Critical care march 2014

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Critical CareBY

ProfIbrahim El-ghazawy

Who is responsible?

>Open ICU The surgeon is responsible for

postoperative care of his patients

> Closed ICU (an intensivist - model ICU) an intensivist - board certified , will care for ICU - patients

Advantage of intensivist – based care

• Shorter ICU – stay• Fewer days of mechanical ventilation• Fewer complications• Lower hospital charges• Lower mortality

The best ICU care according to American College of Critical Care

Medicine

The intensivist and the surgeon proactively collaborate in the ongoing

care of surgical patients in the ICU

Purposes of ICU admission

1. Availability of electronic monitors2. Nurse to patient ratio 1:1 or 1:23. Early detection of a critical change in

status of surgical patient4. To ensure optimal outcome5. Treat M.O.F

Requests for ICU Beds• excellent care• abundant resources

– high nurse-patient ratios– pharmacists,nutritionist, RT’s, etc– high tech equipment

• signs of deterioration quickly identified• “give them a chance”• discomfort with death• convenience• Demand frequently exceeds supply

ICU Admission Criteria• A service for patients with potentially

recoverable conditions who can benefit from more detailed observation and invasive treatment than can be safely provided in general wards or high dependency areas

Factors of High Risk of Morhidity & Moritality

Surgical Factors• Duration of operation : ( > 1.5 hr )

• Extensive surgery : e.g - Esophagectomy - Gastrectomy

• Type of surgery : - Thoracic - Abdominal - Vascular

Surgical Factors• Emergency : e.g Perforated bowel

• Acute Massive blood loss : ( > 2.5 L )

• Septicemia : ( +ve blood culture )

• Multi-trauma : - > 3 organs - > 2 systems - > 2 cavities

Patients FactorsIHDM I Cardiac FailureCOPDRespiratory FailureAge > 70 yrs ( ± Limited reserve )Renal Failure Poorly Controlled DiabetsMorbid ObesityLate-Stage-Vascular DiseasePoor Nutriton

ICU Triage• admission criteria remain poorly defined• identification of patients who can benefit

from ICU care is extremely difficult• demand for ICU services exceeds supply• rationing of ICU beds is common

Prioritization ModelPriority 1

– critically ill, unstable– require intensive treatment and monitoring that

cannot be provided elsewhere– ventilator support– continuous vasoactive infusions– mechanical circulatory support– no limits placed on therapy– high likelihood of benefit


– Require intensive monitoring– May potentially need immediate intervention– No therapeutic limits– Chronic co-morbid conditions with acute severe

illness

Prioritization Model

Priority 3– Critically ill– Reduced likelihood of recovery– Severe underlying disease– Severe acute illness– Limits to therapies may be set

• no intubation, no CPR

– Metastatic malignancy complicated by infection, tamponade, or airway obstruction


– Generally not appropriate for ICU– May admit on individual basis if unusual

circumstances– Too well for ICU

• mild CHF, stable DKA, conscious drug overdose, peripheral vascular surgery

– Too sick for ICU (terminal, irreversible)• irreversible brain damage, irreversible multisystem

failure, metastatic cancer unresponsive to chemotherapy

JCAHCO

Objectives Parameters Model

Vital signs– HR < 40 or > 150– SBP <80– MAP <60– DBP >120– RR > 35


Laboratory values– Sodium < 110 or > 170– Potassium <2.0 or > 7.0– PaO2 < 50– pH < 7.1 or > 7.7– Glucose > 800 mg/dL– Calcium > 15 mg/dL– toxic drug level with compromise


Radiologic– Ruptured viscera, bladder, liver, uterus

with hemodynamic instability– Dissecting aorta


EKG– acute MI with complex arrhythmias,

hemodynamic instability, or CHF– sustained VT or VF– complete heart block with instability


Physical findings (acute onset)– unequal pupils– burns > 10%BSA– anuria– airway obstruction– coma– continuous seizures– cyanosis– cardiac tamponade

Intermediate Care Units• monitoring and care of patients with moderate or

potentially severe physiologic instability• require technical support• frequent monitoring of vital signs• frequent nursing interventions• not necessarily artificial life support• do not require invasive monitoring• require less care than ICU• require more care than general ward

Intermediate Care Units

• reduces costs• no negative impact on outcome• improves patient/family satisfaction

ICU Triage

“Too well to benefit”– Possibility of being detrimental by providing

overly aggressive care– Procedure complications– Increased chance of multi-resistant infections– Patients who will survive anyway should not be

admitted for anticipatory monitoring

ICU Triage“Too sick to benefit”

–Hopelessly ill patients should not be admitted to an ICU

Critical CarePatients needing ICU care

Emergency• Multiple trauma (including burns)• Leaking AAA• Severe acute pancreatitis• Post-operative complications:

- Surgical - Cardiac - Respiratory - Renal• Severe spesis

Elective• Major vascular eg, AAA• Oesophagectomy• Cardiac operations• Major procedures - Whipple’s - Patients in ASA 2 category or more

Critical CareTools for critical care

Respiratory

• Pulse oximetry - O2 saturation of arterial blood

• Capnography - CO2 tension in expired gas

Cardiovascular

• Arterial lines• CVP• Pulmonary artery flotation catheter (PAFC)• Cardiac output measurement

Conventional monitoring techniques: .Arterial blood pressure .Heart rate .CVP .Haematocrit .ABGs .Urine output .Capillary refill .Skin temperature .Core temperature .Blood biochemistry

Conventional monitoring techniques: Arterial blood pressure. Heart rate. CVP. Haematocrit. ABGs. Urine output. Capillary refill. Skin temperature. Core temperature. Blood biochemistry.

Advantages of conventional techniques :• Useful in guiding the initial resuscitation.• Easy to obtain.• Not costly.• Safe.• Sufficient for non complicated cases.

Disadvantages :• They do not assess O2 debt and overall tissue

perfusion. • Not sufficient for complicated cases.

Advantages of conventional techniques :• Useful in guiding the initial resuscitation.• Easy to obtain.• Not costly.• Safe.• Sufficient for non complicated cases.

Disadvantages :• They do not assess O2 debt and overall tissue

perfusion. • Not sufficient for complicated cases.

Critical CarePulse oximetry

• 95% - 100% = normal

• 93% =Warning!

• < 90% = patient is in severe trouble

Critical CarePulse oximetry

• Gives estimate of percentage saturation of oxygen binding sites

• Related to Pa02 by oxygen dissociation curve

Capnography

• Infra-red absorption through gas stream• Relies on rapid equilibration of CO2 between alveolus

and pulmonary capillary• Useful guide to PaCO2 but beware of lung disease• Continuous measurement

Critical Care

Critical CareArterial line

Indications

• Continuous BP measurement• Access for serial arterial blood gas analysis

Complications

• Bleeding• Thrombosis• Infection• Pseudoaneurysm• Accidental drug injection

Site the line in the radial artery of the non-dominant hand. Allen’s test should be performed.

Critical CareArterial Line

Allen’s test

The fist is tightly clenched, both wrist pulses are tightly obstructed and the fist then released. Pressure is released from the ulnar artery first. Allen’s test is positive when the medial part of the hand remains blanched.

Haemodynamic monitoring

Indications: Continuous monitoring of blood pressure. Frequent sampling of arterial blood.

e.g. Shock (any aetiology). Acute hypertensive crisis. Use of vasoactive inotropic drugs. Respiratory support. High risk patients (extensive operations). Sequential analysis of blood gases, pH.

No absolute contraindications, except for specific sites (infection, prosthesis, distal ischemia, ….).

Indications: Continuous monitoring of blood pressure. Frequent sampling of arterial blood.

e.g. Shock (any aetiology). Acute hypertensive crisis. Use of vasoactive inotropic drugs. Respiratory support. High risk patients (extensive operations). Sequential analysis of blood gases, pH.

No absolute contraindications, except for specific sites (infection, prosthesis, distal ischemia, ….).

Arterial Catheterization:Arterial Catheterization:

Clinical utility of arterial catheterization

Measure SBP. Measure DBP. Measure MAP. Pulse rate.

This reflects:

Intravascular volume. Heart contractility. Vascular tree status

(periph. vascular resistance).

Measure SBP. Measure DBP. Measure MAP. Pulse rate.

This reflects:

Intravascular volume. Heart contractility. Vascular tree status

(periph. vascular resistance).

Sites of catheterization: Radial A (most common). Femoral A. Dorsalis pedis A. Superficial temporal A. Axillary A. Brachial A. (not used; inadequate collateral circ. Frequency of

catastrophic ischemic complication).

For radial A: Modified Allen test. Pulse oximetry. Doppler US.

Disadvantages: Mean, end diastolic p: accurate; SBP; overshoot (in stiff, arteriosclerotic A).

Sites of catheterization: Radial A (most common). Femoral A. Dorsalis pedis A. Superficial temporal A. Axillary A. Brachial A. (not used; inadequate collateral circ. Frequency of

catastrophic ischemic complication).

For radial A: Modified Allen test. Pulse oximetry. Doppler US.

Disadvantages: Mean, end diastolic p: accurate; SBP; overshoot (in stiff, arteriosclerotic A).

Axillary A:Advantages: Large size. Close proximity to aorta. Accurate representation of aortic p. waveform. Minimal S.P. overshoot. Pulsations/ pressure are maintained even in

presence of shock (periph. vasoconstriction). Good collateral circ. bet. subclarian & distal

axillary A.

Axillary A:Advantages: Large size. Close proximity to aorta. Accurate representation of aortic p. waveform. Minimal S.P. overshoot. Pulsations/ pressure are maintained even in

presence of shock (periph. vasoconstriction). Good collateral circ. bet. subclarian & distal

axillary A.

Clinical utility of arterial catheterization

Complications of Arterial Cannulation

Failure to cannulate. Hematoma formation. Disconnection with bleeding. Radial A. thrombosis (use Teflon, smaller size: better)

use Heparin contin flow. Infections, (0 – 9%) factors: which ↑catheter infections.

Surgical cut-down. Duration > 4 days.

Retrograde cerebral embolization. A-V fistula. Pseudoaneurysm formation.

Failure to cannulate. Hematoma formation. Disconnection with bleeding. Radial A. thrombosis (use Teflon, smaller size: better)

use Heparin contin flow. Infections, (0 – 9%) factors: which ↑catheter infections.

Surgical cut-down. Duration > 4 days.

Retrograde cerebral embolization. A-V fistula. Pseudoaneurysm formation.

Central venous Catheterization

Indications: Access for fluid therapy. Drug infusions. Parenteral nutrition. CVP monitoring. Placement of cardiac pacemakers. IVC filters. Hemodialysis access.

Contraindications to specific site: Vessel thrombosis. Local infection inflammation. Trauma Previous surgery.

Indications: Access for fluid therapy. Drug infusions. Parenteral nutrition. CVP monitoring. Placement of cardiac pacemakers. IVC filters. Hemodialysis access.

Contraindications to specific site: Vessel thrombosis. Local infection inflammation. Trauma Previous surgery.

Clinical utility of central venous catheter:

Measure CVP. (DD: hypovolemia vs cardiac tamponade

CVP-tracing:a-wave: absent in atrial fibrillation.V-wave: prominent in tricuspid insufficiency.

Measure: Rt. atrial pressure, Rt. ventricle end-diastolic pressure.

Clinical utility of central venous catheter:

Measure CVP. (DD: hypovolemia vs cardiac tamponade

CVP-tracing:a-wave: absent in atrial fibrillation.V-wave: prominent in tricuspid insufficiency.

Measure: Rt. atrial pressure, Rt. ventricle end-diastolic pressure.

Sites of central venous catheterization: Subclarian V. Int. jugular V. Ext. Jug. V. Femoral V. Brachiocephalic V.

Subclavian V: Easy, high rate & success. Easy secure of catheter & dressing.

Disadvantages: Higher risk of penumothorax. Inability to compress vessel if bleeding occurs.

Internal jugular V: Easy cannulation, difficult in volume depletion. Easily compressed if bleeding occurs.

Sites of central venous catheterization: Subclarian V. Int. jugular V. Ext. Jug. V. Femoral V. Brachiocephalic V.

Subclavian V: Easy, high rate & success. Easy secure of catheter & dressing.

Disadvantages: Higher risk of penumothorax. Inability to compress vessel if bleeding occurs.

Internal jugular V: Easy cannulation, difficult in volume depletion. Easily compressed if bleeding occurs.

Complications of central venous catheterization

Catheter malposition. Arrhythmias. Embolization. Vascular injury: (vessel laceration, hematoma, aneurysm, A-V

fistula). Cardiac injury (atrial, ventricular). Pleural injury (pneumothorax, hemothorax, hydrothx.) Mediastinal injury:

Hydro-mediastinum. Hemomediastinum. Neurologic injury:

Phrenic n. Rec. laryngeal n. Brachial plexus

Others: trachea, thyroid, thoracic duct. Long-term: infection, sepsis, septicemia

Thrombosis.

Catheter malposition. Arrhythmias. Embolization. Vascular injury: (vessel laceration, hematoma, aneurysm, A-V

fistula). Cardiac injury (atrial, ventricular). Pleural injury (pneumothorax, hemothorax, hydrothx.) Mediastinal injury:

Hydro-mediastinum. Hemomediastinum. Neurologic injury:

Phrenic n. Rec. laryngeal n. Brachial plexus

Others: trachea, thyroid, thoracic duct. Long-term: infection, sepsis, septicemia

Thrombosis.

Critical CareCentral venous catheterisation

Indications

• Invasive monitoring for estimation of fluid status and right heart function

• Long term infusions: TPN, chemotherapy

• Haemodialysis

• Lack of peripheral venous access

• Access for pulmonary artery catheterisation

Critical CareCentral venous catheterisation

Complications

• Inadvertent - arterial puncture - thoracic duct puncture - lung puncture• Air embolus• Catheter-related sepsis• Clot formation• Malposition and rupture of vein

Critical CarePulmonary artery wedge pressure

(PWAP)

It is an accurate representation of the left atrial pressure which closely parallels the left ventricular end-diastolic pressure thus helping to guide fluid therapy.


Introduced in 1970s by two cardiologists, Drs Swanand Ganz. Used to measure:

• Pressure within the pulmonary artery• Pulmonary artery wedge pressure• Cardiac output by thermodilution or dye dilution method• Sampling of mixed venous blood

Critical CarePulmonary artery catheterisation

Indications

• Complex operations in patients with complex cardiopulmonary disease

• Multisystem failure• Major trauma• Sepsis• Situations where accurate haemodynamic status needs to be

ascertained


Complications

• Valvular damage• Ventricular rupture• Pulmonary artery rupture• Aneurysm or infarction• Those of central venous catheterisation

Critical CareStandard values

• Central venous pressure (CVP): 0-6 mm Hg• Right ventricular pressure: 25 mm Hg• Pulmonary artery pressure (PAP): 25 mm Hg• Wedge pressure (PAWP): 6-12 mm Hg• Cardiac index (CI): >2.8-3.6 L / min / m2

• Systemic vascular resistance(SVR):770-1500 dynes / sec / cm2

• Oxygen delivery: 600ml / min / m2

• Oxygen consumption: 150 mls / min / m2

Haemodynamic paramters (by Pulm. A. catheter)

100 – 140 mmHg 1- SBP

60 – 90 mmHg 2- DBP

15 – 30 mmHg 3- PASP

4 – 12 mmHg 4- PADP

9 – 16 mmHg 5- MPAP

15 – 30 mmHg 6- RVSP

0 – 8 mmHg 7- RVEDP

0 – 8 mmHg 8- CVP

2 – 12 mmHg 9- PAOP

Critical Care A 60 year old man had a right hemicolectomy.

On the 1st postoperative day he has developed a temperature of 390 C, is very short of breath and looks slightly cyanosed; his oxygen saturation is 92%. What will you suspect and how will you manage the condition?

Critical CarePostoperative pulmonary collapse

Although atelectasis and collapse are often used synonymously, atelectasis strictly speaking refers to lung parenchyma that has never been expanded.


Clinical features

• Tachypnoea• Pyrexia• Productive cough• Cyanosis• Dullness on percussion• Bronchial breathing


This arises from reduced ventilation of the lung bases resulting in accumulation of bronchial secretions. This may be basal, segmental, lobar or complete lung collapse. The degree of hypoxia depends upon the extent of collapse.

Infection with consolidation supervenes with the organisms being Haemophilus influenza, streptococcus pneumoniae, coliform, MRSA and pseudomonas.


Management

• Antibiotic – amoxycillin• O2 therapy with inspired O2 concentration of 30-40% with humidification• Vigorous physiotherapy • Urgent fibreoptic bronchoscopy• Minitracheostomy

Continue with physiotherapy and monitor with blood gases and pulse oximetry- aim for oxygen tension to be no less than 10kPa

Critical CarePost-operative hypoxia

Surgical patients at risk of hypoxia

• Smokers• Chronic pulmonary disease• Elderly• Obesity• Pre-operative opiates and sedatives• Abdominal emergency surgery• Orthopaedic surgery (fat emboli)

Critical CareEffects of post-operative hypoxia

• Central nervous system - Obtunded pain sensation - Post-operative confusion• Cardiovascular system - Tachycardia - Myocardial ischaemia• Respiratory system - Hypercapnoea (airway obstruction) - Respiratory muscle failure• Renal - Renal failure

Critical CareEffects of post-operative hypoxia (contd)

• Gastrointestinal - Ulceration - Reduced immunoprotection• Hepatic - Ischaemic necrosis of hepatocytes• Haematological - Reduced platelet function - Coagulation problems• Wound healing - Impaired wound healing

Critical CareRespiratory failure

Respiratory failure is defined as an arterial oxygen tension (PaO2) at sea level of less than 8 kPa, i.e. hypoxia due inadequate gas exchange within the lung.

Critical CareRespiratory Failure

Type IHypoxia

Failed O2 uptake

PaO2 <8kPa (Hypoxia)

+Normal PaCO2 (7kPa) or low

Critical CareRespiratory Failure

Type IIHypoxia + Hypercapnia

Failed O2 uptake + Failed CO2 removal

PaO2 < 8kPa+

PaCO2 > 7kPa

Respiratory monitoring

Aim: To decide if mechanical ventilation

is indicated.

Assess response to therapy.

To decide if a weaning trial is

indicated.

Aim:To decide if mechanical ventilation

is indicated.

Assess response to therapy.

To decide if a weaning trial is

indicated.

Ventilation monitoringLung volumes:Tidal volume:

)VT :( the volume of air moved in andout of lungs in any single breath.

Lung volumes:Tidal volume:

)VT :(the volume of air moved in and out of lungs in any single breath.

IF :IF :

IF :IF :

Lung Volumes (CONT)Vital capacity = (VC): The maximal expiration following a maximal inspiration. VC is reduced in diseases involving respiratory muscles,

in obstructive & restrictive diseases of lungs.

Minute volume (VE): Is the total volume of air leaving the lung each minute.

Dead space (VD): Is the portion of tidal volume that doesn’t participate in

gas exchange; 2 parts: Anatomical dead space. Alveolar dead space

Vital capacity = (VC): The maximal expiration following a maximal inspiration. VC is reduced in diseases involving respiratory muscles,

in obstructive & restrictive diseases of lungs.

Minute volume (VE): Is the total volume of air leaving the lung each minute.

Dead space (VD): Is the portion of tidal volume that doesn’t participate in

gas exchange; 2 parts: Anatomical dead space. Alveolar dead space

Blood gas analysisParametersParameters

70 – 100 mmHgo Arterial blood O2 tension

(PaO2)

> 92%o Arterial hemoglobin O2

saturation (SaO2)

35 – 45 mmHgo Mixed venous O2 tension

(PVO2)

65 – 80%o Mixed venous hemoglobin O2

saturation (SVO2)

o O2 consumption

o O2 utilization coefficient

o Physiologic shunt

o Alveolar O2 tension

Respiratory Monitoring (Contin…)

Capnography: Is the graphic display of CO2

concentration as a waveform.

Capnometry: Is the numerical presentation of the

concentration of CO2 without a

waveform.

Capnography: Is the graphic display of CO2

concentration as a waveform.

Capnometry: Is the numerical presentation of the

concentration of CO2 without a

waveform.

Pulse Oximetry: Measures arterial hemoglobin saturation, by

measuring the absorbance of light transmitted through well-perfused tissue, such as finger or ear.

The absorbance differs according to oxyhemoglobin & deoxyhemoglobin.

Pulse-oximetry is influenced by: Hypotension Hypovolemia Hypothermia Vasoconstrictor infusions Motion artifact Electrosurgical interference

Pulse Oximetry: Measures arterial hemoglobin saturation, by

measuring the absorbance of light transmitted through well-perfused tissue, such as finger or ear.

The absorbance differs according to oxyhemoglobin & deoxyhemoglobin.

Pulse-oximetry is influenced by: Hypotension Hypovolemia Hypothermia Vasoconstrictor infusions Motion artifact Electrosurgical interference

Critical Care

A 65 year old lady had a hip replacement 10 days ago. She is ready to be discharged. She went to the toilet just prior to leaving the ward for home. She collapsed in the toilet. What is your diagnosis and management?

Critical CarePulmonary embolus

Clinical diagnosis

• Dyspnoea• Tachypnoea• Pleuritic chest pain• Small haemoptysis• Calf tenderness and swelling


Management

• Resuscitation

• Investigations

• Treatment


Management

• The stable patient

• The unstable patient


InvestigationsThe stable patient

• ECG & CXR; blood gases• VQ scan• Duplex Doppler u/s of leg veins• Pulmonary angiogram• Contrast venography & plethysmography


InvestigationsThe unstable patient

• Echocardiogram• Pulmonary angiogram• Spiral CT – very sensitive


Treatment

• Anticoagulation• Emergency embolectomy• IVC filters• Thrombolysis – in haemodynamically unstable patient

with refractory shock - Intravenous - Pulse spray directly into embolus

Indications for insertion of IVC filter

Therapeutic

• Recurrent PE despite effective anticoagulation• Anticoagulation is contraindicated• Post pulmonary embolectomy to prevent recurrence• Pulmonary hypertension from chronic recurrent PE• Extensive PE• Iliofemoral DVT propagation despite adequate anticoagulation• Free-floating IVC thrombus• Bilateral free-floating DVT

Prophylactic

• Venous thrombolysis ( 20% develop PE )• Hip and knee replacement ( controversial )• Multiple trauma ( controversial )

Critical CareShock

Definition

Shock is a clinical state and is defined as inadequate tissue oxygenation which leads to impairment of cellular function.

Critical CareShock

Clinical features• Hypotension• Tachycardia• Tachypnoea• Cold, clammy extremities• Sweating

Critical CareShock

Types• Hypovolaemic• Septicaemic• Cardiogenic• Neurogenic• Anaphylactic

Critical Care

A 60 year old patient of ASA 1 anaesthetic risk underwent a total gastrectomy for cancer stomach. While in the ITU, 12 hours postoperatively, his BP has fallen to 80 mm hg systolic, has not put out any urine over the last 3 hours and is hypoxic with O2 saturation of 92%. What will you suspect and how will you manage?

Critical CareAnswer

Post-operative hypotension from bleedingQ. Where would the bleeding come from?Slipped left gastric artery ligatureQ. Where does the left gastric artery arise from?The coeliac axis

Critical CarePost-operative hypotension

Investigations

• Monitor BP• Continuous ECG, pulse oximetry• Monitor urine output• Monitor core and peripheral temperature• Blood samples: U&Es,FBC, Cross match Coagulation screen

Critical CarePost-operative hypotension

Management

• ABC• Oxygen• Raise legs• IV Fluids• CVP line – particularly in over 60 years• Control bleeding – re-exploration

Critical CareHypotension

One of the commonest post-operative complications

Definition

Systolic BP < 90 mm hgor

Reduction from usual BP of > 30%

Critical CareHypotension

Causes

• Inadequate pre-load• Decreased contractility

Critical CareCauses of inadequate pre-load in hypotension

Absolute reduction of fluid

• Blood loss (obvious or occult)

• Dehydration with inadequate fluid replacement

Relative reduction of fluid

• Venodilatation• Mechanical interference - tension pneumothorax - pulmonary embolism - tachycardia - arrythmia

Critical CareCauses of decreased contractility in hypotension

Toxic

• Ischaemic• Hypoxic• Acidosis• Drugs• Electrolyte disturbance• Sepsis• Jaundice

Mechanical

• Fluid overload• Cardiac tamponade

Critical Care

A 60 year old woman has been admitted as an emergency with a 4 day history of severe right upper quadrant pain, vomiting, jaundice and intense pruritis and is very toxic – high temperature with rigors and hyperdynamic circulation. What will you suspect and outline the management.

Critical CareSeptic shock from acute calculous biliary obstruction +/-

Acute pancreatitis

Management

• Resuscitation• Confirmation of diagnosis• Definitive treatment

Critical CareAcute calculous biliary obstruction

+Septic shock +/- Acute pancreatitis

Resuscitation

• Analgesia• IV Dextrose; Mannitol; Antibiotics after blood culture• Urinary catheter• CVP line

Critical CareAcute calculous biliary obstruction

Investigations & definitive treatment

• Blood: Culture, U&Es, FBC, CRP, LFTs, Serum amylase, Coagulation profile • Radiological: Urgent US of biliary tract• ?MRCP• ERCP + Endoscopic papillotomy +/- stenting• ? Laparoscopic cholecystectomy later

Critical CareBacteraemic shock

• Caused by release of endotoxins• Vasoactive substances eg, kinins released• Capillary permeability increased• Peripheral resistance decreased• Fever: hyperdynamic circulation• Treatment: O2; circulatory support; inotropes

Critical CareThe Septic Patient

The term SIRS is used to describe the widely disseminated inflammatory reaction which can complicate a wide range of disorders eg, pancreatitis, trauma, ischaemia.

The term SEPSIS is used in those patients in whom SIRS is associated with proven infection

Caritical CareSystemic inflammatory response syndrome

(SIRS)

• Cytokine mediators of SIRS: TNF, IL-1, IL-6, IL- 8

• Secondary inflammation mediators: - Arachidonic acid metabolites - Nitric oxide - Oxygen radicals - Platelet activating factor

Critical CareSystemic inflammatory response syndrome

(SIRS) Systemic changes

• Loss of microvascular integrity• Increased vascular permeability• Systemic vasodilatation• Depressed myocardial contractility• Poor oxygen delivery• Increased microvascular clotting

Critical CareEarly features of sepsis

• Fever or hypothermia• Leucocytosis or leucopenia• Tachycardia• Tachypnoea• Organ dysfunction: Brain - altered mental state Lungs - hypoxia Kidneys - oliguria

Critical CareNosocomial Infections

(Hospital acquired infections) (Gk: nosokomeion)

Gk: nosos- of disease; komeo – to nurse• The patient in the ITU who has some degree of organ dysfunction is

vulnerable to nosocomial infections.• Good principles of infection control and avoidance of cross-infection by

staff • Bacteria in the GI tract of the patient is the commonest source• Nosocomial pneumonia occurs from spillage from the upper GI tract into

the lungs• H2 receptor antagonists encourages nosocomial infections• Sucralfate used as stress ulcer prophylaxis is also bacteriostatic and thus

reduces the incidence

Critical Care A 70 year old patient, ASA anaesthetic category 3,

underwent an emergency closure of a perforated duodenal ulcer. The anaesthetic and operation were uneventful. On the 1st post-operative day he complained of feeling very unwell with a systolic bp of 80 mm hg with no unusual signs in his abdomen; there was impaired conscious level and peripheral vasoconstriction. What will go through your mind and outline your management.

Critical CareCardiogenic shock from myocardial infarction

• Patient already has a drip• ECG - ST elevation in precordial leads - Development of new Q waves – wide & / or deep - T wave inversion• Pulse oximeter• Blood for: CK-MB ( creatine kinase, membrane bound ) ALT ( alanine aminotransferase ) AST ( aspartate aminotransferase ) LDH ( lactic dehydrgenase ) Troponin T assay• Transfer to CCU

Critical CareCardiogenic shock from myocardial infarction

CCU management

• CVP• Consider PAFC• O2 therapy• Aspirin• Nitrates, ACE inhibitors and opiates• IV beta blockers• Consider reperfusion strategy

Critical CareCardiogenic shockComplications of MI

• Cardiac arrest ( ventricular fibrillation, VF )• Pump failure• Arrhythmias• Ventricular septal defect ( VSD )• Cardiac rupture• Pericardial tamponade• Ventricular aneurysm• Mitral regurgitation

MunschC & Shah R in Handbook of Postoperative Complications .Ed Leaper DJ & Peel ALG. 2003, OUP

Critical CareCardiogenic shock

• Risk of perioperative MI in the general surgical population = 0.07%

• Risk of MI if surgery is performed within 3 months of MI = 25%

Risk factors

• Previous MI• Unstable angina• Disabling angina• Silent ischaemia• Hypertension

MunschC & Shah R in Handbook of Postoperative Complications .Ed Leaper DJ & Peel ALG. 2003, OUP

Critical CareCardiogenic shock

Definition

Cardiogenic shock indicates a state of inadequate circulatory perfusion caused by cardiac dysfunction.

Causes

• Mycardial infarction• Cardiac arrhythmias• Tension pneumothorax• Cardiac tamponade• Vena caval obstruction• Dissecting aneurysm

Critical Care

Management of a critically ill patient is a medical skill you must gain it.

Critical Care

Neurogenic and spinal shock

Neurologic monitoring

Methods: Intracranial pressure monitoring.

Electrophysiologic monitoring.

Trans-cranial Doppler

ultrasonography.

Jugular venous oximetry.

Methods: Intracranial pressure monitoring.

Electrophysiologic monitoring.

Trans-cranial Doppler

ultrasonography.

Jugular venous oximetry.

A) Intracranial pressure monitoring:Indications of measurement of ICP: Severe head injury:

GCS ≤ 8 Or Motor Score ≤ 5

Value: Permits calculation of cerebral perfusion pressure (CPP)

CPP = MAP – ICP Thus increase of ICP or decrease of MAP will result in

decrease in CPP. Maintaining CPP at least 70 mmHg is just sufficient to

maintain adequate cerebral blood flow especially to injured brain.

A) Intracranial pressure monitoring:Indications of measurement of ICP: Severe head injury:

GCS ≤ 8 Or Motor Score ≤ 5

Value: Permits calculation of cerebral perfusion pressure (CPP)

CPP = MAP – ICP Thus increase of ICP or decrease of MAP will result in

decrease in CPP. Maintaining CPP at least 70 mmHg is just sufficient to

maintain adequate cerebral blood flow especially to injured brain.

2) Other indications to measure ICP: Subarachnoid hemorrhage. Hydrocephalus. Post-craniotomy. Massive strokes. Encephalitis. Post-cardiac arrest states.

Methods: Intraventricular catheter. Epidural catheter. Subarachnoid catheter.

Complications: Infection. Hemorrhage. Malfunction. Obstruction.

2) Other indications to measure ICP: Subarachnoid hemorrhage. Hydrocephalus. Post-craniotomy. Massive strokes. Encephalitis. Post-cardiac arrest states.

Methods: Intraventricular catheter. Epidural catheter. Subarachnoid catheter.

Complications: Infection. Hemorrhage. Malfunction. Obstruction.

Neurologic monitoring

Electrophysiologic monitoring:

EEG (electro-encephalogram)

To monitor the adequacy of cerebral

perfusion during carotid Endarterectomy.

Cerebro-vascular surgery.

Open heart surgery.

Epilepsy.

Neurologic monitoring (contin…)

Transcranial Doppler ultrasonography: (TCD)

To monitor cerebral blood flow.

It records blood flow-velocity in the basal

cerebral arteries.

It detects vasospasm and it helps in

identification of hypremic/ low-flow areas.


Glasgow Coma Score (GCS)Eyes Open: Spontaneous 4 To verbal command 3 To painful stimulus 2 Do not open 1……………………………………........................

Verbal: Normal oriented conversation 5 Confused 4 Inappropriate words 3 Sounds 2 No sounds 1 Intubated T………………………………………………………

Motor: Obeys commands 6 Localize pain 5 Withdrawal/ Flexion 4 Abnormal flexion (Decorticate) 3 Extension (Decerebrate) 2 No motor response 1

Jugular venous oximetry: An invasive method of continuous monitoring

of jugular venous bulb oxyhemoglobin

saturation.

Readings of 55 to 71%: normal cerebral

perfusion

Measurement < 50% is indicative of cerebral

ischemia.

Jugular venous oximetry: An invasive method of continuous monitoring

of jugular venous bulb oxyhemoglobin

saturation.

Readings of 55 to 71%: normal cerebral

perfusion

Measurement < 50% is indicative of cerebral

ischemia.


Critical Care

A fit 30 year old lady while gardening suddenly became very short of breath, had intense itching with rash and complained of a painful red spot on her arm. She has been brought to the A&E department and is hypotensive, hypoxic and cold. What is your diagnosis and how will you manage?

Critical CareAnaphylactic Shock

• Acute medical emergency

• Follows insect bites, drugs, vaccines, shellfish

• Apprehension, urticaria, bronchospasm, laryngeal oedema, respiratory distress, hypoxia, massive vasodilatation, hypotension and shock

• Treatment: Lie patient down, elevate leg, adrenaline, oxygen, iv hydrocortisone

Critical Care Anaphylactic Shock

Mechanism

The antigen combines with immunoglobulin (IgE) on the mast cells and basophils, releasing large amounts of histamine and SRS-A (slow-release substance-anaphylaxis). These compounds cause the symptoms.

Mortality about 10%

Critical Care A 50 year old man underwent a laparoscopic closure of

a perforated duodenal ulcer. His post-operative period during the first 4 to 5 days was uneventful. However, thereafter he did not progress satisfactorily, had a swinging pyrexia, hiccoughs, was tachypnoeic, toxic and complained of pain in the right upper quadrant and right shoulder tip . What would you suspect and outline the management.

Critical CareIntra-abdominal sepsis

Sub-phrenic abscessManagement

• Resuscitation• Confirmation of diagnosis• Definitive treatment

Critical CareSub-phrenic abscess

Resuscitation• Oxygen• Analgesia• IV fluids• Antibiotics after blood has been sent for

culture


“Pus somewhere, pus nowhere, pus under the diaphragm.”

Investigations for confirmation

• Blood: Culture, FBC, CRP• CXR• Ultrasound• ?CT


Treatment

• US or CT guided needle drainage. This may require more than one attempt because there may be several loculi of the abscess.

• Open operation – extra-peritoneal approach – anterior or posterior depending upon the site

Critical CareHow many sub-phrenic spaces are there and what are they?

• 7 spaces in all• 4 intra - peritoneal – 2 right and 2 left ( important ones )• 3 extra - peritoneal• 2 right intra-peritoneal – Right anterior ( R subdiaphragmmatic ) Right posterior (R subhepatic or Morison’s hepato-renal pouch)

• 2 left intra-peritoneal – Left anterior ( L subdiaphragmmatic ) Left posterior ( L subhepatic or lesser sac or omental bursa )

• 3 extra-peritoneal – 2 around the upper pole of each kidney and 1 over bare area of liver

The extra-peritoneal spaces are not clinically important. Rarely the bare area of the liver may be involved in a liver abscess from amoebic infection.


Investigations

• Blood cultures• U&Es, FBC, CRP, Clotting studies, LFTs• CXR• Appropriate imaging studies for source


Management

• Supportive measures: - Oxgenation - Ventilation if necessary - IV fluids - Inotropic support - Nutritional support

• Specific measures - Antibiotics - Drainage

Critical Care

A 70 year old man underwent emergency operation for a leaking AAA. While in the ITU, after 2 days, he became oliguric, has abdominal distension and cardio-respiratory compromise. His CVP is 10 cm of water. He is still on the ventilator. What will you suspect and how will you manage?

Abdominal Compartment Syndrome

This is a condition in which there is a sustained increase in intra-abdominal pressure resulting in inadequate ventilation from type 2 respiratory failure, disturbed cardiovascular and renal function.


Aetiology

• Blunt and penetrating abdominal trauma with liver, vascular and splenic damage

• More likely after abdominal and pelvic trauma• Risk increases with increase in Injury Severity Score• Repair of AAA (Emergency or Elective) – 3.8% after repair of ruptured

AAA• Burns – should be suspected as a cause for renal failure inspite of

adequate fluid resuscitation

Abdominal Compartment SyndromeDiagnosis

• Patients usually in ICU• Tense abdomen• Cardio-respiratory compromise in the absence of

hypovolaemia• Renal failure• Round belly sign ( Ratio of AP to transverse abdominal

diameter > 0.80 )


Presentation

• Tense abdomen• Cardio-respiratory compromise• Oliguria / Anuria


Pressures

• Measure intra-abdominal pressure (IAP) with a catheter directly into peritoneal cavity

• Transurethral bladder pressure reflects IAP – most commonly used

• Normal IAP: Men: 3.5 - 10.5 mm hg Women: 3.0 - 8.8 mm hg

• IAP . 15 – 25 mm hg is diagnostic


Treatment

• Decompression

• Leave abdomen open and cover temporarily with mesh, plastic bag fascial closure, plastic or silicone sheet or vacuum pack

• Mortality: 63 – 72%

• Ventral hernia: 63%

Critical Care

A 77 year old man underwent a TURP. On the 2nd post-operative day he is confused, restless and has some visual disturbance. What will you suspect and how will you manage?

Critical CarePost TURP syndrome

(Dilutional hyponatraemia)Clinical features

• Restlessness, muscle twitching, disorientation, visual disturbances, seizures & collapse

• Hypertension, severe hyponatraemia


Cause

Occurs following prolonged prostatic resection of large glands and likely when more than 9 L of glycine (1.5%) irrigation is used. Large volume of irrigating fluid enters the vascular space causing dilutional hyponatraemia resulting in disturbance of muscle and nerve function.


Treatment

• Needs ITU monitoring – CVP, serum osmolality, serum Na

• Supportive• Frusemide• Hypertonic saline through CVP line (250-500 mls of 3

to 5 %) when there are seizures

Caritical CarePost TURP syndrome

Prevention

• Keep level of irrigating fluid below 20cm above the operating table

• Stop resection if large veins are opened• Use irrigating resectoscope• IV normal saline postoperatively for 12 hours

Critical Care

A 60 year old man underwent a Whipple’s operation for periampullary carcinoma. On the 2nd postoperative day, while still in the ICU, his urinary output has reduced to 300 mls in the previous 12 hours. The catheter is not blocked. What will you suspect and how will you manage?

Critical CareHepato-renal syndrome

• Can occur following an operation in a patient with obstructive jaundice

• Reduced GFR – not known why• Circulating endotoxins - endotoxinaemia• Absorption of endotoxin produced by the intestinal

microflora In the jaundiced patient there is a relationship between impaired renal

function and the presence of circulating endotoxins


Prevention• Adequate hydration and pre-operative induction of diuresis• For 12 - 24 hours pre-operative 5% dextrose saline iv• Mannitol (osmotic diuretic) or Frusemide (loop diuretic) iv at anaesthetic

induction• Catheterise - hourly urine output• Further diuretics if urine output < 40ml/hr in peri-operative and post-

operative period• Pre-operative oral chenodeoxycholate and oral lactulose for a few days –

controversial


Treatment

• Treat hyperkalaemia• Peritoneal dialysis• Hemofiltration• Haemodialysis

Critical CareRenal failure

Treatment of hyperkalaemia

• 10 to 20 mls of10% Ca gluconate or chloride iv : stabilises the myocardial membrane

• 50 mls of 50% dextrose + 10 units of soluble insulin: drives potassium into cells

• 200 to 300 mls of 1.4% sodium bicarbonate iv: drives potassium into cells and corrects acidosis; beware of fluid overload in ARF

• Calcium resonium 15 g tds orally or rectally: binds potassium and releases Ca in exchange

• Renal replacement therapy

Critical CareRenal failurePredisposing causes

• Preoperative renal impairment• Surgery associated with major blood loss and fluid shifts• Hypovolaemia• Hypotension• Sepsis• Nephrotoxic drugs

Critical Care

A 60 year old man underwent a successful embolectomy of his leg. The next day he developed severe throbbing pain in the leg which on examination did not look ischaemic and was warm to touch. What would you suspect and how would you manage the condition?

Critical Care

Acute limb compartment syndrome

What are the causes of this condition?

How do you diagnose it?

How do you treat the condition?

Acute Limb Compartment Syndromea

This is a condition in which raised pressurewithin a closed fascial space reduces capillary perfusion below a level necessaryfor tissue viability.

Acute Limb Compartment Syndrome

Aetiology

• Orthopaedic• Vascular• Iatrogenic• Soft tissue injury


Presentation

• Pain – severe and out of proportion to the apparent injury• Pain on passive movement• Swollen and tense compartment• Progression of the above over a short time period• Paraesthesia – especially loss of two point discrimination• Pallor and pulselessness – usually with a vascular injury• Paralysis – late symptom


Pressures

• Normal resting: 0 - 8 mm hg• Pain and paraesthesia: 20 – 30 mm hg• Fasciotomy: > 30 mm hg

• If pressure of > 30 mm hg is present for 6 – 8 hours irreversible damage occurs


Treatment

Fasciotomy

• Forearm: Volar and dorsal compartment

• Hand: Carpal tunnel decompression

• Thigh: 3 compartments – anterior, posterior, medial

• Leg: 4 compartments – anterior, lateral,deep and superficial posterior

Critical CarePain relief

Post-operativeIntractable pain


Post-operative pain

• Diclofenac suppositories• LA to incision site• IV narcotic drugs• Regional analgesia eg, caudal block, intercostal block• Continuous epidural analgesia• Continuous IV opiate analgesia• PCA by IV or epidural opioid analgesia

Critical CareDrugs for treatment of post-operative pain

• Simple analgesics: Paracetamol, Aspirin

• NSAIDs

• Intermediate drugs: Tramadol, Co-dydramol

• Opioids: Morphine, Diamorphine

• Local anaesthetics: Lignocaine, Bupivacaine


Intractable pain

Intractable pain is defined as chronic and continuous pain where the cause cannot be removed or the origin cannot be determined.

Causes: Benign Malignant

Critical CareRelief of Benign Intractable Pain

• LA + / - steroid injections• Nerve stimulation procedures• Nerve decompression• Sympathectomy

Critical Care Relief of Malignant Intractable Pain

Neurolytic techniques

• Subcostal phenol injection• Coeliac plexus block –

alcohol• Intrathecal phenol• Percutaneous

anterolateral cordotomy

Miscellaneous methods

• Injection of opiate: - subcutaneous - intravenous - intrathecal - epidural• Hormone analogues• Radiotherapy• Steroids

NutritionClinical indications for nutritional support

• Preoperative malnutrition• Postoperative complications: ileus > 4 days, sepsis, fistula• Intestinal fistulae• Massive bowel resection• Severe acute pancreatitis• Inflammatory bowel disease• Maxillofacial trauma• Multiple trauma• Burns• Malignant disease• Renal failure• Coma

NutritionAssessment

• Body weight• Upper arm circumference : < 23cm in females, < 25 cm in males• Triceps skinfold thickness : < 13 mm in females, < 10 mm in males• Serum albumin : < 35 g / l• Lymphocyte count : < 1500 / c mm• Candida skin test : -ve reaction indicates defective immunity• Nitrogen balance studies

NutritionRequirements

• Carbohydrate• Fat• Protein• Vitamins• Minerals• Trace elements

Nutrition

A healthy adult at rest requires 6300 – 8400nonprotein kilojoules per day for energy( 1500 – 2000 calories).

NutritionIn Burns

• Give 25 kcl/kg body weight + 40 kcl / % body surface area burnt in the adult

• The child needs more calories / kg body weight

• The infant needs 90 – 100 kcl / kg

NutritionRequirements

• Carbohydrate provides 16.8 kJ/g (4.1 kcal/g)• Fat provides 37.8 kJ/g (9.1 kcal/g)

The number of nonprotein kilojoules given should bear a definite relationship to the nitrogen intake. A typical regime would feature

8400 kJ (2000 kcal) to 13 g nitrogen ( about 150 to 1 ).

NutritionNitrogen requirements

A healthy adult in positive nitrogen balance needs 35-40 g of protein or 5.5 -6.5g of nitrogen a day.The hypercatabolic patient requiring hyperalimentation may need 3 to 4 times this amount of protein.

NutritionMethods of feeding

Enteral

• Oral• Nasogastric tube• Gastrostomy : Stamm temporary Janeway permanent PEG• Jejunostomy

NutritionComplications of enteral nutrition

• Nutritional and metabolic

• Complications of nutrient delivery

• Gastrointestinal complications

NutritionMethods of feeding

Parenteral

• Used in < 4 – 5% of all hospital admissions

• Used when enteral feeding is not possible or to supplement enteral feeding

• Indications: Short term Long term ( HPN )

NutritionComplications of parenteral nutrition

• Catheter related

• Nutritional and metabolic

• Effect on other organ systems


Catheter related

• Infection• Thrombosis• Occlusion• Fracture


Nutritional and metabolic

• Fluid overload• Hyperglycaemia• Electrolyte imbalance• Micronutrient deficiencies eg selenium in long-term patients


Effect on other organ systems

• Hepatobiliary system – biliary sludge, hepatic steatosis, cholestasis

• The immune system

• Skeleton – metabolic bone disease

NutritionMonitoring feeding regimens in parenteral nutrition

Daily

• Body weight• Fluid balance• FBC, U&E• Blood glucose• Urine and plasma osmolality• Electrolyte and nitrogen analysis of urine and gastrointestinal losses• Acid-base status


Every 10 days

• Serum B12, Folate, Iron, lactate and triglycerides

• Trace elements


Three times weekly

• Serum Calcium, magnesium and phosphate

• Plasma proteins

• LFTs

• Clotting studies

Health & Medicine

Critical care march 2014