Assessment Tools:
- Critical Care Pain Observation Tool (CPOT) (0-8)
- Behaviour Pain Scale (BPS)
- Sedation is Richmond Agitation Sedation Scale (RASS) or Sedation-Agitation Scale (SAS)
Sedation Agents:
- Propofol:
- Rapid onset (1-2 minutes)
- Short duration (3-5 minutes).
- Avoid prolonged infusions greater than 50 mcg/kg/min.
- Monitor BP, triglycerides, adjust lipid calories
- Monitor for propofol infusion syndrome: metabolic acidosis, hemodynamic instability, cardiac failure, arrhythmias, cardiac arrest, rhabdomyolysis, hypertriglyceridemia, kidney failure, and hyperkalemia
- Usually for infusion rates higher than 75-83 mg/kg/min for more than 48 hours.
- Causes respiratory depression, must be intubated.
- Dexmedetomidine: Dexmedetomidine is a highly selective α2-adrenergic receptor agonist. It has effects similar to other α2-adrenergic receptor agonists (think clonidine) and is used as a sedative
- Rapid onset (5-15 minutes)
- Short duration (2-hour half-life)
- Can cause bradycardia and hypotension (again think clonidine). However, initial titrations can cause a vasoconstrictive rise in BP (temporary and usually not clinically significant). It can also have EKG effects.
- Can affect blood sugar.
- Can be used to decrease intracranial pressure.
- Low incidence of delirium.
- Does not cause respiratory depression.
- Dexmedetomidine can have withdrawal symptoms if used long term (1-2 days). Rebound increase in heart rate and blood pressure and increased anxiety unless titrated.
- Adverse effects are mostly additive effects with other sedatives or medications that lower heart rate and blood pressure.
- Ketamine –
- Analgesic and sedative properties.
- Risk of delirium.
- Adverse effects: hypertension, tachycardia, and delirium.
- No respiratory depression
- Delirium
- CAM-ICU Scale – Confusion Assessment Scale for ICU
- ICDSC: Intensive Care Delirium Screening Checklist
- Best course is prevention, including minimizing BZD doses, opioids, and anticholenergic medications.
- Can treat with: haloperidol, quetiapine, olanzapine, risperidone, ziprasidone. Olanzapine and risperidone have the lowest risk of QTc prolongation.
Neuromuscular Blockade
- Never use a neuromuscular blocker on someone who is not sedated and doesn’t have analgesia.
- Drugs/Electrolytes that potentiate block: corticosteroids, aminoglycosides, clindamycin, tetracyclines, polymixin, calcium channel blockers, Type 1a antiarrhythmics, furosemide, lithium, hypocalcemia, hypermagnesemia, hypokalemia
- Drugs/Electrolytes that antagonize block: aminophylline, theophylline, carbamazepine, phenytoin, hyperkalemia, hypercalcemia
- Succinylcholine and atracurium cause direct mast cell release. Pancuronium, rocuronium, and vecuronium cause the least. This is not anaphylaxis.
- When neuromuscular blockers are used in combination with steroids, it increases the risk of acute quadriplegic myopathy syndrome.
- Reverse non-depolarizing agents with neostigmine or edrophonium (acetylcholinesterase inhibitors). DO NOT USE THESE WITH succinylcholine. They make succ induced paralysis worse.
| Onset | Duration | T 1/2 | ||
| Succinylcholine | 30-60 sec | 4-6 m | < 1min | Succ is the only depolarizing agent. Do NOT use neostigmine with succ. |
| Atracurium | 2-3 m | 20-35 m | 2-20 m | no renal or hepatic dosing |
| Pancuronium | 2-3 m | 60-100 m | 110 m | the longest duration of action |
| Rocuronium | 1-2 m | 30 m | 60-70 m | caution in pulmonary HTN |
| Vecuronium | 3-5 m | 45-65 m | 65-70 m | |
| Cisatracurium | 2-3 m | 20-35 m | 22-29 m | does not release histamine |