W3 (1) Flashcards
What are the key numbers to know about oxygen?
Maximum pressure on the manometer when giving a breath (20)
Minimum pressure of oxygen in the tank prior to an anesthetic event (500psi)
Oxygen flowrates
Tidal Volume
(TV): The amount of air that passes into or out of the lungs in a single breath
Based on body weight
Tidal Volume = 5 mls/lb. (10 – 15 ml/kg)
TV = 5 x weight (lbs)
Respiratory Minute Volume
(aka Minute Ventillation): The total amount of air that moves into and out of the lungs in 1 minute
Minute Volume = Tidal volume x RR
What are the Oxygen flowrates at Cscc
Partial Rebreathing system:
- Induction – 3 L/min
- Maintenance Range
- 10-20 L/lb/min
- Minimum of 500 ml/min
- Recovery – 3 L/min
Non-rebreathing system:
- Induction – 3 L/min
- Maintenance Range
- 1.5-2 x (Minute ventilation)
- 1.5-2 x (TV x RR) (units = ml/min)
- Recovery – 3 L/min
What are the rules of the rebreathing bag?
Rebreathing bag size = TV x 5 (mls)
Always round up
What are the components of the anesthesia machine
- Compressed gas supply
- Anesthesia vaporizer
- Breathing circuit
- Scavenging system
Function of inhalation anestetic machines
- deliver volatile anesthetic gases
- delivery is via a carrier gas (oxygen, oxygen / nitrous oxide)
- controlled flow rate of delivery
- container in which liquid anesthetic is placed (vaporizer)
- carrier gas passes over volatile liquid and vapors carried to patient
- move exhaled gases away from patient
- scavenging system
- carbon dioxide absorbing / removing system
Pop-off valve related morbidity and mortality
- Left closed, excessive pressure build in the anesthetic system. In the short term the patient is unable to ventilate which increases PaCO2 and decrease PaO2.
- As pressure builds, pulmonary barotrauma develops; in the extreme, lungs rupture and collapse as pneumothorax develops.
- Hypoxic brain damage, including blindness, can result. Pneumothorax requires chest aspiration and possible chest tube placement. Pyothorax could develop.
- The cost of extended hospitalization and the mental anguish associated the patient’s disease and potential death is incalculable.
Shutting down the oxygen system
- Oxygen tank valve closed
- Pop Off Valve Open
- Oxygen flush valve depressed
- Pressure Manometer at zero
- Tank Pressure Gauge at zero
Pressure checking the anesthesia machine
- Oxygen tank valve open
- Pop off Valve closed
- Occlude opening of Y piece
- Oxygen flush valve depressed OR Open Flow meter
- Pressure Manometer at 20 cmH20
- Watch for Manometer pressure to be maintained
- Open Pop Off Valve
- Assure Manometer pressure is 0 cm H20
- Release opening of Y piece
Non-Rebreathing circuits
Patients Less than 15 lbs.
- Non-Rebreathing circuits are designed to deliver oxygen and anesthetic gases with less resistance to breathing in small patients under 15 lbs. (7 kg)
- These circuits do not use a soda lime canister
- Use specially designed circuits and a higher fresh gas flow to remove carbon dioxide
Mechanical Dead space
- Dead space in the breathing circuit is the space where inhalation and exhalation coincide
- Since the patient breathes in and out of the same tube, they could inhale exhaled gas (containing CO2)
How to switch from Rebreathing to Non-rebreating system
- Removes the CO2 absorber
- Removes the flutter valves
- Removes the manometer
- Removes the y-piece
- Ensure oxygen flow is off
- Disconnect the rebreathing circut at the fresh gas hose
- Attach the fresh gas hose to the non-rebreathing circuit
Will have a different pop-off valve and scavenger connection
What are the pertenant parts of the Respiratory system for inhalant anesthesia
- Trachea
- Bronchi
- Bronchioles
- Alveoli
What are the different gas delivery methods
- Mask
- Chamber
- Endotracheal tube
Endotracheal intubation (Definition and importance)
Placement of a sterile semi-rigid plastic or rubber tube into the trachea through the glottis via the oral cavity.
- Maintains an open airway
- Bypasses the nasal passages and pharynx
- Conducts oxygen and anesthetic gases directly from the oral cavity to trachea to lungs
- Removes carbon dioxide
- Prevents pulmonary aspiration (cuffed tube)
- Prevents the leakage of air and gases around the tube (cuffed)
- Monitor and control patient respirations (manual or mechanical)
- Rapid response to respiratory emergencies
- Connected to an anesthetic machine to maintain anesthesia
What are the possible materials the endotracheal tube can come in
Red Rubber
Polyvinyl Chloride (PVC)
Silicone
Components of Endotracheal tube
A. Valve with syringe attached B. Balloon (Inflation or Pilot) C. Machine end D. Connector or Adaptor E. Tie F. Measurement of length from patient end in cm G. Measurement of internal diameter in mm H. Cuff (Shown inflated) I. Patient end J. Murphy eye
What materials do you need for intubation
Select 3 different sizes of tubes (check cuffs) Gauze (to grasp tongue) Tie (to tie tube in) Lubricant Syringe (to inflate cuff) Laryngoscope Stylet Lidocaine 2%
How to size the endotracheal tube
Charts by weight
Palpate the trachea
Nasal septum : Place a tube on top of the patient’s nasal septum.
- The outside diameter of the tube should equal the width of the septum
What issue can occur if the ET tube is incorrectly sized
if the tube extends an excessive distance inside the trachea, it may enter one main stem bronchus.
- Only one lung will be supplied with oxygen and anesthetic gas, leading to hypoventilation, hypoxemia, and possibly difficulty keeping the patient anesthetized.
Complications of endotracheal intubation
E.T. tube failure / obstruction
Anesthetic Machine failure
Human Error : Over inflation of Cuff, Over Zealous Intubation /Extubation, Endoesophageal intubation
