Post on 13-Jan-2016
description
Shock
Amr Mohsen
What is shock?
Acute circulatory failure
leading to
Inadequate tissue perfusion
that results in
Generalized organ hypoxia
3 components
cardiovascular physiologic reserve
1. Heart Rate2. Stroke Volume [venous return (blood volume)
& myocardial contractility & peripheral resistance]
3. Peripheral Resistance
All exist in dynamic equilibrium. These interactions maintain blood pressure. If one of the three becomes abnormal, the other two compensate.
Compensatory mechanisms
Receptors Respond to ResultsSympatho-Adrenal Response
Carotid & aortic baro-receptors
Reduced baroreceptor stretch
++ HR
++ SV
= maintain CO
VC (selective)
= maintain ABP
Compensatory mechanisms
Receptors Respond to ResultsADH (VASOPRESSIN)
Osmoreceptors Increased osmolality
Water retention
VC
Compensatory mechanisms
Receptors Respond to ResultsRENIN(Angiotensin ii & AldosteronE)
Juxtaglomerular apparatus
Renal ischemia
VC
Salt & water retention
Compensatory mechanisms
Sympatho-adrenal Response
Hypotension is an indication of:
1) An abnormality of Heart Rate, Stroke Volume or Peripheral Resistance
2) Failure of the others to compensate.
Classification of shock
failure
=hypovolemia
maldistribution
loss
• Hypovolemic shock
blood loss, plasma loss (burns), fluid loss
• Cardiogenic shock (pump failure)
Arrhythmias, MI, tamponade
• Maldistribution shock– Septic shock– Spinal shock– Anaphylactic shock
Classification of shock
Pathophysiology
Disturbedconsciousness
LiverFailure
DICUlcers
Translocationileus
ATNARF
Hypotension
ARDS
MOF
………
ARDS
Impaired ventilation
•Stiff lungs (surfactant def.)
•Alveolar oedema
Impaired perfusion
•Shock
•Shunts
Impaired diffusion
•Oedema of alveolo-capillary membrane
ARDS
ARDS
Late findingNormal
Chest X-ray
DIC
DIC
Serious sign
•Low platelet count
•Low fibrinogen
•Prolonged PT & APTT
•Elevated Fibrin-degradation product
Management of Shock & MOF
Treat Cause
SupportBody
SystemsMonitoring
In ICU
Treat Cause
Examples
•Control bleeding
•Eradicate sepsis (pus drainage)
•Antibiotics
Monitoring
Clinical parametersPulseTemp (peripheral & core)Blood pressureRespiratory rate
Continuous
•ECG
•Pulse oxymetry
Monitoring
Urine output
Optimum output 0.5-1ml/kg/hour.
Monitoring(invasive)
(2) CVP
N= 0-8 cmH2O (3) Swan Ganz (PAWP)
(1) Arterial cannula for ABP
MonitoringLaboratory tests
•CBC
•Renal function tests (Urea & elect)
•Arterial Bl Gases (ABGs)
•Lactates
•Liver function tests
•PT, PTT & FDP
Monitoring
Normal Arterial Bl Gases (ABGs)
Normal serum electrolytes
pH ~ 7.4
PO2 ~ 100
PCO2 ~ 40
HCO3- ~ 25 mmol/L
Na+ ~ 142 mmol/L
K+ ~ 4 mmol/L
Cl- ~ 103 mmol/L
-- CVP
++ Lactate
-- Haematocrit
ABGs: --PO2
--pH
--PCO2
-- ABP
++ Pulse
-- Urine flow
Cold sweaty skin
SupportBody
Systems
Respiration
•Clear airway
- Suction of secretions
- Tracheal intubation or tracheostomy
•Oxygen (essential)
- Mask for respiratory distress
- Mechanical ventilation for respiratory failure
PO2 < 60mm Hg RR > 35/m
SupportBody
Systems
Correct acidosis
Careful use of IV sodium bicarbonate
SupportBody
Systems
Circulation
Correction of hypovolaemia (essential)
•Two peripheral venous lines
•One central venous line
•Crystalloids
•Blood
•Plasma
Medications (if the above fail to restore BP)
•Inotropes (e.g., dopamine & dobutamine)
•Vasopressors (noradrenaline)
SupportBody
Systems
Renal
•Adequate volume replacement
•Dopamine improves renal blood flow
•Dialysis in case of acute renal failure (K+ >7mmol/L), until the kidneys recover
SupportBody
Systems
GITRoutine acid suppression
IV H2 blockers or Omeprazole
SupportBody
Systems
Coagulation
Treatment of DIC
•Platelet transfusion
•Fresh Frozen Plasma (FFP) as it contains coagulation factors
Mortality of MOF
1.Renal failure only 8%
2.Renal + other organ failure70%
3.Three failing organs 90%