Cardiovascular Parameters

Normal Values

Cardiac Output (CO) 4 – 8 L/min

Cardiac Index (CI) 2.5 – 4 L/min

Systemic Vascular Resistance (SVR) 800 – 1400

Systemic Vascular Resistance Index (SVRI) 1500 – 2400

Pulmonary Capillary Wedge Pressure (PCWP)

Central Venous Pressure (CVP)

Pulmonary Artery Pressure (PAP) 20 – 30/6 – 15

11 ± 4

7 ± 2

Mixed Venous Oxygen Saturation (SvO2) 70 ± 5

Life's Little Equations

CO = HR* x SV SVR = MAP / CO CI = CO / BSA SVRI = SVR x BSA

CaO2 = (Hgb x 1.34 x SaO

2) + (pO

2 x 0.003)

DO2 = CO x CaO

2

VO2 = CO x (CaO

2 –

CvO

2)

Normal DO2 : VO

2= 5 : 1

*HR decreases CO above 120 – 150bpm

The Pump

Preload ~ ED length ↔ EDV ↔ filling pressure Afterload ~ SVR EDV: preload, ventricular distensibility ESV: afterload, ventricular contractility SV = LVEDV – LVESV Atrial kick 15 – 30% LVEDV EF = SV / EDV

Shock

Types of Shock

CVP and PCWP CO SVRI

Hemorrhagic ↓ ↓ ↑Septic ↕ ↑ ↓

↑ ↓ ↑↓ ↓ ↓↕ ↓ ↓

Cardiogenic

Neurogenic

Hypoadrenal

Shock

Adrenal Insufficiency− Acute – CV collapse unresponsive to IVF / pressors− Chronic – hyperpigmentation, weakness, wt loss,

↑K, ↓Na, fever, hypotension− Steroid potency

1x cortisone, hydrocortisone 5x prednisone, prednisolone, methylprednisolone 30x dexamethasone

Shock

Neurogenic Shock− Loss of sympathetic tone− ↓HR, ↓BP, warm skin− Volume, then phenylephrine

Shock

Hemorrhagic Shock− Initially, ↑diastolic pressure

Shock

Cardiac Tamponade− ↓EDV, ↓SV, ↓CO = hypotension− Beck's triad

Hypotension, JVD, muffled heart sounds

− Pericardiocentesis blood does not clot

Shock

Septic Shock− Early sepsis triad

Respiratory alkalosis, confusion, hyperglycemia

− Early gram negative sepsis ↓ insulin, ↑ glucose (impaired utilization)

− Late gram negative sepsis ↑ insulin, ↑ glucose (insulin resistance)

− Xigris: activated protein C fibrinolysis

Emboli

Fat emboli s/p LE fx, procedure− Petechia, hypoxia, confusion− Sudan stain for fat in urine and sputum

PE− PAP >40, ↓pO

2 and pCO

2, respiratory alkalosis, CP,

cough, dyspnea, ↑HR, hemoptysis Air embolus

− Trendelenburg, left lateral decubitus, aspirate w/ central line or PA catheter

Intra-Aortic Balloon Pump

Inflates on diastole− Improves coronary perfusion and SBP

Deflates on systole− Decreases afterload

Receptors

Alpha-1

− Vascular smooth muscle contraction, gluconeogenesis, glycogenolysis

Alpha-2

− Venous smooth muscle contraction Beta-1

− Myocardium contraction and rate Beta-2

− Bronchial smooth muscle and vascular smooth muscle relaxation, increases insulin, glucagon, renin

Dopamine

− Relax renal and splanchnic smooth muscle

Nifty Drugs

Dopamine− Low dose: renal dopamine− Moderate dose: heart beta− High dose: vascular alpha

Dobutamine− Low dose: beta-1 (contractility)− High dose: beta-2 (vasodilation, HR)

Cool Drugs

Milrinone− Phosphodiesterase inhibitor (↑ cAMP)− ↑ Ca flux and ↑ myocardial contractility− Vasodilation

Phenylephrine− Alpha-1 vasoconstriction

Hydralazine− Alpha blocker

Drugs, Drugs, Drugs...

Norepinephrine− Low dose: Beta-1− High dose: Alpha-1, Alpha-2− Splanchnic vasoconstrictor

Epinephrine− Low dose: Beta-1, Beta-2 (↓BP)− High dose: Alpha-1, Alpha-2

Groovy Drugs

Isoproterenol− Beta-1, Beta-2− Arrhythmogenic!!

Vasopressin− V-1: vasoconstriction− V-2: water reabsorption− V-2: release Factor VIII and vWF

Dynamite Drugs

Nipride− Arterial and venous dilator− Cyanide toxicity

Amyl nitrite, then sodium nitrite

Nitroglycerin− Venodilation decreases preload and myocardial

wall tension

Pulmonary

Compliance = ∆V/∆P− ↓ in ARDS, fibrosis, pulmonary edema, reperfusion

injury Aging

− ↓ FEV1 and VC, ↑ FRC

V/Q− High ~ high− Low ~ low

Ventilator

PEEP− Alveoli recruitment – improves FRC (O

2 reservoir)

− ↓ RA filling, ↓ CO, ↓ renal flow, ↑ PVR Minute ventilation = RR x TV

− Adjust pCO2

PS− Decrease work of breathing

PFT

Chronic Lung Disease

Restrictive− ↓ TLC, ↓ RV, ↓ FVC

− FEV1 ↕

Obstructive− ↑ TLC, ↑ RV, ↓ FEV

1

− FVC ↕

Dead Space

Ventilation, but not perfused by pulmonary circulation

Normal airway to level of bronchiole (150cc) Increased by

− Drop in CO− PE− ARDS− High PEEP

ARDS

Acute onset Bilateral infiltrates on chest radiograph PCWP < 18 mmHg or lack of clinical left

ventricular failure PaO2 / FiO2 < 300 mmHg = ALI PaO2 / FiO2 < 200 mmHg = ARDS Cellular-mediated inflammation, debris, ↑

gradient, ↑ shunt, ↓ compliance

Aspiration

PH <2.5 and volume >0.4 cc/kg associated w/ severity

− Gastric acid prophylaxis Mendelson's syndrome – chemical pneumonitis Posterior RUL and Superior RLL

− Dependant when supine

Atelectasis

Bronchial obstruction and respiratory failure Most common post op fever within 48 hrs Fever, tachycardia Risks

− COPD, Upper abdominal surgery, obesity Ambulate, incentive inspirometer, cough, deep

breathe

Renal Failure

Indications for dialysis A, E, I, O, U

− Acidosis− Electrolyte K+− Ingestion: poisoning− Overload− Uremia / uremic coagulopathy

Brian Death

Precludes diagnosis:− Uremia, T>30, BP<70/40, desaturation w/ apnea

test, drugs, metabolic derangements 6-12 hrs:

− No pain response, absent caloric reflex, absent oculocephalic reflex, positive apnea, no corneal reflex, no gag reflex, pupils F&D

Apnea test:− CO2 >60 or increase in CO2 by 20− If BP drops or pt desats, test terminated