Shock
Shock is a state of acute circulatory failure that leads to tissue hypoxaemia.
Classification and causes of shock
1. Haemorrhagic shock
| Traumatic | Non Traumatic |
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2. Hypovolemic shock
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Fluid loss from vomiting and/or diarrhoea e.g. in cholera, other GI infections.
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Fluid loss in diabetes mellitus, adrenal insufficiency, excessive sweating, exfoliative dermatitis, diabetes insipidus, reaccumulation of ascites after tapping.
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Sequestration of fluid e.g. in intestinal obstruction, pancreatitis.
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Burns.
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Crush injuries.
3. Cardiogenic
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Acute myocardial infarction.
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Cardiomyopathy.
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Cardiac arrhythmias.
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Mechanical causes e.g. valvular disease, outflow tract obstruction, ruptured ventricular septum.
4. Distributive or vasogenic (relative hypovolemia)
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Septic shock; Toxic shock syndrome.
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Anaphylactic.
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Neurogenic.
Salient featuresShock is a progressive disorder which if untreated can lead to severe haemodynamic and metabolic deterioration finally causing multi-organ failure. Stages of shock can be arbitrarily classified as
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Treatment (Stepwise management)
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Immediately start Oxygen therapy 4-6 L/min.
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Initial volume expansion measures. Venous access should be restored as early as possible (within 3-5 min). Peripheral veins should be tried first if failed then central veins like jugular/femoral can be used. Establish 2 wide bore IV lines and infuse crystalloids.
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If venous access can not be achieved in a short period, intraosseous infusion can be given into the bone marrow by putting a bone marrow needle.
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Nature of fluids: Normal Saline/Ringer’s lactate (crystalloids) can be used initially in all types of hypovolemic/haemorrhagic shocks. Colloids are used in conditions with capillary leaks, burns, dengue fever, nephrotic shock. Whole blood can be used as replacement in cases of trauma and haemorrhagic shock, packed cells are used in burn patients.
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Volume of fluids: boluses of 20 cc/kg should be pushed in 5-7 min to restore blood volume quickly through 3 way cannula. Features of recovery i.e. warm skin and improved capillary filling time appear very quickly after fluid replacement. If these do not appear give a 2nd bolus.
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In case no improvement is seen and facilities for monitoring CVP are not available and there are no features of over-hydration, give another bolus and start ionotrope. If facilities for CVP are available modify fluid therapy and inotropes according to CVP as given in Figure 1.
Figure 1. Schematic outline of initial resuscitation of shock
Monitoring
Fluid therapy in patients with hypovolemic shock will improve the peripheral perfusion and monitor pulse rate, respiratory rate, capillary filling time, blood pressure, sensorium and urine output. Final end points for volume resuscitation include warm skin, reestablishment of urine output to 0.5-1.0 ml/kg/hour, adequate capillary refill (<3 sec) and heart rate and blood pressure returning to normal range for that age.
Use of Inotropes
Inotropes are used to increase myocardial contractility. These are given as continuous intravenous infusions preferably with an infusion pump. Initial therapy is undertaken with either dopamine or dobutamine. Those who fail to respond, more potent agents like adrenaline and noradrenaline can be used. Dose of dopamine/dobutamine generally required is 5-10 mcg/kg/min, can be augmented to 20 mcg/kg/min (Table 1).
Table 1. Cardiovascular support drugs
| Drugs | Dose | Comment |
| Dopamine | 5-20 mcg/kg/min | Effects are dose related and complex |
| Dobutamine | 5-15 mcg/kg/min | Selective inotrope, little chronotropic, mild vasodilator |
| Adrenaline | 0.05-1.0 mcg/kg/min | Powerful vasoconstrictor, minimum increase in heart rate, used if other agents have failed |
| Nonadrenaline | 0.05-1.0 mcg/kg/min | Strong vasoconstrictor, mainly useful for prolonged hypotension, not responding to other agents |
Note: Titrate infusion to desired haemodynamic effect.
Preparation of catecholamine infusions in infants and children can be done by following formula:
For Dopamine and Dobutamine 6 X body weight in kg is the dose added to sufficient diluent to create a total volume of 100 ml. 1 ml/h of this fluid will deliver 1 mcg/kg/min.
For adrenaline 0.6 X body weight in kg is used in similar diluent to deliver 0.1 mcg/kg/min.
Response to inotropes is measured in the same way as after fluid push.
If patient shows better peripheral perfusion i.e. improved capillary filling time and warm extremities and blood pressure reaches within normal range, inotropes can be maintained for few hours, till underlying condition shows features of reversal. If patient does not show signs of improvement, should be referred to a tertiary level centre where facilities for ventilation are available.
Metabolic corrections
Metabolic acidosis as a consequence of tissue ischaemia is the most important secondary complication. Correction is indicated only when marked acidosis (pH <7.2). Sodium bicarbonate 1-2 mEq/kg can be used initially but subsequent doses should be based on base deficit (mEq = body weight in kg x base deficit x 0.3).
Ventilatory support - may be required in critically sick patient showing signs of ventilatory fatigue/failure.
Cardiogenic shock
Cardiogenic shock is best viewed as pump failure and common causes are acute myocardial infarction in adults and dysrrhythmia in children. Immediate treatment is same as mentioned above, however invasive monitoring and advanced life support systems are required, hence patient should be referred to a tertiary level centre after initial resuscitation. See section on arrhythmia / myocardial infarction for specific treatment.
Septic shock
Septic shock is a consequence of bacteremia most commonly gram negative organisms but gram positive and viral infections can also cause it. It follows trimodal pattern of haemodynamic presentation: warm shock, cold shock and multisystem organ failure. Initial treatment is as above except volume replacement requirement may be more and aggressive antibiotic therapy should be started early. Disseminated intravascular coagulation (DIC) is a common complication and may require fresh frozen plasma and platelet transfusion, (see section on septicaemia for specific treatment).
For anaphylactic shock see section on Anaphylaxis.
References
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Anaesthesia at the District Hospital. In: World Health Organization in collaboration with the World Federation of Societies of Anaesthesiologists, Geneva, 2nd Edition, 2000, World Health Organization.
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Drugs Used in Anaesthesia. In: WHO Model Prescribing Information, 1989, World HealthOrganization.
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Anaesthesia at the District Hospital. In: World Health Organization in collaboration with the World Federation of Societies of Anaesthesiologists, Geneva, 1988, World Health Organization.
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Fluid Therapy and Medications. In: Textbook of Paediatric Advanced Life Support, 1994, American Academy of Paediatrics, pp 6-1 to 6-11.
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Burns
Burns are a major preventable cause of morbidity and mortality. These can be caused by dry heat or space heating, moist heat-scalds and fat burns, ionizing radiation, electric burns, friction, chemicals and cold-frost bite.
Salient features
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Treatment
Immediate resuscitation and care
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Clear airway, suspect inhalational injury if history of being trapped in close space, facial burns, singeing of eyebrows/nasal hairs, respiratory distress, hoarseness of voice or stridor, altered consciousness and soot in sputum.
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Check for breathing and circulation and provide support.
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Rule out other associated injuries.
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Insert nasogastric tube in all major burns.
Assess the severity of burns
Assessment includes calculation of surface area of burns: Rule of nine/charts, depth of burns, location of burns, patient’s age and presence of associated injury or disease.
Criteria for admission or transfer to a burns center
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Burns of more than 20% body surface area in an adult.
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Burns of more than 10% body surface area in a child under 10 or adult over 50 years.
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Burns of more than 5 % body surface area in an infant.
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Burns to head, face, neck or perineum.
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Respiratory burns or inhalational injury.
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Circumferential burns.
Transfer should be done in a fully equipped ambulance with secured airway and circulatory support.
General Management
1. Fluid resuscitation
Intravenous fluids to be infused through a wide bore cannula (lactated Ringer’s solution) at the rate of 3-4 ml/kg/% burns area. Half of the volume calculated is infused in the first eight hours after the injury and the rest is infused in the next 16 hours (for details see section on fluid & electrolyte imbalance – Adults & in children).
Adequacy of the fluid therapy is best assessed by measuring hourly urine output, which should be maintained at 30-50 ml per hour in adults and 0.5-1 ml/kg body weight in children. Infusion rate should be increased or decreased accordingly.Other features to be assessed are pulse rate, respiratory rate, blood pressure and level of consciousness.
2. Pain relief
Cold compresses using fresh running water; avoid ice cold water. Inj. Morphine sulphate (15 mg/ml) 10-15 mg stat and can be repeated after 4-6 hours.
3. Care of the burns
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Clean the burns with running water except for the chemical burns.
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Remove cloths, dirt, eschar.
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Dressing: aims to minimize pain, absorb exudates and debris, shield the burns from secondary infection and provide protection during transport.
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Fasciotomy in cases of circumferential burns in extremities or chest wall.
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Application of cream- Silver sulphadiazine 1% or Silver nitrate or Framycetin 1%.
- Physiotherapy-range of action movements to prevent contracture.
4. Inj. Ampicillin 500 mg 6 hourly IV.
In children 50-100 mg/kg in 4 divided doses for 7-10 days.
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Inj. Ciprofloxacillin (Infusion 100 mg/50 ml), 500 mg 2 times a day for 7 days.
Secondary infections are treated by appropriate antibiotics according to culture sensitivity results.
Patient is advised to attend physiotherapy: use compression garments to prevent hypertrophic scars. Plastic surgeons advice may be required to correct contractures.
Home management of burns
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Burnt area should be kept under running cold water. Avoid ice cold water.
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Do not puncture the bullae.
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Apply silver sulphadiazine cream 1% Or Framycetin cream 1%.
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Cover with sterile dressing.
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Tab. Paracetamol 500 mg as and when required.
Scalds
Scalds may result from drinking extremely hot fluids or some irritant chemicals. In such cases, the inner side of the mouth and throat becomes red and swollen. Give cold water to drink or ice, followed by milk or egg emulsion to drink and refer the patient to a hospital.
Patient education
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Provide psychological support to the patient and relatives about the extent of burns, possible outcome and complications.
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Parents are educated about prevention of accidents and burns in future by taking necessary preventive steps at home.
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Transport of patient to health care center should be done at the earliest.
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The wound should be covered with a clean cloth.
- Inform the relatives about the medicolegal aspects of the injury and importance of evidence and dying declaration by the patient in case of homicidal brns or suspected dowry deaths.
References
Principle and Practice of Burn Management.Settle John AD (ed), 1996, Churchill Livingstone, New York.
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Cardiopulmonary Resuscitation (CPR)
CPR consists of a series of manoeuvers by which oxygenated blood supply to brain and vital organs is maintained during cardiopulmonary arrest (CPA) i.e. cessation of respiration and circulation.
In children, CPA is not sudden but end result of long period of hypoxemia secondary to inadequate ventilation, oxygenation or circulation. Therefore, prompt management of these is essential to prevent CPA, the outcome of which is poor.
Diagnosis of cardiopulmonary arrest
Cardiac arrest
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Absence of pulse in major arteries (carotid or femoral in older children and femoral or brachial in infants as here due to short neck, carotid is difficult to palpate).
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Absence of heart sounds on auscultation.
- Asystole /ventricular fibrillation on ECG.
Respiratory arrest
Absence of respiration on looking (absent chest movements), listening (absent air flow on bringing ears in front of mouth) and feeling (absent air flow on keeping hands in front of mouth or nose).
Levels of CPR. There are two levels of CPR:
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BLS (Basic life support), The elements of CPR provided without additional equipment. Skill and speed are most essential.
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ACLS (Advanced cardiac life support), Use of equipment and drugs for assisting ventilation or circulation.
Basic life support
Call for help Position the victim supine on firm flat surface with head level with the heart.
a. Airway
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Clear airway by cleaning blood, secretions, foreign particles (suction if available).
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Prevent posterior displacement of tongue due to muscle relaxation during CPA, by head tilt and chin lift or jaw thrust (may use an airway if available).
Head tilt: Put a hand at forehead and tilt head back to sniffing or neutral position in an infant and little more in older children and adults.
(CAUTION: In a patient with suspected cervical spine injury head tilt should be avoided.
Chin lift: Put finger of other hand under bony part of lower jaw at chin and lift chin upward.
Jaw thrust: Place 2-3 fingers under each side of lower jaw at its angle and lift jaw upward with the elbow resting on the surface on which victim is lying.
b. Breathing
Determine the absence of breathing. Give mouth to mouth /nose/mask/airway breath (may use bag and mask if available). Inhale and then make a seal around the mouth and nose together in an infant and seal mouth only in older child and adults (nose pinched with the hand used for head tilt) to exhale smoothly. Rate of breaths should be 20/min for infants;15/min in older child and 10-12/min in adults.
c. Circulation
Determine the absence of pulse after 2 breaths (rescue breaths). External Cardiac massage if asystole and unresponsive to rescue breaths. In children, perform cardiac massage if or HR <60/min with signs of poor perfusion.
Rescuer should stand or kneel at the side of the patient so that his hips are on a level with the victim’s chest.
In a newborn 2 thumbs are positioned side by side on sternum just below the nipple line, with fingers encircling chest and supporting the back and compress sternum by 0.6-1.2 cm (120/min).
In an infant put index finger at the intersection of intermammary line and sternum. Use 2-3 fingers (index, middle and ring) to compress sternum by 1.5-2.5 cm (100/min) and do not lift the finger when compression is released. Two thumb-encircling hands technique can also be used.
In children (1-8 years) use heel of hand on lower half sternum with long axis of heel same as long axis of sternum and compress 2.5-3.5 cm (100/min).
In adults the heel of one hand is placed on the lower sternum and the other hand placed on top of the first. The elbows should be locked in position with the arms straight and the shoulders over the hands. Sternum should depress by 3.5-5.0 cm and the rate of compression should be 80 to 100/min.
(CAUTION: Do not exert pressure on the ribs, costal cartilages or xiphoid)
Combination of ventilation and cardiac massage
If both cardiac and respiratory arrest. Compression : ventilation = 15 : 2 in adults and children>8 years. Children and infants 1-8 years = 5:1. Neonates=3:1]
Advanced cardiac life support (ACLS)
If ACLS facility is available, shift the patient to ACLS as soon as possible. If this is not available then continue cardiac massage till spontaneous HR is more than 60-80/min and continue artificial breathing till adequate respiratory efforts are present (good chest movement, no cyanosis or shock). For ACLS proceed in the following order:
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ECG monitoring (if available)
If ventricular fibrillation, defibrillation
In adults: First shock at 200 Joules; if the first is unsuccessful then a second shock at 200-300 Joules. If both fail, additional shocks at 300-360 Joules are given.
In children: 2 Joules/kg and can be repeated a few times if does not revert to normal rhythm). Continue cardiac massage in the mean time. -
All patients require oxygen (100%) because even with best CPR only a fraction of the cardiac output is provided and also there are other factors causing ventilation perfusion mismatch.
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Establish IV line as early as possible to give drugs and fluids and intubation of trachea should be done to continue artificial ventilation.
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Drugs are used in the following order if indicated.
Inj. Adrenaline
Indication:- Asystole, symptomatic bradycardia unresponsive to ventilation,
In adults: 1 mg IV every 3-5 minutes.
In children: 0.1 ml/kg of 1:10,000 solution (0.01 mg/kg) IV, intra-osseous or 0.1 ml/kg of 1:1000 solution by endotracheal tube followed by several positive pressure breaths. Can repeat every 5 min by either route. IV route is preferred and should be used as soon as IV access is achieved (intracardiac route is not desirable)
Inj. Lignocaine
Indication:- Ventricular tachycardia or fibrillation non responsive to or recurs after defibrillation.
In adults: Initial bolus dose is 1.5 mg/kg. Additional bolus of 0.5-1.5 mg/kg can be given every 5-10 minutes during CPR up to a total dose of 3 mg/kg.
In children: Inj. 1 mg/kg IV stat followed by infusion at 20-50 mcg/kg/min.
Inj. Amiodarone
Indication: Shock refractory ventricular fibrillation (as an alternative to or after failure of lignocaine).
In adults: Initially 300 mg rapid infusion in 20-30 ml saline followed by 150 mg over 10 minutes followed by 1 mg/min for upto 6 h and 0.5 mg/min thereafter.
In children: 5 mg/kg rapid IV and then infusion of 5 mg/kg/day.
Inj. Atropine
Indication: Vagally mediated bradycardia during intubation, HR<80 or asystole in an infant and symptomatic bradycardia with AV block in any child.
0.02 mg/kg bolus (not <0.1mg or >0.5 mg for a child and 1.0 mg for an adult). This dose may be repeated after 5 minutes for a maximum total dose of 1.0 mg for a child and 2.0 mg for an adult.
Inj. Naloxone
Indication: Narcotic overdose or poisoning and newborn resuscitation (if mother has been given morphine or pethidine during labor).
Dose and route: 0.1 mg/kg IV.
Inj. Sodium bicarbonate (NaHCO3)
Not required routinely as it can cause alkalosis later and worsen respiratory acidosis by releasing CO2 in inadequate ventilation.
Indication:- Hyperkalemia, significant metabolic acidosis (pH <7.2) or prolonged CPR .
In adults and in children: Inj. Sodium bicarbonate 1 mEq/kg stat and 0.5 mEq/kg every 10 minutes in protracted resuscitation.
Inj. Calcium
Indication: Not used routinely now a days unless there is hyperkalemia, hypocalcemia or calcium channel blocker toxicity.
Dose and route: (In children) 0.5 ml/kg of calcium gluconate IV. In adults 10 ml to be given as a slow infusion under ECG monitoring.
Inj. Glucose
Indication -Hypoglycemia.
Dose and route – 0.5-1 g/kg IV.
5. Try to get ABG, serum electrolytes and blood sugar (dextrose stick/glucometer) Post resuscitation care
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Maintain mechanical ventilation for several hours to ensure adequate oxygenation and ventilation
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Look for and treat seizures.
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Inj. Mannitol 0.5-1 g/kg IV if raised intracranial tension.
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Maintain temperature, fluid and electrolyte balance and ABG.
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Treat shock with fluids, dopamine, dobutamine and adrenaline infusion as required.
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Treat the underlying pathology causing CPA.Monitoring
Pulse should be palpable and chest expansion should be seen during effective CPR.
Blood pressure, SpO2, Et CO2 (in intubated patient and if facility available),
ABG should be monitored during and soon after CPR.Termination of CPR
If asystole persists for >10 minutes after CPR has been performed, ventricular fibrillation eliminated, successful endotracheal intubation accomplished and confirmed, adequate ventilation provided and appropriate medications given.
Patient education
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Parents: They should know that many causes of CPA are preventable e.g. injuries (by providing safe environment), poisoning (by keeping drugs out of reach of children), foreign bodies (safe toys and avoid beads, balloons etc. and avoid eatables like peanuts in infants). They should closely supervise young children.
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General public should be trained in BLS.
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Health care workers: They should be able to recognise and refer emergencies in time, and also know about BLS.
References
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Management of Cardiac and Respiratory Arrest. In: Wylie and Churchill-Davidson’s A Practice of Anaesthesia, 6th Edition, 1995. pp 1409-1425.
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New Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care- Changes in the Management of Cardiac Arrest. JAMA 2001; 285(10): 1267.
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Cardiopulmonary Resuscitation in Infants and Children. In: Principles of Critical Care Ed. Udwadia FE, 1995. Oxford University Press. Delhi.
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Cardiovascular Collapse, Cardiac Arrest and Sudden Cardiac Death. In: Harrison’s Principles of Internal Medicine. Braunwald E., Fauci AS, Kasper DL et al (eds), 15th Edition, 2000, McGraw Hill Company Inc., New York, pp. 228-233.
Categories: Emergencies Tags: