Analgesia and Procedural Sedation Shawn Dowling Preceptor Dr. Ian Wishart
Analgesia Objectives • Basic Pain Pathophysiology • Assessing Pain • Management • Rx • Not going to cover chronic pain, regional anesthesia
Why do we need to talk pain… • Pain is the most common complaint of ED patients. • 2. One of the most essential missions of all health care • providers should be the relief or prevention of pain and • suffering. • 3. Patients judge physicians by how they treat pain. • 4. We cause pain. • 5. Unrelieved pain is associated with a long list of potential • negative physiologic and psychological outcomes.
Pain Pathophysiology Black Box
Recognizing/Assessment of Pain • Patient report is primary method of pain assessment • Numeric scales can be used as a guide and as a reference for evaluating analgesic effect, physician impression is junk • HR, BP, facial grimacing are poor indicators of pain • Factors such as Ethnicity, Sex, Age, Cognitive functioning affect our assessment of pain • In the initial assessment – Ask what pain meds have worked in the past
Study • Convenience cohort of 71 patients, tertiary ED • >18 yrs of age • Pts were asked to rate their pain w/VAS and NRS @ arrival and at discharge • These ratings were then compared to those given by EP’s/Nurses
Conclusions • Physicians and nurses consistently rated the pain as less than the patient • Pain: • 49% stated pain was not relieved • 38% stated pain was somewhat relieved • 13% stated pain was relieved or completely relieved • ONLY 30% WERE SATISFIED WITH THEIR PAIN CONTROL
Pts in mild-moderate pain were unlikely to receive any analgesia • Only 2/3 of those w/severe pain received any analgesia & only 25% received opioids
This study supports what many prior studies had found • We underestimate pain • We undertreat pain both in the ED and at D/C • And, as a result, pt are dissatisfied
But, we are improving • From 1997-2001, use of analgesics in the ED increased by 18%2 2McCaig. National Hospital Ambulatory Medical Care Survey: 2001 ED Summary. National Center for Health Statistics, 2003
Approach to Pain Control • Local/Regional • Will not cover today - see Bilal’s rounds See this months CJEM for a review of hip # and femoral nerve block • Systemic • Anti-inflammatories (NSAID’s, APAP, COX-2) – see Dr. Ukraintz’s Grand Rounds • Opioids – This we will talk about • Adjuvants • Rx: TCA’s, muscle relaxants, anti-convulsants • Others: Music, distraction, etc.
The principles of pain control3 • In general, we chose if people are going to continue to have pain, not because pain is unavoidable • There is no reliable objective measure of pain • Avoid the “squeaky-wheel-gets-the-oil” phenomenon of pain control • Pain control must be individualized • Anticipate rather than react to pain • When possible, let patient control his or her pain • 3Ducharme J. Acute pain and pain control:state of the art. Ann Emerg Med. June 2000;35:592-603
Opioids should be prescribed at fixed intervals to control pain, with additional as-needed doses as required. As-needed dosing by itself allows for gaps in pain control. • Intramuscular or subcutaneous routes of opioids are generally not indicated • Erratic absorption and do not allow titration • No evidence supporting the idea that these routes are safer • Onset of action is approximately the same as with oral preparations
Opioids • MOA • Bind to specific receptors • Mu – Analgesia, RD, euphoria, physical dependence • Kappa – Analgesia, sedation, RD, miosis • Sigma – Dysphoria, hallucinations, tachypnea, tachycardia • Metabolized in the liver and excreted in the kidney • In renal failure metabolites accumulate and result in prolonged duration of action
Meperidine (Demerol) • Onset of Action 5-10 minutes • Duration of Action 2-3 hours • CNS Toxicity secondary to metabolite normeperidine, a cerebral irritant (anxiety, disorientation, tremors, seizures, hallucinations,psychosis). These effects not antagonized by naloxone. • Care with Renal/Liver Disease (decreased excretion/metabolism – leads to increased normeperidine), in the Elderly, • Avoid in pts on MAOI’s – hypertensive emergency • 1/8 the potency of IV Morphine with less benefits! • More Nausea/dysphoria than morphine • Poor ED analgesic choice!
Morphine Onset of Action 5-10 min Duration 2.5 to 4hrs Routes: IV, IM, PO Mediates histamine release, therefore can cause hypotension Prices between the two are relatively similar Fentanyl Onset of Action 1-2min Duration 30-75min Routes: IV, IM, TM Chest wall rigidity: never any cases in ED (occurs at high doses range of 10-15mcg/kg) Not supposed to cause histamine release 100 x more potent than morphine Common Opioids
Percocet • Onset of Action: 30 minutes, Peak 1 hr • Duration: 2-3 hrs • One Percocet contains 325mg Tylenol, 5 mg oxycodone • Maximum dose is 12/day b/c of Tylenol component (should not exceed 4gm/7) • SE – same as codeine • Abuse potential – HIGH, significant euphoria
T#3’s • What are the three components of T#3’s • Why are these combined/amount? • Tylenol (300mg) – we don’t really know (many theories including CNS COX- inhibitor) • Codeine (8, 15, 30 or 60mg)– we’ll review • Caffeine (15 mg, except T#4 – no caffeine) • two fx – 1) oppose the sedative features of codeine, 2) added analgesia – not well established, but amount of added analgesia varies from 0-40%
Tylenol and Codeine • Codeine needs to be metabolized (specific CP450 enzyme in the liver) to morphine, which then acts as an analgesic at the CNS opioid receptors • 10% of caucasians lack this enzyme!!! • May be one of the factors as to why some people find they “don’t” respond to T#3’s
APAP vs T#3’s-Systematic Review4 • OBJ: To assess whether adding codeine to tylenol has an additive analgesic effect; to assess their safety. • Design: Systematic review with meta-analysis. • Trials: 24 of 29 trials met the inclusion criteria. Models studied in the trials were postsurgical pain (21), postpartum pain (one), osteoarthritic pain (one), and experimentally induced pain (one). Dosages ranged from 400 to 1000 mg tylenol and 10 to 60 mg codeine • Main outcome measures: The sum pain intensity difference (efficacy analysis) and the proportion of patients reporting a side effect (safety analysis). 4Craen. Et al. Analgesic efficacy and safety of paracetamol-codeine combinations versus paracetamol alone: a systematic review BMJ 1996;313:321-325 (10 August)
Results • Single dose pooled efficacy indicated that codeine + tylenol provided a 5% increasein analgesia • Incidence of side effects with each treatment was comparable in the single dose trials. In the multidose studies a significantly higher proportion of side effects occurred with tylenol-codeine preparations. • Conclusion: • The difference in analgesic effect between tylenol -codeine combinations and tylenol alone was small but s.s. • For occasional pain relief a tylenol -codeine combination might be appropriate but repeated use increases the occurrence of side effects.
Limitations • Don’t mention baseline pain scores • Many argued that a 5% increase is not statistically significant (5% of 15mm on a VAS is <1mm) • Another group looked at RR and NNT. The RR was 1.25 (1.09-1.43). • Number Needed to Treat: 9.1 people to get 50% pain reduction with paracetamol plus 60 mg codeine
To Use or not to Use • ? Clinically significant benefit over tylenol alone, with increasing s/e if used for >1 dose • Mod-severe pain – likely not adequate and will likely need more than one dose • Many argue that a NNT of 9 for Tx of pain is sub-optimal • ?Consider in pts who state they respond well to T#3’s
Anti-emetic or not? • Opioid-induced emesis is multi-factorial: histamine release, direct gastroparetic effect and stimulates central chemoreceptor • Occurs in approximately 20% of patients, somewhat dose-dpndt • Effective agents are antihistamines(gravol) or ondansetron • If pt has Hx of significant emesis/nausea, give anti-emetic 15 minutes before opioid • In general, do not need to pre-treat with anti-emetic
Other analgesia options • Music: variable success, • Distraction is a well-known aid for decreasing pain. • Immobilization of injured extremities often decreases pain considerably • Use of regional anaesthesia instead of systemic analgesia should be considered.
Pediatric pain control • Children, including neonates, do feel pain and may suffer adverse events if that pain is not properly controlled • Pain management in children is as important as in adults • In one study no child with an extremity fracture was discharged with an analgesic prescription5 • Only 37% of peds w/ LE # received analgesia while in the ED • Only 24% of peds w/2 or 3 degree burns received analgesia while in the ED6 5Ngai B,Ducharme J. Documented use of analgesics in the emergency department and upon release of patients with extremity fractures [letter]. Acad Emerg Med. 1997;4:1176-1178 6Petrack, E. Pain Management in the ED: Patterns of analgesic utilization. Pediatrics 1997;99(5):711-4.
Analgesia for Musculoskeletal Injuries in Children. A Blinded RCT Comparing Acetaminophen, Ibuprofen and Codeine by Clark, Plint, et al. - unpublished7 • 298 patients aged 7-18, who suffered acute MSK injuries • VAS scales were measured at scheduled intervals • RESULTS: The study groups were similar • At 1 hour, pain scores were lowered by 24.9mm in the ibuprofen group. This was statistically better than improvement from codeine and acetaminophen • At 4 hours, ibuprofen (30.9mm) and Codeine (23.3) both reached s.s. • Tylenol did not s.s. decrease pain (13.3) • By 4 hours 72.5% vs 60.4% vs 52.9% of the codeine, ibuprofen and acetaminophen groups respectively has achieved adequate analgesia. • CONCLUSIONS: • @ 1 Hr only ibuprofen had reached clinically significant decrease in pain • @ 4 Hrs both ibuprofen and codeine had achieved clinically significant pain cont • In the pediatric ED, ibuprofen is the initial drug of choice for acute analgesia.
Opioids and Competence8, 9 • Some have argued that the use of opioids affects ones competence and alters ones ability to give consent • There have been at least two studies that have challenged this dogma • Both show that patients retain their ability to give informed consent despite receiving analgesics • One MD makes the arguments that “If pain meds are withheld, patients may feel pressured to consent in order to obtain medication to relieve their suffering” 8Smithline HA, Mader TJ, Crenshaw BJ. Do patients with acute medical conditions have the capacity to give informed consent for emergency medicine research? Acad Emerg Med. 1999;6:776-80 9Vessey W, Siriwardena A. Informed consent in patients with acute abdominal pain. Br J Surg. 1998;85:1278-80
Procedural Sedation and Analgesia In Skating over thin ice, our safety is in our speed, -Ralph Waldo Emerson
PS is w/i our Scope of Practice • EP’s are well trained to • Monitor patients during procedural sedation • Recognize potential problems early and • Intervene when necessary
Procedural Sedation • Objectives • Goals of PS • Definitions • Indications/Contra-indications • Approach • Rx • Address a few of the many controversies
I apologize in advance • This is an area of EM with lots of ongoing controversy, debate and research • Unfortunately, much of the research is conflicting and less than optimal (not done in the ED setting, very heterogeneous, “doctored”)… • There are some guidelines to help us though
CONSENSUS Guidelines • Innes, Murphy, Nijseen-Jordan. Procedural Sedation and Anaglesia in the ED. Canadian Consensus Guidelines. J of EM vol 17: 145-5610. • Clinical Policy for Procedural Sedation and Analgesia in the ED. Annals of EM; May 1998: 31, 663-67711
PSA • The practice formerly known as “conscious sedation” - • Goals of PS • Sedation, Analgesia,+/-Anxiolysis, +/- Amnesia • Facilitation of procedure • While ensuring pt safety (and not making ourselves cushinoid from all the stress)
Definition • Procedural Sedation • Refers to a technique of administering sedatives or dissociative agents +/- analgesia to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardio-respiratory function/reflexes.
Ideal Rx? • Would provide analgesia, sedation, amnesia, motor control with a rapid onset and short duration • While being safe, effective, simple to administer and reversible • Obviously does not exist and therefore these are 2-hr rounds rather than 5 minutes.
General Approach Pre-Sedation 1. 1st question should I do PS? -emergent or -ASA I/II and -no concerns w/a.w. Hx -PMHx, Previous GA/sedation, Meds/all (egg/soya) -NPO P/E -VS -ASSESS a.w. -Establish baseline LOC -Cardio-respiratory exam 2. Consent -verbal or written 3.Preparation -Equipment, Personel, monitors, IV, Rx/reversal agents, resucitative equipment 4.Documentation • Sedation • . Pre-oxygenate? • . Monitoring • BP, HR, pulse oximetry, LOC- AVPU, +/- capnography, • . ?O2 during PS • . Rx • -Procedural Sedation Drugs • Post-Sedation • 1. Monitor 2. D/c criteria 3. D/C instructions
Case #1 • 38 yr guy has a Dislocated shoulder. Before you reduce it, you plan on giving him some drugs. • What do you need to consider before procedural sedation?
Need to Consider • Is this person a good candidate for PS? • How does one do this? • No ED evidence for this, mostly extrapolated from anesthesia recommendations • All upcoming recommendations are based on CAEP/ACEP PS consensus guidelines unless otherwise stated
CAEP guidelines • A Quick Word… • March 1996 EM committee convened (peds and adults) • Initially Canadian Anesthesia Society was involved – in the end they did not support the final product…. • Extensive review of literature • Recommendations are a combination of clinical trials (few), case series (many) and expert opinion (majority)
Pre-Sedation • Hx: • Recent respiratory illnesses, • PMHx, • Prior GA/PS, • Meds, • Allergies (Rx, foods-why), • Last Oral Intake