Shock Flashcards
T/F The brain lacks the capacity for anaerobic metabolism
T
Criteria for cardiovascular dysfunction (MODS)
1) Despite administration of 60cc/kg isotonic fluid IV, decrease in BP <5th percentile for age or SBP <1 SD below normal for age 2) Need for vasoactive drug to maintain BP in normal range OR 2 of the ff: BE >5, lactate >2x upper limit of normal, UO <0.5cc/kg/hr, CRT >5, core to peripheral temp gap >3C
Criteria for respiratory dysfunction (MODS)
PaO2/FiO2 ratio <300 in the absence of CHD or pre-existing lung disease OR PaCO2 >20 over baseline OR proven need for >50% FiO2 to maintain O2sat ≥92% OR need for invasive or noninvasive mechanical ventilation
Criteria for neurologic dysfunction (MODS)
GCS ≤11 OR acute change in mental status with a decrease in GCS ≥3 points from baseline
Criteria for renal dysfunction (MODS)
Crea ≥2x upper limit of normal for age OR 2x increase in baseline value
Criteria for hepatic dysfunction (MODS)
TB ≥4mg/dL, ALT 2x upper limit of normal for age
Underlying pathophysiologic mechanism leading to distributive shock
State of abnormal vasodilation
Definition of pediatric sepsis
1) Suspected or proven infection or a clinical syndrome associated with high probability of infection 2) SIRS
Definition of severe sepsis
Sepsis + organ dysfunction
Definition of septic shock
Sepsis + cardiovascular organ dysfunction
SIRS criteria
2 of 4, 1 of which must be abnormal temp or abnormal WBC count: 1) Core temp >38.5 or <36 2) Tachycardia or persistent bradycardia over 0.5hr in children <1 y/o 3) RR >2SD above normal for age or acute need for mechanical ventilation not related to neuromuscular disease or general anesth 4) Elevated or depressed WBC for age not secondary to chemo OR >10% immature neutrophils
Tachycardia in definition of SIRS is qualified as
Mean HR ≥2SD above normal for age in absence of external stimuli, chronic drugs, or painful stimuli OR unexplained persistent elevation over 0.5-4 hours
Goals in fluid resuscitation for shock
Normal HR, UO 1cc/kg/hr, CRT <2, improved mental status
Smaller boluses of ___ should be given for cardiogenic shock
5-10cc/kg
Improves systolic function and decreases SVR without causing a significant increase in HR with added benefit of enhancing diastolic relaxation in cases of cardiogenic shock
Milrinone
Inotropes: Vasoconstrictor at high dose, vasodilator at low dose
Dopamine and Epinephrine
Inotropes: Potent inotrope, chronotrope, and direct pressor
Epi and Norepi
T/F Milrinone has no pressor nor chronotrope activity
T
T/F Dobutamine has no pressor activity
T
Type of Shock: DM/DI
Hypovolemic
Type of Shock: Androgenital syndrome
Hypovolemic
Type of Shock: CNS/Spinal injury
Distributive
Type of Shock: Drug intoxication
Distributive, cardiogenic
Type of Shock: Kawasaki
Cardiogenic
Type of Shock: Cardiac tumor
Obstructive
Type of Shock: CO poisoning
Dissociative
Type of Shock: Methemoglobinemia
Dissociative
Breathing pattern: Diseases of decreased lung compliance
Rapid and shallow (decreased tidal volume)
Breathing pattern: Obstructive airway diseases
Deep but less rapid (increased tidal volume)
Extrathoracic vs intrathoracic airway obstruction: Inspiratory stridor
Extra
Extrathoracic vs intrathoracic airway obstruction: Chest wall and subcostal retractions
Extra
Extrathoracic vs intrathoracic airway obstruction: Prolongation of expiration
Intra
Extrathoracic vs intrathoracic airway obstruction: Expiratory wheeze
Intra
Extrathoracic vs intrathoracic airway obstruction: Prolongation of inspiration
Extra
T/F Patient’s general state, respiratory effort, and potential for impending exhaustion are more important indicators for respiratory failure than blood gas values
T
Consensus definition of Acute Lung Injury (ALI)
1) Acute onset (<7 days) 2) Severe hypoxemia (PaO2/FiO2 <300 for ALI, <200 for ARDS) 3) Diffuse bilateral pulmonary infiltrates on frontal radiograph consistent with pulmonary edema 4) Absence of left atrial htn
T/F Both ventilation and perfusion are lower in nondependent areas of the lung and higher in dependent areas of the lung
T
Venous admixture or incomplete arterialization of systemic venous (pulmonary arterial) blood results from
Perfusion in excess of ventilation
Intrapulmonary shunting of systemic venous blood to systemic arterial circulation results from
Perfusion of unventilated areas of the lungs
Diffusion defects manifests as hypoxemia vs hypercarbia
Hypoxemia (diffusion capacity of CO@ is 20x greater than that of O2)
Formula for an estimation of the FiO2 during use of nasal cannula in older children and adults
FiO2 - 21% (LPM x 2)
FiO2 values of a simple mask
0.30-0.65
T/F A high flow nasal cannula provides significant CPAP
T
Provide PAP during exhalation and additional positive pressure during inspiration
BiPAP
Formula for ID or internal diameter of ET tube
Age/4+4
Pressure necessary to move a given amount of air into the lung is determined by 2 factors
1) Lung and chest wall elastance 2) Airway resistance
2 ventilator strategies commonly employed to improve O2 in diseases with decreased FRC
Application of PEEP and increasing iT
What is recruitment
Process of opening atelectatic alveoli
Mechvent mode: Inspiration is initiated at a set frequency with a timing mechanism independent of patient effort
SIMV
Mechvent mode: Each and every patient breath is triggered by pressure of flow generated by patient inspiratory effort and assisted with either preselected inspiratory pressure or volume
AC
Mechvent mode: Machine-delivered volume is the primary control and inflation pressure generated depends on respiratory system’s compliance and resistance
Volume-controlled ventilation
Mechvent mode: Pressure change above baseline is primary control, and the TV delivered to the lungs depends on respiratory system’s compliance and resistance
Pressure-controlled ventilation
Most useful expiratory maneuver in mechanical ventilation
Application of PEEP
Most important clinical benefits of PEEP
Recruitment of alveoli AND increasing FRC
iTime is usually initiated at ___ for neonates, ___ for older children, and ___ for adolescents and adults
0.5-0.7 sec, 0.8-1, 1-1.2
In patients with severe acute hypoxemic respiratory failure, avoidance of TV ___ limits diffuse alveolar damage
≥10cc/kg
Most effective strategy to minimize ventilator associated pneumonia
Regular assessment of extubation readiness and liberation from mech vent as soon as clinically possible
Most objective means of assessing extubation readiness
Spontaneous breathing trial (SBT): CPAP with minimal or no pressure support with no episodes of respiratory or cardiovascular decompensation
Populations at increased risk for extubation failure
1) Young infants 2) Mechanically ventilated >7 days 3) Chronic respiratory or neurologic conditions
MCC of extubation failure in children
Post extubation upper airway obstruction
Minimizes incidence of postextubation airway obstruction
IV corticosteroids, e.g. Dexa 0.5mg/kg q6 for 4 doses prior to extubation
