Increasing numbers of patients are receiving short-term moderate sedation and analgesia (also referred to as conscious sedation) for invasive diagnostic procedures. Even though the anesthesiologist or attending physician assumes responsibility for IV moderate sedation, other healthcare providers may administer the drugs and monitor the patient’s response to these drugs. Advantages of moderate sedation and analgesia include short, rapid recovery; early ambulation; patient preference for light sleep and amnesia; patient cooperation during the procedure; protective reflexes remain intact; vital signs remain stable; and infrequent complications.
The American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists (2002) recommends using the term moderate sedation and analgesia rather than conscious sedation because it is a more accurate description of the goal of administering these drugs. Moderate sedation and analgesia is defined as a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained. There are two goals of moderate sedation and analgesia: (1) to allow the patient to undergo unpleasant procedures by diminishing discomfort, pain, and anxiety (while maintaining adequate cardiopulmonary status and response to verbal commands and stimulation) and (2) to immobilize the patient to expedite complex procedures that require that the patient not move, especially children and uncooperative adults. Because it is not always possible to predict how a specific patient will respond to sedative and analgesic medications, practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended.
The primary drugs used for moderate sedation and analgesia are benzodiazepines and opiates, which are central nervous system (CNS) depressants. Opiates are also used for sedation, as are some tranquilizers (droperidol); for pain relief, fentanyl and morphine are used (Chart 1.5). Combinations of drugs may be more effective than single agents in some instances. Agents must then be appropriately reduced, and there is a greater need to monitor respiratory function. IV sedative and analgesic drugs are to be given in small incremental doses. When the drug is administered orally, rectally, intranasally, intramuscularly, or subcutaneously, allow time for drug absorption before giving another dose.
Clinical Alert
Record ventilatory and oxygen status and hemodynamics before the procedure begins, after administration of sedative and analgesia, on completion of procedure, during initial recovery, and at time of discharge.
Interventions for Adult Patients Receiving Moderate Sedation and Analgesia
Preadministration
Explain the purpose of moderate sedation and analgesia before administering the medications. It is most commonly used for these diagnostic procedures: biopsies, bronchoscopy, ERCP, colonoscopy, gastroscopy, angiogram, cardiac catheterization, electrophysiologic studies, and cystoscopy. Medications may be administered intravenously or by mouth, or both.
Assess the patient’s health status, history of chronic or acute conditions, drug allergies, current medications and potential drug interactions, previous diagnostic test results, level of understanding, orientation, mental status, and ability to cooperate with the procedure. Screen and identify patients who are at high risk for development of complications: the very young; the very old; and those with heart, lung, liver, kidney, or CNS disease, marked obesity, sleep apnea, pregnancy, or drug or alcohol abuse. Patients presenting for moderate sedation and analgesia should undergo a focused physical examination, including vital signs, auscultation of the heart and lungs, and evaluation of the airway.
Explain the process and procedure and what the patient may experience (feeling sleepy, relaxed, decreased anxiety). Use a calm, caring manner. Not all providers agree on the fasting time frames, but there is an agreement that preprocedure fasting decreases risks during moderate sedation. Check your facility policy. For adults, no food or liquid should be taken for 2–6 hours before the procedure to allow for gastric emptying. For infants younger than 6 months, fast 4–6 hours (this includes milk, formula, and breast milk); clear liquids should be avoided for 2 hours before the procedure.
Before beginning the procedure, establish an IV line and keep it open with the ordered IV solution. Monitor patency of the line.
Monitor pulmonary ventilation (exhaled carbon dioxide) and apply pulse oximeter sensor especially if the patient is unable to be directly observed during moderate sedation. Monitor ECG, pulse oximetry, and patient response to verbal commands according to established guidelines before administering moderate sedation. Patient’s vital signs should be documented (before, during, and after the procedure).
Provide a safe and caring environment. A designated individual, other than the healthcare provider performing the procedure, should be present to monitor the patient throughout the procedure. In anticipation of emergency situations, have resuscitation equipment and supplies of appropriate size readily available (oxygen therapy, intubation equipment, IV fluid, reversal agents, and vasopressors).
Intra-Administration
Assess pain or discomfort and sedation levels at frequent established intervals.
Administer sedation and analgesic drugs as ordered, often in incremental doses.
Recognize physiologic effects of agents used for moderate sedation. These medications include the following, among others:
Diazepam hydrochloride
Midazolam hydrochloride
Lorazepam
Droperidol (Check with your pharmacy or institutional policy regarding use of this drug.)
Fentanyl citrate
Morphine sulfate
Monitor the IV site for infiltration, as well as the local analgesia site. Local anesthesia and sedation may cause adverse reactions.
Assess level of consciousness—responses of patients to commands during the procedure serve as a guide to their level of consciousness. If reflex withdrawal from painful stimulation is the only response, the patient is likely to be deeply sedated, approaching the state of general anesthesia.
Monitor pulmonary ventilation by auscultation of breath and observation of spontaneous respiration. Automated apnea monitoring (detection of exhaled CO2) may be used but is not a substitute for monitoring chest movement.
Be cognizant that detecting changes in heart rate and blood pressure for hemodynamics reduces the risk for cardiovascular collapse and hypoedema.
Use pulse oximetry to detect hypoxemia and decrease adverse outcomes such as cardiac arrest and death.
Anticipate and monitor for potential complications. Arrhythmias should be promptly reported and treated if necessary. Many of these medications are respiratory depressants, mandating frequent respiratory assessments. If oxygen saturation drops below acceptable levels (less than or equal to 90%), sedation may need to be held or reversed. Have IV reversal agents such as naloxone and flumazenil readily available. Supplemental oxygen therapy may be necessary until oxygen saturation levels, vital signs, neurologic response, and cardiac rhythms return to normal.
Respond to emergencies rapidly and appropriately during administration of, or recovery from, moderate sedation and analgesia.
Document all observations, including medications administered (including dosages). Record unexpected outcomes, interventions provided, and follow-up care given.
Postadministration
Monitor vital signs, ECG, pulse oximetry, ventilation, neurologic signs, level of consciousness, and patient response to verbal commands according to established guidelines.
Monitor the patient after the procedure until the patient is stable and reactive to preprocedure levels.
Provide both verbal and written posttest instructions to the patient and caregiver. Moderate sedation may not completely wear off for several hours. Patients should not:
Drive or operate power machinery or tools for at least 24 hours.
Consume alcoholic beverages or make legal decisions for 24 hours.
Smoke—if the patient is a smoker, emphasize the risks of smoking in the postsedation state (i.e., falling asleep).
Take tranquilizers, pain medications, or other medications that may interact with drugs used for sedation without first contacting the healthcare provider.
Provide instructions for posttest care and the need for contacting the healthcare provider if any unexpected outcomes should occur.
Evaluate the patient for readiness for discharge. Patients should be alert and oriented or, if altered mental status was initially present, should have returned to baseline. Vital signs should be stable and within acceptable limits. Provide a safe transport or discharge in the presence of a responsible adult.
Allow sufficient time (up to 2 hours) to elapse after the last administration of reversal agents to ensure that patients do not become resedated after reversal effects have worn off.