Acute circulatory failure leading to inadequate tissue perfusion which, if prolonged, causes irreversible damage to all organs.
Mortality is high in the absence of a diagnosis and early treatment.
Etiology and Pathophysiology:
Hypovolemic shock:
– Hypovolemia by real significant decrease in blood volume:
• Hemorrhage externalized or not: post-traumatic, per and postoperative, obstetric (ectopic pregnancy, uterine rupture, etc.), blood loss related to an underlying pathology (peptic ulcer, etc.). A loss of 30 to 50% of blood volume causes a hemorrhagic shock.
• Dehydration: Vomiting and severe diarrhea, cholera, intestinal obstruction, diabetic ketoacidosis or hyperosmolar coma, etc.
• plasma leakage: extensive burns, crushing of limbs, etc.
– Hypovolemia on by inadequate container / vascular content:
• Anaphylactic shock by extreme vasodilatation: allergy to an insect bite; a drug mainly antibiotics, aspirin, muscle relaxants, colloids (dextran, modified fluid gelatin), equine serum, vaccines containing egg protein; to a food, etc.
• Acute Hemolysis: severe malaria, some (few) drug poisoning.
Septic shock:
By often complex mechanism involving vasodilation, heart failure and hypovolemia true: sepsis.
Cardiogenic shock:
For significant decrease in cardiac output:
– Trespass infarction: myocardial contusion trauma, intoxication.
– Indirect mechanism: arrhythmia, constrictive pericarditis, haemopericardium, pulmonary embolism, pneumothorax extended, valvular heart disease, severe anemia, beriberi, etc.
Clinical signs:
Common signs to most states of shock:
– Pallor, mottled skin, cold extremities, sweating, thirst.
– Pulse rapid and thready often seen on large artery only (carotid or femoral).
– Blood pressure (BP) lowered differential pinch, sometimes breathtaking.
– Tachypnea, cyanosis; respiratory signs (dyspnea, tachypnea) are often present in varying degrees depending on the mechanism.
– Conscience generally preserved, but anxiety, confusion, agitation or apathy frequent.
– Oliguria or anuria.
More specific signs of the mechanism responsible:
– Hypovolemic shock
Common signs to shock states described above are typical of hypovolemic shock.
Warning: Do not under estimate hypovolemia. Shock Signs may not become evident until after a 50% loss of blood volume.
– Allergic or anaphylactic shock
• sudden and significant drop in BP
• Tachycardia +++
• Frequent Cutaneous manifestations, erythema, urticaria, angioedema
• possible respiratory signs, dyspnea or bronchospasm
– Septic shock
• High fever or, more rarely, hypothermia (<36 ° C); sometimes chills, confusion.
• In the initial phase, the TA may be retained, but soon even clinical picture in hypovolemic shock.
– Cardiogenic shock
• Respiratory signs indicating a left ventricular failure (acute pulmonary edema) often in the foreground: tachypnea, crackles on auscultation.
• Right ventricular failure signs: jugular turgor, Hepatojugular reflux … sometimes isolated, but most commonly associated with signs of left ventricular failure.
The diagnosis is oriented by:
– Context: notion of trauma, insect bite, taking medication, etc.
– Clinical examination:
• persistent skin fold dehydration
• chest pain of a heart attack, pulmonary embolism
• abdominal pain or defense of peritonitis, distension of an occlusion
• blood in stools, vomiting of gastrointestinal bleeding
• subcutaneous crepitus in favor of anaerobic infections
• fever
Treatment:
The etiological and symptomatic treatments are inseparable.
Conduct in all cases:
– Emergency +++ immediate management of the patient.
– Sick extended warmed legs elevated (unless edema acute lung).
– Wholesale peripheral venous Track gauge (16G in adults).
– Oxygen therapy, mechanical ventilation for respiratory distress.
– Assisted ventilation and external cardiac massage in the event of cardiac arrest.
– Intensive surveillance: awareness, pulse, BP, respiratory rate, hourly diuresis (laying urinary catheter) and evolution of marbling.
What to do depending on the cause:
– Hemorrhage
• Control bleeding (compression, tourniquet, surgical hemostasis)
• Determine the blood group
+++ • Priority: restore the blood volume as soon as possible
Ask venous lines 2 large caliber devices (16G in adults)
modified fluid gelatin: infusing 1.5 times the volume to compensate and / or
Ringer’s lactate or sodium chloride 0.9%: administer 3 times the volume to compensate
• Transfuser: classically, when the estimated blood loss about 40% of blood volume or hematocrit <20%.
Sang previously checked: ABO compatibility (if negative O), HIV, hepatitis B and C, etc.
In the absence of HIV testing, hepatitis B and C, see note on page 38.
– Acute Dehydration
Administer preferably Ringer lactate, or alternatively, sodium chloride 0.9%.
For information :
Children under one year: 100 ml / kg in 6 hours according to the following scheme: 30 ml / kg during the first hour and then 70 ml / kg over the following 5 hours
Children over one year and adults: 100 ml / kg in three hours in the following way: 30 ml / kg over 30 minutes and then 70 ml / kg over the 2 1/2 hours following
In practice, reduce the infusion rate only when the patient has recovered pulse, BP and conscience. Attention to overload accidents in young children and the elderly.
Note: In children severely malnourished infusion solution and the amounts to be administered differ from those of healthy children (see severe acute malnutrition, page 40).
– Anaphylaxis
• Determine the causal agent.
• Stop injections or infusions underway, but keep the IV line if it is in place.
• Epinephrine (adrenaline) is the treatment of choice:
Children: 0.25 mg diluted in 9 ml of sterile water and injected into IV ml per ml, until a correct TA and reduction of tachycardia.
Adult: 1 mg diluted in 9 ml of sterile water and injected into IV ml per ml, until a correct TA and reduction of tachycardia.
If unable to find an IV infusion, epinephrine can be administered sublingually the same doses as the IV route.
In less severe cases, it can also use the SC route: 0.3 to 0.5 mg to be repeated every 5 to 10 minutes if necessary.
In case of persistent shock, administration constant flow of epinephrine IV by syringe pump (see final box) may be required for 6 to 24 hours: 0.1 to 0.5 microgram / kg / minute depending on the clinical course.
• Fluid replacement with Ringer lactate or sodium chloride 0.9%.
• Corticosteroids have no effect in acute phase. However, they should be administered as soon stabilization of the patient’s condition to prevent the short-term relapse.
hemisuccinate IV or IM hydrocortisone
Children: 1-5 mg / kg / 24 hours dividing into 2 to 3 injections
Adults: 200 mg every 4 hours
• If associated bronchospasm: epinephrine is generally sufficient to reduce it.
In case of persistence, give 10 puffs of inhaled salbutamol.
• Special case: pregnant women, to prevent placental vasoconstriction, first use ephedrine high dose, 25 to 50 mg IV.In the absence of immediate improvement, use epinephrine (adrenaline) at the doses indicated above.
– Septic shock
• vascular filling with fluid modified gelatin or Ringer’s lactate or chloride
sodium 0.9%.
• Use of a vasoactive agent:
dopamine IV at a constant rate by syringe pump (see final box): 10 to 20 micrograms / kg / minute, or failing
epinephrine (adrenaline) IV at a constant rate by syringe pump (see final box): from 0.1 micrograms / kg / minute.
Gradually increase the dose until clinical improvement.
• Search the front door (abscess, infection ENT, pulmonary, gastrointestinal, gynecological, urological, etc.)
• Antibiotic therapy according to the front door:
IV ampicillin
Children and adults: 150 to 200 mg / kg / day in 3 divided doses at 8 hours
cloxacillin IV
Children: 100 mg / kg / day in 3 divided doses at 8 hours
Adults: 3 g / day in 3 divided doses at 8 hours
co-amoxiclav (amoxicillin + clavulanic acid) slow IV
Child: 75 to 150 mg / kg / day in 3 divided doses at 8 hours
Adults: 3 g / day in 3 divided doses at 8 hours
IV ceftriaxone slow
Children: 100 mg / kg / day in the first day of injection, and then 50 mg / kg / daily thereafter
Adult: 2 g / once daily
ciprofloxacin PO (stomach tube)
Children: 15 to 30 mg / kg / day in 2 divided doses
Adult: 1500 mg / day in 2 divided doses
gentamicin IM
Children and adults: 3 to 6 mg / kg / day in one or two injections
metronidazole IV
Child: 20 to 30 mg / kg / day divided in 3 infusions of 8:00
Adult: 1 to 1.5 g / day in 3 infusions in 8:00
• Corticosteroids: unnecessary, side effects are more important than profits.
– Cardiogenic shock
The goal is to restore effective cardiac output. The treatment of cardiogenic shock dependent mechanism.
• acute heart failure left by overload
It begins as an acute pulmonary edema (for treatment, see heart failure in adults, page 294).
In case of worsening signs with collapse of blood pressure, use a powerful tonicardiaque:
dopamine IV at a constant rate by syringe pump (see final box): 3 to 10 micrograms / kg / minute
As soon as the situation allows hemodynamic (BP normalization, attenuation of peripheral circulatory failure signs), nitrates or morphine can be introduced carefully.
Digoxin should be used in cardiogenic shock states except in rare cases where the origin is a supraventricular tachyarrhythmia diagnosed by ECG. Its use requires the prior correction of hypoxia.
digoxin slow IV
Child: an injection of 0.010 mg / kg (10 micrograms / kg) Repeat 3 to 4 times / 24 hours if necessary
Adult: an injection of 0.25 to 0.5 mg and 0.25 mg to be repeated 3 to 4 times / 24 hours if necessary
• tamponade: heart failure with discomfort cardiac filling, haemopericardium, septic context, etc.
urgent pericardiocentesis after vascular filling +++.
• suffocating pneumothorax: pneumothorax drainage.
• severe pulmonary embolism: effective anticoagulant treatment in hospital.
The administration of dopamine or epinephrine (adrenaline) at a constant rate imposes a number of conditions:
– Medical supervision in hospital;
– Use of a proprietary intravenous (no other infusions or injections this intravenous), avoiding the bend of the elbow;
– Use a syringe pump;
– Soft start and dose adjustment based on the clinical course;
– Intensive monitoring of the administration and particularly when replacing syringes.
example:
Dopamine: 10 mcg / kg / minute in a patient weighing 60 kg
Or dose schedule: 10 (mcg) x 60 (kg) x 60 (min) = 36 000 g / hour = 36 mg / hour
Dilute with a 50 ml syringe, a dopamine bulb with 200 mg sodium chloride 0.9% to 50 ml of solution containing 4 mg of dopamine per ml.
For the rate of 36 mg / h it will be necessary to administer the solution (4 mg / ml) at 9 ml / h.
In the absence of electric syringe, dilution in an infusion bag may be considered. It should weigh the risks associated with this mode of administration (bolus accidental or inadequate therapeutic dose). The infusion should be constantly monitored to avoid any change, however small, of the prescribed rate.
example:
Epinephrine 0.2 mcg / kg / minute in a patient weighing 60 kg
Either: 0.2 (mcg) x 60 (kg) = 12 mcg / minute
Dilute 2 ampoules of 1 mg (2 x 1000 mcg) epinephrine in 250 ml of 0.9% sodium chloride to obtain a solution containing 8 g / ml.
For the flow rate of 12 g / minute, it will therefore give: (12 ÷ 8 = 1.5) 1.5 ml / min
Given that 1 ml = 20 drops: it will therefore administer 20 (drops) x 1.5 (ml) / 1 (minute) = 30 drops per minute.
