The shock
Objectives
At the end of this session the participants will be able to: • Recognize signs of compensated and decompensated shock • Know the main treatments
The shock
2
General assessment
• General aspect: consciousness and relationship with the environment • Respiratory work: distress or insufficiency • Circulation: color, skin temperature and peripheral and central pulses
The shock
3
Compensated shock
• First phase and compensatory mechanisms: increased arterial resistance, reduction of flow to less noble organs, reduction of vascular bed and tachycardia • Subtle signs: irritability, mild confusion, cold extremities, pale skin, tachycardia, peripheral and central temperature difference, capillary refill, normal systolic and elevated diastolic
The shock
4
Decompensated shock
• Compensation mechanisms become ineffective • Increased anaerobic metabolism resulting in metabolic acidosis • Reduction of tissue perfusion and consequent multi organ failure • BP reduction, capillary refill time increase, tachycardia, cold mottled skin, oliguria, altered state of consciousness
The shock
5
Foundations in the treatment of shock
• Optimization of the oxygen content in the blood • Improved cardiac output volume and distribution • Reduce oxygen demand • Correct metabolic alterations
The shock
6
The shock
Shock classification
Causes
Hypovolaemic
Hemorrhage Diarrhea/vomiting Burns Periptonitis
Distributive
Sepsis Anaphylaxis Spinal cord injury Drug poisoning
Cardiogenic
Congenital heart disease Arrhythmias Cardiomyopathies
Obstructive
Hypertensive pneumothorax Hemo-pneumothorax Cardiac tamponade Pulmonary embolism
Dissociative
Severe amnesia Carbon monoxide poisoning Methemoglobinemia
7
Specific treatment of hypovolemic shock
• Identify the type of leak (hemorrhagic or non-hemorrhagic) • Replacement of intra and extra vascular deficit • Prevent further loss • Restoration of acid-base balance • Correct metabolic alterations
The shock
8
Specific treatment of distributive shock
• Replacement of intra and extra vascular deficit • Broad spectrum antibiotic therapy • Restoration of acid-base balance • Identify and Correct metabolic alterations • Pharmacological treatment: vasopressors and hydrocortisone • Diagnostic insights
The shock
9
Specific treatment of cardiogenic shock
• Give liquids with caution • Pharmacological support • Diagnostic insights: laboratory and nonlaboratory tests
The shock
10
Specific treatment of obstructive shock
• Correction of the cause of cardiac output obstruction • Restoration of tissue perfusion
The shock
11
Specific treatment of dissociative shock
• Correction of the cause of poor oxygenation • Replacement or chelating therapies
The shock
12
Particular situations
The shock
13
Such as
• • • • • • •
The shock
Septic shock Hypovolemic shock Trauma Single Ventricle Pulmonary Hypertension Children with special care needs Intoxications
14
Septic shock • Isotonic Fluids (Crystalloids) (Class IIa, LOE C) • Protocols (Early Goal Directed Therapy): ScvO2 ≥ 70% (Class IIb, LOE B) • Assisted ventilation (Target EGDT) • Etomidate: (Class III, LOE B) inhibition of the adrenal response -> worsening of the prognosis
The shock
15
Hypovolemic shock • Crystalloids (SF or RL) (Class I, LOE A), no added benefit from colloids • Bolus of 20 ml/kg of crystalloids in the presence of signs of shock even with normal blood pressure (Class IIb, LOE C) • Continue with boluses (20 ml/kg) if perfusion does not improve • Insufficient data on the hypertonic solution
The shock
16
Trauma #1 Common errors in the resuscitation of the pediatric trauma patient: • Inability to maintain an adequate airway • Inappropriate administration of fluids • Failure to recognize occult bleeding Early involvement of an experienced trauma surgeon and early referral to an experienced pediatric trauma center is desirable
The shock
17
Trauma #2
• Avoid head and neck movements and use jaw thrust to open and maintain an open airway • If the airway cannot be opened with jaw thrust, use “head tilt – chin lift” because a patent airway is a priority anyway • It may be useful to place a pad under the back and shoulders • Avoid hyperventialtion • Short-term hyperventilation (moderate or controlled hypocapnia) may be used if signs of herniation are present (increased ICP if measured, unilateral non-lightresponsive mydriasis, bradycardia, and hypertension)
The shock
18
Trauma #3 • Always think about chest injuries in systemic trauma (Pneumothorax, hemothorax and pulmonary contusion impairment of B and C) • In the presence of craniofacial trauma or in the suspicion of a skull base fracture, it is preferable not to insert the SNG (Class IIa, LOE C) • In particular situations of cardiac arrest (penetrating trauma) there may be an indication for thoracotomy (Class IIb, LOE C) • Always consider internal bleeding, pneumothorax hypertension, cardiac tamponade, and spinal injuries as causes of shock The shock
19
Single Ventricle • • • • •
Increase pulmonary flow Heparin Oxygen with 80% SaO2 target ETCO2 not reliable Newborns in periarrest: PaCO2 50-60 mmHg • Systemic vasodilators (alpha-lytic eg. phenoxybenzamine, milrinone, nipride) • ScvO2 (central venous blood O2 saturation) monitoring • In patients undergoing Stage procedure it is reasonable to consider ECMO (Fontan-type Physiology or BDG) The shock
venous blood (poor in oxygen) Arterial blood (rich in oxygen) Mixture of venous and arterial blood Pulmonary stenosis Single ventricle
20
Pulmonary Hypertension • • • •
Standard PALS Correct hypercapnia Fluids to maintain the preload Inhaled nitric oxide or nebulized prostacyclin to reduce pulmonary vascular resistance • Alternatively, intravenous prostacyclin can be used • ECMO useful if used early in resuscitation
The shock
21
Children with special care needs • Know the techniques for maintaining a clear and open airway, repositioning the tracheostomy tube, and performing CPR using the main airway • If the lung does not expand after aspiration, mouth-stoma or bagstoma ventilations can be performed • If the upper airways are patent, it is possible to ventilate with a bag and mask, keeping the tracheostomy manually occluded
The shock
22
Post-resuscitation treatment
The shock
23
Objectives
• Preserve neurological function • Prevent secondary damage • Diagnose and treat the underlying disease • Ensure transportation to an expert pediatric center • Reevaluate frequently
The shock
24
Respiratory function Hyperoxemia increases the oxidative damage following reperfusion Use minimum O2 flow necessary to maintain SaO2 ≥ 94% and ≤ 99% Check the resolution of the metabolic acidosis and the reduction of lactates and the normalization of venous O2 saturation End-tidal CO2 detected with capnography Control the pain with analgesics and sedatives Monitor PETCO2 especially in case of transport and during diagnostic procedures Insert an SNG to prevent gastric distension
The shock
25
Circulation • Monitor FC and PA, and diuresis • 12-lead ECG • Remove I.O. access (if present) when at least 2 peripheral venous accesses have been positioned • Chest x-ray, Lactates, ScvO2 • Myocardial dysfunction (post-cardiac arrest) is quite common in this phase
The shock
26
Circulation - Drugs
The shock
•
Adrenaline: large inter-individual variability, titrate dose to desired effect • Low dose (< 0.3 mcg/kg/min) beta adrenergic action • High dose (> 0.3 mcg/kg/min) alpha adrenergic action
•
Norepinephrine: very useful in shock with reduction of peripheral vascular resistance (septic, anaphylactic, spinal or vasodilator)
•
Dopamine: 2-20 mcg/kg/min
•
Dobutamine: selective effect on ß1 and ß2 receptors. It improves myocardial contractility and can lower peripheral resistance
•
Nitroprusside: reduction of peripheral vascular resistance and improvement of CO. Useful in association with inotropes
•
Inodilators: CO improvement with little effect on O2 consumption. In highly complex settings to treat myocardial dysfunction in the presence of increased peripheral or pulmonary resistance. They have a long half-life with some delay in reaching effect after dosage changes (from 18 hours with inamrinone to 4.5 hours with milrinone). In case of toxicity, prolonged effects even after suspension. 27
Nervous system
The shock
•
Avoid hyperventilation. It has no benefit and many damage the CNS by reducing CO cerebral perfusion
•
Con trolled hypothermia (32-34 °C) may be considered for children who remain comatose after cardiac arrest (Class IIb, LOE C ) especially if witnessed (Class IIa, LOE C)
•
Monitor temperature and aggressively treat fever when > 38°C (Class IIa, LOE C)
•
Aggressively treat epileptic seizures
•
Avoid too rapid heating from 32 to 34 °C (> 0.5°C/2h)
28
Unexpected death in the pediatric age
The shock
29
Unexpected death in the pediatric age
Incidence (USA) • 0.6-6.2/100.000 subjects without heart disease • 20-25% during sport • 100/100.000 patients with heart disease
The shock
30
Unexpected death in the pediatric age
2010 (New argument): in the event of sudden cardiac death with no apparent cause in a child or young adult, a personal and family medical history should be obtained (including list of episodes of syncope, epileptic seizures, drownings/accidents with no apparent cause or sudden and unexpected deaths < 50 years of age), as well as review previous ECGs. Infants, children and young adults suffering sudden and unexplained death should, where resources permit, undergo a full and unrestricted autopsy, preferably by a pathologist trained and experienced in cardiovascular pathology. Tissues should also be preserved for genetic analysis to establish the presence of channelopathy.
The shock
31
Unexpected death in the pediatric age
Motivation: as evidenced by a growing body of evidence, some cases of sudden death of infants, children and young adults may be associated with genetic mutations that cause defects in cardiac ion transport, known as channelopathies. Such defects can cause fatal arrhythmias and correctly diagnosing them can be of great importance to the victims’ living relatives.
Possibility of diagnosis in survivors!!!
The shock
32
Guidelines 2010 New considerations on pediatric MI
• The doctor’s task does not end with the resuscitation phase • In cases of MI, refer to the acquisition of data/information to exclude genetic diseases • Shockable rhythms in pediatric arrest: not so rare
The shock
33