Amnestics Definition Loss of memory, inability to recall events Examples Benzodiazepine Ketamine
Levels of Sedation Awake Moderate Sedation Deep Sedation General Anesthesia
Moderate Sedation Purposeful response to verbal stimulation Airway patent Spontaneous ventilation adequate Cardiovascular function unaffected
Deep Sedation Difficult to arouse Purposeful response only to painful stimulation Airway may be obstructed Spontaneous ventilation may be impaired Cardiovascular function usually unaffected
General Anesthesia Loss of consciousness Positive pressure ventilation Cardiovascular function may be affected
Choosing a Sedation Plan Remember mnemonic AMPLE!! A llergies M edications P ast Medical History L ast Meal E vents leading to sedation
Allergies Drug allergies Environmental allergies Egg & soy allergy no Propofol Contrast allergies
Medications Knowing current medications & therapeutic interventions can help tailor your sedation plan… Sedatives already being used Vasoactive medications Neuromuscular blockers Respiratory medications Hemofiltration/dialysis And so on…
Past Medical History Know current patient problem list and significant past medical/surgical history Respiratory (hypoxia, pneumothorax) Cardiovascular (hypotension, myocardial dysfunction) Neurologic (increased ICP, seizure disorder) Hepatic/Renal failure
Past Medical History Past history of sedation Medications used in the past Prior adverse events with sedation Ability to manage airway (Pierre Robin, croup, mediastinal mass, prior radiation, asthma) Family history of problems with sedation
Past Medical History ASA Physical Status Score ASA I : normally healthy patient ASA II: mild systemic disease ASA III: severe systemic disease ASA IV: severe systemic disease that is a constant threat to life ASA V: moribund patient not expected to survive without operation
Physical Exam Mallampati/Samsoon Classification Class I: soft palate, uvula, pillars Class II: soft palate, portion of uvula Class III: soft palate, base of uvula Class IV: hard palate only Other predictors of difficult airway Obesity with short neck Reduced neck movement Inability to protrude the lower teeth Reduced mouth opening Receding mandible Thyromental distance of less than 3 fingers
Last Meal Full stomach is a risk of aspiration during sedation!!! NPO status Last solid intake > 6 to 8 hours Last opaque liquid/formula intake > 4 hours Last clear liquid/breastmilk intake > 2 hours These guidelines do not apply for patients with GI disturbances
Last Meal Full stomachs include the following… Any patient with material in their stomach Food Medications Contrast Charcoal Blood Any patient with delayed gastric emptying Morbid obesity Small bowel obstruction Pyloric stenosis GI dysmotility And so on…
Events leading to sedation… Know why your patient needs sedation!! Is it safe to sedate your patient?? What kind of sedation are you trying to achieve?? Analgesia, anxiolysis, amnesia, or a combination Anticipated duration of therapy
Choosing the Right Drug There is no magic cocktail…all drugs have potential complications Drugs to consider should fit your goals for sedation with minimum risk to the patient Considerations when choosing a drug Route of administration Onset of action Duration of action Contraindications Therapeutic advantages
Propofol Onset: 30 sec Duration: 3-10 min Dose: 1 mg/kg Infusion: mcg/kg/min Disadvantages: respiratory depression, hypotension, bradycardia, NO analgesia, metabolic acidosis with prolonged infusion
Ketamine Onset: 30 sec (IV), 3-4 min (IM) Duration: 5-10 min (IV), min (IM) Dose: mg/kg (IV), 4-5 mg/kg (IM) Infusion: 5-20 mcg/kg/min Analgesia and amnesia preserves upper airway tone and reflexes Disadvantages: excess secretions, increased ICP, emergence reaction
Pentobarbital Onset: 3-5 min (IV) Duration: min Dose: 1-2 mg/kg Disadvantages: NO reversal agent, no analgesia (enhances pain perception)
Fentanyl Onset: 2-3 min Duration: min Dose: 1 mcg/kg 100x more potent than morphine Available reversal agent Naloxone Disadvantages: no amnesia/ anxiolysis, “steel chest”
Morphine Onset: 5-10 min (IV) Duration: 4-6 hours Dose: mg/kg Available reversal agent: Naloxone Disadvantages: no amnesia/ anxiolysis, histamine release
Onset: 2-6 min Duration: min Dose: mg/kg Available reversal agent Flumazenil Retrograde amnesia Disadvantages: NO analgesia, paradoxical reactions Midazolam (Versed)
Diazepam (Valium) Onset: hours (oral) Duration: variable but LONG (oral) Dose: mg/kg/day (oral) Useful for tapering Disadvantages: accumulation, long half-life, avoid rapid IV push
Lorazepam (Ativan) Onset:15-30 min (IV) Duration: 3-4 hours (up to 12 hrs) Dose: mg/kg Disadvantages: mixed with propylene glycol Anion gap metabolic acidosis, osmolar gap Avoid infusions
Dexmedetomidine (Precedex) IV alpha-2 agonist 1700x more selective for alpha 2 Onset: min Duration: min Dose: load with mcg/kg Infusion of 0.3 – 1.5 mcg/kg/hr Disadvantages: bradycardia, only approved for 24 hr infusions
Contraindications All drugs should be used judiciously!!! Commonly seen relative contraindications and adverse effects Ketamine increased ICP, excess salivation, emergence reaction Propofol hypotension, acidosis Dexmedetomidine bradycardia, arrhythmia Benzodiazepine hypotension
Therapeutic Advantages Not all side effects are harmful Considerations for choice of drug Ketamine bronchodilator Pentobarbital or Midazolam anti- convulsant Diazepam muscle relaxation
Case #1 An 8 year old known asthmatic is in the ED having received continuous albuterol nebs, steroids, and subcutaneous epinephrine. You check on him and find him unresponsive with a RR of 6 and very poor air movement. An RT runs in with a ABG showing pH 6.9, pCO What medications do you consider for intubation & sedation?
Case # 2 A transport team has just arrived to pick up a 4 year old child with severe stridor. On exam she is alert, sitting in Mom’s lap & maintaining her sats, but has severe retractions with every breath and drooling. She appears frightened, and the paramedic asks you to order something to sedate her so that she can be strapped to the gurney. What is your response?
Case # 3 You consult in the ED on a 7 year old who has presented with sore throat and noisy breathing. He has received 2 gm of chloral hydrate 1/2 hour before for an attempted CT scan of the neck. In the ED you find him in the back room with his mother, with a sat probe on his finger not attached to a monitor. He has retractions and poor air movement with every breath. What happened and what would you do?
Case # 4 You are taking care of a 9 mo post-op cardiac patient who is intubated and requiring sedation. She initially had issues with heart block and required pacing but is now in a sinus rhythm of 110. She has been difficult to sedate with Fentanyl & Midazolam and the nurses ask you if you can add a 3 rd agent. What agents would you want to avoid in this patient and what do you need to consider?
Case # 5 You are called to the ED to see a 6 year old trauma patient who luckily has a normal head CT but unfortunately has a severely displaced tib-fib fracture. The orthopedic surgeons are gathering equipment to reduce and splint the fracture. What drugs do you think about using and what else do you consider?
Preventative Medicine is Key!! Optimize your patient prior to sedation Correct acidosis Keep euvolemic Know “AMPLE” Anticipate difficulties and be prepared Bag, mask, oxygen, +/- airway box Suction Normal saline/Lactated Ringer’s Monitors – O2, CO2, CR monitor, BP Titrate medications to effect…it is easier to give more drug than it is to remove it!!!
Summary Many situations require sedation in the ICU Components of sedation include anesthesia, analgesia, anxiolysis, & amnesia There are several levels of sedation Remember mnemonic “AMPLE” when evaluating a patient for sedation Choosing the right drug involves knowing the goals of sedation alongside drug profile for sedatives Always anticipate possible complications & be prepared to deal with them