HAP/VAP and Electrolyte Disorders

HAP/VAP Pathophysiology

common risk factors structural lung disease, age, malnutrition, supine position

dx CXR lung infiltrate, fever/leukocytosis/hypoxia/rales, noninvasive sputum culture

HAP= 48hrs after admission, VAP= 48hrs after intubation

Bugs Empiric Therapy

MRSA= vanc or linezolid

Pseudomonas= pip/tazo, cefepime, ceftazidime, mero/imi/aztreonam, cipro/levo, gent/tobramycin, amikacin, colistin, polymixin B

MSSA= pip/tazo, cefepime, mero/imipenem, levo

VAP Empiric Therapy

if IV abx within 90d, spetic shock, ARDS, >5d hospitalizations, renal replacement cover MRSA (also if >10% S. aureus=MRSA) and double pseudo (also if >10% resistance)

HAP Empiric Therapy

no MRSA/mortality risk= pip/tazo, cefepime, levo, imi/meropenem

MRSA risk (IV abx within 90d, >20% S. aureus=MRSA)= same or aztreonam plus vanc or linezolid

MRSA/mortality risk (septic shock, ventilation)= same or aztreonam/gent/tobra/amikacin plus vanc or linezolid

double pseudo if structural lung disease or septic shock/ventilation

HAP/VAP Drugs

van monitoring target trough 15-20 AUC 400-6000, AE infusion reaction, nephrotoxic

linezolid can transition to PO, AE thrombocytopenia, serotonin syndrome

beta-lactams renally adjusted, extended infusions preferred, AE GI, neurotoxic, allergic rxn

fluoroquinolones AE tendonitis, CNS effects, QTc, DDI warfarin, polyvalent cations

aminoglycoside gent/tobra peak 9-10 trough <1, ami peak 25-30 trough <4, BBW nephro/ototoxicity, should not be used as monotherapy

HAP/VAP Duration

improvement after 48-72hrs, can use negative MRSA nares PCR to rule out

generally 7d, shorter if improving and no organisms, longer if no improvement

procalcitonin biomarker guidance iffy

Electrolytes

support membrane homeostasis

interconnected (Ca-P, K-Mg)

intracellular= K,Mg,P extracellular= Na, Ca

Na

low <135

• presents AMS/seizures

• from increased solutes, sodium/water loss, hypervolemia, SIADH

• treat hypovolemic replace Na, hypervolemic diuretics/hypertonic saline/vaptans, euvolemic fluid restriction/replace Na/vaptans

high >145

• presents irritable and vascular rupture

• from decreased volume

• treat hypotonic fluids (D5W), DDAVP

Ca

low total <8.5, ionized (not albumin bound) <1.1

• presents muscle cramps

• from malnutrition, high P, 2nd HPT, low vit D, renal failure

• treat IV CaCl 1gram= Ca gluconate 3gram, also PO Ca carbonate and vit D

low total >10.2, ionized >1.3

• presents muscle weakness and AMS

• from hyperPT, bone cancer

• treat IV fluids, diuretics, calcitonin, bisphosphonates/denosumab

P

low <2.5

• presents neuromuscular and muscle weakness

• from malnutrition, GI losses, alcohol use, renal replacement

• treat IV or PO or nutritional

high >4.5

• presents asymptomatic

• from hypocalcemia and hypoxia

• treat decrease in diet, binders, HD

K

low <3.5

• presents rhabdo, EKG changes

• from low Mg, GI losses, excretion or shift (diuretics, amphotericin B)

• treat PO if mild, IV if severe (<2.5), also treat Mg if low

high >5.0

• presents weakness, EKG peaked T waves

• from renal dysfunction, excretion or shift (ACE/ARB, diuretics, dig)

• treat acute with Ca (CaCl irritating), shift using insulin, bicarb, albuterol, excrete using loop diuretics, binders, HD

Mg

low <1.5

• presents hyperactive reflexes, tremors

• from decreased intake or meds (tacrolimus, cyclosporine, aminoglycosides)

• treat with PO oxide or IV sulfate (slow admin due to hypotension risk)

high >1.1

• presents asymptomatic until >4, then weakness/hypotension

• from renal failure, adrenal insufficiency, hypothyrodism, lithium toxicity

• treat limit Mg in diet, diuresis, or Ca for membrane stabilization