Sedation in Traumatic Brain Injury

Table 4

	Morphine	Fentanyl	Alfentanil	Sufentanil	Remifentanil
Pharmacodynamics	𝜇1, 𝜇2, κ and Δ agonists
Elimination 𝑡1/2 (h)	3	3.7	1.5	2.2	0.25
Distribution 𝑡1/2	3–11 min	10–30 min	15 min	5 min	1 min
Neuroprotective effects	May increase ICP	Minimal effect beyond the analgesic effect on CBF and CMRO2
Pharmacokinetics	Onset 6 min; Peak effect 20 min (IV); 30% protein bound; Hepatically metabolised to active metabolites; Renal clearance	95% protein bound; High lipid solubility; 75% first pass pulmonary uptake; Hepatically metabolised to active metabolites; Renal clearance	Onset; Peak 90 s; Duration 5–10 min; 90% protein bound; Hepatically metabolised; Renal clearance	Hepatically metabolised; Renal clearance	Peak 60 s; Small Vd; Rapid clearance; Rapid ester hydrolysis by plasma esterases to inactive metabolite; (Independent of renal & hepatic function)
Advantages	Lower cost; Relative haemodynamic stability; Hypnotic agent sparing; Analgesic properties	Lower cost; Relative haemodynamic stability; Hypnotic agent sparing; Analgesic properties	Relative haemodynamic stability; Hypnotic agent sparing; Analgesic properties	Relative haemodynamic stability; Hypnotic agent sparing; Analgesic properties	Very rapid onset/offset; Less nausea; Relative haemodynamic stability; Hypnotic agent sparing; Analgesic properties
Disadvantages and major side effects			Hypotension; Bradycardia; Respiratory depression; Cough reflex suppression; Seizures; Rigidity; Constipation; Spasm sphincter of Oddi; Nausea; Pruritis
Dosage	0.05–0.1 mg/kg/hr	Induction: 1–3 mcg/kg; Maintenance: 0.5–2 mcg/kg/h	Induction: 10–50 mcg/kg; Infusion: 0.5–1 mcg/kg/min	Induction: 4 mcg/kg	Bolus: 1 mcg/kg; Infusion: 0.0125–1 mcg/kg/min
Appropriate uses in TBI	Long term analgesia; Palliation	Co-Induction agent; Continuous infusion; Palliation	Co-Induction agent	Co-Induction agent	Co-Induction agent; Continuous infusion; infusion