Approach to Procedural Sedation & Analgesia(PSA)

อ.พญ.อภิ�ชญา มั่�นสมั่บู�รณ์�ภิาควิ�ชาเวิชศาสตร�ฉุ�กเฉุ�น คณ์ะแพทยศาสตร�ศ�ร�ราชพยาบูาล

Scope

• General approach to PSA• Pharmacodynamic and pharmacokinetic of

drugs• How to select drug(s)

GENERAL APPROACH TO PSA

Procedural Sedation & Analgesia

“Use of short-acting analgesic and sedative medications to enable clinician to perform procedures effectively, while monitoring the patient closely…”

Contraindication & precaution

• Relative contraindication– Older age– Significant medical comorbidities– Signs of difficult airway - Lower starting dose

- Slower rate - Less frequent repeated dose

Performing procedural sedation

• Informed consent• Prerequisites and personnel• Equipment• Monitoring and preoxygenation• Medications

Equipments

• Suction• Airway adjuncts: BVM, oral/nasal airways• Endotracheal intubation• IV access• Resuscitation medications

Monitoring & preoxygenation

• Blood pressure• ECG monitor• O2 saturation• Monitor dept of sedation• End-tidal CO2 (EtCO2)

http://emedicine.medscape.com/article/2044822-overview#showall

Monitor dept of sedation

• Ramsay Sedation Scale • Observer's Assessment of Alertness/Sedation

Scale

Monitoring End tidal CO2

Normal ventilation

Hypoventilation

• Sedatives & analgesics synergistic effect• Titrate dose

Medications

PHARMACODYNAMIC & PHARMACOKINETIC OF

DRUGS

Medications

Propofol

Etomidate

Midazolam

Ketamine

Fentanyl

No Analgesia!!!

Propofol

• Phenol derivative• Lipophilic cross blood-brain barrier• Sedative & amnestic• Onset: 40 seconds• Duration: 6 minutes• Dose: initial 0.5-1 mg/kg then 0.5 mg/kg IV q 3-5 minutes

Propofol

• Pharmacokinetics– Unchanged in impaired kidney or liver function– plasma level in elderly (>55 yo)– dose 20-60% & slower bolus in 3-5 minutes

• Side effect– Hypotension– Respiratory depression

Propofol

Etomidate

• Imidazole ring• Cardiovascular stability• Onset: immediate• Duration: 5-15 minutes• Dose: 0.1-0.15 mg/kg IV over 30-60 seconds then q 3-5 minutes

Etomidate

• Pharmacokinetics– Prolonged effect in elderly, renal or hepatic

dysfunction• Side effect– Myoclonus– Respiratory depression– Adrenal suppression– Nausea/vomiting

Etomidate

Ketamine

• Phencyclidine derivative• Dissociative sedative• Sedation, analgesia & amnesia• Preserve upper airway muscle tone, airway protective reflex & spontaneous

breathing• Brief painful procedure: fracture reduction,

laceration repair

Ketamine

• Onset: immediate• Duration: 10-20 minutes• Dose: 1-2 mg/kg IM or IV over 1-2 minutes

then 0.25-0.5 mg/kg IV q 5-10 minutes• Significant adverse event rarely occur• Most common SE: emergence prevent by

midazolam 0.05 mg/kg IV (2-4 mg)

Ketamine

Midazolam

• Lipophilic • Minimal sedation, anxiolytic and amnesia• Combine with fentanyl for deeper sedation & analgesia• Onset: 2-5 minutes• Duration: 30-60 minutes• Dose: 0.05-0.1 mg/kg over 1-2 min then q 2-5 min

Midazolam

• Pharmacokinetics– Prolonged effect in elderly, obese, renal or hepatic

dysfunction– Repeat dose accumulate in adipose tissue

• Side effect: respiratory depression

Midazolam

Short-acting opioid

• Start before PSA• Fentanyl• Alfentanyl • Remifentanyl

Fentanyl

• No amnesia • Previously frequent used with midazolam• Potency: 75-125 times of morphine• Onset: 2-3 minutes• Duration: 30-60 minutes• Dose: 1-3 mcg/kg q 2 minutes (max 5 mcg/kg)

Fentanyl

• Pharmacokinetics– Prolonged effect in elderly, renal or hepatic

dysfunction• Side effect– Respiratory depression

Fentanyl

Combination

• Ketamine + Propofol• Midazolam + Fentanyl• Propofol + Remifentanil

Ketamine + Propofol (ketafol)

• Synergistic & reduce side effects

Dose Propofol Ketamine

Initial 0.5 – 0.75 mg/kg 0.5 – 0.75 mg/kg

Midazolam + Fentanyl

• Ultrashort-acting unavailable• Can cause hypoxia & apnea

Dose Midazolam

Wait

Fentanyl

Initial 0.02 mg/kg 0.5 mcg/kg

Subsequent q 2 min 0.25 mg/kg 0.25 mcg/kg

HOW TO SELECT THE DRUG(S)

How to select drug(s)

• Type of procedure levels of sedation• Patient status

Levels of sedation

• Minimal sedation– Lumbar puncture– Simple fracture reduction– Incision & drainage

• Moderate sedation– Shoulder dislocation – Thoracostomy tube insertion– Synchronized cardioversion

case

• 40 year-old man with suspected meningitisProcedure: lumbar punctureLevel of sedation: minimalMedication: fentanyl +/- midazolam

case

• 30 year-old man with fracture distal end of radius

Procedure: close reductionLevel of sedation: moderateMedication: fentanyl propofol

Drugs Cautions

Healthy, stable HD

Propofol Hypotension

Etomidate Myoclonus, adrenal suppression

Ketamine Agitation,

Risk of hypotension

Etomidate

Ketamine

Airway compromise Ketamine

Elderly Lower starting dose, slower rate, less frequent repeated dose

HD; hemodynamic