What is the recommended dosage and administration of adrenaline (epinephrine) infusion in a 50ml syringe pump for a critically ill adult patient with hypotension unresponsive to noradrenaline (norepinephrine) and vasopressin?

Adrenaline Infusion in 50ml Syringe Pump

For critically ill adults with hypotension unresponsive to noradrenaline and vasopressin, prepare adrenaline (epinephrine) infusion by adding 5 mg to 50 mL of normal saline or D5W (concentration: 100 mcg/mL), and initiate at 0.05-0.1 mcg/kg/min (3.5-7 mL/h for a 70 kg patient), titrating every 5-15 minutes to achieve a mean arterial pressure of 65 mmHg. 1

Preparation Protocol

Standard 50 mL Syringe Concentration:

• Add 5 mg (5 mL of 1:1000 solution) of adrenaline to 45 mL of normal saline or D5W 1
• Final concentration: 100 mcg/mL 1
• This concentration allows precise titration in critically ill patients requiring vasopressor escalation 1

Alternative Concentration for Lower Doses:

• Add 1 mg adrenaline to 50 mL saline (20 mcg/mL concentration) 1
• Use this dilution when initiating therapy or for patients requiring minimal doses 1

Initial Dosing and Administration

Starting Dose:

• Begin at 0.05-0.1 mcg/kg/min (equivalent to 3.5-7 mL/h for a 70 kg patient using 100 mcg/mL concentration) 1
• For the 100 mcg/mL concentration: 1 mL/h delivers approximately 1.7 mcg/min 1

Administration Route:

• Central venous access is strongly preferred to minimize extravasation risk and tissue necrosis 2, 3
• If central access is unavailable, peripheral IV or intraosseous administration can be used temporarily during initial resuscitation 2
• Never delay adrenaline administration while awaiting central line placement in life-threatening hypotension 1

Titration Strategy

Monitoring Frequency:

• Check blood pressure and heart rate every 5-15 minutes during initial titration 2, 3
• Place an arterial catheter as soon as practical for continuous monitoring 2

Dose Escalation:

• Increase by 0.05 mcg/kg/min every 5-15 minutes based on hemodynamic response 1
• Target mean arterial pressure ≥65 mmHg 2, 3
• Also assess tissue perfusion markers: lactate clearance, urine output >50 mL/h, mental status, capillary refill 2

Maximum Dosing:

• Typical range: 0.1-0.5 mcg/kg/min 2
• In refractory shock, doses may reach 1-2 mcg/kg/min, though mortality increases at higher doses 3

Clinical Context for Adrenaline Use

When to Add Adrenaline:

• Add adrenaline when noradrenaline reaches 0.25 mcg/kg/min and hypotension persists despite adequate fluid resuscitation (minimum 30 mL/kg crystalloid) 2
• Adrenaline is indicated as second-line therapy after noradrenaline and vasopressin in vasodilatory shock 1, 4
• In anaphylaxis refractory to bolus epinephrine, commence infusion after more than three boluses administered 1

Advantages of Adrenaline:

• Provides both alpha-agonist (vasoconstriction) and beta-agonist (inotropic, bronchodilator) effects 1
• Reduces further mediator release in anaphylactic reactions 1
• May improve cardiac output in patients with myocardial dysfunction 1

Critical Safety Considerations

Extravasation Management:

• If extravasation occurs, immediately infiltrate phentolamine 5-10 mg diluted in 10-15 mL of saline intradermally at the site 2, 3
• Pediatric phentolamine dose: 0.1-0.2 mg/kg up to 10 mg 2

Fluid Resuscitation Requirements:

• Ensure minimum 30 mL/kg crystalloid bolus before or concurrent with adrenaline initiation 2
• Vasoconstriction in hypovolemic patients causes severe organ hypoperfusion despite "normal" blood pressure 2

Drug Compatibility:

• Never mix adrenaline with sodium bicarbonate or other alkaline solutions in the IV line, as catecholamines are inactivated in alkaline solutions 2

Adverse Effects to Monitor:

• Excessive tachycardia and tachyarrhythmias 4
• Increased myocardial oxygen consumption 3
• Hyperglycemia and hyperlactatemia 4
• Excessive vasoconstriction leading to end-organ ischemia 3

Alternative Vasopressor Considerations

If Adrenaline Causes Arrhythmias:

• Consider switching to phenylephrine, though this is NOT recommended as first-line therapy 2
• Phenylephrine may raise blood pressure while worsening tissue perfusion 2

Adding Inotropic Support:

• If persistent hypoperfusion exists despite adequate vasopressors, add dobutamine up to 20 mcg/kg/min 2
• Start dobutamine at 2.5 mcg/kg/min, doubling every 15 minutes according to response 5

Pediatric Dosing Modifications

Pediatric Adrenaline Infusion:

• Starting dose: 0.1 mcg/kg/min, titrating to clinical effect 2
• Typical range: 0.1-1.0 mcg/kg/min 2
• Maximum doses up to 5 mcg/kg/min may be necessary in exceptional circumstances 2

"Rule of 6" for Pediatric Preparation:

• Multiply 0.6 × body weight (kg) = number of milligrams 2
• Dilute to total 100 mL of saline 2
• Then 1 mL/h delivers 0.1 mcg/kg/min 2

Weaning Protocol

When to Decrease Adrenaline:

• Once hemodynamic stability achieved and tissue perfusion restored 3
• Decrease by 25% of current dose every 30 minutes as tolerated 3
• Monitor for recurrent hypotension during weaning 3