience in airway and ventilatory monitoring and management make them ideal partners with the physician during procedural sedation. RCPs have naturally been thought of as the monitoring clinician and assistant during bronchoscopy and other pulmonary procedures, but they do not have to be limited to that role as long as their state practice act allows them to administer intravenous medications used during procedural sedation.

There are essentially two categories of medications used during procedural sedation: those used to sedate the patient and those used to relieve pain.4 It is important for the RCP to keep in mind that sedative agents such as midazolam do not provide pain relief. Therefore, analgesics such as morphine or fentanyl are used together with sedation for painful procedures. An RCP who takes on the responsibility of monitoring a patient undergoing procedural sedation must understand the pharmacology of the medications being administered. Midazolam is the most common sedative used in both adults and children. Fentanyl is a popular analgesic for procedural sedation because it has a faster onset and shorter duration than morphine, and it does not stimulate the histamine release that is seen with morphine and meperidine. Morphine and meperidine are more commonly used when longer-term pain relief is required, such as procedures lasting longer than 45-60 minutes. Ketamine is a dissociative agent limited to use in children because adults can have disturbing hallucinations and become agitated as they emerge from sedation.

The best approach to medication administration is to use small doses and titrate drug dosing to achieve the desired patient response while reducing the risks of overmedication. For a brief overview of common medications used for procedural sedation and analgesia, see Table 3. For a more detailed discussion of all aspects of procedural sedation, including medications and a discussion of the use of these agents in children, please refer to the book cited in reference four.

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Reversal agents can be used for severe hypoventilation or apnea. But the RCP must thoroughly understand the effects of acute reversal of opioid-induced analgesia, including severe pain, tachycardia, and hypertension. The ASA recommends that, before administering a reversal agent to treat respiratory depression, the clinician should encourage or stimulate the patient to take deep breaths. Should this be ineffective, administer positive pressure ventilation and supplemental oxygen if spontaneous breathing is inadequate while the reversal agent is being prepared and administered.14 If reversal agents are given, the patient must be observed long enough to assure sedation or respiratory depression does not recur.

Discharging the Patient
Patient monitoring must continue until the effects of the medication and the risk of airway obstruction have passed. Many hospitals have scoring systems; a patient is assessed in areas such as motor activity, respiration, oxygenation, level of consciousness, and vital signs. Once a certain score is achieved, the patient can be considered for discharge.21 Critical elements for discharge include:
• airway and vital signs are stable; and
• patient is alert and mental status has returned to baseline.

If the patient is going home instead of being discharged to a hospital unit, the patient must have reliable transportation, must be observed by a responsible adult, and must be instructed not to make any important decisions, operate machinery, play sports, or try to drive until the following day. Furthermore, the patient should abstain from alcohol consumption for at least 24 hours to avoid any interaction with medications administered.

Procedural sedation is becoming more common as newer drugs and noninvasive monitoring devices allow procedures to be carried out safely in a variety of settings. This is a significant advance in the quality of patient care. Procedures that were once frightening and painful can now be carried out with appropriate sedation and analgesia so that the patient is comfortable. Since airway compromise and hypoventilation are two of the greatest risks for patients receiving sedation and analgesia, the RCP is an ideal health care professional to monitor patients undergoing these procedures. A thorough knowledge of medications, maximal use of noninvasive monitoring technology by the RCP, and a collaborative team approach with the physician will contribute to positive patient outcomes.

Baruch Krauss, MD, EdM, is an instructor in pediatrics at the Harvard Medical School, and on the faculty of the Division of Emergency Medicine, Children’s Hospital in Boston. Patricia Carroll, RRT, RN, MS, is an adjunct member of the faculty for the respiratory care program at Manchester Community College, and is a per diem, board-certified emergency nurse who administers procedural sedation in her practice at Manchester Memorial Hospital, both in Manchester, Conn.

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