BSUH ED PROCEDURAL SEDATION WORKBOOK

Transcription

1 BSUH ED PROCEDURAL SEDATION WORKBOOK

2 Introduction: Procedural sedation is the process of inducing an altered level of consciousness in a patient, usually to allow us to perform an otherwise painful or distressing procedure. It is commonly done in our EDs and should be considered a core skill of all Emergency Physicians. This work book will give you an introduction into the process we use including our checklist and the available drugs and also provides links to the background reading we will expect you to have done. Background reading: RCEM Article: CEM Guideline 2012: BMJ Review article 2014: UpToDate Article: YouTube Video: Depth of sedation: The ASA describe four levels of sedation: Minimal sedation (anxiolysis), Moderate sedation/analgesia ( conscious sedation ), Deep sedation/analgesia, General anaesthesia. We feel it is better to highlight that sedation is a continuum and that the further down the continuum you move the greater the risk of complications as a result of the sedation: Alert-anxious Alert-calm (anxiolysis) Drowsy but clear mentation (sedation) Eyes open, speech slurred Eyes closed but answers questions appropriately Opens eyes to voice, is confused Oxygen desaturation on room air Opens eyes to pain, responds purposefully Eyes closed; moans and withdraws from pain CO 2 retention Oxygen desaturation on 2L O 2 No response to pain Bradycardia poor gag reflex Apnoea hypotension Death Of note, sedation with Ketamine results in a dissociative state, a trance-like cataleptic state of profound analgesia and amnesis with retention of protective airway reflexes, spontaneous respirations and cardiopulmonary stability. As such the above continuum is not fully applicable however over sedation with ketamine will still lead to physiological compromise and the same degree of caution is required. Patients may move up and down the continuum dependent on the drugs given and the external stimuli the patient is subjected to. Remember that removal of pain (by reduction of a dislocated joint or plastering of a fracture) will likely result in the patient becoming more sedated and so the immediate post procedure period is one of particular risk. All patients must be monitored in Resus until fully awake

3 Patient assessment: Assessment of health: i) The American Society of Anaesthesiologists (ASA) uses the following description for assessment of fitness prior to surgery and this has been widely adopted in the UK when assessing for procedural sedation: ASA Classification I II III IV V VI Health status of patient A normal healthy patient A patient with mild systemic disease A patient with severe systemic disease A patient with severe systemic disease that is a constant threat to life A moribund patient who is not expected to live without the operation A declared brain-dead patient whose organs are being removed for donor purposes ii) An adequate history to include at least the components of the AMPLE (allergies, medications, past medical history, last oral intake and events/what happened) history. Airway assessment: All patients undergoing procedural sedation should have an assessment of their airway made before a decision to proceed with procedural sedation. The airway assessment should include: i) A Mallampati score: Patient must be seated, head neutral, mouth wide open and tongue protruding. I Full visibility of uvula and soft palate II Visibility of hard and soft palate, upper portions of tonsils and uvula III Soft and hard palate and base of uvula visible IV Only hard palate visible

4 ii) An assessment of the physical characteristics that might predict a difficult airway. Consider using the LEMON assessment: Look (facial trauma, large incisors, beard/moustache, large tongue, cachexia with missing teeth) Evaluate rule (3 fingers mouth opening, 3 fingers between mentum and hyoid, 2 fingers between hyoid and thyroid cartilage) Mallampati Obstruction the presence of anything causing obstruction Neck mobility Decision on whether to sedate in ED: The ED shop floor consultant should be made aware of all procedural sedation that is being performed before it is started. Exercise caution in the following: Fasting state: food <6 hours, fluid <2 hours Any positive LEMON findings Mallampati score 3 or 4 ASA 4 or 5 may not be suitable for ED sedation Obese, elderly or children High risk of aspiration e.g. acute alcohol intoxication. Special cases: Some patients attend frequently and may have management plans in place. Discuss with a senior permanent member of staff if the patient has attended frequently for the same reason. Consent: Needs to be documented in the written notes Requirements for sedation: The RCEM guideline sets out the national requirements for equipment and staff as per different levels of sedation. In our opinion, all patients receiving procedural sedation other than those being given only nitrous oxide should be managed in the resuscitation area, with a doctor performing the sedation, at least one other (usually a doctor) performing the procedure and a nurse. The equipment required for each episode of procedural sedation is recorded in the checklist that should be used in each case.

5 BSUH procedural sedation checklist: Record Keeping: All episodes of procedural sedation should be recorded in the patient notes and the drugs used should be prescribed and signed for on the prescription chart. Mention should be made of who performed the sedation, the drugs used, that the checklist was used and whether there were any complications. Each procedural sedation must be recorded in the procedural sedation book in Resus. Any adverse event should be recorded and the shop-floor consultant should be informed immediately.

6 MEDICATION CAUTION: The following dosing recommendations are only a guide dosing of sedative agents should be done with caution and consideration of the specific patient factors of each case should be taken into account. Dose, rate of injection, co-morbidities and concurrent administration of other sedative drugs such as opioids will alter the properties of the sedative agents. There is no one single perfect dose or sedative for every patient and each recommendation should be taken as a guide about what the maximum is likely to be not as a target.

7 Sedatives: Entonox: Entonox is a ready-to-use medical gas mixture consisting of 50% nitrous oxide and 50% oxygen which works as a low potency inhalation anaesthetic and high potency analgesic. At a constant inspired concentration the rise time of alveolar concentrations is faster than that of any other anaesthetic agent. The elimination of nitrous oxide equally is faster than that of any other anaesthetic. Use in procedural sedation: Analgesic bridge whilst awaiting e.g. IV access and IV opiates. Adjunct to other analgesics when performing painful procedures e.g. as an adjunct to haematoma block in manipulation of a Colles fracture or as an adjunct to IV opiate when reducing a dislocated shoulder. As a single agent when performing a very brief manipulation e.g. relocation of a dislocated patella. NB: prolonged used beyond a few minutes must be avoided by providing adequate alternative analgesia ENTONOX Presentation: 50:50 mixture of oxygen and nitrous oxide (N 2 0) presented in canisters Administration: Self-administered via mouthpiece with a filter. The purge valve should not be used. Dose: Self-administered as required but see notes above Onset: Effective within a few breaths Maximum effect: 2-3 minutes Side effects: Euphoria, disorientation, sedation, nausea, vomiting, dizziness and generalised tingling are commonly described. These events are generally minor and rapidly reversible once the patient stops breathing entonox. Longer term side effects from the BOC Entonox Essential Guide: Nitrous Oxide can affect Vitamin B12 synthesis by inhibiting methionine synthetase. This effect is of importance if the therapeutic exposure to Entonox exceeds a total of 24 hours, or more frequently than every 4 days.. Nitrous oxide can also interfere with folate metabolism and DNA synthesis, which can impair bone marrow function. Contraindications: any pneumothorax air embolism decompression sickness following a recent dive following air encephelography severe bullous emphysema abdominal pain and/or distension in patients having received recent intraocular injection of gas (such as SF₆). Reversal Agent: There is no reversal agent for Entonox but effects will recovery completely within 5 minutes (often more rapidly)

8 Midazolam: Midazolam is an imidazobenzodiazepine that is water soluble in its acid formulation but is highly lipid soluble in vivo. It has a relatively rapid onset of action and high metabolic clearance when compared to other benzodiazepines. No analgesic nor retrograde amnesic properties. MIDAZOLAM Presentation: Vials 5mg/5ml Administration: Slow IV injection over 30 seconds. May be diluted with Sodium Chloride 0.9% or Glucose 5% to facilitate slow injection. Dose: Adults <60 years: Adults 60 years/chronic illness: Initial dose: 2-2.5mg 0.5-1mg Titration doses: 1mg 0.5-1mg Total Dose: mg <3mg Onset: Approximately 2 minutes Maximum effect: Approximately 5 minutes Duration: Usually mins Side effects: Central respiratory depression enhanced when used with opiate. Reversal Agent: Flumazenil Dose: 200mcg followed by 100mcg at 60 second intervals. Usual dose range mcg; maximum dose 1mg Administration: Undiluted. Rapid IV injection over 15 seconds Onset of reversal: 1 to 2 minutes; peak onset: 6-10 minutes. Duration: 20 minutes. If re-sedation occurs dose may be repeated after 20 minutes. Notes: If considering using flumazenil, please seek senior ED advice. A competitive antagonist shorter duration of action than benzodiazepines so careful ongoing monitoring if used. Risk of inducing seizure activity particularly those known to be epileptic, on long term benzodiazepines. From Toxbase: flumazenil is an appropriate treatment in patients poisoned only with a benzodiazepine who have developed reduced ventilation and coma and who otherwise would require mechanical ventilation. It is not necessary or appropriate in cases of benzodiazepine poisoning to fully reverse CNS depression; adequate ventilation is the aim. Flumazenil has a short half-life (about an hour) and an infusion may therefore be required

9 Ketamine: The closest to a true "complete" anaesthetic agent, producing anxiolysis, amnesia, immoblisation and profound analgesia. Emerging from Ketamine sedation can be disturbing for a significant proportion of patients. This effect can be markedly reduced by treating the patient with a small dose (1-2mg) of midazolam prior to Ketamine administration and this is recommended. KETAMINE Presentation: Vials of 10mg/ml, 50mg/ml and 100mg/ml NB: these presentations represent potential risk for over dosing patients. Extreme caution is required be sure of which concentration you are using. Administration: The 10mg/ml & 50mg/ml solutions can be given undiluted The 100mg/mL solution must be diluted to a maximum concentration of 50mg/mL with Sodium Chloride 0.9% or Glucose 5% prior to administration. Slow IV injection over at least 60 seconds to minimise respiratory depression and enhanced pressor response. Dose: Adults Initial dose: IV 0.5-1mg/kg. IM 5mg/kg this route can be used if sedation is urgently required but IV/IO access unavailable Titration doses: Generally given as an IV bolus starting with 0.5mg/kg Total Dose: Doses >1mg/kg should be discussed with the shop floor Consultant Onset: 30 seconds IV 3-4 mins IM Duration: 5-10 mins IV mins IM Side effects/complications: General: Nausea and vomiting Tachycardia and hypertension due to sympathetic stimulation Emergence More marked if >60 years use caution in this age group reactions: avoid premature awakening and unnecessary stimulation during sedation use midazolam 1-2mg to attenuate (will prolong recovery phase) and as perform sedation and awakening in as quiet a space as possible. Relative contraindications: Severe hypertension Raised intracranial pressure and head injury (but there is debate about this seek advice) Severe cardiac disease Stroke Acute porphyria Eclampsia & pre-eclampsia Reversal Agent: There is no reversal agent for ketamine

10 Propofol: A dose dependent sedative and intravenous anaesthetic. It has no analgesic properties. PROPOFOL Presentation: vials 1% (10mg/ml) or 2% (20mg/ml) white liquid we use 1% in ED Administration: Slow IV injection, undiluted. Dose: Adults <60 years: Adults 60 years/chronic illness: Initial dose: mg/kg mg/kg Titration doses: mg/kg mg/kg Total Dose: 200mg 100mg Onset: Usually less than 40 seconds (caution in low cardiac output states e.g. arrhythmia seek senior advice) Maximum effect: seconds Duration: 3-5 mins (single bolus) Side effects/complications: Higher dose may cause deepening sedation and airway obstruction. Hypotension secondary to myocardial depression. Respiratory depression - enhanced with opiate use. Reversal Agent: There is no reversal agent for propofol Analgesia: When considering opiate analgesics, it is worth being mindful of the differing times to peak onset of each. This is demonstrated in the below graph:

11 Fentanyl: Fentanyl citrate is a potent opioid agonist. A dose of 100 mcg (0.1 mg) (2 ml) is approximately equivalent in analgesic activity to 10 mg of morphine. FENTANYL Presentation: 2ml vials of 50mcg/ml Administration: Undiluted. Slow IV injection over 1-5 minutes for total dose. Dose: Adults <60 years: Adults 60 years/chronic illness: Initial dose: mcg mcg Titration doses: 25mcg every 2 to 3 minutes as needed (longer in those with low cardiac output and the elderly) Total Dose: Depends on the clinical situation but doses above 100mcg (50mcg in the elderly) should be used with caution Onset: 1-2 minutes Maximum effect: 3-5 minutes Duration: mins It has the particularity of corresponding to a three-compartment model, with a distribution time of 1.7 minutes, redistribution of 13 minutes, and a terminal elimination half-life of 219 minutes. Side effects/complications: Respiratory depression The peak respiratory depression occurs 5-15 mins after the administration. It is of note that there also exists a diminished sensitivity to CO 2 stimulation which may persist longer that the depression of respiratory rate. Reversal Agent: Naloxone Dose: mcg IV every 1 to 2 minutes as necessary, simultaneously with assisted respiration. Administration: Can be given undiluted or diluted in 0.9% saline. Rapid IV injection. Onset of 1-2 minutes reversal: Duration: Peaks at 30 minutes, duration of action minutes. Side effects: Notes: Should be administered cautiously to persons who are known or suspected to be physically opiate dependent See prompt card for dosing of naloxone infusion if necessary.

12 Morphine sulphate: Although commonly used as an analgesic in the ED, morphine is not normally our first choice for analgesia in procedural sedation due to the prolonged time to peak onset. MORPHINE Presentation: Vial of 10mg/ml, clear, colourless or almost colourless. Administration: By slow IV injection. Dilute to 10mL with Sodium Chloride 0.9% to aid slow administration. Inject at a rate of approximately 1mg/min. Dose: Adults <60 years: Adults 60 years/chronic illness: Initial dose: 4-10mg iv slow over 4-5 minutes 2-5mg iv slow over 4-5 minutes Titration doses: 2-8 mg every 4 to 15 minutes as needed 1-4mg every 4 to 15 minutes as needed Total Dose: Depends on clinical situation but IV doses above 10mg should be used with caution Overdose: Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations. Depresses cough reflex. Onset: 2-3 minutes Maximum effect: minutes Duration: 1-4 hours. Side effects: Respiratory depression: occurs more frequently in elderly or debilitated patients and in those suffering from conditions accompanied by hypoxia, hypercapnia, or upper airway obstruction such as: o chronic obstructive pulmonary disease o cor pulmonale o a substantially decreased respiratory reserve (e.g., severe kyphoscoliosis) o hypoxia or hypercapnia Hypotension: in an individual whose ability to maintain blood pressure has already been compromised by circulatory shock or concurrent administration of drugs such as phenothiazines or general anaesthetics. Head injury, intracranial lesions or a preexisting increase in intracranial pressure: respiratory depressant effects its potential to elevate cerebrospinal fluid pressure (resulting from vasodilation following CO2 retention) may be markedly exaggerate Notes: Patients who use or have used intravenous opiates recreationally should be offered IV opiate analgesia in the same manner as other patients. Reversal Agent: Naloxone Dose: mcg IV every 1 to 2 minutes as necessary, simultaneously with assisted respiration. Administration: Can be given undiluted or diluted in 0.9% saline. Rapid IV injection. Onset of reversal: 1-2 minutes Duration: Peaks at 30 minutes, duration of action minutes. Side effects: Notes: Should be administered cautiously to persons who are known or suspected to be physically opiate dependent See prompt card for dosing of naloxone infusion if necessary.

13 Patient discharge: Patients should only be discharged once fully awake and they have been seen to be back to their normal mobility Have a low threshold for HRDT involvement +/- a short stay on CDU/SSW All patients should be discharged with verbal and written instructions (BSUH ED patient leaflet) Pitfalls: Inadequate analgesia prior to sedative agent (which also involves waiting for analgesia to take effect). Failing to adapt dose to patient comorbidities and age. Too rapid titration of sedative agent. Not waiting for sedative to reach maximal effect particularly in low cardiac output states such as arrhythmia. Premature discontinuation of monitoring e.g. for repeat x-ray. Discharge without adequate supervision. Discharge without written instructions. Failure to document in notes and sedation log Administration information is taken from the National Injectable Medicines Guide online. For full administration information the Guide can be accessed via BSUH Intranet Pharmacy page.

14 SIGN OFF PAPERWORK

15 Midazolam: Date Hosp No Procedure Analgesic Observer Notes Ketamine: Date Hosp No Procedure Analgesic Observer Notes Propofol: Date Hosp No Procedure Analgesic Observer Notes

16 Airway management: Date Discussion Manikin practice Notes Observer Sign Off: Drug Reading 5 cases Airway Mx Name Signature Date Midazolam Ketamine Propofol Opioid analgesia