Equations and Fun Facts

Question 1

Maximum heart rate

Answer 1

220-age

Question 2

Target blood pressure for hypertensive patients

Answer 2

135/85 unless they have renal disease or diabetes in which 130/80 is the goal

Question 3

lung cancer associated with pancoast tumors

Answer 3

Squamous cell carcinoma

Question 4

3 procedures you should obtain a CXR after

Answer 4

1. transthoracic needle aspiration
2. thorancentesis
3. central line placement

Due to risk of pneumothorax

Question 5

Acute respiratory failure definition

Answer 5

Hypoxia: PaO2 less than 60 mmHg and PaCO2 greater than 50 mmHg
Hypercapnia: partial pressure of CO2 greater than 50 mmHg

Question 6

Ventilation vs oxygenation

Answer 6

Ventilation=PaCO2
To decrease PaCO2 one must increase RR or increase tidal volume

Oxygenation=O2 saturation and PaO2
To decrease PaO2 in ventilated patient one must decrease FiO2 or decrease PEEP

Question 7

Hypoxemic Respiratory Failure

Answer 7

Low PaO2 with normal or low PaCO2
O2 is less than 90% despite FiO2 greater than .6

Causes: ARDS, pneumonia, pulmonary edema
V/Q mismatch-responsive to O2
intrapulmonary shunting-atelectasis or fluid buildup in alveoli
not responsive to supplemental O2

Question 8

Hypercarbic respiratory failure

Answer 8

High PaCO2
Due to decreased minute ventilation or increase in physiological dead space

Causes: COPD, asthma, CF, severe bronchitis
CNS depression, neuromuscular diseases, respiratory fatigue
DKA, Sepsis and hyperthermia-increased CO2 production

Question 9

Indications for mechanical ventilation

Answer 9

Significant respiratory distress high RR or respiratory arrest
Impaired or reduced level of consciousness with absent gag or cough reflex
Metabolic acidosis
Respiratory muscle fatigue
Significant hypoxemia (PaO2 less than 70)
Or hypercapnia (PaCO2 greater than 50)
Respiratory acidosis: ph less than 7.2 with hypercapnia

Question 10

Parameters of ventilation

Answer 10

Minute Ventilation: 10-12 breaths per minute
FiO2: start at 100% quickly titrate down to maintain PaO2 of 50-60 or O2 saturation greater than 90% (can add PEEP or CPAP to reduce FiO2) less than 60% is safe
I:E ratio: 1:2 is normally used
PEEP: 2.5 cm to 10 cm H2O is the appropiate initial seeting

Question 11

Amount of time you must be abstinent from alcohol to receive liver transplantation in cirrhosis

Answer 11

6 months

Question 12

green/yellow vs. brown vs black gallstones

Answer 12

yellow/green: (cholesterol stones)obesity, diabetes, hyperlipidemia, multiple pregnancies, oral contraceptive use, chron’s disease, ileal resection, advanced age, native americans, cirrhosis, cystic firbrosis

Brown: biliary tract infection

Black: hemolysis or alcoholic cirrhosis

Question 13

Calculation of maintenance fluids

Answer 13

100/50/20 rule
100 for first 10 kg, 50 for second 10 kg, 20 for each 10 kg after that, divided by 24
70 kg man=100x10=1,000, 50 x 10=500, 20 x50=1,000
2,500=total/24=104 ml/hr

OR

4/2/1 rule
4 ml for first 10 kg, 2 for second 10 and 1 for each kg over 20
70 kg=40+20+50=110 ml/hr

Question 14

ionized calcium equation

Answer 14

total calcium-(serum albumin x.8)

Question 15

LDL cholesterol equation

Answer 15

Total cholesterol-HDL-TG/5