Mechanical Ventilation

Acute Respiratory Failure: PaO2 and PaCO2 levels

PaO2: <50/60 mmHg

PaCO2: >50mmHg

ET Tube

Placed into the trachea (2-3 cm above carina)

ET Tube Indications

1. During CPR

2. Maintain pt airway

3. For mechanical ventilation

ET tubes are not used when pts have ___ (2)?

1. Completely obstructed upper airway

2. Massive trauma to upper airway

(in both the pt would be recommended for a tracheostomy)

2 Types of ET Tubes

1. Cuffed (for adult and children pts)

2. Cuffless (for infants)

ET Tube: Cuff

- Prevents aspiration

- Prevents leaks

ET Tube: Pilot Balloon

Allows air to be pumped into the cuff

ET Tube: Connection

Connects to mechanical ventilator

ET Tube: Reference Marks

Shows how deep the tube is

2 Ways to Secure ET Tubes

1. Hollister/ET tube holder/Anchor fast

2. Tape

Indications for Tracheostomy

1. Nasal/oral intubation not feasible

2. Upper airway obstruction

3. Impaired respiratory function

4. To assist weaning from the ventilatory support

Trach Tube: Faceplate

- For support

- Trach ties are secured on each side of the faceplate

Trach Tube: Cuff

- Prevent leaks

- Ensure amount of volume delivered

Trach Tube: Pilot Balloon

- Allows air to be pumped into cuff

- Indicator of whether cuff is inflated or not

(inflated = cuff inflated)

Trach Tube: Inner Cannula

- Fits into the outer cannula

- Changed when there is secretion build up

Passy Muir Valve (PMV)

One way valve

Enables trach pts to speak by:

- Allowing inspiration through valve

- But forces exhalation through upper airway

What must you do when using a PMV?

Deflate the trach cuff completely so that the pt can breathe

3 Ways to Provide Humidity for Trachs

1. Heat moisture exchanger (HME)

- Can be used with or without the ventilator

- Good for transport

2. Aerosol

- Only with trach mask and aerosol bootle

- Cannot be used w ventilator

3. Heated humidifier

- Used w ventilator

2 Ways to Secure Trach Tubes

1. Foam trach ties

2. Ties

Mandatory Breaths

- Given according to a set rate

- Either pressure or volume limited

- Vent or pt initiated

Spontaneous Breaths

- Rate and depth determined by pt's effort

- Pt initiated only

Control Vent Mode

No spontaneous breaths

- Vent does all the work for the pt

Assist-Control Ventilation (A/C) Vent Mode

Delivers mandatory breaths

- Pt can initiate mandatory breaths

- No spontaneous breaths

(more commonly seen)

Intermittent Mandatory Ventilation (IMV) Vent Mode

Mandatory breaths given to a set rate

- Allow pt to breathe spontaneously in between each mandatory breath

- Pt's spontaneous breaths not assisted

- Mandatory breaths not synced w pt's effort

Synchronized Intermittent Mandatory Ventilation (SIMV) Mode

Mandatory breaths tries to be in sync w pt's effort

- Spontaneous breaths can be assisted

(more commonly seen)

3 Types of Mandatory Breaths

1. Volume control (VC)

2. Pressure control (PC)

3. VC+(840)

VC Breaths

Mandatory breaths delivered by vent have a fixed volume (Vt)

What pts are VC breaths good for?

Less severe lung disease

PC Breaths

Mandatory breaths delivered by vent have a fixed peak pressure (PIP)

What pts are PC breaths good for?

Very low lung compliance

840 Breaths

Mandatory breaths delivered by vent have a targeted volume (target Vt)

2 Spontaneous Vent Modes

1. Continuous positive airway pressure (CPAP)

2. Bilevel positive airway pressure (BIPAP)

CPAP

Vent provides a consistent pressure (PEEP) to keep alveoli open

CPAP: All breaths are ___

Spontaneous

CPAP: Pt ___ initiate breaths

Can

CPAP: Volume and respiratory rate

Both vary for each breath

CPAP: Is support given during spontaneous breaths?

No

BIPAP

Vent provides a consistent pressure (PEEP) to keep alveoli open

BIPAP: Can the pt initiate breaths?

Yes

BIPAP: All breaths are ___?

Spontaneous

BIPAP: Respiratory rate and volume

Vary per each breath

BIPAP: Is support given during spontaneous breaths?

Yes

Ventilator Terms: f

Respiratory frequency (RR)

Ventilator Terms: Vt

Volume of breath sets

Ventilator Terms: PS

Pressure Support

- Amount of extra pressure given on each spontaneous breath

Ventilator Terms: O2

Amount of oxygen given to pt in a % (aka FiO2)

Ventilator Terms: PEEP

The amount of constant pressure given to the pt to keep their alveoli open

Ventilator Terms: Pi

Inspiratory pressure set for each mandatory breath

Ventilator Terms: Ti

Inspiratory time for each mandatory breath

Ventilator Terms: Ppeak (aka actual PIP)

Maximum inspiratory pressure achieved by pt during breath

Ventilator Terms: ftot

Total number of breaths taken by pt (includes mandatory and spontaneous)

Ventilator Terms: Vte

The actual volume of the breath taken in by the pt

SpO2

Oxygen saturation level measured by pulse oximeter

Normal SpO2

Above 93%

SaO2

Oxygen saturation level measured in blood gas analysis

Normal SaO2

Above 93%

PaO2

Partial pressure of oxygen measured in blood gas analysis

Normal PaO2

Above 8-cmH20

FiO2

Fraction of amount of oxygen delivered to pts via the vent

Room Air FiO2

0.21

Vt Normal Range

Usually set at 6-8cc/kg of IBW

RR Normal Range

Usually between 12-16 breaths per min

Normal PIP or Ppeak

Typically kept below 30cmh2O (an increased pressure indicates poor lung compliance)

Normal PEEP

Typically > 5 cmH2O

2 Factors on Vent Affecting Oxygenation

1. FiO2

2. PEEP

3 Factors on Vent Affecting Ventilation (CO2 levels)

1. Vt or PIP

2. RR

3. PSV

Loss of Pneumatic Power Alarm

Activated if air or O2 sources drop below a certain pressure

Control Circuit Alarm

Activated when a combo of incompatible control variables are set by RT on vent

Output Alarms

Alarms for pressure, flow, volume, and time

- Activated when the measurement is outside the range you set

High Pressure Alarms

If the pressure exceeds the set limit

- Obstruction, secretions, kink, cough, or pneumothorax

Low Pressure Alarm

Might indicate a leak

High or Low Baseline Pressure

Indicates air trapping (high) or leak in system (low)

Low Expired Tidal Volume

If the pt is breathing spontaneously this alarm needs to be set with the spontaneous volume in mind so that it will not alarm with every spontaneous breath

High and Low Minute Ventilation Alarms

- High alarm may indicate hyperventilation

- Low alarm may indicate decreased RR, apnea, or leak

High Respiratory Rate Alarm

May indicate hyperventilation

High and Low FiO2 Alarms

Set +/1 5% ordered FiO2

Patient Ventilator Asynchrony

Patient is fighting or bucking the vent

Common Causes of Patient Ventilator Asynchrony

- Pressure triggering set too negative

- Flow triggering se too high

- Inspiratory rate set too low

If pt is bucking the vent and an RT is not available, what do you do?

- Disconnect pt from the ventilator circuit

- Attach the ambu bag to their ETT or trach

- Bag the pt

Pts must be ___ to use CPAP or BiPAP?

Spontaneous breathing

NM Blocking Agents

- Used to perform endotracheal intubation

- M paralysis/relaxation during surgery

- Helps lower airway pressure and systemic O2 consumption on mechanically ventilated pts

2 Types of NM Blocking Agents

1. Depolarizing

2. Nondepolarizing

Depolarizing NM Blocking Agent

Prevents further stimulation/contraction of m fiber

Nondepolarizing NM Blocking Agent

Blocks acetylcholine from binding to receptors

Is depol or nondepolarizing NM blocking agents fast acting?

- Depolarizing are short acting

- Nondepolarizing are long acting

Goal of Paralytic Agents of Ventilated Pts

Improve ventilation and oxygenation while reducing ventilating pressures

Potential complication of paralytic agents on ventilated pts?

Muscle atrophy after periods of prolonged m disuse

Train of Four

A technique of shocking the mm to check responsiveness to paralytic

Hypnotics = ___

Sleep

Sedatives = ___

Relaxation

Barbiturates cause a generalized ___?

CNS depression

General Aesthethics

Cause CNS depression producing a total loss of consciousness

Propofol

Rapid short acting general anesthetic

- pt is asleep within 40 secs and awake within minutes of termination

- not an analgesic

2 Types of Analgesics

1. Narcotics

2. Nonnarcotics

Narcotics

Alleviate mod to severe pain, acting within the CNS

Nonnarcotics

Treat mild to med pain and produce anti-inflammatory responses

- Alleviate pain w a direct effort on the CNS along w peripheral effects at the site of tissue trauma

5 Weaning Methoda

1. T piece trials

2. CPAP

3. SIMV

4. PSV

5. PSVmax

T Piece Trials

- Pt is sat up in bed

- Taken off vent (still intubated) and placed on a T piece w an FiO2 equal to or slightly greater than on the ventilator for 15 mins

- After each successful trial increase the duration of being off ventilator until reach 1-2 hours at a time

Why are T piece trials uncommon?

Amount of staff required

CPAP (invasive)

Spontaneous breathing mode while vent is still on and intubated