Conscious sedation
Editor in Chief: Liudvikas Jagminas, M.D., FACEP [1] Phone: 401-729-2419
Assessment
ASA Physical Status Classification
Assessed and recorded by Operator
- Class I: There is no organic, physiological, biochemical or psychiatric disturbance. The pathologic process for which the procedure is to be performed is localized and not a systemic disturbance.
- Class II: Mild to moderate systemic disturbance caused by the condition to be treated procedurally or by other pathophysiological processes.
- Class III: Severe systemic disturbance or disease from whatever cause, even though it may not be possible to define the degree of disability with finality.
- Class IV: Indicative of the patient with severe systemic disorder already life-threatening, not always correctable by the procedure.
An anesthesia consult should be strongly considered.
- Class V: The moribund patient who has little chance of survival but is submitted to the procedure in desperation.
If not an emergency, requires an anesthesia consult.
Patient Assessment by M.D. and R.N.
- Medical history; concurrent medical problems
- Physical assessment esp. airway, chest & cardiac
- Current medications and medication allergies
- Baseline vital signs, height, weight
- Level of consciousness, ability to cooperate
- Ability to communicate
- Ability to tolerate positioning
- General physical condition
- ASA classification (>4 requires anesthesia consult)
- “At Risk”
- Anesthesia Consult Considered
- Limited Head/Neck ROM
- Abnormal Cranio-Facial Anatomy
- Morbid Obesity
- Any other condition which might impede the procedure: sleep apnea, severe pain, problematic body habitus
- Anesthesia Consult Required
- ASA class 5
- Hx Fiberoptic Intubation
- Mallampati III
- Hx of Difficult or Failed Intubation
- “Hi Risk” : additional personnel are required
- Procedure is particularly complex
- Patient’s medical condition requires management beyond capacity of the practitioner(s)
- Anesthesia Consult Considered
Recommended Aspects in Medical History
- Abnormalities of the major organs systems
- Previous adverse experience with sedation/analgesia as well as regional anesthesia
- Drug allergies, current medications, and potential drug interactions
- Time and nature of last oral intake
- History of tobacco, alcohol or substance use or abuse
Malampati
- Airway classification:
- patient sitting upright and looking directly forward
- opens mouth and extends tongue
- Class 1: uvula, faucial pillars, soft palate visible
- Class 2 : facial pillars, soft palate visible
- Class 3 : only soft palate visible (Anesthesia consult required)
Procedure preparation
- Patients (or legal guardians in the case of minors or legally incompetent adults) should be informed of and agree to the administration of sedation/analgesia, including its benefits, risks, and limitations associated, as well as possible alternatives
- Patients undergoing sedation/analgesia for elective procedures should not drink fluids or eat solid foods for a period of time to allow for gastric emptying before their procedure
- In urgent, emergent, or other situations in which gastric emptying is impaired the potential for pulmonary aspiration of gastric contents must be considered in determining:
- The target of level sedation
- Whether the procedure should be delayed
- Whether the trachea should be protected for intubation
Preprocedure Fasting Guidelines
Ingested Material: Minimum Fasting Period* Clear liquids: 2 h Breast Formula: 4h Infant Formula: 6h Nonhuman milk: 6h Light meal: 6h These recommendations apply for healthy patients who are undergoing elective procedures
- The fasting periods apply to all ages
Inform Consent
- Must include the risks and alternatives to IVCS and the procedure
- JCAHO standards: require patient involvement in pain management
- Consent for Procedure and other procedure-specific consent forms revised to include standardized IVCS information
Personnel
Number of Personnel
- Operator :(LIP- MD or DMD)credentialed to perform the procedure and credentialed to perform IVCS. Both sets are required to perform a procedure using IVCS
- Monitor : (licensed MD, RN, DMD, PA ,NP) shall have no other significant responsibilities which would compromise her/his ability to monitor the patient
- Other: (additional personnel PRN for “High-Risk” patients/procedures)
Escentials of Training
- Operator:
- Onsite and available from 1st dose through recovery
- airway management
- pharmacology of IVCS drugs
- Understand the role of pharmacologic antagonists for opioids and benzodiazepines
- Monitor:
- airway management
- pharmacology of IVCS drugs
- monitors appropriate Physiological parameters to procedure and IVCS
- capable of assisting with resuscitative measures
- completes “Learning Module” ( revalidated annually)
Monitoring
Monitoring and Setting for IVCS
- Monitor and Document every 5-10 minutes
- Blood Pressure
- Heart Rate and Rhythm
- Risk assessment drives monitoring parameters
- Respiratory Rate: ventilation status
- Oxygen Saturation
- Sedation Scale
- Pain Scale
IVCS Setting
- Means to deliver PPV including Ambu w/ various mask sizes and airways
- Source of Suction w/ Yankauer and supplies
- Crash Cart & Defibrillator and means to contact emergency support posted
- Oxygen and O2 delivery supplies
- Blood Pressure & Stethoscope
- Cardiac Monitor w/ audible alarms
- Pulse Oximeter w/ audible alarms
- Pharmacological Reversal Agents
Monitored Parameters
At a minimum, it should be:
- Before the beginning of the procedure
- After administration of sedative-analgesic agents
- At regular intervals during the procedure
- During initial recovery
- Just before discharge
Intravenous Conscious Sedation Review(IVCS Review)
- Conducted prior to the procedure
- Assures IVCS is indicated and appropriate
- state of consciousness and medical condition
- pre-procedure consultations with appropriate specialists are strongly considered
- prep studies for the procedure and the IVCS are completed
- known allergies and sensitivity are documented
- PMH and current drug regime obtained and reviewed
- NPO for 6 hrs, except for clear liquids up to 2 hours prior to IVCS
- Medications may be taken with a sip of water
- Informed consent is validated
- Discharge plans for ambulatory patients are reviewed
- Immediately prior to the procedure; validation the the patient’s condition and the procedure plan have not changed
- Physical exam has been conducted and includes
- estimated weight
- vital signs; baseline BP, HR, RR pattern and quality
- baseline O2 saturation
- airway assessment: evaluation performed in anticipation of possible need for PPV
- head/neck rom, abnormal cranio-facial anatomy, Mallampati
- pulmonary and cardiac status
- general neurological status e.g., mental status, neurological deficits
- ASA: physical status classification
- Immediately Prior to Administration of IVCS:
- The monitor/operator assures there is documentation the initial assessment and plan has not changed
- Documented on Pre-IVCS review form by the Operator
- Pre-IVCS conducted by an NP or PA must be co-signed by an IVCS credentialed MD who will be involved with the procedure.
- The monitor obtains a baseline pre-sedation assessment
- VS, O2 sat and O2 requirements, cardiac rhythm, loc, pain scale, sedation scale, patient ability to tolerate positioning required for procedure and recovery, confirms functioning IV, patient instructed to report problems with procedure or IVCS
- The monitor/operator assures there is documentation the initial assessment and plan has not changed
IVCS Record
- Prior to the procedure the Monitor will:
- Validate that the Pre-IVCS review form has been signed and completed
- Validate a signed written consent for the IVCS and Procedure
- Conduct a pre-sedation review of the patients VS, O2 sat, sedation scale, pain scale,NPO status, airway assessment, discharge arrangements,cardiac rhythm, loc, presence of a patent IV, equipment safety check,ASA status
- During the procedure: Monitor ascertains and records pts. response to IVCS and procedure
- medications: drug name, time, dose, route, site
- pain scale ( 1-10) and sedation scale ( 0-4)
- amount and means of O2
- vital signs: BP, RR and quality, HR and level of responsiveness every 5-10 min. as warranted
- continuous cardiac monitor: ASA > 3, hx. Of cardiac/pulmonary disease
- continuous O2 stat, documented every 5-10 min.
- check patient’s head position for patent airway
- medications: drug name, time, dose, route, site
- Following the Procedure: The Monitor:
- ascertains and records physiological parameters every 10 minutes for a minimum 30 min. following the last dose of sedation
- beyond this period, if stable, document these parameters every 15 minutes until patient returns to pre-procedure state
- the patient MUST be observed for 30 min. following the procedure
- reversal agents; extend recovery at least 2 hours
Sedative/analgesic agents
IVCS Administration Guidelines
Approved by the Pharmacy and Therapeutics Committee For Use by Non-Anesthesiologists Close monitoring of Vital Signs per policy All medications can be associated with Respiratory Depression Hypotension Dizziness/Drowsiness Nausea/Vomiting
IVCS Considerations
- Certain patients may not tolerate recommended doses
- geriatric or debilitated
- history or pulmonary or cardiac disease
- history of hepatic or renal disease
- known hypersensitivity or idiosyncratic reactions
- known increased intracranial pressure
- known debilitating neurological condition
- Potential medication interactions: P450 system activation, proteins binding, acidosis
Combination of sedative-Analgesic Agents
- Combinations of sedative and analgesic may be administered as appropriate for the procedure being performed and the condition of the patient
- Ideally, each component should be administered individually to achieve the desire effect
- Appropriate management of the dose of each component to avoid complications
Titration of IV Sedative/Analgesic Medications
- Small and incremental doses of intravenous sedative/analgesic drugs until the desired level of sedation or analgesia is achieved is preferable than a single dose based on patient size, weight or age
- Incremental drug administration improves patient comfort and decreases risks
Drugs NOT Permitted for Sedation
- Etomidate - ( Amidate )
- Fentanyl Oralet - Fentanyl Lollipop
- Fentanyl Transdermal- (Fentanyl Skin Patches)
- Ketamine- Ketaject or Ketaler
- Methohexital (Brevital)
- Neuromuscular Blocking Agents
- Propofol (Diprivan)
- Thiopental
Sedative and Analgesic Medications
- Diazepam
- midazolam
- Morphine
- Fentanyl
- Synthetic opioid
- 100 times more potent than morphine
- Rapid onset of analgesia with short duration
- Known side effects include bradycardia and “stiff chest syndrome”
- Treatment: Neuromuscular Blocking Agents
- Prepare for Intubation
- Consider Narcan
- Titrate to desired effect, repeat dose every 10 minutes to Maximum dose: 3mcg/kg/hr Initial
- Initial Dose: 0.3mcg/kg - 1.4mcg/kg
- Onset: Immediate; 1-2 minutes
- Duration: 30-60 minutes
- Dosage: 25-100 ug over 3 minutes
- Reduce dose by 1/2 when given with benzos or to the elderly
- Clearance: hepatic/renal
- Precautions: bradydysrhythmias
- Contraindications: hypersensitivity
- Side Effects: muscle rigidity, bradycardia, nausea and vomiting
Reversal Agents
- Before or concomitantly with pharmacologic reversal, patients who become hypoxemic or apneic during the sedation/analgesia should:
- Be encouraged to or stimulated to breath deeply
- Receive supplemental oxygen
- Receive positive pressure ventilation if spontaneous ventilation is inadequate
- Flumazenil (Romazicon)
- Specific benzodiazepine receptor reversal agent
- Reversal of benzodiazpaine induced respiratory depression
- Administered IV only
- Onset: 1 minute Peak: 2-6 minutes
- Clinical duration :45-90 min--respiratory depression may recur!!
- Dosage: 0.2 to a max. dose of 1 mg administer in .2mg increments over 15 seconds may repeat in 45 seconds if initial response is inadequate and again in 1 min. intervals to 1mg
- Max dose: 1mg/dose and 3 mg/hr
- Clearance: Hepatic
- Administer: Large vein - decrease pain on inj.
- Monitor: Vital Signs and O2 saturation closely
- Precautions: Benzo withdrawal induced seizures, re-sedation, head trauma w/ elevated ICP, concurrent neuromuscular blockers, drug/alcohol dependant pts., tricyclic antidepressant Rx.
- Contraindications: hypersensitivity, benzo use for life-threatening conditions e.g., intracranial hypertension, status epilepticus
- Side Effects: Seizures, dizziness /agitation
- Naloxone (Narcan)
- Specific receptor antagonist for opioid effects
- Administered IV or IM
- Clinical duration 30-45 min, respiratory depression may recur!
- Administer every 2-3 minutes as needed to increase resp. rate and alertness
- Dosage: Dilute 0.4 mg ampule ( 1cc) with 9cc NS
- Administer: 1 ml increments of dilution (.04mg)
- Call for help if no response after 0.4 mg administered
- Effective ONLY for resp. depression caused by opiates
- Monitor VS closely
- Onset:1 minute
- Duration:1-4 hours (less for resp. depression) cannot reverse Naloxone
- Clearance:Hepatic
- Precautions: opiate dependence, hyper/hypotension, pulmonary edema, V. tach/fib., CVD, potential for elevated ICP
- Contraindications: hypersensitivity
- Side Effects: nausea/vomiting,hypertension, tachycardia, ventricular arrhythmia's, pulmonary edema
Drugs Modifications for AIDS Patients
- Protease inhibitors (Ritonovir, Aprotinin, Cox 2 inhibitors) alter cytochrome P-450 activity
- Reduces liver metabolism of Midazolam and Diazepam
- Increased plasma drug concentrations can occur with altered CNS effects
- Avoid benzodiazepines if possible or significantly reduce the dosage
- Lorazepam (Ativan) has a different elimination pathway. Obtain an anesthesia consult
Complications
Reasons for Complications in IVCS
- Inappropriate patient selection
- NPO status
- Patient unable to tolerate positioning
- Procedure requires more than conscious sedation
- Patient Expectation
- Unable or Unwilling to cooperate
- Pain Management
- Expanded scope and/or timeframe of procedure
- Unanticipated responses from patient or equipment
- Team members unfamiliar with equipment
- Plans for dealing with emergency situations not addressed
- Team unfamiliar with medications and typical patient response
- Unanticipated response to the procedure
- Unanticipated medication interaction
- Overmedication
- Loss of contact with the caregiver !
- Agitation, irritability, non compliance
- Airway Complications: Most common complication of IVCS
- Loss of protective airway reflexes
- Airway obstruction and apnea
- Hypoxemia and hypercarbia
- Hemodynamic instability
- Unanticipated need for a more involved procedure
Recovery Care
Recovery Care Principles
- Medical supervision of recovery and discharge is the responsibility of the operating practitioner or a licensed physician
- Recovery area should be equipped with or have direct contact with monitoring and resuscitation equipment
- Patients receiving moderate sedation should be monitored until appropriate discharge criteria are satisfied
- Level of consciousness, vital signs and oxygenation should be recorded at regular intervals
- A nurse or another individual trained to monitor patients and recognize complication should be in attendance until discharge criteria are fulfilled
- An individual capable of managing complications should be immediately available until discharge criteria are fulfilled.
Guideline for Discharge
- Patients should be alert and oriented
- Vital signs should be stable and within acceptable limits
- Use of scoring systems may assist in documentation of fitness for discharge
- Sufficient time (up to 2 h) should have elapsed after the last administration of reversal agents to ensure that patients do not become resedated after reversal effects have worn off
- Outpatients should be discharged in the presence of a responsible adult who will accompany the home and be able to report any postprocedural complication
- Outpatients and their escorts should be provided with written instructions regarding postprocedure diet, medications, activities, and a phone number to be call in case of emergency
IVCS Record
- Discharge Criteria: 10 point scale
- VS stable w/in 20% of baseline: 2pts.
- O2 sat stable w/in 2% of baseline: 2pts.
- Swallow, cough, gag reflexes present to baseline: 1pt.
- Patient alert or approp. to baseline:2pts.
- Patient able to sit/walk approp. to baseline or procedure:2pts.
- Minimal nausea and dizziness: 1pt.
- RN may discharge per criteria w/ written MD order
- A score of 8 or greater required for RN discharge
- A score of 7 or less requires the patient to be evaluated for discharge by a physician
- Separate and additional criteria for discharge related to the procedure will also apply
References
- PMID 11964611