Initiation of Mechanical Ventilation Flashcards
Name 2 full support ventilator modes in which you can set a respiratory rate:
Controlled Mandatory Ventilation (CMV); and Assist control (A/C)
Name 2 partial support ventilator modes in which you can set a respiratory rate:
Intermittent Mandatory Ventilation(IMV); and Synchronized intermittent mandatory ventilation(SIMV)
What two settings on the ventilator allow you to manage the patient’s CO2?
Respiratory rate and tidal volume
Which patients should be started at an FiO2 of 100% on the initiation of mechanical ventilation?
Patients with cardiopulmonary issues
What constitutes acute ventilatory failure?
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)
For a patient with a NIF or MIP of less than 20 cmH2O, you should do what in this situation?
Intubate the patient
is the criteria for impending respiratory failure?
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
What is an absolute contraindication for initiating mechanical ventilation?
An untreated tension pneumothorax
Why would you initially set tidal volumes lower than 8-12 mL/kg of ideal body weight?
Low compliance (ARDS 6 – 8mL/kg), increased compliance, air trapping; or the need for reduced lung volumes (pneumonectomy)
What is the most common method of I:E change?
Changing the flowrate
What causes mechanical ventilation failure?
(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%
When initiating mechanical ventilation, when should you use a volume-cycled ventilator?
If there is any problem with the lungs. For example; ARDS, pneumonia , COPD etc.
When initiating mechanical ventilation, when should you use a pressure-cycled ventilator?
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.
What are the complications associated with positive pressure ventilation to initiate a mechanical ventilation?
Decreased venous return, decreased urine output, loss of dignity, development of ventilator dependency.
How do you monitor the readiness to wean or to stop mechanical ventilation?
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.
What is SIMV/IMV mode?
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.
What is Assist/Control mode?
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.
What is Control mode?
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.
What is Pressure Control Ventilation (PCV) mode?
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.
What is Inverse Positive Pressure Ventilation (IPPV)?
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.
What should you do if PaO2 is low?
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.
What should you do if PaCO2 is high?
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
What should you do if PaCO2 is low?
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.
What should you do if PaO2 is high?
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.
