Moderate Sedation/ Analgesia (Conscious Sedation) Anuradha Patel M.B.B.S., M.D., D.A., F.R.C.A. ( I ), D.A.B.A. Assistant Professor, Department of Anesthesiology and Perioperative Medicine UMDNJ, Newark
Introduction These guidelines are designed to be applicable to procedures performed in a variety of settings by practitioners who are not specialists in anesthesiology.The purpose of these is to allow clinicians to provide their patients with the benefits of sedation /analgesia, while minimizing associated risks.These guidelines are intended to be general in their application and broad in scope.
Depth of Sedation Minimal Sedation(Anxiolysis) - is a drug induced state during which patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilatory and cardiovascular functions are unaffected.
Depth of Sedation Moderate Sedation/Analgesia (Conscious Sedation) - is 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.
Depth of Sedation Deep Sedation/Analgesia - is drug induced loss of consciousness during which patients cannot be easily aroused but respond purposefully* following repeated stimulation. The ability to independently maintain ventilatory function is often impaired.Patients may require assistance in maintaining a patent airway and positive pressure ventilation may be required. Cardiovascular function may be impaired.
Depth of Sedation General Anesthesia - is a drug induced loss of consciousness during which patients are not arousable, even by painful stimulation. The ability to independently maintain ventilatory is often impaired. Patients often require assistance in maintaining a patent airway, and positive pressure ventilation may be required. Cardiovascular function may be impaired.
Depth of Sedation • Protective airway reflexes-includes the ability of an individual to counteract noxious events, especially to defend breathing passages against foreign material. • Reflex withdrawal from a painful stimulus is NOT considered a purposeful response • Sedation is a continuum, it is not always possible to predict how an individual will respond. • Practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended.
Radiology Department Medical Special Procedures Dental Clinic Emergency Department Progressive Care Units Procedure Unit E-Yellow Critical Care Units Echocardiology Lab Cardiac Catheterization Lab Clinics (Audiology, Neurology) Pre-operative holding area Locations of M.S./Analgesia
Patient Evaluation • History/ Physical exam • Airway evaluation • Abnormalities of the major organ systems • Previous adverse experience with sedation • Drug allergies, current meds.,potential interaction • Focused physical exam- vital signs, auscultation of heart and lungs, evaluation of the airway • NPO status • Lab data
Patient Evaluation Airway Evaluation Mallampati Classification • Relates tongue size to pharyngeal size • Performed with the patient in the sitting position, the head held in a neutral position, the mouth wide open, and the tongue protruding to the maximum • May vary if the patient is in the supine position (instead of sitting) • If the patients phonates, this falsely improves the view. • If the patient arches his or her tongue, the uvula is falsely obscured.
Patient Evaluation Airway Evaluation Mallampati Classification Class I = visualization of the soft palate, fauces, uvula, anterior and posterior pillars.Class II = visualization of the soft palate, fauces and uvula.Class III = visualization of the soft palate and the base of the uvula.Class IV = soft palate is not visible at all.
ASA Physical Status • Class I- normal, healthy • Class II- mild systemic disease • Class III- severe systemic disease, e.g. HTN COPD, • Class IV-severe systemic disease that is a constant threat to life, e.g. unstable angina • Class V- moribund patient not expected to live with or without the procedure
ASA class III or higher Airway abnormalities Morbid obesity Sleep apnea Previously failed sedation Major allergy or anaphylactic reaction Complex procedure Prolonged sedation needed New procedure Unusual position Unusual location Patient EvaluationWhen an anesthesiologist or other specialist may be needed.
Pre procedure preparation • Informed consent • Pre op fasting • Clear liquids 2h • Breast milk 4h • Infant formula 6h • Milk 6h • Light meal 6h
Equipment • Self inflating bag and mask • Oxygen – 2 outlets • Suction ( working ) • Pulse oximeter, ECG monitor, BP. Monitor • ? Capnometer • Pharmacologic antagonists • Emergency equipment – airway kit (age appropriate) crash cart, defibrillator
Monitoring and Documentation • Pre-procedure -V.S., SpO2 • Procedure -Continuous SpO2, E.C.G. -V.S. q 5 min. -L.O.C. q 5 min.(level of consciousness) • Post Procedure -Continuous SpO2, V.S. q 5 min. for 15 min., then q 15 min. until discharge criteria met
Personnel • The minimal number of available personnel should be two: The operator (performs procedure) The monitor (administers drugs, monitors airway and vital signs. The second individual may assist with minor interruptible tasks. Both personnel must be credentialed in Moderate Sedation/ Analgesia
Personnel Personnel who can administer Moderate Sedation/ Analgesia or monitor a patient, include: - A physician, or dentist who has been credentialed Under the supervision of the above, the following persons may administer M.S. - CRNA, or a student CRNA, - resident physician or resident dentist -registered nurse, under special situations.
Training of Personnel • Individuals responsible for patients should understand the pharmacology of agents used for sedation and antagonists for opiates and benzodiazepines. • Individuals monitoring patients should be able to recognize associated complications. • One individual capable of estabilishing a patent airway and positive pressure ventilation should be present. • All personnel must be ACLS certified.
Discharge Criteria Patients will be discharged according to the Aldrete score. The patients must have a score of ten. Aldrete score is printed at the end of the Moderate sedation/Analgesia record Patients who receive reversal agents need to remain in the procedure area for at least one hour after the last dose.
Meperidine (Demerol) Morphine Fentanyl (Sublimaze) Ketamine Diazepam (Valium) Midazolam (Versed) Droperidol (Inapsine) Phenobarbital Naloxone (Narcan) Flumazenil (Romazicon) DrugsDrugs commonly used for M.S.
Drugs Drugs EXCLUDED for M.S./ Analgesia by non-anesthesia staff are: • Sodium Thiopental • Propofol • Brevital (metho hexital) • Etomidate • Sufentanil • Remifentanil
Combinations of Drugs • IV.drugs should be given in small, incremental doses, titrated to end points of analgesia/sedation. • Allow time for onset before repeating • Benzo. and opiates have synergistic effects • Non IV routes, eg. Oral,rectal,im.,tm.-allow adequate time for absorption. Repeat doses not recommended(unpredictable absorption)
Synergy • Effects of Benzodiazepine and Opiate are additive (synergistic) • For example, 2 mg. Midazolam or 10 mg. Morphine equals no apnea • 1 mg Midazolam plus 5 mg morphine equals apnea
Basic Considerations • Low cardiac output equals slow onset • Consider the age of the brain • Consider the physical condition of the patient • What effect is desired? • Is post-procedure pain control needed? • When in trouble, back out • Titrate drugs to effect, wait for onset.
Reversal agents • Specific antagonists, naloxone/flumazenil should be available • May be administered if apnea or hypoxemia develops, but routine use is strongly discouraged. • Patients need to be observed longer in recovery (at least 2 hrs.) if reversal agents are used.
Opiates • Dose-dependent binding to opioid receptors (especially mu) leads to: • Analgesia • Sedation • Respiratory Depression • Side effects: • Nausea/vomiting • Miosis • Decreased Peristalsis
Morphine • Average Dose: 5-15 mg • Incremental Dose: 2.5 mg • Time Between Doses: 5-10 min • Onset Time: 5-10 min • Duration of Effect: 3-4 hrs • Paradoxical Reaction • Pruritis • Anaphylactoid Reaction • Active Metabolites
Meperidine (Demerol) • Average Dose: 50-150 mg • Incremental Dose: 25 mg • Time Between Doses: 5 min • Onset Time: 3-5 min • Duration of Effect: 2-3 hrs • Caution: Not used with MAO Inhibitors, Antidepressants, Antiparkinsonian drugs • Remember “Libby Zion” • Active Metabolite can accumulate with renal dysfunction
Benzodiazepines • Enhance GABA transmission in CNS • Most are lipid soluble only (except midazolam) • Effects: • Amnesia • Anticonvulsant • Anxiolytic • Behavioral disinhibition • Muscle relaxant
Diazepam • Average Dose: 5-20 mg • Incremental Dose: 2.5 mg • Time Between Doses: 2-3 min • Onset Time: 1-2 min • Duration of Effect: 0.5-2 hrs • Several active metabolites prolong effects • Elimination t1/2 15-21 hrs
Midazolam (Versed) • Average Dose: 1-5 mg • Incremental Dose: 0.5-1 mg • Time Between Doses: 3-5 min • Onset Time: 3-5 min • Duration of Effect: 0.5-2 hrs • Water and lipid soluble • Active metabolites, which are less potent • Elimination t½; 2-4 hrs
Diphenydramine • Sedating antihistamine with anticholinergic properties • PO/IV/IM • Maximum sedative effect 1-3 hrs, duration; 4-7 hrs • Elimination t1/2: 2-8 hrs
Fentanyl (Sublimaze) • Average Dose: 0.025-0.15 mg • Incremental Dose: 0.025 mg • Time Between Doses: 2-3 min • Onset Time: 1-2 min • Duration of Effect: 0.5- 1 hrs • Elimination t1/2: 3.1-6.6 hrs • May cause muscle rigidity
Naloxone (Narcan) • Reversal of opiates • Side effects: • Pain • Hypertension • Tachycardia • Ventricular dsyrhythmias • Pulmonary Edema • Re-narcotization –Delayed respiratory depression
Naloxone (Narcan) • Average Dose: 0.4 mg • Incremental Dose: 0.04 mg • Time Between Doses: 2-3 min • Onset Time: 1-2 min • Duration of Effect: 0.5-1 hrs
Flumazenil (Romazicon) • Average Dose: 1 mg • Incremental Dose: 0.2 mg • Time Between Doses: 1 min • Onset Time: 1-2 min • Duration of Effect: 0.5-1.5 hrs • Resedation • Seizures
Performance Improvement • All departments are responsible for PI activities related to moderate sedation • Data collection monthly, quarterly reporting of complications on 6 PI indicators • All complications must be reported to Department of Anesthesiology PI representative A copy of the record needs to be sent to Dr. A Patel • Moderate sedation data is presented at the Invasive Procedure Committee and Hospital PI committee
P.I. Indicators • Respiratory complications- need for oral airway, bag mask ventilation, intubation etc. • Cardiovascular complications- hypotension, arrythmias, etc. • Use of reversal drugs • Admission to hospital,if outpatient • Pre sedation evaluation done • Discharge criteria documented