CNS Depressant Poisoning/Overdose

Question 1

Definition

Answer 1

Depression of the CNS as a result of a drug

Question 2

Goal of Care

Answer 2

Primary airway management, adequate oxygenation, support of ventilation and transport

Question 3

Common CNS Depressants

Answer 3

frequently involve alcohol, opiates or benzodiazepines
GHB, Tricyclic Antidepressants (TCA)

**Recreational drug overdoses are often due to combined agents (polysubstance)

Question 4

Cues

Answer 4

pts will have levels of consciousness ranging from mildly altered to unresponsive and may progress to cardiovascular collapse and death

Question 5

Guiding Principals

Answer 5

Always consider other potential causes of ALOC
pts w/ medicinal or recreational drug overdose may have trauma, CNS infection or other serious illness in addition to the poisoning

Where there is evidence of trauma or potential head inj, treat appropriately and transport

Question 6

Causes - TCA

Answer 6

TCA overdoses are time critical. Deterioration can be rapid and unexpected

• Tachycardia w/ widening QRS complex
• Contact EPOS conside sodium bicarbonate in any suspected TCA overdose w/ significant tachycardia

Question 7

Causes - Opiod

Answer 7

Overdoses require optimal ventilation and oxygenation prior to consideration of naloxone

• Naloxon is often not required and should only be given if the RR is <10 and ALOC not responding to stimulation
  SC and IM is absorbed more slowly than IV providing a smoother emergence

Titrating IV dose 0.1-0.4 mg IV to target re-establish respiration, circulation and airway control is often safer than giving higher doses initially

Beware of complications of naloxone administration:

• combativeness, violence especially if other drugs are on board
• acute withdrawal sometimes accompanied by a seizure
• acute respiratory distress (rare)
• Deterioration after 20-30mins as naloxone effect diminishes and the opiate re-establishes its effect

Question 8

Causes - GHB

Answer 8

GHB overdoses can cause rapidly fluctuating states from combative to unresponsive w/ respiratory depression.

Management consists of safe and expeditious transport

Question 9

Intervention Guidelines

Answer 9

• Position pt
• Supplemental O2
• Assist resps w/ IPPV if necessary
• Correct suspected or confirmed hypoglycaemia
• Correct Narcotic Intoxication

PCP 
correct hypoglycaemic
Glucagon 1mg IM
Dextrose 10-25g D10W IV
Naloxone
1st 0.4mg IM
2nd 0.4mg IM
3rd 0.8mg IM
4th 2.0mg IM

0.1-2.0mg IV (titrate to target RR)