Physiology
When carbon dioxide levels in the blood rise, the rate and depth of ventilation increases/decreases
Increases to blow off CO2
Increased or Decreased V/Q Ratio:
Oversedation due to opioid overdose
Decreased V/Q Ratio
Perfusion/flow is there but patient is not taking in air because of depressive effects of opiates on the respiratory center in the CNS
Determine whether this is hypercapnic or hypoxemic ARF:
Patient is on a non-rebreather mask and PaO2 is less than 60mmHg
Hyopoxemic ARF
Place the following steps of the phathophysiology of ARDS in order:
1. Alveolar Collapse
2. Triggering of Mediators
3. Fibrotic Tissue Formation
4. Onset of pulmonary edema
2, 4, 1, 3
Name that protective ventilation setting:
This mode is frequently used to initiate mechanical ventilaton. Assisted breaths are triggered by inspiratory effort, but if the respiratory rate falls below a preset number, ventilator-controlled breaths are delivered. All breaths whether assisted or controlled are delivered at a specific tidal volume or pressure.
Assist control mode ventilation
Difference between this and SIMV is that in SIMV the volume of patient-iniated breaths is controlled by the patient not by the pre-set volume. Ventilotor controlled breaths are delivered at a pre-set volume.
True or False
CO2 causes vasoconstriction in the cerebral vessels and vasodilation in the peripheral vessels.
False
opposite is true
Vasodilation in cerebral vessels which is why headache is a common initial symptom
Pneumothorax
Decreased V/Q Ratio
Patient who has COPD presents with a PaCO2 of 65mHg, which is over 10mmHg above their baseline
Hypercapnic ARF imposed on chronic respiratory failure
Which of the following is not an early sign of ARDS:
1. Bradycardia
2. Tachypnea
3. Dyspnea
4. Alterations in LOC
1
Bradycardia occurs later as the body cannot compensate anymore
Tachycardia is an early compensatory mechanism.
Name the two ventilator settings that are used during the weaning process.
Synchronized Intermittent Mandatory Ventilation and Presssure-support ventilation.
SIMV exercises respiratory muscles. Pressure-support is gradually withdrawn during weaning.
CPAP also used.
Ventilation is affected by the ________ rate and _______ volume.
Respiratory Rate
Tidal volume: the amount of air inhaled and exhaled with each breath
In fournier article
Atrial Septal Defect
Increased V/Q
The ability to take in air (Ventilation) is not affected. Blood that leaves the heart to get pumped to the body is not fully oxygenated (perfusion)
Patient presents with severe trauma to the chest wall and a PaCO2 of 55, pH 7.33
Hypercapnic ARF
Ventilation problem
Early ARDS will show respiratory acidosis/alkalosis due to hyperventilation/hypoventilation
Respiratory acidosis occurs later due to hypoventilation and depletion of bicarb
Which of the following can contribute to dysfunctional ventilatory weaning response? SATA
1. Airway congestion
2. Inadequate Rest
3. Inadequate Nutrition
4. Non supportive environment
All of them and also pain, anxiety
Pearson pg. 1055
Receptor sites in the medulla and pons are sensitive to high levels of serum ____ while receptor sites aortic arch/carotid artery are sensitive to low levels of serum ____.
Medulla Pons: serum CO2
Aortic arch: O2
Injury to the brainstem
Decreased V/Q Ratio
Patient is hypovolemic due to an active GI bleed
Suspect Hypoxemic ARF
This drug reduces intrapulmonary shunting and improves oxygenation by dilating blood vessels in better ventilated areas of the lungs.
Inhaled Nitric Oxide
Which of the following is not a benefit of frequent position changes:
1. Reduces incidence of a healthcare acquired infection
2. Reduces risk of skin breakdown
3. Reduces risk of ICU-induced delirium
4. Improves V-Q Ratio
3 is not a benefit of positon changes.
Other benefits inlude reduces ICU length of stay and reduces ventilator days, mobilizes secretions and resolves atelectasis
V/Q mismatch is the most common cause of ________.
Hypoxemia
Atelectasis
Increased V/Q
Diffusion problem. Can take in air but cannont diffuse due to collapsed alveoli
Patient presents with ARDS
ARDS is a type of Hypoxemic ARF
True or False:
Drug overdose is a direct cause of ARDS.
False
Drug overdose is considered an indirect cause of ARDS
1. Explain all the alarm sounds and what they mean
2. Explain to the family that their loved one can't hear them so its okay to talk over or about the patient.
3. Encourage frequent family visits
4. Provide anxiolytics as needed
2. Pearson says explain the patient can hear and understand so important not to talk over or about the patient. But talking to the patient about every day things reduces patient sense of isolation and fear.