click below
click below
Normal Size Small Size show me how
Linda Test 2
med lectures
Question | Answer |
---|---|
Name 3 factors which the efficiency of external respiration is dependent on. | 1- VA - is it adequate? 2- V/Q - is it well-matched? 3- Membrane diffusion across alveolar capillary membrane - are there issues? Destruction of alveolar surface? |
List the 3 factors involved in oxygen delivery. | 1- Oxygen Loading 2- Oxygen Transport 3- Oxygen Unloading |
Describe Oxygen Loading | The gas exchange between the alveoli, atmosphere, and pulmonary capillaries. |
Describe Oxygen Transport | You must factor in 1: Cardiac Output, a function of HR and 2: Stroke volume, the volume of blood that is ejected from ventricles per contraction. |
Describe Oxygen Unloading | Internal Respiration: The exchange of gases between systemic capillary level, blood and cells. The oxygen unloaded is the oxygen available for metabolism. |
Why does V/Q mismatching occur even in the normal lung? | Even in normal people, V/Q mismatching occurs because in a normal upright position there is still mismatching at the bases of the lungs ( due to gravity), and perfusion is greatly dependent. |
The normal amount of anatomic deadspace found in the airways of a 150 pound adult would be - | 150 ml |
The normal VD/VT ratio in a spontaneously breathing individual is approximately ____, with a somewhat (higher/lower) ratio being acceptable for patient on mechanical ventilatory support. (which is ? ) | < 0.4 higher < 0.6 |
The distribution of ventilation in the lung depends on regional differences in ____ and ___. | Lung compliance and Airway resistance. |
A VD/VT ratio of 0.7 means that.. | 70% of the VT is lost to VD. |
Calculate the cardiac output. Stroke Volume - 80 cc Heart Rate - 85 BPM Is this within normal range? | SV X HR = CO 80 X 85 = 6800 cc = 6.8 L Yes, normal range is 4-8 |
At residual volume, most gas entering the lung would go to the ____ | apices. |
Most gas inhaled during normal breathing from normal FRC enters the ____ | bases |
Will a change in FRC affect distribution of ventilation? | Yes. |
A pt's minute ventilation is 101 l/m, RR is 22, PaCO2 is 55 torr. Which of the following is she NOT experiencing : 1- increased shunting 2- Increased deadspace ventilation 3- Increased WOB 4- Decreased compliance 5- Decreased Alveolar ventilation | 1- Increased shunting ( with the data given, there is no way to tell ) |
A pulmonary embolus would increase (shunt/deadspace) in the affected area. | deadspace |
The ( lower/higher) the V/Q, the lower is the PO2 that leaves the unit. | lower. |
Increased VD will (increase/decrease) the WOB and 02 demand. | increase. |
Normal anatomic shunt is approximately ___% of cardiac output. | 3% |
List any 2 possible clinical causes of increased anatomic shunting. | 1- any cardiovascular congenital anomalies 2- ventricular septal defect |
____ diffuses 20 times faster than oxygen across the a-c membrane. | Carbon Dioxide |
Name the 2 major requirements for successful pulmonary diffusion. | 1- Surface area 2- Sufficient time |
List the 2 major factors which determine oxygen's ability to dissolve in plasma. Which of these factors determine the volume of oxygen that dissolves in plasma? | _________________ |
At a Pa02 of 100 torr, the volume of 02 dissolved in plasma is ___ How did you arrive at your answer? | 0.3 vol% _______ |
What does volume percent really meant? | Volume of solute/ volume of solution X 100 |
Diffusion of oxygen throughout the body as well as in the cells and on the hgb is controlled by the ( oxygen's solubility coefficient/ the Pa02/ neither of these) | the PaO2 |
HBG tends to combine with 4 oxygen molecules or with none. ( T/F) | True |
Oxygen combines with the ___ sites of the HBG molecule. | heme |
Name the normal HGB value/range for males and females. | Males - 15 g / 100 ml of blood Females - 13-14 g/ 100 ml of blood |
___ is the term used to describe either a decrease in total HGB/RBC count | Anemia |
Name 2 types of abnormal HGB. | HGB F, HGB S, met HGB, carboxyhemoglobin, etc. |
_____ occurs when a quantity of blood is perfused but not ventilated. | Shunting |
___ results from the additive effects of anatomic and capillary shunts. | Physiologic Shunting |
______ is the quantity of gas remaining in the airway after each breath. | anatomic deadspace |
This form of deadspace is represented by a VQ >1. | Relative alveolar deadspace. |
This represents the sum of all alveolar and anatomic deadspace. | Physiologic deadspace. |
A ventilated but not perfused alveolus would represent this form of deadspace. | True alveolar deadspace. |
Represented by the volume of exhaled gas remaining within a ventilator circuit or an oxygen mask which is then inspired on the next breath. | Mechanical deadspace. |
This form of shunting would be represented by an alveolus at which the volume of perfusion exceeds the volume of ventilation to the alveolus. | Relative capillary shunting. |
The pleural, bronchial, and thesbian largely veins contribute to this form of normal shunting. | Anatomic shunting. |
'wasted' ventilation | deadspace |
This type of shunting would be represented by a totally atelectatic alveolus. | true capillary shunting |