SHOCKSHOCK

CVS Monitoring and ShockCVS Monitoring and Shock

Definitions of shock: Definitions of shock:

““An acute circulatory failure with inadequate or An acute circulatory failure with inadequate or inappropriately distributed tissue perfusion resulting in inappropriately distributed tissue perfusion resulting in

generalised cellular hypoxia and generalised cellular hypoxia and global global hypoperfusionhypoperfusion.” .”

““A situation when the intravascular space is larger than A situation when the intravascular space is larger than the existing intravascular volume – the existing intravascular volume – volume deficitvolume deficit ” ”

““A complex clinical syndrome that isA complex clinical syndrome that is the body’sthe body’s responseresponse to to cellularcellular metabolic insufficiency metabolic insufficiency””

Global hypoperfusionGlobal hypoperfusion

Clinical assessment:Clinical assessment:

Peripheries:Peripheries:• Evaluate skin colour and temperatureEvaluate skin colour and temperature• SweatingSweating• Pulse volumePulse volume• Capillary refillCapillary refill• Skin turgorSkin turgor

Level of consciousness:Level of consciousness:• as indicator of the cerebral perfusionas indicator of the cerebral perfusion

Global hypoperfusionGlobal hypoperfusion

Measurement:Measurement:

Vital signsVital signs:: Heart rateHeart rate Blood pressure*Blood pressure* Respiratory rateRespiratory rate Pulse oximetryPulse oximetry Urine output (a measure of renal perfusion)Urine output (a measure of renal perfusion)

*NB: some patients will maintain a normal blood pressure, despite *NB: some patients will maintain a normal blood pressure, despite hypovolaemia as a result of massive catecholamine releasehypovolaemia as a result of massive catecholamine release

Global hypoperfusionGlobal hypoperfusionLaboratoryLaboratory::

compromised tissue perfusion leads to cellular hypoxia, compromised tissue perfusion leads to cellular hypoxia, anaerobic glycolysis and production of lactic acid, anaerobic glycolysis and production of lactic acid, resulting in:resulting in:

Metabolic acidosis (Metabolic acidosis (Base deficitBase deficit)) Low pHLow pH Raised blood Raised blood llactate level (above 2.0 mmol/l)actate level (above 2.0 mmol/l) Reduced mixed venous oxygen saturation (SReduced mixed venous oxygen saturation (SvvOO22

<65%) or central venous oxygen saturation (S<65%) or central venous oxygen saturation (SCVCVOO22 <70%)<70%)

Microcirculatory changesMicrocirculatory changes

Early:

• blood / fluid returns to circulation due to increased sympathetic tone and autoregulation (sympatho-adrenal response)

• mobilization of interstitial fluid

Late:

• tissue damage promotes release of inflammatory mediators

• complement, cytokines, platelet activating factor, products of arachidonic acid metabolism, lysosomal enzymes

• inappropriate vasodilatation

• capillary permeability increases (capillary leak syndrome) causing:

•hypotension

•Increased viscosity

•intravascular coagulation

Effects of Sympatho-adrenal responseEffects of Sympatho-adrenal response

Immediate:

• Increased contractility and heart rateto support cardiac output in patient with moderate hypovolaemia

• Venoconstriction increases cardiac filling

• Arteriolar constrictionmaintains blood pressure

• Blood flow re-distributed (centralisation) to vital organs brain, heart, kidneys, liver, respiratory muscles

Effects of Sympatho-adrenal responseEffects of Sympatho-adrenal response

Delayed:

• Kidney reduced filtration and increased re-absorption restores

circulating volume via Renin-Angiotensin-Aldosterone System

• Capillary reduced hydrostatic pressure leads to fluid moving

from ECF to intravascular space, causing haemodilution and volume expansion

Effects of Sympatho-adrenal responseEffects of Sympatho-adrenal response

OrganOrgan EffectEffect

Eye Dilates pupil

Heart Increases rate and force of contraction

Lungs Dilates bronchioles

Digestive tract Inhibits peristalsis

Kidney Increases renin secretion

Skin Cold, sweating

Penis Promotes ejaculation (!)

Could be irreversible!Could be irreversible!

In the 1940s, Carl Wiggers simulated haemorrhagic shock in dogs In the 1940s, Carl Wiggers simulated haemorrhagic shock in dogs and developed an animal model of 'and developed an animal model of 'irreversibleirreversible shockshock' in ' in

which all animals would die despite aggressive resuscitation.which all animals would die despite aggressive resuscitation.

If abnormalities of tissue perfusion are allowed to If abnormalities of tissue perfusion are allowed to persist, the function of vital organs will be impaired persist, the function of vital organs will be impaired (from compensated to uncompensated and finally (from compensated to uncompensated and finally

irreversible phases).irreversible phases).

“Shock is a syndrome resulting from a depression of many functions but in which reduction of effective circulating volume and pressure are of basic importance and in which impairment of the circulation steadily progresses until it eventuates in a

state of irreversible circulatory failure.”

Types of shockTypes of shock

Shock with low CVP:Shock with low CVP:Hypovolaemic shock - lack of circulating blood volume

Distributive shock - abnormal peripheral microcirculation

Shock with raised CVP:Shock with raised CVP:Cardiogenic shock - “pump failure”

Obstructive shock - mechanical impediment to forward flow

Hypovolaemic ShockHypovolaemic Shock

• Exogenous lossesExogenous losses haemorrhagehaemorrhage diarrhoea and vomitingdiarrhoea and vomiting burnsburns

• Endogenous lossesEndogenous losses into the surrounding tissues or into the body cavitiesinto the surrounding tissues or into the body cavities

• intestinal obstructionintestinal obstruction• occult haemorrhageoccult haemorrhage• ascitesascites

Hypovolaemic ShockHypovolaemic Shock

Clinical signs reflecting Clinical signs reflecting intravascular volume intravascular volume deficitdeficit include: include:

• Capillary refill, pCapillary refill, pulse volume and heart rateulse volume and heart rate• Jugular or central venous pressure (JVP/CVP)Jugular or central venous pressure (JVP/CVP)• Oliguria Oliguria

uurine outputrine output less than 0.5ml/kg/hr less than 0.5ml/kg/hr for 2 consecutive hours /for 2 consecutive hours / less than 400ml per 24 hoursless than 400ml per 24 hours

urine output should be interpreted in the light of all other urine output should be interpreted in the light of all other clinical signsclinical signs

• Trend in arterial pulse wavesTrend in arterial pulse waves increased Systolic Pressure Variability – SPVincreased Systolic Pressure Variability – SPV may be visible on Pulse Oximetermay be visible on Pulse Oximeter

SPV and PVISPV and PVI

Distributive ShockDistributive Shock

associated with severely decreased SVR leading associated with severely decreased SVR leading to intravascular volume deficit to intravascular volume deficit

• sepsissepsis• anaphylaxisanaphylaxis• spinal cord injuryspinal cord injury• vasodilatory drugsvasodilatory drugs

Cardiogenic ShockCardiogenic Shock

Reduced contractilityReduced contractility

• acute LVFacute LVF• myocardial infarctionmyocardial infarction• arrhythmiasarrhythmias• cardiomyopathycardiomyopathy

Obstructive ShockObstructive Shock

Impediment to forward flow:Impediment to forward flow:

• tension pneumothoraxtension pneumothorax• pulmonary emboluspulmonary embolus• cardiac tamponadecardiac tamponade

Management of shockManagement of shock

• A-B-C:• OXYGEN THERAPY• VENTILATORY SUPPORT• HAEMODYNAMIC SUPPORT

• MONITOR AND CLOSE OBSERVATION:- bp, HR, SpO2, resp. rate every ½-1 hr depending on situation- Fluid balance - input/output hourly- Consider invasive monitoring early in A&E- Temperature- GCS when indicated

• TIME-SENSITIVE CARE: • Correct the underlying cause Correct the underlying cause

• e.g. - surgical intervention to stop haemorrhage, treat ileus or e.g. - surgical intervention to stop haemorrhage, treat ileus or diarrhoeadiarrhoea, identify fluid losses, treat infection and sepsis, identify fluid losses, treat infection and sepsis

Hypovolaemic ShockHypovolaemic Shock

Areas of circulatory supportAreas of circulatory support

Circulatory support involves manipulation of the main Circulatory support involves manipulation of the main determinants of Cardiac Output:determinants of Cardiac Output:

1.1. PreloadPreload via volume replacementvia volume replacement

2.2. Myocardial contractilityMyocardial contractility via ivia inotropic notropic agentsagents

3.3. AfterloadAfterload via vasoactive agentsvia vasoactive agents

1:Preload and volume replacement1:Preload and volume replacement

General principlesGeneral principles

• The appropriate rate of fluid administration should be guided by clinical reassessment and sensible limits

• Choose the type of fluid which will best treat the deficit or maintain euvolaemia

• Where a fluid deficit is identified (e.g. haemorrhage, diarrhoea, vomiting, insensible or renal losses), the nature (content) of this deficit should be identified

• “Goal Directed Therapy” - implementation of the proposed clinical endpoints and monitoring of fluid status

Initial fluid resuscitation strategy Initial fluid resuscitation strategy

Dehydration vs. ShockDehydration vs. Shock

Dehydration does not cause death, but Dehydration does not cause death, but shock doesshock does..

Dehydration includes significant depletion of Dehydration includes significant depletion of allall fluid fluid compartments in the body and compartments in the body and may eventuallymay eventually lead to shock lead to shock

The treatment of dehydration requires The treatment of dehydration requires gradual gradual replacement of replacement of fluids, with electrolyte content similar to the specific lossesfluids, with electrolyte content similar to the specific losses

The treatment of The treatment of shockshock requires requires rapidrapid restoration of restoration of intravascular volume by giving fluid that approximates plasma intravascular volume by giving fluid that approximates plasma electrolyte content electrolyte content ((bolus 20 ml/kg over 30 minbolus 20 ml/kg over 30 min))

Fluid requirements in illnessFluid requirements in illnessCrystalloids:Crystalloids:

Pro:Pro: cheap, convenient to use, free of side effectscheap, convenient to use, free of side effects

Con: Con: volume expansion transient (half-life 20-30 min) volume expansion transient (half-life 20-30 min) fluid accumulates in interstitial spacefluid accumulates in interstitial space

pulmonary oedema may resultpulmonary oedema may result ((initial resuscitation: 20 ml/kg bolus over 30 mininitial resuscitation: 20 ml/kg bolus over 30 min))

Colloids:Colloids: (starch - Volulyte, gelatin - Isoplex) (starch - Volulyte, gelatin - Isoplex)

Pro:Pro: greater increase in plasma volumegreater increase in plasma volume

more sustained (half-life 3-6 hrs) more sustained (half-life 3-6 hrs)

Con:Con: costcost

allergic reactionsallergic reactions

clotting abnormalities clotting abnormalities ((initial resuscitation: 0.2-0.3g/kg bolus over 30 mininitial resuscitation: 0.2-0.3g/kg bolus over 30 min))

Fluid requirements in illnessFluid requirements in illnessBlood Blood andand blood products: blood products:

Pro:Pro: clearly indicated in haemorrhagic shockclearly indicated in haemorrhagic shock

maintain Hb concentration at an acceptable level*maintain Hb concentration at an acceptable level*

Con:Con: costcost

risk (small, but significant consequences)risk (small, but significant consequences)(keep Hb>7g/dl unless patient has ischaemic heart disease, then 10g/dl)(keep Hb>7g/dl unless patient has ischaemic heart disease, then 10g/dl)

AlbuminAlbumin Pro:Pro: similar to colloid in terms of long half-lifesimilar to colloid in terms of long half-life

possibly some benefit from transport function of possibly some benefit from transport function of albuminalbumin

Con:Con: costcost

((should be used only in special circumstances - for example: burns, cirrhotic liver should be used only in special circumstances - for example: burns, cirrhotic liver disease and children with septic shock)disease and children with septic shock)

Table: Contents of common crystalloids in mmol/LTable: Contents of common crystalloids in mmol/L

NaNa K K Ca Ca Cl HCO3 Osmolality pH Cl HCO3 Osmolality pH

PlasmaPlasma 140140 4.34.3 2.32.3 100100 26 285-300 7.426 285-300 7.4

Na Cl 0.9%Na Cl 0.9% 154 154 0 0 0 0 154154 0 0 308 308 5.05.0

Dextrose 5%Dextrose 5% 0 0 0 0 0 0 0 0 0 0 278 278 4.0 4.0

Dextrose Saline Dextrose Saline (4%/0.18%)(4%/0.18%) 3030 0 0 0 0 30 30 00 283 283 4.0 4.0

Hartmann’s solutionHartmann’s solution 131 131 5.05.0 2.02.0 111111 0 0 275 6.5 275 6.5

Lactate 29 Lactate 29

Lactated Ringer’sLactated Ringer’s sol’nsol’n 130 130 4.04.0 2.22.2 109109 0 0 273 6.9 273 6.9

Lactate 28Lactate 28

Na Bicarbonate 1.2%Na Bicarbonate 1.2% 150 150 0 0 0 0 0 0 150 150 300 300 8.0 8.0

Na Bicarbonate 8.4%Na Bicarbonate 8.4% 10001000 0 0 0 0 0 0 10001000 20002000 8.0 8.0

Fluid requirements in illnessFluid requirements in illness

The volume of fluid (water) within a The volume of fluid (water) within a compartment is determined by its membrane compartment is determined by its membrane

properties and solute concentrationsproperties and solute concentrations

Intracellular fluids

K + 100, Na + 10As a result of amembrane-bound

ATP-dependent pump ex changes Na for K+

potassium is the most important de terminant of

intracellular osmotic pressure

ICF – 60% of TBW

TBW = 60% of body weight in male, 50-55% in female

ECF – 40% of TBW

80%

Interstitial

fluids

Na + 140

K + 4

Cl – 105

HCO3 - 28

20%

Intra

vascu

lar P

las

ma

pro

tein

s (a

lbu

min

)

Cell m

emb

rane

Va

scu

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do

the

lium

!<------------------------------------------------------------------------------------------------------------------------ 5% Dextrose/Dextrose Saline!<------------------------------------------------ 0.9% Na Cl / Ringer’s Lactate

!<------------------- Colloids

Fluid requirements in illnessFluid requirements in illness

Goals of fluid therapy may be:Goals of fluid therapy may be:• ResuscitationResuscitation restoration of intravascular volume restoration of intravascular volume• Replacement Replacement of deficit and ongoing lossesof deficit and ongoing losses• MaintenanceMaintenance alone alone

MaintenanceMaintenance - Normal requirements could be estimated from table:- Normal requirements could be estimated from table:

WEIGHTWEIGHT RATERATEFor the first 10 kg For the first 10 kg 100 ml/kg/24hrs100 ml/kg/24hrs oror 4 ml/kg/hr 4 ml/kg/hrFor the next 10-20 kg For the next 10-20 kg Add 50 ml/kg/24hrsAdd 50 ml/kg/24hrs or +or +2 ml/kg/hr 2 ml/kg/hr For each kg above 20kg For each kg above 20kg Add 20 ml/kg/24hrsAdd 20 ml/kg/24hrs oror +1 ml/kg/hr +1 ml/kg/hr

So, the maintenance fluid requirement for a 25kgSo, the maintenance fluid requirement for a 25kg child is:child is:1000 + 500 + 100 = 1600 (ml/24hrs) 1000 + 500 + 100 = 1600 (ml/24hrs)

or 40 + 20 + 5 = 65 (ml/hr)or 40 + 20 + 5 = 65 (ml/hr)

ReplacementReplacement

Overt lossesOvert losses

Loss of fluid to the exteriorLoss of fluid to the exteriorbleeding, vomiting, bleeding, vomiting, excessive excessive diuresis or diarrhoeadiuresis or diarrhoea

Occult lossesOccult losses

Fluid sequestration Fluid sequestration in body cavities orin body cavities or tissues tissuesobstructed bowel,obstructed bowel, ascites ascites, intramuscular haematoma, intramuscular haematoma

ReplacementReplacement

Predictable fluid lossesPredictable fluid losses

Increased insensible lossesIncreased insensible losseshyperventilation, fever and sweating (hyperventilation, fever and sweating (extra 500ml/day is required for extra 500ml/day is required for every degree Celsius above 37°C)every degree Celsius above 37°C)

““Capillary leak syndrome”Capillary leak syndrome”characterized by prolonged and severe increase in capillary characterized by prolonged and severe increase in capillary permeability as a result of hypoalbuminaemia, septicemia and toxinspermeability as a result of hypoalbuminaemia, septicemia and toxins

EvaporativeEvaporative losses lossesdue to large wounds or burns; directly proportional to the surface area due to large wounds or burns; directly proportional to the surface area exposed and/or the duration of the surgical procedure exposed and/or the duration of the surgical procedure

““Third Third sspacing“pacing“ internal redistribution of fluids within soft tissues; massive fluid shifts internal redistribution of fluids within soft tissues; massive fluid shifts (tissue swelling in peritonitis, pancreatitis, other infection sites)(tissue swelling in peritonitis, pancreatitis, other infection sites)

NB: called into question (Brandstrup et al 2006)NB: called into question (Brandstrup et al 2006)

Some examples of predictable lossesSome examples of predictable losses

Redistributive and evaporative perioperative surgical lossesRedistributive and evaporative perioperative surgical losses

Degree of Tissue Trauma Degree of Tissue Trauma Additional Fluid requirementAdditional Fluid requirement

Minimal (eg herniorrhapy)Minimal (eg herniorrhapy) 0-2 ml/kg/hr (25ml/kg/day)0-2 ml/kg/hr (25ml/kg/day)Moderate (eg cholecystectomy)Moderate (eg cholecystectomy) 2-4 ml/kg/hr (>50ml/kg/day)2-4 ml/kg/hr (>50ml/kg/day)Severe (eg bowel resection)Severe (eg bowel resection) 4-8 ml/kg/hr (>100ml/kg/day)4-8 ml/kg/hr (>100ml/kg/day)

PARKLANDS FORMULA for patient with severe burns:PARKLANDS FORMULA for patient with severe burns:

4ml x body weight (kg) x % burns = ml/day4ml x body weight (kg) x % burns = ml/day

Regime: Regime: -- 11stst 8 hours: ½ the calculated volume 8 hours: ½ the calculated volume- Next 16 hours: remaining ½ calculated volume- Next 16 hours: remaining ½ calculated volume

Fluid to useFluid to use:: -- Use predominantly crystalloid in the first 12-24 hrsUse predominantly crystalloid in the first 12-24 hrs-- Add colloids after 24 hrsAdd colloids after 24 hrs

NB: now being questioned (Azzopardi et al 2009)NB: now being questioned (Azzopardi et al 2009)

GIFTASUP 2008GIFTASUP 2008

GIFTASUP recommendationsGIFTASUP recommendations

Number RecommendationEvidence

level

1 Don’t use ‘Normal Saline’ 1b

2 Don’t use Dextrose/D. Saline 1b

3 For maintenance, use low Na+, high K+ 5

8

‘Normal saline’ for hypochloraemiaReplace stomach losses with potassium in a crystalloidReplace bowel losses with balanced crystalloid

2,5,5

9 Use ‘Goal-directed therapy’ 1b

10Use invasive monitoring, preferably ‘Flow-based’If unavailable, clinical and laboratory measurements

1b

11Treat blood loss with blood; treat hypovolaemia with crystalloid or colloid

1b

12 If diagnosis of hypovolaemia in doubt, fluid challenge 1b

2:2: ContractilityContractility and and Inotropic Inotropic agentsagents

General principlesGeneral principles

If signs of shock persist despite volume replacement, If signs of shock persist despite volume replacement, inotropic or inotropic or other vasoactiveother vasoactive agents may be given to improve blood pressure agents may be given to improve blood pressure and cardiac output. and cardiac output.

The effects of a particular drug in an individual patient are The effects of a particular drug in an individual patient are unpredictable and the response must be closely monitored. unpredictable and the response must be closely monitored.

Invasive monitoring (CVC, A-line) mandatory in most casesInvasive monitoring (CVC, A-line) mandatory in most cases

All drugs have very short biological half lives (1-2 min).All drugs have very short biological half lives (1-2 min). steady state concentration achieved in 5-10 min from the beginning of IV steady state concentration achieved in 5-10 min from the beginning of IV

infusioninfusion

Effects are associated with aEffects are associated with ann increased myocardial oxygen increased myocardial oxygen consumption and could be damaging to the myocardiumconsumption and could be damaging to the myocardium..

Choice of DrugsChoice of Drugs

InotropesInotropes• Predominant Predominant Beta effect (Beta effect (DirectDirect or or IndirectIndirect))

VasopressorsVasopressors• Predominant Alpha AgonistsPredominant Alpha Agonists• VasopressinVasopressin

VasodilatorsVasodilators• NitratesNitrates• Some Some Beta-2 Agonists Beta-2 Agonists

Inotropic Inotropic agentsagents

Direct predominant action on Direct predominant action on ββ receptors receptors::• Adrenaline (via CVP line only)Adrenaline (via CVP line only)• Dobutamine (might reduce SVR)Dobutamine (might reduce SVR)• Dopamine (cardiac versus renal doseDopamine (cardiac versus renal doses)s)

Indirect actingIndirect acting: : • EphedrinEphedrinee

3: Afterload and Vasoactive drugs3: Afterload and Vasoactive drugs

3. Afterload:3. Afterload: VasopressorsVasopressors

Alpha agonist with some beta effects:Alpha agonist with some beta effects:• NoradrenalineNoradrenaline the most potent (via CVP line only)the most potent (via CVP line only)

Synthetic Alpha agonists:Synthetic Alpha agonists:• MetaraminolMetaraminol• Phenylephrine Phenylephrine can all be given peripherallycan all be given peripherally

• MethoxamineMethoxamine

OthersOthers• Ephedrine Ephedrine indirect Alpha and Beta effectindirect Alpha and Beta effect

• VasopressinVasopressin if patient not responding to if patient not responding to NoradrenalineNoradrenaline

3. Afterload:3. Afterload: VasodilatorsVasodilators

• Nitrates: Nitrates: GTN (Glyceryl Trinitrate)GTN (Glyceryl Trinitrate) donate nitrosyl group -donate nitrosyl group -

Sodium nitroprussideSodium nitroprusside aka nitric oxideaka nitric oxide

• Beta Agonists:Beta Agonists:DopexamineDopexamine increased cardiac increased cardiac

outputoutput

IsoprenalineIsoprenaline causes reflex causes reflex vasodilationvasodilation

Properties of commonly usedProperties of commonly used inotropic inotropic and vasopressor and vasopressor agentsagents

Beta-1Beta-1 Beta-2Beta-2 Alpha-1Alpha-1 Alpha-2Alpha-2 DA-1DA-1 DA-2DA-2

Adrenaline:Adrenaline:

Low doseLow dose ++++ ++ ++ ++ N/AN/A N/AN/A

High doseHigh dose ++++++ ++++++ ++++++++ ++++++ N/AN/A N/AN/A

NoradrenalineNoradrenaline ++++ 00 ++++++ ++++++ N/AN/A N/AN/A

DobutamineDobutamine ++++++++ ++ ++ 00 00 00

Dopamine:Dopamine:

Low doseLow dose ++ 00 ++ ++ ++++ ++

High doseHigh dose ++++++ ++++ ++++ ++ ++++ ++

Summary of hypovolaemia treatmentSummary of hypovolaemia treatment

First priority is to secure the First priority is to secure the AAirway and, if necessary, irway and, if necessary, provide mechanical ventilation (provide mechanical ventilation (BB))

Adequate volume replacement is essential in all cases (Adequate volume replacement is essential in all cases (CC))

Vasopressors may be needed to improve blood pressure Vasopressors may be needed to improve blood pressure and hence perfusion, until euvolaemia is restoredand hence perfusion, until euvolaemia is restored

If continued evidence of impaired tissue oxygenation, If continued evidence of impaired tissue oxygenation, inotropesinotropes may be given to further increase oxygen delivery. may be given to further increase oxygen delivery.

Tissue perfusion must be restored by maintaining an Tissue perfusion must be restored by maintaining an adequate cardiac output and systemic blood pressure with adequate cardiac output and systemic blood pressure with reference to premorbid valuesreference to premorbid values

Distributive shockDistributive shock

Excessive dilatationExcessive dilatation• Sepsis – treat causeSepsis – treat cause• Drugs – avoid administrationDrugs – avoid administration• Neurogenic – will generally resolve in timeNeurogenic – will generally resolve in time• Anaphylaxis – treat and avoid further exposureAnaphylaxis – treat and avoid further exposure

MaldistributionMaldistribution• Arteriovenous shunts are normally closedArteriovenous shunts are normally closed• May be caused to open, particularly in sepsisMay be caused to open, particularly in sepsis• Blood ‘takes the shortcut’ and misses tissuesBlood ‘takes the shortcut’ and misses tissues

Cardiogenic shockCardiogenic shock

Cardiogenic shockCardiogenic shock

Reduced contractility (usually) due to Reduced contractility (usually) due to ischaemia and infarction of myocardiumischaemia and infarction of myocardium

• Features of shock:Features of shock: High LVEDPHigh LVEDP Low COLow CO Pulmonary congestionPulmonary congestion

Shock with high Shock with high CVPCVP

ManagementManagement

DiagnosisDiagnosis• Hx IHD, chest pain, ECG, Hx IHD, chest pain, ECG, • troponin, enzymestroponin, enzymes

TreatmentTreatment• Supportive measuresSupportive measures

Oxygenation, filling, cardiac supportOxygenation, filling, cardiac support

• ThrombolysisThrombolysis• AngiographyAngiography

- PTCA and stenting- PTCA and stenting

Obstructive shockObstructive shock

• Tension pneumothoraxTension pneumothorax• Cardiac tamponadeCardiac tamponade• Pulmonary embolismPulmonary embolism

Shock with high CVP

Tension pneumothoraxTension pneumothorax

Diagnosis Diagnosis often often young patientyoung patient with history of sudden shortness of with history of sudden shortness of

breath, possibly associated with trauma or asthmabreath, possibly associated with trauma or asthma examination of the affected side shows poor expansion, examination of the affected side shows poor expansion,

absent breath sounds and hyper-resonant percussion noteabsent breath sounds and hyper-resonant percussion note trachea and apex beat may be shifted to opposite sidetrachea and apex beat may be shifted to opposite side

Treatment Treatment needle decompression needle decompression chest drain with chest drain with

underwater sealunderwater seal

Cardiac tamponadeCardiac tamponade

Heart cannot fill, so (again) features of shock with high CVP

Cardiac tamponadeCardiac tamponade

DiagnosisDiagnosis• History of trauma or cardiac surgery, myocardial History of trauma or cardiac surgery, myocardial

infarction, uraemia, anticoagulation.infarction, uraemia, anticoagulation.• May be difficult to distinguish from cardiogenic shockMay be difficult to distinguish from cardiogenic shock• Echocardiography may help, exploration is definitiveEchocardiography may help, exploration is definitive

TreatmentTreatment• Supportive measuresSupportive measures

Oxygen, filling, cardiac support.Oxygen, filling, cardiac support.• Sub-xiphoid pericardiocentesis, ideally with Sub-xiphoid pericardiocentesis, ideally with

fluoroscopic controlfluoroscopic control• Surgical explorationSurgical exploration

Pulmonary embolismPulmonary embolism

• Large clot in pulmonary artery causes acute overloading of Large clot in pulmonary artery causes acute overloading of RV and hypovolaemia of LA and LVRV and hypovolaemia of LA and LV

• Features of shock with Features of shock with high high CVPCVP• Crushing central chest painCrushing central chest pain• Evidence of DVT may be presentEvidence of DVT may be present• May look very similar to cardiogenic shockMay look very similar to cardiogenic shock

• ECG may help – SECG may help – SII Q QIIIIII T TIIIIII (only in 30% of cases) (only in 30% of cases)

• Diagnose with invasive pulmonary angiography or CTPADiagnose with invasive pulmonary angiography or CTPA• Supportive treatment : oxygen, filling, cardiac supportSupportive treatment : oxygen, filling, cardiac support• After After resuscitationresuscitation - a - anticoagulation, thrombolysis, surgerynticoagulation, thrombolysis, surgery

CVS MonitoringCVS Monitoring

Non-invasive techniques: Non-invasive techniques: • Clinical assessment of tissue perfusion Clinical assessment of tissue perfusion • ECG, NiBP, pulseECG, NiBP, pulse oximetry; oximetry; • Non-invasive CO studies – Echo, NiCO methodNon-invasive CO studies – Echo, NiCO method

Invasive Monitoring:Invasive Monitoring:• Central venous pressure monitoring; Central venous pressure monitoring; • Direct arterial line pressure monitoring;Direct arterial line pressure monitoring;• Cardiac Output studies (Pulmonary Artery Catheter)Cardiac Output studies (Pulmonary Artery Catheter)

Central Venous CatheterisationCentral Venous Catheterisation

Internal jugular veinInternal jugular vein Subclavian veinSubclavian vein Axillary veinAxillary vein Femoral veinFemoral vein

TThe he absolute valueabsolute value is often unhelpful, except in extreme is often unhelpful, except in extreme cases of severe hypovolaemia, significant fluid overload, or cases of severe hypovolaemia, significant fluid overload, or heart failure.heart failure.

Correct interpretation requires assessment of the Correct interpretation requires assessment of the change in change in central venous pressurecentral venous pressure in response to a in response to a fluid challengefluid challenge in conjunction with alterations in other monitored variables.in conjunction with alterations in other monitored variables.

Complications of central cathetersComplications of central catheters

• On insertionOn insertion Cardiac arrythmiasCardiac arrythmias Pneumothorax / haemothoraxPneumothorax / haemothorax Air embolismAir embolism Surrounding tissue injuries Surrounding tissue injuries Cardiac tamponadeCardiac tamponade

• Post insertionPost insertion Infection (consider removal after 7 days)Infection (consider removal after 7 days) Cardiac arrhythmiasCardiac arrhythmias Displacement of catheterDisplacement of catheter Blockage of lumen(s)Blockage of lumen(s) Air / material embolismAir / material embolism Thrombus formationThrombus formation

Direct arterial pressure monitoringDirect arterial pressure monitoring

Invasive cannulation of an artery for continuousInvasive cannulation of an artery for continuous monitoring of direct BP; used in:monitoring of direct BP; used in:

-Haemodynamically unstable patient, patient in shockHaemodynamically unstable patient, patient in shock-Patient receiving inotropic Patient receiving inotropic / vasoactive / vasoactive agentsagents-For blood sampling (ABG’s, U&E’S, glucose etc)For blood sampling (ABG’s, U&E’S, glucose etc)-Patient with physiological difficulties for NIBP (obesity, AF)Patient with physiological difficulties for NIBP (obesity, AF)

Stroke volume variationStroke volume variation (SVV) : difference between the largest and the

smallest arterial wave traces during respiratory cycle

Techniques Techniques toto assess cardiac assess cardiac output output (Flow-based techniques)(Flow-based techniques)

Oesophageal DopplerOesophageal Doppler• based on determination of RBC velocitybased on determination of RBC velocity

TTrans-oesophageal Echocardiography (TOE)rans-oesophageal Echocardiography (TOE)• Gold standard Gold standard inin US US

Arterial pulse Arterial pulse wave wave analysisanalysis• eg Pieg PiCCO, Vigileo, LiDCOCCO, Vigileo, LiDCO

Partial CO2 re-breathing techniquePartial CO2 re-breathing technique• based on exhaled CObased on exhaled CO22 measurement (capnography) eg NiCO measurement (capnography) eg NiCO

Bioimpedance / BioreactanceBioimpedance / Bioreactance• Change in amplitude / frequency of a transmitted electrical signalChange in amplitude / frequency of a transmitted electrical signal

Oesophageal DopplerOesophageal Doppler

Pulse contour analysisPulse contour analysis

Pulmonary artery catheterisationPulmonary artery catheterisation

Dr. Jeremy Dr. Jeremy SwanSwan and Dr. William and Dr. William GanzGanz Developed 1971 Developed 1971 Catheterisation of the pulmonary artery with a balloon flotation Catheterisation of the pulmonary artery with a balloon flotation

catheter allows to measure:catheter allows to measure:

• PPreload - indirect assessment of the filling pressure of the left reload - indirect assessment of the filling pressure of the left ventricle (pulmonary artery occlusion or wedge pressure)ventricle (pulmonary artery occlusion or wedge pressure)

• Contractility – by using ‘thermodilution’ techniqueContractility – by using ‘thermodilution’ technique

• Afterload or SVR - by calculating from the formulaAfterload or SVR - by calculating from the formulaSVR = CO / MAPSVR = CO / MAP

(PAC; PAFC; PAOP; PAWP)(PAC; PAFC; PAOP; PAWP)

QuestionsQuestions

Case 1Case 1

A A 40 year old man comes to the ED having fallen on the 40 year old man comes to the ED having fallen on the path and hurt his left lower ribs. He is alert and in pain. path and hurt his left lower ribs. He is alert and in pain. He is cool and clammy to touch. His observations are: He is cool and clammy to touch. His observations are:

pulse 110 bpmpulse 110 bpm blood pressure 140/90 mmHgblood pressure 140/90 mmHg respiratory rate 22/minrespiratory rate 22/min

Q1: could he have a life-threatening haemorrhage?Q1: could he have a life-threatening haemorrhage?

Q2: what immediate steps would you take?Q2: what immediate steps would you take?

Q3: how would you decide which way to proceed?Q3: how would you decide which way to proceed?

Case 1Case 1

YesYes. It is highly possible that this man has ruptured his spleen. . It is highly possible that this man has ruptured his spleen.

He could have lost 20‑30% of his circulating blood volume already He could have lost 20‑30% of his circulating blood volume already and needs urgent fluid resuscitation, imaging and surgery.and needs urgent fluid resuscitation, imaging and surgery.

This patient has cold peripheries and is tachycardic but not This patient has cold peripheries and is tachycardic but not hypotensive.hypotensive.

A 40‑year‑old man with a severe bleed may compensate by A 40‑year‑old man with a severe bleed may compensate by vasoconstriction.vasoconstriction.

Case 1Case 1

Immediate management: A-B-C.Immediate management: A-B-C.

• A - Airway is okay.A - Airway is okay.• B - Check breathing and insert two large bore cannulae B - Check breathing and insert two large bore cannulae

for fluid.for fluid.• C - Circulation is assessed by looking at the vital signs C - Circulation is assessed by looking at the vital signs

and for signs of hypoperfusion (for and for signs of hypoperfusion (for example, example, skin temperature, capillary refill). skin temperature, capillary refill).

Case 1Case 1

Treatment of hypovolaemia Treatment of hypovolaemia • Rapid iv fluid boluses (Hartmann’s, colloid, etc)Rapid iv fluid boluses (Hartmann’s, colloid, etc)• Blood given to maintain Hb above 7.5g/dlBlood given to maintain Hb above 7.5g/dl• Regular reassessment of all parametersRegular reassessment of all parameters• Repeated fluid boluses including:Repeated fluid boluses including:

blood productsblood products colloids and crystalloidscolloids and crystalloids

• Definitive treatment – surgical with or without imagingDefinitive treatment – surgical with or without imaging• If becomes hypotensive despite fluid resuscitation If becomes hypotensive despite fluid resuscitation

consider invasive monitoring and vasopressors or consider invasive monitoring and vasopressors or inotropic drugs via central line.inotropic drugs via central line.

Case 1Case 1

Or, treatment of pneumothorax:Or, treatment of pneumothorax:• Immediate needle decompressionImmediate needle decompression

22ndnd ICS, mid-clavicular line ICS, mid-clavicular line 14G cannula14G cannula

• Chest drain insertionChest drain insertion 55thth ICS, mid or anterior axillary line ICS, mid or anterior axillary line Superior surface of ribSuperior surface of rib Blunt dissectionBlunt dissection Forceps introductionForceps introduction

• Chest X-rayChest X-ray

Case 1Case 1

Next steps:Next steps:• CT scan to assess severityCT scan to assess severity

of splenic injuryof splenic injury• Conservative vs surgeryConservative vs surgery• Critical care admissionCritical care admission• Invasive monitoringInvasive monitoring• Bed rest 72 hoursBed rest 72 hours• Immediate surgery if decompensates laterImmediate surgery if decompensates later

Case 2Case 2 A 55‑year‑old man is on the Coronary Care Unit when A 55‑year‑old man is on the Coronary Care Unit when

he develops a low urine output (<0.5 ml/kg per hour he develops a low urine output (<0.5 ml/kg per hour for the last 2 hours). He has cool hands and feet. His for the last 2 hours). He has cool hands and feet. His vital signs: vital signs: • pulse 90bpm, pulse 90bpm, • blood pressure 110/50 mmHg, blood pressure 110/50 mmHg, • respiratory rate 22 per minute, respiratory rate 22 per minute, • core temperature 37°C. core temperature 37°C.

He had an inferolateral infarct 24 hours ago.He had an inferolateral infarct 24 hours ago.

Suggest some causes.Suggest some causes.

How do you manage this patient?How do you manage this patient?

Case 2Case 2

Possibilities:Possibilities:• HypovolaemiaHypovolaemia

Poor intake, increased outputPoor intake, increased output

• CardiogenicCardiogenic Further cardiac eventFurther cardiac event

• ObstructiveObstructive Pneumothorax from invasive line, PE from immobilityPneumothorax from invasive line, PE from immobility Unlikely due to thrombolysis / anticoagulationUnlikely due to thrombolysis / anticoagulation

Differentiation is difficultDifferentiation is difficult Requires clinical skills and investigationsRequires clinical skills and investigations Examine drug chartExamine drug chart Consider other features in presenting complaintConsider other features in presenting complaint

Case 2Case 2 Reduced intake:Reduced intake:

• Nausea, nil by mouth for procedures, loss of appetiteNausea, nil by mouth for procedures, loss of appetite

Increased output:Increased output:• Vomiting, sweating, iatrogenic diuresis for failureVomiting, sweating, iatrogenic diuresis for failure

Management:Management:• Listen to lungs for signs of failure and exclude tensionListen to lungs for signs of failure and exclude tension• CXR looking for pulmonary oedemaCXR looking for pulmonary oedema• ABG – base deficit ABG – base deficit suggestssuggests dehydration dehydration• Fluid challenge – watch response carefullyFluid challenge – watch response carefully• Consider invasive monitoring (A line, CVC)Consider invasive monitoring (A line, CVC)• If still unclear, cardiac output monitoringIf still unclear, cardiac output monitoring

Case 3Case 3

An 80‑year‑old lady is admitted with abdominal An 80‑year‑old lady is admitted with abdominal pain and malaena. She has a permanent pain and malaena. She has a permanent pacemaker and is treated for congestive cardiac pacemaker and is treated for congestive cardiac failure, which is under control. Her pulse and failure, which is under control. Her pulse and blood pressure are normal. blood pressure are normal.

Q. How can you assess her volume status?Q. How can you assess her volume status?

Case 3Case 3

The elderly do not respond physiologically to bleeding The elderly do not respond physiologically to bleeding in the same way as younger patients. in the same way as younger patients.

• The history of a gastrointestinal bleed points to volume depletion, as does The history of a gastrointestinal bleed points to volume depletion, as does chronic diuretic use. chronic diuretic use.

• Although she has a "normal" blood pressure ‑ is it normal for her?Although she has a "normal" blood pressure ‑ is it normal for her?

• Special attention must be paid to other markers of hypoperfusion in this Special attention must be paid to other markers of hypoperfusion in this lady, as pulse and blood pressure (including orthostatic measurements) lady, as pulse and blood pressure (including orthostatic measurements) will be of little value. will be of little value.

Case 3Case 3 Management:Management:

• Look at peripheral skin temperature and respiratory rateLook at peripheral skin temperature and respiratory rate

• Obtain an ABGObtain an ABG

• Urinary catheter to monitor hourly urine output. Urinary catheter to monitor hourly urine output.

• In this case volume status can be incredibly difficult to assess without In this case volume status can be incredibly difficult to assess without using flow based techniques. using flow based techniques.

When direct flow measurements are not possible When direct flow measurements are not possible fluid fluid challenges should be given and the response challenges should be given and the response

assessedassessed. .

Case 4Case 4

A 53 year old motorcyclist is brought by Air A 53 year old motorcyclist is brought by Air Ambulance having been involved in a high speed Ambulance having been involved in a high speed RTA with a truck.RTA with a truck.

Blood pressure is unrecordable, pulse is not Blood pressure is unrecordable, pulse is not palpable, except in carotid and femoral regionspalpable, except in carotid and femoral regions

A 14G cannula has been inserted by ‘cutdown’ in A 14G cannula has been inserted by ‘cutdown’ in the left great saphenous veinthe left great saphenous vein

He is intubated and ventilatedHe is intubated and ventilated

Q1: What are the possible causes of his low bp?Q1: What are the possible causes of his low bp? Q2: What should the management comprise?Q2: What should the management comprise?

Case 4Case 4

ManagementManagement::• ABC approachABC approach• Volume resuscitationVolume resuscitation• Achieve stabilityAchieve stability• Transfer to CT scan for ‘Trauma series’Transfer to CT scan for ‘Trauma series’• Act upon findingsAct upon findings

A and B are checked and clearedA and B are checked and cleared• No pneumothorax detected clinicallyNo pneumothorax detected clinically• CXR confirms no extrapulmonary airCXR confirms no extrapulmonary air

Case 4Case 4

Circulation:Circulation:• Despite ongoing fluid infusion, bp hardly Despite ongoing fluid infusion, bp hardly

respondingresponding• Additional venous access obtained (14G)Additional venous access obtained (14G)• Radial arterial line inserted, showing invasive Radial arterial line inserted, showing invasive

bp of 85/40bp of 85/40

What might be happening?What might be happening? What could be done to investigate?What could be done to investigate?

Case 4Case 4

FAST scanFAST scan• Suggests some free fluid in abdomenSuggests some free fluid in abdomen• Small amount of fluid in pericardiumSmall amount of fluid in pericardium• Otherwise normal heart appearanceOtherwise normal heart appearance

How does this help you?How does this help you? What could be done, in view of the What could be done, in view of the

continuing instability?continuing instability?

Case 4Case 4

ThoracotomyThoracotomy• Aorta clampedAorta clamped• Blood pressure improves somewhat (110/60)Blood pressure improves somewhat (110/60)• Heart appears to be pumping wellHeart appears to be pumping well• Patient stable for now, can go to CTPatient stable for now, can go to CT

CT resultsCT results• Small splenic and liver injuries (both Grade 2)Small splenic and liver injuries (both Grade 2)• Undisplaced T6 spinal fracture, no brain injuryUndisplaced T6 spinal fracture, no brain injury• Femoral fractureFemoral fracture

Case 4Case 4

TheatreTheatre• Laparotomy shows only mild blood loss in Laparotomy shows only mild blood loss in

abdomenabdomen• Aortic clamp removed, chest drain placedAortic clamp removed, chest drain placed• Ex-fix placed on femur to prevent bleedingEx-fix placed on femur to prevent bleeding• CVP line placed, shows low CVP (~2 mmHg)CVP line placed, shows low CVP (~2 mmHg)• Requiring moderate dose of noradrenaline to Requiring moderate dose of noradrenaline to

maintain adequate blood pressuremaintain adequate blood pressure

Why is the blood pressure still poor?Why is the blood pressure still poor?

Case 4Case 4

In Critical CareIn Critical Care• Patient noted to be moving arms but not legsPatient noted to be moving arms but not legs• When woken from sedation, still could not When woken from sedation, still could not

move legsmove legs• MRI shows cord damage at T6 levelMRI shows cord damage at T6 level• Presumably spine was displaced enough to Presumably spine was displaced enough to

damage cord then returned to normal damage cord then returned to normal anatomical positionanatomical position