The goal of breathing and circulation is..
Dead space units
Alveoil that are ventilated but not perfused
Alveoli that are perfused but not ventilated
Normal resting oxygen consumption is approximately...
- 250 ml/min
- Increases with activity, stress, and temp
Murray Lung Injury Scale quantifies the injury level using 4 factors:
- Chest X ray findings
- PaO2/FIO2 ratio
- PEEP settings
The most accurate and reliable measure of oxygenation efficiency is direct computation of...
The physiologic shunt (Qs/Qt)
Alveolar-Arterial Oxygen tension defference
P(A - a)O2
- Is a useful mesure of the efficiency of gas exchange
- If elvated indicates gas exchange problem
A healthy person breathing room air has a P(A - a)O2 of...
- 5 to 15 mm Hg
- 100 - 150 if breathing 100%
- The arterial PO2 to inspired oxygentation has become important is the determination of the extent of acute lung injury (ALI) and Acute respiratory distress syndrome (ARDS)
- Most reliable index of gas exchange when FiO2 > .5 and PaO2 < 100
A normal PaO2/FiO2 Ration while breating room air is...
About 400 to 500 mm Hg or greater than 380
- ALI PaO2/FiO2 Ration <300 mm Hg
- ARDS PaO2/FiO2 Ration <200 mm Hg
The volume of oxygen used by the body in milliliters per minute
Oxygen consumption may be useful in determining:
- Nutritional requriments
- Adequacy of oxygen delivery
- May occasionally help determine the cause of high ventilation requriments
Alveoli that are receiving either partial ventilation or partial perfusion
- Most accurate and reliable measure of oxygentation efficiency
- Need arterial and mixed venous sample
What is the single best indicator of effective ventilation?
Normal compliance of lung and chest wall!
60 - 100 ml/cm H2O
- 1 -2 cm H2O/sec
- 5-10 for intubated patients
Peak airway pressure than 50-60 cm H2O is discouraged because...
Increasked risk of barotrauma and hypotension
Plateau pressure should not exceed...
- 30 cm H2O
- It increases the risk of ventilator induced lung injury
- Intrinsic PEEP
- Alters trigger sensitivity
- Leads to errors in compliance calculations
- Overcome with applied PEEP, decrease tidal volume, Increase E time
For healthy person the average total work of breathing is...
0.3 to 0.5 J/L
The normal VC is...
A VC less than 10 to 15 ml/kg indicates...
Considerable muscle weakness which may inhibit the ability to breathe spontaneously
Maximun Voluntary Ventilation
A measure used to assess respiratory muscle reserve, endurance, or fatigue
Normal MVV values for adults!
120 to 180 L/min
Normal O2 coast of breathing!
- 2-5 % of VO2Amount of O2 consumes by ventilatory muscles
Central Venous-Right Atrial pressure
- Is a measure of RA preload
- The amount of venous return to the heart
What is the normal CVP!
- 2 to 6 mm Hg
- It is the lowest of all heart chambers
Placement of a swan-ganz catheter allows...
Determation of CVP, PAP, and PCWP
Placement of catheter carries risk of...
- The pressure that stretches the ventricular walls at the onset of ventricular contraction
- Estimated with PCWP
- LA pressure qhich reflects end diastolic pressure
- Increased with LV failure
Normal arterial blood pressure!
Normal heart rate!
Normal pulmonary arterial pressure!
25/10 mm Hg
Normal pulmonary capillary wedge pressure!
5-10 mm Hg
Normal cardiac output!
Normal systemic vascual resistance!
900- 1400 dynes-sec/cm5
Normal pulmonary vascular resistance!
- The load at which the ventricles must contract
- reflected as increased in SVR
- The muscle tension requried by the left ventricle to generate blood flow
Three primarily reason to measure Interacranial pressures:
- to monitor patients at risk of life threatening intracranial hypertension
- to monitor for evidence of infection
- Th assess the effect of therapy aimed at reducing ICP
Normal mean ICP of a supine patient!
10 to 15 mm Hg
The ICU came out of the...
Polio epidemic of the 1950's
Signals or values may be inaccurate due to?
- Caused by motion
- shift or spike
- self resolving
- real and out of range
- temporary but may need attention
- Normal sinus Rhythm
- The PR interval is consistant
- The QRS complex is no longer than 0.12
- Sinus arrhythmia
- Recognized by irregular spacing between the QRS complex
- First degree heart block
- PR interval is longer than .20 sec
- Premature ventricular contractions
- The QRS is wider than normal
- Ventricular Fibrillation
- The most life threatening arrhythmia
- Requries rapid defilbration and CPR