Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
Normal VT
|
10-20 mL/kg in most domestic species
|
|
Alveolar Ventilation ( VA) =
|
RR x (VT– VD)
|
|
Hypercapnia: PaCO2 > 45 mmHg
|
§ From 45 - ˜100 mmHg it is a respiratory stimulant, § CNS stimulant and vasodilator § In excess of 100mmHg it is an anesthetic & CNS depressant
|
|
PAO2 =
|
[(Patm-PH20) x FiO2] - PaCO2 /0.8
|
|
“Cyanosis” requires >
|
5gm/dL of deoxygenated Hb
|
|
CaO2=
|
(Hg x %Sat x 1.34)+ (0.003 x PaO2)
|
|
Apnea Monitor
|
detects air flow, rate only, alarms w/apnea §continuous, auditory signal
|
|
Ventilometry
|
•Measures the volume of a breath (tidal volume) §simple turbine-propelled vWright’s respirometer §computerized, flow-generated
|
|
Pulse oximetry
|
•Detects infrared light absorption at two wavelengths, and calculates saturation of hemoglobin with O2 •Contains algorithm to subtract non-pulsatile reflectance •PaO2 = SpO2 – 30 (estimate)
|
|
MAP needed for
1.brain 2.renal 3.muscles |
Cerebral and coronary (50-60 mmHg) §Renal and mesenteric (60-70 mmHg) §Muscle compartments (>70 mmHg)
|
|
pulse Not palpable lower than MAP of about
|
40
|
|
sphyngomanometry:
|
uses a cuff to occlude arterial supply to a known pressure, and define the return of flow (systolic)
|
|
oscilometric:
|
uses cuff, but computer detects oscillations of artery. (S, D and M)
|
|
calculated MAP=
|
D+1/3(S-D)
|
|
Pulse Oximetry•Accuracy
|
•Fair SpO2 ,<> 75-90% •Overestimation SpO2< 70% • Underestimation SpO2 > 90%
|
|
Heart Rate limits on CO
|
•Heart rate directly contributes to CO up to a point, then it decreases CO: §Decreasing preload (most of filling occurs in first half of diastole) §Decreasing SV §Decreasing myocardial oxygenation potential (coronary arteries fill in diastole)
|
|
•Type of murmur changes treatment during anesthesia:
|
§Restrictive conditions require increased filling pressures §Regurgitant conditions are aided by increasing forward flow §Failing myocardium requires contractile assistance
|
|
Central Venous Pressure
Monitoring |
•Zero reference = RA •Measurement in cmH2O • with a water column •Or in mmHg with • a pressure transducer •1 mmHg = 1.36 cmH2O •CVP = 0-5 cmH2O in SA •CVP> 12 cmH2O, High •CVP < 0 cm H20, Low
|
|
BP cuff should be what % of limb circumference
|
30-40%
|
|
Results of cooling
|
Increased recovery time: mortality in some studies nDecreased metabolic rate and MAC (5% for each C°) nDecreased oxygen demand of tissues
|
|
Capillary Filtration Pressure
|
•Net Driving Pressure into Capillary •[(Pc-Pi) – (pp- pi)] §Pc = capillary hydrostatic pressure vArteriole approx. 35 mmHg vVenuole approx. 15 mmHg §Pi = interstitial hydrostatic pressure (0) §pp = plasma oncotic pressure (20-28 mmHg) §pi = interstitial oncotic pressure (3mmHg) •Balance » 10 mmHg fluid OUT of capillary • » 10 mmHg fluid IN to venule
|
|
Disadvantages of Colloids
|
•Circulatory overload •Anaphylactic reactions (incidence 0.033%) •Coagulation disorders: §‘Coating of platelets’ §Volume dilution of clotting factors vDextrans (worst) vStarches (hetastarch) vGelatins (not in use)
|
|
Assessment of Hydration
|
•Hydration is the presence of fluid in the interstitial space (intravascular and intracellular are far more difficult parameters to assess) §Dehydration for <3 days 80% ECF, 20% ICF §Dehydration for >3 days 60% ECF, 40% ICF •Koch and Graber
|
|
Emergency Fluid Resuscitation
|
•Aim: restore tissue perfusion & oxygenation •Shock fluid rates (high end value- constant re-evaluation will most likely limit these numbers): •Think ¼ blood volume to start §Blood volume: vDog 80-90 ml/kg (isotonic) vCat 60-70 ml/kg (isotonic) vColloid (dextran or hetastarch) 20ml/kg §7.5% Hypertonic saline in colloid 4ml/kg over 10min
|
|
Acute Blood Loss
|
•Goal: restore circulating blood volume (CBV) •Initially any fluid type will restore volume and maintain cardiac output •Volume of crystalloid must be 3 x volume of colloid for the same CBV •Replace red cells or use whole blood once bleeding is under control, or when loss exceeds 20% of blood volume •What comes out must go in
|