Mechanical Vents Setting
Total Volume V1
Volume of gas delivered to the pt during each ventilator breath.
Oxygen concentration (FIO2)
- Fraction of inspired oxygen to be delivered to the patient.
- Room air is 21% or .21
- FIO2 is set between 21% and 100% (.21-1.0)
- Adjust to maintain PaO2 greater than 60mmHg and SpO2 greater than 90%.
Positive end-expiratory pressure
- Positive pressure appplied at the end of expiraton of ventilator breath.
- Usual setting is 5cm of water.
- Assists in the prevention of alveolar collapse.
Controlled Mandatory Ventilation
- Ventilator delivers a preset number of breaths/min of a preset volume.
- Additional breath CANNOT be triggered by the patient.
- Used in patients who are paralyzed either by chemical means or by spinal cords injury or neromuscular disease.
- The are unable to initiated spontaneous breaths.
Assist/Control or Assist/Mandatory Ventilation
- Ventilator delivers a preset volume at a preset rate andd when patient initiates a breath.
- Pt can breathe faster than the rate, but not slower.
- Every breath is supported by the ventilator.
- Risk for Hyperventilation, if pt breathis spontneously.
- *Pay close attention to pts breaths
Synchronized intermittent mandatroy ventilation.
- Delivers a preset volume at a preset rate.
- Permits spontaneous beathing.
- The ventilator will synchronize the madatory breaths with the pt's own breath.
- In between "mandatory breaths" (breaths delivered by the ventilator due to the preset rate), the pt can breathe aat their own rate and volume.
- *Good for weaning
Pressure support ventilation
- Fixed amount of pressure augments each breath.
- When pt initates a breath, a high flow of gas is delivered at the preselected pressure level and this pressure is maintained throughout the inspiration.
- Pt controls rate, inspiratory time and flow rate.
- Often used when weaning from the ventilator.
Positive End-Expiratoroy Pressure
- Positive pressure is applied at the end of exhalagtion in the mechanically vented pt.
- Restoresfunctional residual capacity by keeping alveoli open at end of expiration and between breaths.
- Goal: Maintain/improve oxygentation while decreasing risk of oxygen toxicity.
- If PEEP is used, FiO2 can usually be decreased.
Continuous Positive Airway Pressure
- Continuous postive airway pressure to prevent upper airway collapse.
- Pressure is continuous during spontaneous breathing.
- Frequently used for sleep apnea.
- Its is usually administered through a tight fitting mask as humidified oxygen or aas a ventilator setting.
- The presure of flow is constant during both exhaling and inhaling and he level of pressure is determined based on each individual .
- Mechanicl ventilation increases intrathoracic pressure
- Thoracic vessels are compressed
- Decreased venous return to the the heart
- Decreased CO
- Berotrauma and Volutrauma
- Pneumothorax/Tension Pneumothorax
- Fluids and protens can move inot the alveolar space.
- Ventilator Associated Pneumonia VAP
- Pneumonia that occurs 48h or more after ET intubation.
- ET bypasses upper airway defenses.
- Aspiration of bacteria from oropharynx is leading cause.
- Occurs with inappropriate ventilator setting; leakage of air from ventilator tubing, around ET tube or cuff; lung secreation/obstruction; or low ventilation-perfusion ratio.
- Respiratory acidosis, cardiac dysrythmias, atelectasis.
- Mechanical overventilation or pt hyperventilating.
- Spontaneous corrects the problem
- Mechanical vent pt baseline should be the therapeutic goal.
- Ventilator Dependence
- Can be difficult to wean pts who require long term ventilation (COPD, neuromuscular disease.
- PPV and PEEP can increase intracranial pressure by impeding venous drainage.
- Elevate HOB and keep head in alignment.
- Proper positioning to prevent contractures, pressure ulcers, foot drops, and external rotation of hips and legs.
- Prevent problems associated with immobility(PE, DVT).
- Stress Ulcer and GI bleeding
- r/t serioius illness, immobility, discomfort of ventilator, decreased CO to gastric mucosa, steroids, pre-existging ucler.
- Peptic uler prophylaxis.
- Tube feedings.
- Paralytic Ileus
- Change in thoracic and abd cavity pressure
- Affects absorption of nutrients.
- Physical and emotional stress
- Pt is unable to eat, speak, move, or breathe normally.
- Pain, fear, anxiety
- Ordinarry ADLs are extremely difficult.
- The overwhelming need of ICU pt is to feel safe.
- Pt will feel safe if communication, reassurance, decision-making (control), Build a truisting relationship.
- Machine disconnection or malfunction
- Ensure alarms or ON
- Have a plan for manual ventilation
Cardiac Output vs. Cardical Index
- Cardiac Output (CO) = HR X SV
- Volume of blood pumped b the heart in 1 min
- Cardiac Index (CI)
- Measurement of CO adjusted for body size.
- More precise measurement
- Increased: Hyperdynamic states (fever, sepsis)
- Decreased: Hypovolemia, cardiogenic shock, heart failure.
- Amount of muscle fiber stretch at the end of diastole
- Volume in the ventridcle at the end of diastole
- PAWP reflexts L ventricle and diastolic pressure = left ventricular preload.
- Pressure or resistance of blood flow out of the ventricle
- Aterial blood pressure is a major factor affecting afterload
Sytemic Vascular Resistance (SVR)
- Opposition encountered by left ventricle.
- Preload, afterload, & contractility determine SVR
- SVR and aterial BP = comoponents of left bentricular afterload.
Pulmonray Vascular Resistance
- Opposition encountered by right ventricle
- PVR and pulmonary artery pressure = components of rt ventricular afterload.
- Force of heart contractiosn
- Increased contractility means increased SV and increased myocardial O2 requirements.
- Decreased contractility occurs in a failing heart.
- Increase or improve contractility
- Epinephrine and Norepinephrine (Levophed)
- Isoproterenol (Intropin/Dopamine)
- Digitalis-like drugs
- Decrease or diminish contractility
- Calium Channel Blockers
- B-adrenergic blockers
Continuous Atrerial Pressure Monitoring
- Acute hyper or hypotensioin
- Acute respiratory failure
- Neurological Inj
- Coronary interventional procedures
- Continuous infusion of vasoactive medication
- Frequent ABGs
- Cannulate a peripheral artery (radial or femoral)
- Suture cath in place
- Insertion site MUST be immobilized (prevents dislodging of cath line, Line are not kinked)
- Types Of Measurements:
- Systolic, diastolic and mean BP
- Catheter dislodges or line becomes disconnnected.
- Prevention (use Leur-Lock connections, Check arterial Waveform, Ensure alarms are on.
- Inspect for local signs of systemic infection
- Pressures tubing, flush bag, and transducer should be changed every 96 hour.
- circulatory impairment can occure from ( clot, spasm, occulusions of circulation from cath)
- Neurovascular Impairment
- If limb is compromised, it will appear pale, cool, and cap refill less 3 sec; pt may feel tingling, pain, or paresthesia.
- Loss of Limb
- If neurovascular circulation is not restored to the affected limb, pt may loose limb.
- Compromised neurovascular status is an emergency.
Art line Interventions
- Allen Test
- Assess continous flush bag every 1-4 hrs
- maintain line patency andlimit thrombus formations
- ensure bag is inflated to 300mmHg
- ensure bas has fluid in it
- ensure system is delivering 3-6ml/hr of fluid 1-2gts/min
- Nuero checks
- evaluate neurovascular status distal to the arterial insertion site hourly
Pulmonary Artery Flow Directed Cath
- Management of acute, complicated cardiac, pulmonary, and intravascular volume problems.
- Used to measure pulm artery (PAP) pressure and pul ater wedge pressure (PAWP)
- Increased: heart failure, fluid volume overload, embolism, pulmonary edema, pulmonary HTN
- Decreased: fluid volume depletion and pulmonary valve stenosis.
Cental Venous Pressure Measurement
- CVP = measurment of rt ventricular preload
- Norm = 2-8 mmHg
- Measured witha PA cath or a central venous cat (CVC)
- CVP reflects fluid volume problems
- Increased CVP: Rt ventricular failure, volume overload.
- Decrease CVP: hypovolemia
Mixed Venous Oxygen Saturation (SvO2)
- % of Hgb bound to O2 in venous blood
- Norm = 60-80
- Procedure = take specimen form distal prot of PA cath, or can be done continuously
- Reflects pt's ability to balance O2 supply and demand at tissue level.
- Increased SvO2: Over 80% adequate supply, but decreased consumption
- Decreased SvO2: Less 60% decreased O2 supply, increased O2 consumption.
- Decreased CO can be a cause
Measurement of PWAP
- Measures left ventrical end diastolic presssure or left ventricular pre load
- NORMAL RANGE 6-12mmHg.
- Increased: LV failure, cardiac temponade, pulmonary edema, mitral valve regurgitation of stenosis, hypervolemia.
- Decreased: hypovolemia, vasodilators
Complications of PA Cath
- Infection & Sepsis
- Air embolism
- Ventricular dysrhythmias
- PA cath cannot be wedged
- Pulmonary infarction or PA rupture.
- Never inflate balloon more than 8-15 sec.
- Monitor PA pressrue waveforms for evidence of cath occlusions, dislocation, or spontaneous wedging.
- Cont flush with heparinized saline to reduce risk of thrombus formation.
- Maintain proper functioning of the monitoring system
- collect, document and interpret data accurately
- recognized early clues of complications
- Baseline data obtained
- General appearance, LOC, sking color/temp, VS, peripheral pulses, urine output.