Critical Care Exam 3

What is acute respiratory failure (ARF)?

inability of the respiratory system to provide appropriate gas exchange.

What are the clinical manifestations for acute respiratory failure?

What is type 1 of acute respiratory failure?

oxygenation problem! PaO2 is less than 60. caused by hypoventilation, intrapulmonary shunting, V/Q mismatch, diffusion effects.

What are the six barriers to diffusion?

surfactant, alveolar epithelium, interstitial fluid, capillary endothelium, plasma, RBC membrane.

What is the V/Q mismatch for type 1 ARF?

perfusion mismatch

What is type 2 of acute respiratory failure?

ventilation failure! Causes a rise in CO2. Can be caused by CNS abnormalities, neuromuscular disorder, drug OD, chest wall abnormalities.

What is the V/Q mismatch for type 2 ARF?

ventilation mismatch! volume of air that enters the upper airway but does not participate in gas exchange is considered the dead space. (25-30%)

What is acute respiratory distress syndrome (ARDS)?

most severe form of acute respiratory failure. This is caused by acute injury that leads to an aggressive immune response.

What is the treatment for acute respiratory failure?

think ABCD. maintain patent airway, optimize O2 delivery, minimize the O2 demand, treat the cause, and prevent complications.

What are the risk factors for ARDS?

obesity, disease severity, age, race, gender, season.

What are the signs and symptoms of ARDS?

dyspnea, tachypnea, hypoxemia, respiratory alkalosis, retractions, respiratory distress, metabolic acidosis.

What are the direct causes of ARDS?

aspiration of gastric contents (most common in elderly and children), multi-system trauma, pneumonia.

What are the indirect causes of ARDS?

Burns, cardiopulmonary bypass, drug OD, fractures of the long bones, multiple blood transfusions, pancreatitis, sepsis.

What is the Berlin criteria?

Mild: 201-300mmHg

Moderate: 101-200mmHg

Severe: less than or equal to 100mmHg.

How do we determine the ARDS scoring?

divide the PaO2 by FiO2. It is important to know this because it correlates with mortality.

What is the acute phase of ARDS?

happens in the first week. uncontrolled inflammatory response which can cause the formation of emboli. Fluid leaks in during this phase and can cause pulmonary edema.

What is the fibrotic phase of ARDS?

2-3 weeks after onset. This is considered "the end," alveoli become extremely stiff and there is severe shunting. MODS will develop.

what is the proliferative phase of ARDS?

1-3 weeks from onset. resolution of pulmonary edema, formation of fibrin matrix. This overlaps with the fibrotic phase.

What is the treatment for ARDS?

adequate oxygenation, intubation, CPAP, BiPAP, ECMO, corticosteroids, prone positioning, hypothermia.

What is acute lung injury (ALI)?

What are the clinical manifestations for acute lung injury?

What is the treatment for an acute lung injury?

What are some evidence based practices that enhance outcomes in treating clients with impaired gas exchange?

oral care q2-4hrs, DVT prophylaxis, pressure ulcer prophylaxis, turning q2hrs, restraints on intubated patients.

What is oxygenation?

Supplying oxygen to body's cells

What is ventilation?

Movement of gasses in and out of alveoli

What is perfusion?

movement of oxygenated blood to tissues

What is the work of breathing (WOB)?

effort required to inspire and expire

What is diffusion?

Movement of O2/CO2 from higher to lower pressure

What is lung compliance?

lungs ability to change in volume with inhalation and exhalation

What is the normal pH?

7.35-7.45

What is the normal PACO2?

35-45 mmHg

What is the normal HCO3?

22-26 mEq/L

What are some causes of respiratory acidosis?

low pH, high CO2

Hypoventilation, CNS depression (anesthesia, overdose), neuromuscular disorders, trauma, restrictive lungs, COPD

What are some causes of respiratory alkalosis?

high pH, low CO2

Hyperventilation, hypoxemia, anxiety, fear, fever, pain, stimulants, excessive ventilation

What are some causes of metabolic acidosis?

low pH, low HCO3

DKA, renal failure, lactic acidosis, drug overdose, diarrhea

What are some causes of metabolic alkalosis?

high pH, high HCO3

Vomiting, NG suction, diuretics, excessive antacids, sodium bicarb

What are the early signs of hypoxemia?

Skin: pallor, cool, dry

Cardiac: tachycardia, HTN, dysrhythmias, chest pain

Resp: Adventitious breath sounds, tachypnea

CNS: anxiety, restless, confusion, fatigue, agitation

What are the late signs of hypoxemia?

Skin: cyanosis

Cardiac: bradycardia, hypotension

Resp: dyspnea, use of accessory muscles

CNS: coma

What is FiO2?

Oxygen, from 0.21 (room air) to 0.6 (21%-60%). Can go up to 1.0 (100%) in emergencies

What is tidal volume?

Amount of air delivered with each preset breath, based on ideal body weight (4-8)

What is PEEP?

Positive pressure into airways during expiration (5-20), holds the alveoli open to increase oxygenation and prevent collapse maximizing gas exchange.

What is Volume Assist/Control (V-A/C)?

Preset RR and Vt for every breath (spontaneous and ventilated breaths.)

Could cause respiratory alkalosis

Who would benefit from Volume Assist/control?

pts who are too weak to perform WOB (post surgery, sedation, paralyzed, pneumonia). NOT indicated for COPD pts

What is Volume Intermittent Mandatory Ventilation (V-IMV)?

Preset RR and Vt, but Vt only given for ventilator initiated breath. Not given on patient initiated breath!

What is CPAP?

positive airway pressure during expiration, when the alveoli normally close. No mandatory breath given/patient performs WOB, so much have respiratory drive

Prevents alveoli from collapsing, good for sleep apnea

What is Pressure Assist Control (P-A/C)?

pressure given with mandatory and spontaneous inspiration, breaths with and without the ventilator.

Set RR, set at 15-25 H2O

Good for ARDS and noncompliant lungs

What are some complications of ventilated patients?

high pressure alarms, low pressure alarms, tube displacement, unplanned extubation, Oral/Nasal mucosa damage, barotrauma, O2 toxicity, Respiratory acidosis or alkalosis, infection, Dysphagia, and aspiration

What is the nursing management for a patient on a ventilator?

Have ambu, suction equipment, trach supplies, and restraints at bedside, Auscultate for lung sounds, get chest x ray, monitor RR assessment/vitals, Change ETT position q4/daily, Perform, VAP bundle (DVT prophylaxis (heparin), PUD prophylaxis (PPI), HOB up, daily sedation vacation, assess ability to go off of vent, oral care q2), speak to them as if they are awake.

What is barotrauma?

alveolar rupture from excessive pressure, pneumothorax can occur. can be caused by having PEEP too high for too long.

What is volutrauma?

when the mode or settings on the ventilator lead to overdistention of alveoli

What is oxygen toxicity?

prolonged FiO2 exposure, atelectasis can occur

What makes a high pressure alarm go off on a vent?

patient biting on tube, kinks in tube, secretions in airway, anxiety, pain, coughing, gagging, mucous plugs, fighting vent, increased airway resistance, decreased lung compliance

What makes a low pressure alarm go off on a vent?

leaks in ventilation, disconnection from tubing, cuff leak, tube out of position.

SHOULD BE ASSESSED FIRST

What medications can be given to provide comfort and reduce stress in patients receiving mechanical ventilation?

Sedatives: propofol, Ativan, Versed, Precedex

Analgesics: Fentanyl, morphine

Paralytics: Nimbex, vecuronium

How do we know when a patient is ready to be weaned off the vent?

PaO2/FiO2 ratio >150-200, PEEP < 5-8, FiO2 < 0.4, Hemodynamically stable, no vasopressors/stable HR, Able to initiate a breath, Conduct a SBT to see if they can breathe for 30-120 minutes, Chest Xray clear, Minimal secretions, Normal breath sounds