Initiation of Mechanical Ventilation

Question 1

Name 2 full support ventilator modes in which you can set a respiratory rate:

Answer 1

Controlled Mandatory Ventilation (CMV); and Assist control (A/C)

Question 2

Name 2 partial support ventilator modes in which you can set a respiratory rate:

Answer 2

Intermittent Mandatory Ventilation(IMV); and Synchronized intermittent mandatory ventilation(SIMV)

Question 3

What two settings on the ventilator allow you to manage the patient’s CO2?

Answer 3

Respiratory rate and tidal volume

Question 4

Which patients should be started at an FiO2 of 100% on the initiation of mechanical ventilation?

Answer 4

Patients with cardiopulmonary issues

Question 5

What constitutes acute ventilatory failure?

Answer 5

The patient cannot sustain spontaneous ventilation to provide adequate oxygenation and ventilation; pH < 7.25, PaCO2 > 50; COPD (uncompensated respiratory acidosis with PaCO2 above the patients normal value, which will be high)

Question 6

For a patient with a NIF or MIP of less than 20 cmH2O, you should do what in this situation?

Answer 6

Intubate the patient

Question 7

is the criteria for impending respiratory failure?

Answer 7

Tidal volume < 5 mL/kg of ideal body weight, vital capacity < 10 mL/kg of ideal body weight, respiratory rate >35 or < 10, minute ventilation > 10 L/min, NIF < -20 cwp, RSBI > 105

Question 8

What is an absolute contraindication for initiating mechanical ventilation?

Answer 8

An untreated tension pneumothorax

Question 9

Why would you initially set tidal volumes lower than 8-12 mL/kg of ideal body weight?

Answer 9

Low compliance (ARDS 6 – 8mL/kg), increased compliance, air trapping; or the need for reduced lung volumes (pneumonectomy)

Question 10

What is the most common method of I:E change?

Answer 10

Changing the flowrate

Question 11

What causes mechanical ventilation failure?

Answer 11

(1) MIP < -20 cmH2O, (2) respiratory rate < 8, (3) minute ventilation < 10 L/min, (4) vital capacity < 10 mL/kg, (5) tidal volume < 5 mL/kg, (6) MEP < 40 cmH2O, (7) VD/VT > 60%, (8) QS/QT >20%

Question 12

When initiating mechanical ventilation, when should you use a volume-cycled ventilator?

Answer 12

If there is any problem with the lungs. For example; ARDS, pneumonia , COPD etc.

Question 13

When initiating mechanical ventilation, when should you use a pressure-cycled ventilator?

Answer 13

If there is any problem other than with the lungs, that’s when you should use a pressure-cycled ventilator. For example; neurological cases, drug overdose, myasthenia gravis, etc.

Question 14

What are the complications associated with positive pressure ventilation to initiate a mechanical ventilation?

Answer 14

Decreased venous return, decreased urine output, loss of dignity, development of ventilator dependency.

Question 15

How do you monitor the readiness to wean or to stop mechanical ventilation?

Answer 15

The patient may be ready to ready to wean if: (1) All vital signs are stable, (2) ABGs are good, (3) Their spontaneous tidal volume is > 5 mL/kg, (4) Their vital capacity is > 10 mL/kg, Their MIP is > 20 cmH20, (6) the QS/QT is < 20%, (7) the Vd/VT is < 60%, (8) The underlying problem has been resolved.

Question 16

What is SIMV/IMV mode?

Answer 16

It is good for weaning, and also good for patients who breathe on their own to a small degree. This mode offers a less likelihood of barotrauma. Be sure to avoid hyperventilation. It is often used on anxious patients until sedation wears off, then a control mode can be used. It consists of a mandatory rate and also allows spontaneous breathing in between the mandatory breaths.

Question 17

What is Assist/Control mode?

Answer 17

It provides a set tidal volume at a set rate. Also, the set tidal volume is delivered even when the patient spontaneously initiates breaths above the set rate. It’s a good mode and works with most patients. Alert patients tend to find it uncomfortable and may need sedation and anxiety controlling medications.

Question 18

What is Control mode?

Answer 18

It is used for unconscious patients. It does not allow patients to determine the rate or tidal volume. For this mode, patients should be sedated or paralyzed. This mode is not common but will provide ventilation just as good as any other mode.

Question 19

What is Pressure Control Ventilation (PCV) mode?

Answer 19

It is used when peak pressures are a primary concern above 50 cmH2O by volume ventilation. There is no tidal volume setting; only inspiratory pressure and inspiratory time. You must set exhaled tidal volume alarms. It is a good mode for high PIP and for hypoxemia patients. It is not a good initial ventilator mode.

Question 20

What is Inverse Positive Pressure Ventilation (IPPV)?

Answer 20

It’s not a good initial mode. It can be used on the same patients as those eligible for pressure control ventilation (ARDS). It may be useful for patients requiring high peak pressures due to low lung compliance.

Question 21

What should you do if PaO2 is low?

Answer 21

You should raise the FiO2 by 5 – 10% until you reach 60%. Then you can raise the PEEP level by 5 cmH2O. If PEEP gets very high (above 20 cmH2O) be sure to monitor the patient’s hemodynamics and cardiac output. If the cardiac output falls, then you should lower the PEEP to the last previous value and begin raising FiO2 if hypoxemia persists.

Question 22

What should you do if PaCO2 is high?

Answer 22

First, you should remove deadspace if the PCO2 is only off by 1 point. Second, you should increase the tidal volume, but be sure to stay in the correct range. Third, you should increase the rate, which is the most common, but only choose it if first two are not options, or if the PaCO2 is 4 mmHg more than the target

Question 23

What should you do if PaCO2 is low?

Answer 23

First, add deadspace if PCO2 is only off by 1 point. Second, you should decrease the rate. Third, you should decrease the tidal volume, but stay in normal range.

Question 24

What should you do if PaO2 is high?

Answer 24

You should decrease the FiO2 until it’s below 60%, then begin lowering the PEEP. If the FiO2 is 60% or below, then immediately focus on the PEEP. You should decrease the PEEP by decrements of 5 cmH2O. Then you can move the FiO2 by 5 – 10% at a time.

Question 25

What does it mean to add Pressure support?

Answer 25

Pressure support helps to overcome the resistance of the circuit tubing during spontaneous breathing. Pressure support helps spontaneous breathing patients accomplish larger tidal volumes. It also helps to wean patient and keep their tidal volume above 5 mL/kg.

Question 26

While in full ventilatory support, how should you position the patient?

Answer 26

Semi-fowler’s position is the best for gas distribution during mechanical ventilation