Procedural Sedation in the Emergency Department Deon Stoltz

Objectives What does it mean What needs to be considered. What do we normally use it for. Review commonly used agents Briefly discuss alternatives to PSA

Overview DISCLAIMER…. This is a very simplified overview of a complex topic. It is not a substitute for in-depth research, background knowledge and training.

What is Procedural Sedation? To reduce patient anxiety and awareness To facilitate a painful medical procedure Patient maintains their airway & breathing - a.k.a “conscious sedation” “deep sedation”

Procedural Sedation Positives Negatives Avoids the discomfort associated with local or regional anaesthetic techniques. Doesn’t affect anatomy Relatively simple technique Negatives Consumes resources General anaesthesia in the ED is frowned upon…

The goals of PS To consider patient safety & welfare the first priority. To provide adequate analgesia, anxiolysis, sedation and amnesia during the performance of painful diagnostic or therapeutic procedures in the ED. To minimize the adverse psychological responses associated with painful or frightening medical interventions. To control motor behaviour that inhibits the provision of necessary medical care. To return the patient to a state in which safe discharge is possible.

How low should you go? Depth of Procedural Sedation Minimal Sedation (Anxiolysis) Moderate Sedation/Analgesia Deep Sedation/Analgesia General Anaesthesia Normal LOC ASA/Joint Commission of Accreditation of Healthcare Organizations – Definitions of Levels of Sedation Minimal sedation: normal response to verbal commands. Ventillatory & CV function unaffected. Moderate sedation: pt responds to verbal commons +/- light tactile stimulus. No interventions required to maintain airway. Spont resp. CV function maintained. Deep sedation: pt cannot be aroused, but responds purposefully to repeated or painful stimulation. May require assistance maintaining a patent airway. Spont vent may be inadequate. General anaesthesia: Pt is unarousable. Patient typically requires assistance maintaining an airway +/- PPV.

Uses Reduction of dislocations: shoulder, elbow, hip, patella, ankle Reduction of fractures: wrist, ankle washout compound fracture Paediatric injuries: wound inspection, closure, suturing Abscess I&D

Considerations for PS in the ED Patient Agent Environmental

Case – Mr. F. B.

Case A 40 yo man presents with a painful, swollen right wrist after a fall. You do an x-ray…

So what about our patient? Allergies: Eggs Medications: Enalapril Salbutamol Flovent Past Medical History: Asthma Obstructive sleep apnea Hypertension DM II Last Meal: 30 minutes ago Events: Patient came immediately to the hospital after falling.

To sedate or not to sedate… 86 yo female with a dislocated hip Allergies: NKDA Meds: Metoprolol Nitroglycerin patch Enalapril Lasix ASA Atrovent Last meal: NPO for 4 hours PMHx: MI x 2 (multi-vessel CAD) Angina with minimal activity PVD HTN CVA CRF Events: Pt felt a pop while trying to get up from a chair. CAD… Limited ability to tolerate hypotension

To sedate or not to sedate… 22 yo intoxicated male with an ankle fracture Allergies: NKDA Meds: unknown PMHx: unknown Last meal: Smells like EtOH Unknown Events: No one really knows Aspiration & airway reflexes: Will he protect his airway? No idea of NPO status Increased risk of aspiration Consent Double doctor is possible Consider timing of reduction

To sedate or not to sedate… 28 yo female with a fractured wrist What risks are associated with sedation during pregnancy? Difficult intubation Difficult BVM Increased risk of aspiration

Patient Assessment The AMPLE history Physical Exam Allergies Medications Past medical history Last meal Events before & after the incident Physical Exam Airway assessment Respiratory exam Cardiovascular exam

ASA Physical Status Classification Healthy Patient Mild systemic disease – no functional limitation Severe systemic disease – definite functional limitation Severe systemic disease that is a constant threat to life Moribund patient that is not expected to survive with the operation Low inter-observer reliability.

“It’s only a little chest pain” ASA Scores & PSA The ASA classification is not validated outside of the OR. Malviya et al showed an increased risk of adverse sedation-related events in paediatric patients with an ASA > 2. The ASA was developed to help identify patients at risk of developing complications as a result of undergoing general anesthesia. ASA: No formal support by emergency medicine associations; Supported by the American society of anestheologists

“The patient’s ASA status should be determined “The patient’s ASA status should be determined. For non-emergent procedures, ED sedation and analgesia should be limited to ASA class 1 or 2 patients.” Class B, Level III Procedural sedation and analgesia in the emergency department Canadian Consensus Guidelines The guidelines go on to say that for ASA III-IV patients, anesthesia should be consulted and OR management should be considered. ASA status was not addressed in the American guidelines.

The Last Supper Fasting & PSA ANZCA recommendations for healthy elective GA patients: 2 h NPO for liquids 6 h NPO for solids The risk of aspiration during PSA is extremely low. There is no evidence that fasting improves outcome during procedural sedation and analgesia. One large paediatric study of ED procedural sedation showed no increase in the number of adverse events in patients that were not fasting. In addition, the ASA indicates that there is no role for the use of antacids and gastric motility agents to prevent aspiration during elective GA in healthy patients. The ACEP guidelines apply this recommendation to ED PSA patients, while the Cdn guidelines recommend their use in patients who do not meet NPO criteria. Green proposes a number of reasons why the the ASA guidelines should not be generalized to ED PSA Aspiration is most likely to occur during airway manipulation – this should not be happening during PSA. PSA is typically performed in younger patients. The risk of aspiration is higher in older patients. Most agents used during PSA are not pro-emetic, unlike the gases which are commonly used in the OR. Ideally, PSA should be in the range of moderate sedation with intact airway reflexes The use of dissociative amnestics (ketamine) theoretically reduces the risk of aspiration because airway reflexes are “intact”

Starved for how long…? Controversial. Probably not as rigid as anaesthetic guidelines for GA... Depends on degree and duration of sedation Starship CED paediatric guideline: Clear fluids: at least 2 hours Non-clear fluids and solids: at least 4 hours

PATIENT SELECTION Can you hold the fort if something goes wrong? BREATHING & CIRCULATION: Lung disease? Stable cardiac status? BP stable? Medications Allergies (e.g. watch out for soy, eggs: Propofol)

Airway Assessment Can you bag? Can you intubate?

Predictors of Difficult BVM Ventilation Beard Obesity Old (age > 55 yrs) Toothless Snores Langeron O, Masso E, Huraux C, et al. Prediction of difficult mask ventilation. Anesthesiology. 2000; 92:1229-36.

The LEMON Method of Airway Assessment Look for external characteristics known to causes problems with BVM or intubation. Evaluate the 3-3-1 Rule: Mouth opening > 3 fingers Hyoid – chin distance > 3 fingers Anterior low jaw subluxation > 1 finger Mallampati Score Obstruction – any pathology within or surrounding the upper airway Neck Mobility - full flexion & extension

Considerations for PS in the ED Patient Agent Environmental

The Perfect Drug Provides adequate sedation and analgesia for: Patient comfort Easy completion of the procedure Maintains airway reflexes Does not affect hemodynamics Does not affect respiratory function

Commonly Used Agents Propofol Fentanyl Ketamine Midazolam

Commonly Used Agents Propofol Category Sedative-Hypnotic What is it? 2,6-diisopropofol, an alkylphenol oil in an emulsion How does it work? Potentiates GABA activity How much do you need? Starting dose of 0.5 - 1 mg/kg Actual half-life of propofol is 4-7 hrs Clearance is independent of renal or liver function and is not affected by renal or hepatic disease. Onset is one arm-brain circulation with peak affect at 90-100 s. Anti-emetic properties

Commonly Used Agents Propofol What else does it do? CNS: Mild analgesic properties; euphoria CVS: Myocardial depressant; vasodilation Resp: Respiratory depressant GI: Antiemetic MSK: Myoclonus What does the body do with it? Rapid redistribution Hepatic and extrahepatic metabolism

Commonly Used Agents Propofol Pros Shown to be safe for ED PSA use Rapid onset and recovery Cons Must be combined with an analgesic agent May cause apnea & loss of airway reflexes Myocardial depressant and vasodilator Symington and Thakore conducted a review of the safety of using propofol for procedural sedation in the ED and concluded that while the rate of “minor” adverse events (including transient hypoxia) was similar to other agents, the drug was overall very safe and offered advantages over other agents.

Commonly Used Agents Fentanyl Category Analgesic agent What is it? Synthetic opioid How does it work? Decreases conduction along nociceptive pathways and increases activity in pain control pathways in the brain. How much do you need? Starting dose of 1-2 mcg/kg Doses > 5 mcg/kg bolused rapidly are required to cause chest wall rigidity. Rigidity is managed with paralysis or reversal agents. May cause coughing in 50% of patients. Peak effect in 2-3 min

Commonly Used Agents Fentanyl What else does it do? CNS: Euphoria (or dysphoria) Resp: Respiratory depressant; chest wall rigidity CVS: May decrease HR GI: Decreased motility What does the body do with it? Hepatic metabolism (inactive metabolite) Renal excretion

Commonly Used Agents Fentanyl Pros Good hemodynamic stability Rapid onset and recovery Cons Must be combined with an amnestic agent May cause bradycardia May cause chest wall rigidity May cause apnea & loss of airway reflexes Cardiology study using high dose fentanyl for cardiac surgery – patients were hemodynamically stable and pain free.

Commonly Used Agents Midazolam Category Amnestic What is it? Benzodiazepine How does it work? Bind to benzodiazepine receptors which up- regulate GABA activity How much do you need? 0.02 – 0.1 mg/kg IV Use with caution in patients with renal failure b/c of potential buildup of metabolite.

Commonly Used Agents Midazolam What else does it do? CNS: Anxiolysis CVS: Slight decrease in PVR & decreased contractility. Resp: Respiratory depression What does the body do with it? Hepatic metabolism (active metabolite) Renal excretion

Commonly Used Agents Ketamine Category Dissociative Amnestic What is it? Derivative of phencyclidine with some opioid properties. How does it work? Stimulates the limbic system while inhibiting the thalamus & cortex (dissociation) Binds to NMDA and opioid receptors Metabolite (norketamine) has 20-30% less activity than ketamine Onset within 30 s of administration (IV) Distribution half life is 11-16 minutes (two compartment metabolism)

Commonly Used Agents Ketamine What else does it do? CNS: Emergence reactions CVS: Increased contractility, HR and PVR through sympathetic stimulation. Direct myocardial depressant. Resp: Laryngospasm, bronchodilation, increased secretions What does the body do with it? Hepatic metabolism Renal excretion

But won’t it give him nightmares? Ketamine & Emergence Reactions Frequency is reported to be anywhere from <1% to 50% in adults. Treatment with benzodiazepines is the most effective way to prevent emergence reactions. Emergence reaction: Anxiety, nightmares, hallucinations & delirium while waking up Ketamine is extensively used in developing countries with great success. Evidence for benzos is debateable – several peds trials show no benefit. Anecdotally, some people will wait for signs of emergence before giving midazolam while others give it with ketamine. Two trials from the 70’s show a reduction in the incidence of emergence reactions when adult patients were pretreated with midazolam

Commonly Used Agents Ketamine How much do you need? 1 – 2 mg/kg IV How much midazolam? 0.7 mg/kg given at the time of ketamine injection. Several authors pointed out that this dose of midazolam may be higher than required to prevent emergency reactions.

Mix & Match Commonly used combinations: Propofol + Fentanyl Fentanyl + Midazolam Propofol + Midazolam + Fentanyl Ketamine + Midazolam Combinations of propofol + fentanyl, fentanyl + midazolam etc lead to synergistic effects on the cardiovascular system. This results in greater than expected amounts of hypotension, which is tolerated in the young health individual, but may be problematic in someone with less reserve. Midazolam may decrease the rate of ketamine metabolism, resulting in greater duration of sedation.

How low should you go? Depth of Procedural Sedation Minimal Sedation (Anxiolysis) Moderate Sedation/Analgesia Deep Sedation/Analgesia General Anaesthesia Normal LOC ASA/Joint Commission of Accreditation of Healthcare Organizations – Definitions of Levels of Sedation Minimal sedation: normal response to verbal commands. Ventillatory & CV function unaffected. Moderate sedation: pt responds to verbal commons +/- light tactile stimulus. No interventions required to maintain airway. Spont resp. CV function maintained. Deep sedation: pt cannot be aroused, but responds purposefully to repeated or painful stimulation. May require assistance maintaining a patent airway. Spont vent may be inadequate. General anaesthesia: Pt is unarousable. Patient typically requires assistance maintaining an airway +/- PPV.

Considerations for PS in the ED Patient Agent Environmental

PREPARATION Prepare for the worst…. What can go wrong? Unexpected drug reaction or anaphylaxis Vomit and aspirate Obstructed airway (e.g. laryngospasm, tongue) Apnoea, respiratory arrest Profound hypotension

PREPARATION Not quite the worst … What can go wrong? Disinhibition / agitation Terrors, nightmares Unexpected drug reactions: dystonias Inadequate sedation Unsuccessful procedure… still needs GA

USE OF INTRAVENOUS SEDATION FOR PROCEDURES IN THE EMERGENCY DEPARTMENT PREPARATION ACEM POLICY DOCUMENT - USE OF INTRAVENOUS SEDATION FOR PROCEDURES IN THE EMERGENCY DEPARTMENT © ACEM. 5 December 2001

PREPARATION ENVIRONMENT The procedure must be performed in a suitable clinical area with facilities for: Monitoring, Oxygen Suction immediate access to emergency resuscitation equipment, drugs and other skilled staff.

PREPARATION ENVIRONMENT Readily available equipment must include: resuscitation trolley defibrillator

PREPARATION ENVIRONMENT Readily available equipment must include: resuscitation trolley Defibrillator Bag-Valve-Mask device for ventilation

PREPARATION MONITORING Cardiac rhythm, non-invasive blood pressure and pulse oximetry must be monitored throughout the procedure and recovery period

PREPARATION PERSONNEL The involvement of at least two clinical staff is required: PERSON PERFORMING PROCEDURE must understand the procedure and its potential complications. PERSON GIVING DRUGS AND MONITORING PATIENT - must have training and experience of resuscitation, emergency drugs and …. (details of) the drugs used. This person is not involved in the performance of the procedure but is dedicated to care and monitoring of the patient.

PREPARATION PERSONNEL The involvement of at least two clinical staff is required: PERSON PERFORMING PROCEDURE must understand the procedure and its potential complications. PERSON GIVING DRUGS AND MONITORING PATIENT - must have training and experience of resuscitation, emergency drugs and …. (details of) the drugs used. This person is not involved in the performance of the procedure but is dedicated to care and monitoring of the patient.

PREPARATION PERSONNEL The involvement of at least two clinical staff is required: SUPERVISING PERSON – a specialist or advanced trainee in emergency medicine who has specific experience in airway control and resuscitation must be either directly involved in the procedure (taking one of the above roles) or must be aware of the procedure and provide overall supervision and back-up assistance.

PREPARATION PATIENT PREPARATION Explanation Consent Secure IV access is mandatory.

PREPARATION Other requirements Separate space to perform the procedure A recovery space: ideally quiet, available for 1-2 hours, easily observed.

READY TO GO… Explain Pre-oxygenate IV Access and IV fluid running Splints or plaster or equipment all ready to go Hand over your phone or pager…

To sedate or not to sedate…

Phone a friend… Consider sending the at-risk patient to the OR.

So what ARE you going to do?

Questions?

Key Points Be prepared Know your drugs and your drug interactions Consider all your options

Other References Guidelines Godwin SA, Caro DA, Wolf SJ, Jagoda AS, Charles R, Marett, BE and Moore J. Clinical policy: procedural sedation and analgesia in the emergency department. Annals of Emergency Medicine. 45:2. February 2005; pp 177-196. Innes G, Murphy M, Nijessen-Jordan C, Ducharme J and Drummond A. Procedural sedation and analgesia in the emergency department. Canadian consensus guidelines. The Journal of Emergency Medicine. 17:1. January 1999; pp 145 – 156. Textbooks Miller RD. Miller’s Anesthesia, 6th Ed. 2005 Marx JA. Rosen’s Emergency Medicine, 5th Ed. 2002. Roberts JR. Clinical Procedures in Emergency Medicine, 4th Ed. 2004 Tintinalli JE. Emergency Medicine: A Comprehensive Study Guide, 6th Ed. 2004

Other References Journal Articles Syminton L and Thakore S. A review of the use of propofol for procedural sedation in the emergency department. Emergency Medicine Journal. 2006:23. 89-93. Green SM and Krauss B. Propofol in emergency medicine: pushing the sedation frontier. Annals of Emergency Medicine. 2003:42. 792-797. Bahn EL and Holt KR. Procedural sedation and analgesia: a review and new concepts. Emergency Medicine Clinics of North America. 2005:23. 503-517. Green SM. Fasting is a consideration – not a necessity – for emergency department procedural sedation and analgesia. Annals of Emergency Medicine. 2003:42. 647-650. Green SM and Sherwin TS. Incidence and severity of recovery agitation after ketamine sedation in young adults. American Journal of Emergency Medicine. 2005:23. 142-144. Green SM and Li J. Ketamine in adults: what emergency physicians need to know about patient selection and emergency reactions. Academic Emergency Medicine. 2000:7(3). 278-280

Procedural Sedation & Analgesia in the Emergency Department