IV sedation I Flashcards
What ways can we monitor the respiratory system during sedation?
Basic clinical signs
* Respiratory rate
10 – 18 per minute
* Depth of breathing
* Pattern of breathing
* Cyanosis
Advanced
* Pulse oximetry
(mandatory)
* Carbon dioxide monitoring
(Optional)
What type of communication is maintained throughout conscious sedation?
verbal communication
Conscious sedation, a technique in which use of drugs produces depression of nervous system enabling treatment to carried out, but during which verbal communication is maintained throughout the period of sedation
What are the limitations of pulse oximetry?
Limitations:
* Ambient light
* Movement
* Cold peripheries
* Nail varnish
* Measurement lag
What is capnography?
- Detects exhaled CO2 in breath
- Usually via nasal prongs
- Waveform displayed on a monitor
- Allows confirmation of adequate ventilation and an open airway
- Patient has to be breathing through their nose!
what are the respiratory complications during sedation?
Upper Airway Obstruction –> Hypoventilation
what happens during a upper airway obstruction?
sedation leads to decreased muscle tone causing collapse of tongue on to wall of pharynx (called pharyngeal collapse)
Mild cases lead to partial airway obstruction
More severe leads to complete obstruction
what are the signs of airway obstruction?
Signs of airway obstruction
* Snoring
* Stridor
* Drop in O2 saturations
* Loss of CO2 trace
* Seesaw respiration
what is the management of an airway obstruction?
Management
* Supplementary oxygen
* Careful titration of sedation
* Basic airway opening maneuvers
* Airway adjuncts
How to sedative drugs cause hypoventilation?
- Sedative drugs also sedate the Respiratory center in the brain
- Also reduce receptor sensitivity to CO2
- Leads to reduced respiratory rate or complete cessation of breathing
- CO2 levels can build up leading to narcosis
What is hypoventilation?
breathing that is too shallow or too slow to meet the needs of the body. If a person hypoventilates, the body’s carbon dioxide level rises. This causes a buildup of acid and too little oxygen in the blood. A person with hypoventilation might feel sleepy.
How do you detect if someone is hypoventilating?
- Monitoring of respiratory rate (increased)
- Drop in Oxygen saturation
How is hypoventilation managed?
- Reversal of sedation with Flumazenil or Naloxone
- Assisted ventilation with self-inflating ambubag (bag - valve - mask)
What ways can we monitor the cardiovascular system during sedation?
Basic clinical signs
* Heart rate (from pulse oximeter)
* Heart rhythm
* Conscious level
* Skin colour
* Capillary refill
Advanced
* Non-invasive blood pressure (Mandatory)
* ECG monitoring (Optional)
Explain the use of non-invasive blood pressure (NIBP) in sedation?
- Automated machines
- Cuff around arm or calf
- Automatic cycling – every 5 minutes
- Mandatory when giving a sedative technique
what is NIBP affected by?
– Movement
– Wrong size cuff
When should ECG monitoring be used when sedating?
in patients with a history of significant cardiovascular disease
what can a ECG detect?
- Can detect arrhythmias and also signs of cardiac ischaemia and infarction
- Usually a 3-lead configuration
what are cardiovascular complications when sedating?
- Hypotension
- Cardiac Arrhythmias
- Cardiac Arrest
How is hypotension caused during sedation?
Causes:
* Vasodilation caused by sedative drugs
* Some drugs decrease the strength of heart contraction
* Dose related
* More likely to occur in the elderly, and those with existing cardiovascular disease
How is hypotension treated during sedation?
Treatment:
* Prevention better than the cure!
* Stop administering agent
* Place patient head down and with feet elevated
* IV fluids may be required
How is cardiac arrhythmias caused during sedation/ risk factors?
- Multi-factorial aetiology
- May be precipitated by adrenaline in LA
- More likely in elder and those with CVS disease
- Raised blood CO2 levels also increase risk
How is cardiac arrhythmias treated during sedation?
- Call for expert help
- ALS standard algorithms (ALS – advanced life support)
- ABCDE
- give o2 if appropriate (monitor vitals)
- follow ALS flowchart
—> if pt goes into cardiac arrest CPR 30:2 with defibrillator needed
What can cause respiratory complications during IV sedation?
Decreased muscle tone
Body not expelling enough CO2
