SHOCK Abdul.Kader WEISS M.D CHIRURGIE GENERALE ET VISCERALE /CHIRURGIE COELIOSCOPIQUE D.E.S , A.F.S ,A.F.S.A , DU / FRANCE Reference : Editors: Pierce A. GraceNeil R. Borley / Title: Surgery at a Glance 2ed Blackwell Science Editors : Seymour i. Schwartz, M.D. / Title :Principles of Surgery Companion Handbook McGraw-Hill Companies, Inc

SHOCK SHOCK IS A PATHOPHYSIOLOGIC CONDITION CLINICALLY RECOGNIZED AS A STATE OF INADEQUATE TISSUE PERFUSION. THERE ARE FOUR DISTINCT CATEGORIES: HEMATOGENIC NEUROGENIC VASOGENIC CARDIOGENIC It is clear that shock is a SYSTEMIC DISORDER that disrupts vital organ function as the eventual result of a variety of causes. Whereas hemorrhagic or traumatic shock is characterized by global hypoperfusion, septic shock may be associated with hyperdynamic circulation resulting in a maldistribution of regional or intraorgan blood flow.

KEY POINTS Identify the cause early and begin treatment quickly. Shock in surgical patients is often over looked-unwell, confused, restless patients may well be shocked. Unless a cardiogenic cause is obvious, treat shock with urgent fluid resuscitation. Worsening clinical status despite adequate volume replacement suggests the need for intensive care.

PATHOPHYSIOLOGY Many conditions can lead to an inadequate delivery of oxygen to vital structures of the body. An aide-mémoire can be categorised as : ● Decrease in oxygen uptake by the lungs ● Reduced venous return ● Impaired cardiac function ● Reduced arterial tone ● Impaired organ autoregulation ● Decreased oxygen uptake and utilisation by tissues

COMMON CAUSES

HYPOVOLAEMIC SHOCK TRUE LOSS COMMON EXAMPLES BLOOD LOSS GASTROINTESTINAL HAEMORRHAGE RUPTURED AORTIC ANEURYSM TRAUMA PLASMA LOSS DIARRHOEA AND VOMITING DIABETIC KETOACIDOSIS PANCREATITIS OSMOTIC DIURESIS HYPONATRAEMIA BURNS FISTULA AND OSTOMIES APPARENT LOSS VENODILATORS NITRATES, OPIATES, I.V LOOP DIURETICS GLUCOCORTICOID DEFICIENCY

CARDIAC SHOCK ENDOCARDIAL INFECTIVE ENDOCARDITIS PAPILLARY MUSCLE RUPTURE MYOCARDIAL VENTRICULAR FAILURE ISCHAEMIA/INFARCTION MYOCARDITIS DRUGS TOXINS CARDIOMYOPATHY EPICARDIAL ACUTE TAMPONADE VENTRICULAR WALL RUPTURE MALIGNANCY POST SURGERY CONSTRICTIVE PERICARDITIS VIRAL TUBERCULOSIS RADIOTHERAPY

ANAPHYLACTIC SHOCK Anaphylaxis is an acute reaction to a foreign substance to which the patient has already been sensitised. This leads to an immunoglobulin E (IgE) triggered rapid degranulation of mast cells and basophils . Anaphylactoid reactions have an identical clinical presentation but are not triggered by IgE and do not necessarily require previous exposure. Furthermore, they may not produce a reaction every time.

COMMON CAUSES OF ANAPHYLAXIS/ANAPHYLACTOID REACTIONS DRUGS (PROTEIN AND NON-PROTEIN) – COMMONLY PENICILLIN OR OTHER Β LACTAM DRUGS, BLOOD PRODUCTS, AND IMMUNOGLOBULINS VACCINES FOOD – ESPECIALLY NUTS, SHELLFISH VENOMS – ESPECIALLY BEES, WASPS, AND HORNETS PARASITES CHEMICALS LATEX ANAPHYLACTOID COMPLEMENT ACTIVATION COAGULATION/FIBRINOLYSIS SYSTEM ACTIVATION DIRECT PHARMACOLOGICAL RELEASE OF MEDIATORS EXERCISE INDUCED IDIOPATHIC

TOXIC OR SEPTIC SHOCK Gram –ve or, less often, Gram +ve infections. Retained tampon Abscess Empyema Surgical wound infection Osteomyelitis Cellulitis Infected burns Septic abortion

NEUROGENIC SHOCK A spinal lesion above T6 can impair the sympathetic nervous system outflow from the cord below this level. As a consequence both the reflex tachycardia and vasoconstriction responses to hypovolaemia are eliminated. The result is generalised vasodilatation, bradycardia and loss of temperature control As neurogenic shock leads to a reduction in blood supply to the spinal column, it gives rise to additional nervous tissue damage.

CLINICAL FEATURES HYPOVOLAEMIC AND CARDIOGENIC SEPTIC Pallor, coldness, sweating and restlessness. Tachycardia, weak pulse, low BP and oliguria. SEPTIC Initially warm, flushed skin and bounding pulse. Later confusion and low output picture.

INVESTIGATIONS AND ASSESSMENT Monitor pulse, BP, temperature, respiratory rate and urinary output. Establish good i.v. access and set up CVP line (possibly Swan–Ganz catheter as well). ECG, cardiac enzymes, echocardiography. Hb, Hct, U+E, creatinine. Group and crossmatch blood: haemorrhage. Blood cultures: sepsis. Arterial blood gases.

COMPLICATIONS • ‘SIRS’ (systemic inflammatory response syndrome) may ensue if shock not corrected. • Acute renal failure (acute tubular necrosis). • Hepatic failure. • Stress ulceration.

SIRS (SYSTEMIC INFLAMMATORY RESPONSE SYNDROME) SIRS (systemic inflammatory response syndrome) is a systemic inflammatory response characterized by the presence of two or more of the following: • hyperthermia >38°C or hypothermia <36°C • tachycardia >90 bpm • tachypnoea >20 r.p.m. or PaCO2 <4.3 kPa • neutrophilia >12 × 10*9 l–1 or neutropenia <4 × 10*9 l–1. Sepsis syndrome is a state of SIRS with proven infection. Septic shock is sepsis with systemic shock.

ESSENTIAL MANAGEMENT • AIRWAY & BREATHING: • CIRCULATION: Give 100% O2, sit up, consider ventilatory support if necessary. • CIRCULATION: Ensure good IV access, urinary catheter, monitor cardiac rate and rhythm.

DEAL WITH THE CAUSE OF THE SHOCK ESSENTIAL MANAGEMENT DEAL WITH THE CAUSE OF THE SHOCK ( e.g. stop the bleeding, drain the abscess, remove the source of the anaphylactic antigen, etc.).

ESSENTIAL MANAGEMENT ANAPHYLACTIC I.V. FLUIDS. I.V. ADRENALINE. I.V. ANTIHISTAMINES. I.V. HYDROCORTISONE.

ESSENTIAL MANAGEMENT CARDIOGENIC • Optimize rate and rhythm (e.g. cardioversion, drugs). • Optimize preload (e.g. adequate volume, diuretics). • Optimize afterload (e.g. vasoconstrictors/dilators). • Optimize cardiac function (e.g. thrombolytic therapy, inotropes, assist devices).

ESSENTIAL MANAGEMENT SEPTIC • Fluids to restore circulating volume. • Antibiotics or surgery. • Support cardiac function (e.g. inotropes).

ESSENTIAL MANAGEMENT HYPOVOLAEMIC • Identify and arrest losses (may include surgery). • Restore circulating volume (crystalloids, colloids or blood). • Support cardiac function.

THANK YOU Abdul.Kader WEISS M.D