H476 Exam 1 (Modules 1&2)

hemodynamics

blood flow and pressure needed to deliver oxygen to tissues and support organ perfusion

MAP

average arterial pressure driving systemic organ perfusion; 70-100 mmHg (initial goal is >65)

CVP/RAP

central venous pressure/right atrial pressure; one clue to venous congestion and right heart-preload (about 2-6 mmHg)

PAP

pulmonary artery pressure; reflects right ventricular output and pulmonary vascular load (systolic 15-30, diastolic 4-12, mean 10-20 mmHg)

POAP/PCWP

estimates left-arterial and left-sided filling pressures; important in CV patients (6-12 mmHg)

CO/CI

cardiac output/cardiac index; blood pumped each minute; CI adjusts cardiac output for body surface area (CO: 4-8 L/min, CI 2.5-4.0 L/min/m2 (less than 2.2 being low output in shock))

SV/SVI

stroke volume/stroke volume index; blood ejected with each beat; influenced by preload, afterload, and contractility (SV: 60-100 mL/beat)

SVR

systemic vascular resistance; resistance against left-ventricular ejection; an estimate of systemic afterload (800-1200 dyn s/cm5)

SvO2/ScvO2

balance between oxygen delivery and tissue oxygen consumption (SvO2: 60-80%, ScvO2 70-75%)

PVR?

estimates right-ventricular afterload

SVR?

estimates left-ventricular afterload

WBC

4.0-11.0 x10^3; reflects circulating leukocytes; care about infection/inflammation, immune suppression, marrow failure, and the differential/trend

Hemoglobin

12-17.5; reflects O2 carrying capacity; care about bleeding, anemia, hemodilution, hypoxemia, ischemia, and transfusion context

Hematocrit

36-53%; proportion of blood volume made of RBCs; care about blood loss, hemoconcentration, dilution, and trend with hemoglobin

Platelets

150-400x10^3; central to primary hemostasis; care about bleeding, DIC, HIT, sepsis, procedures, and antiplatelet therapy

Sodium

134-145 - water balance and neurologic function; rapid changes can cause seizures, cerebral edema, or osmotic injury

Potassium

3.5-5 - cardiac conduction and muscle function; severe high or low values can produce lethal dysrhythmias

Chloride

98-106 - fluid and acid-base balance; trends may help explain metabolic acidosis/alkalosis and effects of IV fluids

Bicarbonate/ total CO2

22-29 - metabolic component of acid-base balance; interpret with pH and PaCO2 when the patient is unstable

Magnesium

1.7-2.2 - myocardial stability and neuromuscular function; low levels can worsen dysrhytmias and make potassium difficult to correct (muscles)

Phosphorus

2.5-4.5 - ATP, diaphragm function, and cellular metabolism; severe depletion can contribute to weakness and ventilator weaning failure

Total calcium

8.5-10.5 - contraction, conduction, and coagulation; ionized calcium is often more useful in critically ill patients

BUN

7-20 - affected by renal function, hydration, catabolism, GI bleeding, and protein intake; interpret with creatinine and volume status

Creatinine

0.6-1.3 - marker used to estimate kidney filtration; a rising trend may signal AKI even before dramatic absolute elevation

Serum osmolarity

275-295 - reflects concentration of circulating solutes; useful with sodium disorders, toxic alcohols, DKA/HHS, and osmolar therapy

Urine specific gravity

1.005-1.030 - reflects urine concentration; interpret with renal function, fluid balance, diuretics, and endocrine disorders

Adult urine output

0.5ml/kg/hr is a common perfusion/AKI surveillance threshold; trend output rather than relying on one our alone

pH

7.35-7.45 - overall acid-base status; severe acidemia or alkalemia can impair cardiovascular and neurologic function

PaCO2

35-45 - respiratory component; rises with hypoventilation and falls with hyperventilation

HCO3

22-26 - metabolic component; low values suggest metabolic acidosis and high values suggest metabolic alkalosis in the appropriate context

PaO2

80-100 on room air at sea level - arterial oxygen tension; interpret with age, FiO2, PEEP, lung disease, and oxygenation goal

base excess

-2 to +2 - helps estimate the metabolic contribution to an acid-base disturbance

rising or elevated lactate

can signal inadequate perfusion or unresolved disease even when blood pressure appears acceptable

PT

11-13.5 - evaluates the extrinsic/common pathway; affected by warfarin, liver dysfunction, factor deficiency, and DIC

INR

0.8-1.1 without anticoagulation; standardized PT; therapeutic targets are indication-specific

aPTT

25-35- evaluates the intrinsic/common pathway; may be used with unfractionated heparin

Fibrinogen

200-400 - substrate for clot formation; low or rapidly falling levels are concerning in DIC and major hemorrhage

D-dimer

reflects fibrin breakdown but is nonspecific in ICU patients

Troponin

indicated myocardial injury but not necessarily type 1 MI

BNP/NT-proBNP

elevation supports cardiac wall stress but is not specific for acute heart failure

AST and ALt

10-40 and 7-56 - markers of hepatocellular injury; very rapid elevations can occur with ischemic hepatitis after shock

Alkaline phosphatase and total bilirubin

44-147 and 0.1-1.2 - useful when cholestasis or biliary obstruction is suspected

INR usefulness

can provide more immediate information about hepatic synthetic dysfunction than albumin when liver failure is acute

Norepinephrine

vasoconstrictor with some inotropy; common first-line support for vasodilatory/septic shock; titrate to MAP and end-organ perfusion

Epinephrine

strong adrenergic vasopressor/inotrope; used in refractory shock, anaphylaxis requiring infusion support, bradycardic/low-output states, and post-arrest instability

Vasopressin

non-adrenergic vasoconstrictor; commonly added for vasodilatory shock; many adult protocols used a fixed dose rather than bedside titration; can cause a squeeze on vasculature thus long-term use causing loss of fingers or toes

Phenylphrine

predominately alpha-1 vasoconstrictor; may be selected when vasodilation is prominent and tachyarrythmia limits beta-adrenergic stimulation

Dobutamine

beta-1 predominant inotrope; used for low cardiac output with adequate blood pressure, cardiogenic shock, and selected sepsis-related myocardial dysfunction

Milrinone

inodilator; common in advanced heart failure, right-ventricular dysfunction, pulmonary hypertension, and pediatric cardiac critical care; watch hypertension and renal clearance

Dopamine

adrenergic/dopaminergic agent; now less favored as first-line septic-shock therapy because of arrhytmia risk

Propofol

sedative-hypnotic for ventilated adults and procedures; rapid onset/offset; monitor hypotension, triglycerides, and risk for propofol infusion syndrome with high/prolonged exposure

Dexomedetomidate

alpha-2 agonist sedation that can preserve arousability; common for ventilator/light sedation and agitation; monitor bradycardia and hypotension

Midazolam

benzodiazepine sedation and seizure therapy; can accumulate with prolonged infusion and contribute to hypotension and delirium risk

Fentanyl

opioid analgesic frequently used for severe pain and ventilator tolerance; monitor respiratory depression, chest-wall rigidity with rapid/high exposure, ileus, and tolerance

Ketamine

dissociative anesthetic/analgesic; used for procedures, analgesia, sedation, and selected refractory broncospasm or status epilepticus; some ICU uses are off-label

neuromuscular blockers such as cisatracurium, rocuronium, and vecuronium

used for selected severe ventilator dyssynchrony, procedures, or refractory hypoxemia; paralysis never replaces analgesia and sedation

Unfractionated heparin

anticoagulation for VTE, ACS, mechanical support, and selected devices; monitor the protocol-defined assay, bleeding, platelets, and HIT risk

Bivalirudin

direct thrombin inhibitor used in PCI and increasingly selected ECMO/VAD or HIT situation; monitor bleeding and the institution-specific assay

IV insulin

hyperglycemic emergencies and selected critically ill patients; frequent glucose and potassium surveillance are essential because errors can cause rapid severe harm

Hypertonic NaCl

used for severe symptomatic hyponatremia and intercranial hypertension; sodium correction and neurologic response must be closely monitored

IV potassium and phosphate replacement

concentrated electrolytes are high alert; use standarized concentrations/rates and monitor renal function, ECG when indicated, and repeat levels

Amiodarone

IV antiarrhytmic for selected atrial and ventricular dysrhytmias; monitor rhythm, OT, blood pressure, and bradycardia

Lidocaine

IV antiarrythmic for selected ventricular dysrhythmias; neurologic toxicity can occur with accumulation

Nitroprusside

potent arterial/venous vasodilator for selected hypertensive emergencies or afterload reduction; requires close blood-pressure monitoring and attention to toxicity with prolonged/high exposure

Nitroglycerin

venodilator/coronary vasodilator used for ischemia, acute pulmonary edema, and selected hypertensive cardiac emergencies; titrate to symptoms/hemodynamics

Nicardipine or clevidipine

titratable arterial vasodilators frequently used for controlled BP reduction, including neurologic critical care; monitor for overshoot hypotension

Epoprostenol

prostacyclin infusion for pulmonary arterial hypertension and selected severe right-heart/pulmonary vascular disease; interruption can cause rapid clinical deterioration

shock

inadequate oxygen delivery or utilization that threatens cellular and organ function

early cues of shock

tachycardia, narrowed pulse pressure, delayed capillary refill, anxiety, cool skin, or declining urine output

worsening cues of shock

hypotension, AMS, weak pulses, oliguria/anuria, rising lactatr, and metabolic acidosis

hypovolemic shock

inadequare circulating volume reduces preload and cardiac output

hypovolemic shock causes

hemorrhage, GI losses, dehydration, burns/capillary loss, and significant third spacing

recognizing hypovolemic shock (NCLEX)

unexplained tachycardia plus cool skin and decreasing urine output after trauma

infusions with hypovolemic shock

use blood products and a massive-transfusion pathway when clinically indicated rather than relying on large volumes of crystalloid for major hemorrhage if large volumes of crystalloid used - correct the underlying fluid/electrolyte cause

cardiogenic shock

pump failure reduces forward flow despite adequate or elevated filling pressures

cardiogenic shock causes

acute MI, decompensated HF, myocarditis/cardiomyopathy, mechanical complications, and severe dysrhytmias

cues of congestion (with cardiogenic shock)

crackles, pulmonary edema, JVD, peripheral edema, or elevated filling pressures

cardiogenic shock NCLEX clue

a large fluid bolus can worsen pulmonary congestion when the primary problem is pump failure rather than volume loss; avoid an automatic large fluid bolus

cues of cardiogenic shock

hypotension plus pulmonary congestion and oliguria

anaphylaxis

can cause vasodilation, capillary leak, bronchoconstriction, and airway edema

airway cues (anaphylaxis)

hoarseness, stridor, tongue/lip swelling, dysphagia, and rapidly progressive edema

breathing cues (anaphylaxis)

wheezing, broncospasm, increased WOB, and hypoxemia

circulatory cues (anaphylaxis)

hypotension, syncope, tachycardia, and poor perfusion; skin may be warm or flushed early

anaphylaxis NCLEX

do not wait for a rash before treating a patient with sudden airway or circulatory compromise after an exposure

neurogenic shock

loss of sympathetic vascular tone, most often after high cervical or thoracic spinal cord injury

cues of neurogenic shock

hypotesnion with inappropriate bradycardia, warm dry skin, vasodilation, and impaired temperature regulation

spinal shock

neurologic loss of reflexes and motor/sensory function below the injurt

priorities with neurogenic shock

maintain spinal alignment, airway, and ventilation while rapidly evaluating for hemorrhage and other causes of hypotension

obstructive shock

mechanical barrier prevents adequate cardiac filling or forward blood flow

causes of obstructive shock

tension pneumothorax, cardiac tamponade, and high-risk pulmonary embolism with cardiopulmonary failure

priority in obstructive shock

relief of the obstruction

septic shock

sepsis with severe circulatory and metabolic dysfunction that threatens organ perfusion

common sources of septic shock

pulmonary, urinary, abdominal, skin/soft tissue, vascular-line, and other device-related infection

complications of septic shock

AKI, ARDS, DIC, encephalopathy, hepatic dysfunction, and multiple-organ dysfunction

possible cues of septic shock

fever or hypothermia, tachycardia, tachypnea, hypotension, AMS, oliguria, hypoxemia, or mottled skin

infusions with septic shock

give antimicrobials ideally within one hour, and at least 30mL/kg crystalloid in the first 3 hours

DIC

disseminated intravascular coagulation; systemic pathologic coagulation activation that can produce both microvascular thrombosis and consumption-related bleeding

common triggers of DIC

sepsis, major trauma, obstetric catastrophes, malignancy, and other severe inflammatory states

DIC cues

oozing from lines/wounds, petechiae, ecchymosis, GI/GU bleeding, ischemic digits, organ dysfunction, or unexpected thrombosis

DIC lab values

falling platelets, prolonged coagulation times, low fibrinogen, elevated D-dimer/fibrin degradation products, and falling hemoglobin