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Jiraporn sri-on Jiraporn sri-on Emergency medicineEmergency medicine
Bangkok metropolitan Bangkok metropolitan administration and vajira administration and vajira
hospitalhospital
OutlineOutlineShock
PathophysiologyDeterminants of oxygen deliveryShock syndromes
Hemodynamic monitoringCase discussion
QuestionQuestion #1#1Which of the following is necessary in
the definition of shock?(a) Hypotension(b) Tissue hypoxia(c) Use of pressors(d) Multiple organ dysfunction
Question #1Question #1Which of the following is necessary in
the definition of shock?(a) Hypotension(b) Tissue hypoxia(c) Use of pressors(d) Multiple organ dysfunction
ShockShocka multifactorial syndrome resulting
in inadequate tissue perfusion and cellular oxygenation.
Lead to tissue hypoxiaanaerobic metabolismactivation of an inflammatory cascadeorgan dysfunction hypotension
Irin and Rippe,s Intensive care medicine 6 th edition chapter161Michael L. Cheatham Ernest F. J. Block
PathophysiologyPathophysiologyOxygen demand can’t be evaluate
Determined by metabolic demandOxygen uptake (VO2) or Oxygen
supply(O2 uptake) VO2 = DO2 * ERO2
Oxygen delivery (DO2)
Oxygen extraction ratio (ERO2)proper distribution, SVR
PathophysiologyPathophysiology(O2 uptake) VO2 = DO2 * ERO2
Mark E Astiz critical care fifth edition chapter 107
O2 uptake(VO2)
O2 delivery (DO2)
shock
(O2 uptake) VO2 = DO2 * ERO2
normal
Question #2Question #2Which is the least important
determinant of O2 delivery(DO2) ?(a) Hemoglobin level(b) Cardiac output(c) PaO2
(d) SaO2
Question #2Question #2Which is the least important
determinant of O2 delivery(DO2) ?(a) Hemoglobin level(b) Cardiac output(c) PaO2
(d) SaO2
Oxygen Delivery (DO2)Oxygen Delivery (DO2)= Cardiac Output x Oxygen ContentOxygen Content= CO x [(1.3 x Hb x SaO2) + (0.003 x
PaO2)]Hb concentrationCO SaO2 % of O2 in artery
PaO2 (minimal) pressure of O2 in artery
Inadequate DO2 occurs most often because of low cardiac output
Cardiac OutputCardiac OutputDetermined by:
Stroke volumeHeart rate
Stroke volume determined byPreloadAfterloadContractility
CO = SV * HR
SV ~ Preload * Contractility
Afterload
ConclusionConclusionShock lead to tissue hypoxiaOxygen uptake (VO2) < Oxygen demandO2 uptake (VO2)
= O2 delivery (DO2) * O2 extraction ratio (ERO2)
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3 x Hb x SaO2) + (0.003 x PaO2)]
SV ~ (Preload * Contractility) / Afterload
Classification of shockClassification of shock
Hypodynamic CO
Hyperdynamic CO
Mark E Astiz critical care fifth edition chapter 107
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE,cardiac temponade ,tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload * Contractility
Afterload
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE,cardiac temponade ,tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload * Contractility
Afterload
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE,cardiac temponade ,tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload * Contractility
Afterload
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE,cardiac temponade ,tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload (left heart) * Contractility
Afterload (right heart)
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE, cardiac temponade, tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload * Contractility
Afterload
Classification of shockClassification of shock
Hypodynamichypovolemic (hemorrhagic, nonhemorrhagic)cardiogenic obstructive ( PE,cardiac temponade ,tension pneumothorax)
Mark E Astiz critical care fifth edition chapter 107
O2 delivery (DO2) = Cardiac Output x Oxygen ContentOxygen Content = [SV x HR] x [(1.3x Hb x SaO2) + (0.003x PaO2)]SV ~ Preload * Contractility
Afterload
O2 extraction ratio (ERO2) proper distribution
Hyperdynamic CO but improper distribution, SVR
distributive sepsis adrenal insufficiencyanaphylaxis
O2 uptake (VO2) = O2 delivery(DO2) * O2 extraction ratio(ERO2)
DiagnosisDiagnosis of Shockof ShockLow BP or a rapid, thready pulse.without hypotension
Oliguria or mental status changePeripheral cyanosis and pallor, cool skin
Tachycardia Metabolic acidosis and elevated lactate
53-year-old female with Hx of hyperthyroidism
At 15.20น. 4/8/52
Case discussionCase discussion
CC:fever with dyspnea
Vital signs : T 37.2, BP 80/50, PR 100, RR 24
Oxygen Sat. 100% (RA)
Initial ManagementIV access with NSS starting with 1000 ml
loading in 15 minutesOn cardiac monitoringCollecting blood samples for laboratory
studies include : CBC, BUN, Cr, electrolytes, BS, lactate
Hemoculture x 2, TFT, cardiac markers
HPIShe has had low grade fever
(unmeasured) with dry cough for 2 weeks prior to presentation. The cough became worse when she laid down during the night. She walked up the stairs at home and developed very short of breath which made her come to our ED.
PMHx : Hyperthyroid[PTU(50)2x2 + Propranolol]
She has skipped the medication for nearly 2 weeks.
ALL : NKDA FHx : 2 Sisters with diabetes. SHx : Occasional alcohol
Regular use of over-the-counter drugs (for relieving pain, fatigue and muscle
strain)
General : Alert, middle-aged woman with moderate discomfort,shortness of breath and sweating.
HEENT : Mild pallor, anicteric sclera, no exopthalmos, no lid retraction, mild pharyngeal erythema.
CVS : mildly tachycardic, regular rhythm, no heart murmurs or gallops, no heaving.
RS : Clear bilaterally
Abdomen : Soft, not tender, liver and spleen not palpable.
Ext : No leg edema or tenderness
Skin : No abnormal skin rash
CBC : Hb 13.9, Hct 40, WBC 12000 (N64/L26) PLT 417000, Band 0
Blood ChemistryElectrolyte : Na 123, K 5.6, Cl 87, CO2 21
Cal 9.7, Mg 2.9, PO4 6.6BUN 23, Cr 0.8, BS 751Lactate 5.0CPK 984, Trop-T 4.28, CK-MB 179LFT AST 3164 ALT 2016 ALP 223 TB 0.6 DB 0.3 TP
5.3 Alb 2.3
• Urinalysis : Glu 4+•
Echo bedside : EF 40% IVC 1.4Global hypokinesia with mild
MR, mild TR RV not enlarge
Differential diagnosis
ManagementFluid resuscitationCVPAntibioticEchocardiography
Fluid Challenge Test
Initial CVP <8 8-15 >15 cm H2O PAOP <12 12-16 >16 mm Hg
Volume & Rate 200 mL/10 min 100 mL/10 min 50 mL/10 min
During infusion, CVP rises >5 cm H2O or PAOP rises >7 mm Hg Yes No
Stop challenge Complete the volumeWait 10 min Wait 10 min
CVP change >5 3-5 <2 3-5 <2PAOP change >7 4-7 <3 4-7 <3
CVP and Blood Volume (BV)
Normal CVP - Normovolemia - Hypovolemia c venoconstriction, ventricular
dysfunction - Hypervolemia c hyperdynamic heart function
Low CVP - Absolute or relative hypovolemia (vasodilatat
ion) - - - Hyper , hypo , or normovolemia c hyperdyna
mic heart or negative ITP High CVP
- Hypervolemia - - Hypo or normovolemia c positive ITP, ventric
ular dysfunction, obstruction of blood flow (TS , PS, cardial tamponade)
ข้�อบ่�งชี้�ข้อง Central Venous Line1. CVP measurement and
monitoring2. Lack of peripheral vein 3. Rapid venous access4. Administration of drugs
4.1 Hyperosmolar solution: TPN, hypertonic glucose
4.2Irritating solution: extreme pH, cancer chemotherapy, KCl >40 mEq/L
4.3 Vasopressor: high dose dopamine, NE, adrenaline
5. Frequent blood sampling6. Insertion of other catheters
Inotropic use:Commonly used First-Line Agents
Cause of Hypotension
Pulmonary Capillary Wedge Pressure
Cardiac Output
Systemic Vascular Resistance Preferred Agent(s)
Unknown ? ? ? Dopamine
Hypovolemia ↓ ↓ ↑ Nonea
Decompensated heart failure
↑ ↓ ↑ Dopamine, dobutamine
Cardiogenic shock ↑↔ ↓ ↑ Dopamine
Hyperdynamic sepsis
↓↔ ↑ ↓ Norepinephrine, dopamine
Sepsis with depressed cardiac function
? ↓ ↓ Dopamine, norepinephrine plus dobutamine
Anaphylaxis ? ? ↓ Epinephrine
Anesthesia-induced hypotension
? ? ↓ Phenylephrine, ephedrineb
aVolume resuscitation with intravenous fluids and/or blood products recommended.bFor obstetric patients.
Michael M. Givertz James C. Fang :Irwin and Rippe’s Intensive care medicine 6th edition 2008 pp 335
Ultrasound:Estimation of central venous pressure
IVC size (cm) Respiratory change RA pressure (cm)
<1.5 Total collapse 0-5
1.5-2.5 > 50% collapse 5-10
1.5-2.5 <50% collapse 11-15
>2.5 <50% collapse 16-20
>2.5 No change >20
Robert F.reardon and Scott A.joing : Emergency ultrasound pp 129
IVC measurement demonstrating normal IVC collapse.IVCDmax (expiration) 17.9 mm; IVCDmin (inspiration) 8.9 mm. IVC-CI : IVCDmax– IVCDmin/IVCDmax: (17.9 – 8.9)/17.9; 50% collapse.
Take Home PointsShock is defined by inadequate tissue
oxygenation, not hypotension
Oxygen delivery depends primarily on CO, Hb and SaO2 (not pO2)
Volume expand with crystalloids and blood, if indicated; then add vasoactive drugs to improve vital organ perfusion
Early treatment of shock is critical