Cheat Sheets Cont.
Endotracheal Tubes- Children

Up until age of about 8 , a child's cricoid ring is the narrowest part of the her airway and forms a natural seal with the ET tube.  
For this reason uncuffed ET tubes are typically used in children under 8.  You can determine what size ET tube to use by
matching it the diameter of their pinky finger, or use the formula: Age plus 16 divided by 4= size in mm.
Rubor of Dependency Test
Have patient lie on his back and raise one of his legs about 45-60 degrees.  Hold leg up for a minute.  If his circulation is poor,
his foot will turn grayish-white (pallor) when it is elevated, and then will turn bright red (rubor) when you sit him back up and
let his foot dangle.  RN vol.67, No.11

Ankle-Brachial Index
Take the patient's blood pressure in his arm and again at the ankle.  Divide the systolic BP measured at the ankle by the
systolic pressure in the arm.  The resulting ratio is called the Ankle-Brachial Index.  An index of 1 - 1.3 is normal
0.75 - 1 is considered mild arterial insufficiency,  0.05 - 0.75 is moderate arterial insufficiency,  <0.05 indicates severe lower
extremity arterial disease.  RN vol.67, No.11
Clinical Research

One of nursing’s primary roles is that of teaching.  Being a patient advocate is made difficult if the research you base your practice, is flawed.  
Unfortunately many studies that are done are done poorly; results of those studies though may make it to the press and be quoted by your
patients as reasons for their changing your carefully prepared care plan.

To be acquainted with some of the terms and values of a study can greatly enhance your practice and your patients well being.  Properly being
able to weigh results will enable you to decide whether or not your practice should include knowledge gained by another study.

Things to look for:

Can you identify any
Bias?  {Factors that skew the data in one direction or another}?   

Did they
Blind the study? {Deliberately concealing any study-related information from the subjects and /or clinicians}?

Do they give a
Confidence Interval?  Sometimes shown as CI, ( usually shown at 95%, the smaller the range, the more reliable the results)?

What is the
P value?  The probability that the result occurred by chance ( the lower the p value, the lower the result was by chance.  A p value is
usually considered significant if it is ≤ 0.05)

Was it a
Prospective study?  (Does the study look forward in time)

Were the subjects
Randomly chosen?  Having a equal chance to be in the control group or treatment group.

What does their
Reference List look like?  A minimal list may tell volumes as to how well they researched their subject before starting the study.

Other terms helpful to know:  

Mean – the average value calculated by taking the sum of all values and dividing by the total number of values.
Median- The middle value when data are arranged in order lowest to highest.
Meta-analysis- A statistical method of combining the numerical results of several independent studies.

Wooten, J. RN, Vol.68, No 1 pg. 23
Mean Arterial Pressure
Systolic BP is more a reflection of cardiac output, while diastolic BP reflects Total Peripheral Resistance, (resistance in
blood vessels in the entire circulatory system).  Tissue perfusion becomes compromised in shock.  To determine the
degree of tissue hypoperfusion: Take 1/3 of the pulse pressure, which is the difference between the systolic and
diastolic readings and add it to the diastolic pressure. This result is the Mean Arterial Pressure,(MAP).  In a patient with
a BP of 120/80 the MAP is 93.
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