Multisystem (14%) Flashcards
Normal ABG values
pH: 7.35-7.45
PaCO2: 35-45
HCO3: 22-26
Compartment syndrome
When pressure within a closed muscle compartment exceeds the perfusion pressure and results in muscle and nerve ischemia and death of tissue
6 P’s – pain, poikliothermia, pallor, pulselessness, paresthesia, paralysis
Common areas – LOWER LEG, forearm, wrist, hand
A strong pulse does not rule out compartment syndrome
Treatment – OR for fasciotomy
Distributive shock (e.g., anaphylaxis, neurogenic, septic) (minus cardiac parameters and treatment)
- What is happening: massive vasodilation
- Pathophysiology: systemic event causes the loss of the normal response to vascular smooth muscle and vasoconstriction coupled with a direct vasodilation
- Common causes: septic shock, anaphylaxis, and neurogenic shock
Distributive shock cardiac parameters
- SBP: < 90
- CVP: ↓ (plenty of fluid but vessels are wide open so they seem empty)
- CO/CI: ↓ (fluid isn’t returning to heart because vessels are too wide)
- SVR: ↓ (vessels are wide open)
- SvO2: ↓ or ↑
Distributive shock treatment (per each cause)
- Septic: treat cause of infection
- Anaphylactic shock: volume replacement, epinephrine, glucocorticoids (IV or PO; extends life of Epi), antihistamine
- Neurogenic shock: volume replacement followed by alpha antagonists (ex: phenylephrine)
Hypovolemic shock
- What is happening: nothing to fill up the vessels
- Pathophysiology: most common form of shock in trauma; multiple organ failure d/t inadequate circulating volume leading to inadequate tissue perfusion
- Common causes: acute hemorrhage, severe hydration, severe burns
- Cardiac pressures: SBP < 90, ↓ CVP (nothing in vessels), ↓ CO/CI (no fluid to circulate), ↑ SVR (vasoconstriction to try and compensate). ↓ SvO2 (not enough fluid to circulate to oxygenate)
- Treatment: treat underlying cause; volume replacement; transfuse PRN
Cardiogenic shock
- What is happening: have enough fluid, but pump isn’t working
- Pathophysiology: inadequate tissue perfusion secondary to loss of contractile function; “pump failure”
- Common causes: acute MI, acute HF, dysrhythmia
- Cardiac pressures: SBP < 90, ↑ CVP (fluid backs up), ↓ CO/CI (pump isn’t working), ↑ SVR (not d/t vasoconstriction, rather fluid backing up putting pressure on vessels), ↓ SvO2 (can’t pump blood out to circulate)
- Treatment: treat underlying cause; support CO with inotropes; support oxygenation
Obstructive shock
- What is happening: something blocking the filling of vessels and ventricles
- Pathophysiology: obstructive filling leads to the inability to produce good CO
- Common causes: PE, tension pneumothorax, cardiac tamponade
- Cardiac pressures: SBP < 90, ↑ CVP (fluid is backed up), ↓ CO/CI (vessels and ventricles can’t fill so they can’t pump anything out), ↑ SVR (fluid backing up putting pressure on vessels), ↓ SvO2 (can’t fill so can’t put out oxygenated blood)
Sepsis
Pathophysiology: dysregulated response to infection resulting in severe vasodilation, tissue perfusion, and organ dysfunction
Initially will be in hyperdynamic shock/”warm shock” but as compensatory mechanisms fail, will progress to hypodynamic shock/”cold shock”
Treatment is based on the surviving sepsis management
Surviving sepsis management of septic shock
Within 3 hours of presentation: measure lactate, obtain blood cultures prior to antibiotics, administer broad spectrum antibiotics, administer 30 ml/kg crystalloid for hypotension or lactate ≥ 4
Within 6 hours of presentation: apply vasopressors (levophed) (for hypotension that doesn’t respond to initial fluid resuscitation to maintain MAP ≥ 65; if persistent hypotension after initial fluid bolus or if lactate was ≥ 4 – reassess volume status, re-measure lactate if initial was elevated
Follow-up: repeat focused exam (after initial fluid resuscitation)
Overall goals of treatment: CVP 8-12, MAP ≥ 65, urine output ≥ 0.5 ml/kg/hr, and SvO2 > 70%
Hemodynamic parameters
CVP (2-6 mmHg): reflects the amount of blood returning to the heart
PCWP (8-12 mmHg): left ventricular pressure when mitral valve is open
SVR (900-1400): the resistance of the systemic vascular bed
CO (4.8-6.4): volume of blood pumped out of the heart in 1 minute
CI (2.5-4.2): amount of blood pumped by the heart in 1 minute based on BSA
SvO2 (70-75%): the amount of O2 in the blood that’s returning to the heart
Ventilator modes: assist control (AC)
Ventilator delivers a specific number of preset supported breaths
Additional patient breaths trigger a fully-assisted breath
May be pressure or volume targeted
Do not use in tachypnea (can lead to hyperinflation and respiratory alkalosis)
Ventilator modes: synchronized intermittent mandatory ventilation (SIMV)
Ventilator delivers a minimum number of breaths that are synchronized with patient’s efforts
Additional patient breaths are possible with a TV that’s determined by patient’s effort
May be pressure or volume targeted
Non-invasive positive pressure ventilation (NIPPV)
CPAP – constant pressure maintained throughout respiratory cycle with no additional inspiratory support
BiPAP – a set expiratory positive airway pressure and inspiratory positive airway pressure
Common causes of fever
Infectious – bacterial (most common cause in acute care setting), viral, fungal, rickettsial, parasitic
Non-infectious – autoimmune, inflammatory, drug reaction