Perf Tech 3 Test 7

Question 1

pH formula

Answer 1

pH= -log [H+]

• [H+] must be in Eq/L (not mEq/L)
• normal= 3-5 nEq/L
• extreme range= 10-160 nEq/L

Question 2

Body Fluids pH

Answer 2

arterial= 7.4
venous= 7.35
interstitial= 7.35
-intracellular= 6-7.4 (metabolic waste in cells)
-urine= 4.5-8 (change in H in urine)
-Gastiric HCl= .8

Question 3

Systems that Regulate [H+]

Answer 3

1) chemical acid-base buffers= don’t eliminate, just keep tied up= immediate
2) Respiratory Center= regulates CO2 removal= minutes
3) Kidneys= eliminates excess acid or base = hours/days

Question 4

Buffer

Answer 4

substance that reversibly binds to H+

1) Bicarb buffer system- extracellular
2) phosphate buffer system- extra and intracellular and tubular fluid
3) proteins as buffers- intracellular
- if one changes, they all change cuz equilibrium

Question 5

Bicarbonate Buffer System

Answer 5

extracellular
2 components= weak acid H2CO3 and bicarb salt NaHCO3
carbonic anhydrase= in RBC, alveoli, epithelial cells of renal tubules

Question 6

Henderson-Hasselbalch Equation

Answer 6

pH= pK + log (base/acid)
pH= pK + log (HCO3/ pCO2x.0301

pK= pH where concentration of acid=base
pK for bicarb @ 37 degrees= 6.1
-as temp increase= dissociate= pH, pKa decrease

Question 7

Phosphate Buffer System

Answer 7

mostly in tubular fluid and intracellular (little in extra)
-hydrogen phosphate accepts H
-dihydrogen phosphate releases H
pK for phosphate buffer at 37 degrees= 6.8

Question 8

Protein as Buffer

Answer 8

60-70% of chemical buffering within the cell (especially with RBC and amino acids)
–intracellular

Question 9

Respiratory Center

Answer 9

increase metabolic= increase CO2= increase H= increase alveolar ventilation= blow off CO2= ECF PCO2 decrease
-Negative feedback loop- chemoreceptors sense [H]= increase respiration in medulla oblongata= diaphragm contract more frequently

Question 10

Kidneys

Answer 10

=excrete acids and base by 3 ways

1) secrete H
2) reabsorption of filtered HCO3
3) produce new HCO3

amount of H and HCO3 entering tubules are equal= they combine to make CO2 and H20

Question 11

HCO3 reabsorption

Answer 11

4320 mEq/day filterted and 1 mEq/day excreted
85%- proximal reabsorbed
10%- thick asc reabsorbed
5%- distal reabsorbed

-CO2 + water turns into bicarb and H inside the cell
=Na/HCO3 cotransporter into interstitial
=Na/H counter-transports H into tubular lumen
(in distal intercalated cells= HCO3/Cl counter transports HCO3 into interstitial and H is ATPed out tint tubular lumen)

Question 12

H Secretion

Answer 12

by Na/H counter transporter

• excess H secreted by phosphate and ammonia buffer in urine
• Tubules secrete more H when they sense more PCO2 (respiratory) or H (respiratory or metabolic acidosis) in ECF

Question 13

Things that increase H secretion and HCO3 reab

Answer 13

increase PO2, increase H or decrease in HCO3, low ECF

-angiotensin II, aldosterone, and hypokalemia (K goes out, H comes in, which makes H go out= metabolic alkalosis)

Question 14

Non-Cardiac Applications of CPB

Answer 14

accidental hypothermia, neurosurgery, lung/liver transplant, ILP, chemotherapy, chest trauma
-support= circulation, ventilation, temperature, surgical, drug delivery

Question 15

Accidental Hypothermia

Answer 15

• mild 32-35= shiver, increase BP/HR, diuresis (cuz of vasoconstriction)= Passive rewarming, external
• moderate 30-32= decrease shiver/BP/HR, stiff, supra ventricular arrhythmia= active core rewarm, external, CPB if unstable
• severe <30= cardiac arrhythmia, no rhythm, high viscosity/sludge= CPB (with no CPG, rewarm 4 degrees per hour, need increase volume, can defibrillator at 32 degrees, metabolic acidosis, high K/urine/permeability

Question 16

Pulmonary Problems

Answer 16

• pulm embolectomy= use CPB if hypotension (systolic <90), hypoxia <60, urine <200cc/hr
• chronic respiratory failure= polymehtylpente fiber membrane and double lumen percutaneous cannula (AVALON Duel Lumen)- drains SVC and IVC

Question 17

Neurosurgery

Answer 17

big basilar/cerebral aneurysms= CPB with DHCA
-fem to fem, TEE, no X-clamp, motor LV pressures
Venous Thrombolism= Angiovac (v-v bypass)

Question 18

Taurma

Answer 18

Aorta= DHCA
Thoracic aorta= LH bypass
-careful with heparin cuz other wounds
-cardiohelp for emergencies

Question 19

Liver Transplants

Answer 19

venous-venous bypass= cannulate portal vein/IVC to drain and axillary/IJ vein to return

• allows filling pressure and CO
• less air risk

Question 20

Isolated Limb Perfusion

Answer 20

• chemotherapy dose to isolate limb without systemic toxicity
• need oxygenator, reservoir, centrifugal
• flow 400-500 ml/min, start chemo at 39=40 degrees, don’t cool when terminate
• black light

Question 21

Liver Therapies

Answer 21

ELAD (extracorporeal liver assist device)= liver support up for 10 days= takes cells from plasma and plasma goes thru cartridge with C3A liver cells

Question 22

Hyperthermia in Perfusion

Answer 22

high temps to kill cancer
-local= external, intraluminal/endocavity, interstitial
-regional= deep tissue, CHPP (continuous hyperthermic peritoneal perfusion
=whole body

Question 23

HIPEC, IPHC, IPCH, CHPP

Answer 23

HIPEC- hyperthermic intrapertioneal chemotherapy
IPHC= intraperitoneal hyperthermic chemotherapy
IPCH= intraperitoneal chemohyperthermia
CHPP= continuous hyperthermic peritoneal perfusion

Question 24

Peritoneal Carcinosis

Answer 24

tumor in abdominal organs

Perfusion= open/coliseum, closed, percutaneous

Question 25

HIPEC Protocol

Answer 25

drift to 35 during CRS, 1 l/min, 1.5 hour circulation at 42= warm to 38.8 at most
-types of pumps= RanD, Belmont, ThermoChem