Renal I Flashcards
Kidney pain, SNS, and PNS innervation
Pain T10-L1. SNS T8-L1. PNS via vagus, S2-4
%CO kidney receives
25%
Po2 cortex v medulla
50 v 10-20
Blood flow through nephron
Renal A- arcuate- interlobar- cortical radial a- afferrent arteriole- glomerular capillaries- 25% to Bowman’s capsule/rest—> efferent arteriole- peritubular capillaries or vasa recta - venous system
Vessels supplying cortical nephrons
Short loops of henle, efferent arterioles drain into peritubular capillaries
Vessels supplying juxtamedullary nephrons
Long henle, efferent arterioles drain into vasa recta
How glomerulus affects gfr q
Efferent constricts- gfr increases. Afferrent constricts- decreases
What is freely filtered vs excluded from glomerular diltrate
Free filter: h20, na, glucose, urea, cations. Exc: negative, hgb, albumin
Areas of high metabolic activity in renal tubule, implication
Proximal convuluted tubule, DCT, thick ascending limb of henle. All at risk for ischemia
Areas of h20 reabsorp, most to least
Proximal tubules 65%, loops of henle 15%, distal tubules and collecting ducts 10%
Proximal convoluted tubule: substances resorbed
65% of na/k/cl/h20. Glucose, lactate, aa, ca.
PCT: continuation of what, what secreted/exchanged here
Bowmans capsule, H sec for HCO3
Loop of henle: contin of, forms what
PCT, hypertonic fluid
Juxtaglomerular apparatus: what it contains, function
Macula densa- mesangial cells contract when exp to ang II- dec area of glomerulus. Granular cells sec renin w b1 stim- dec gfr w baroreceptor activ
DCT: what is resorbed here, under influence of what
Na/cl/h20, adh/app (v2) and aldosterone
DCT: secretes what
H ions and k
Collecting duct: reabsorbs what thru what, secrets what
H20 (adh), na/h20 in each for K. Secretes H ions/reabsorbs hco3
Two most imp parts of kidney for acid base balance
Late distal tubule and collecting duct
Three responses via hormones to hypovolemia
SNS/Ang II (dec gfr/inc na reabsorption). Aldosterone- inc na reabsorption. ADH- in h20 reabs in collecting duct
Renal responses to hypervolemia
ANP (inc gfr by dilating). Red sns/ang II (dilation, filter na). Dec aldosterone- dec na reabsorption. Dec vaso- less h20 reabsortpion
Where aldosterone effects kidney
Distal tubule and collecting duct
Where ADH/vaso effects kidney
Collecting duct
SNS (alpha 1) and ang II stim high v low concentration effects
High= afferrent vasoconstriction Low= efferent vasoconstriction
Vaso preferentially vasoconstricts
Efferent arterioles
Adenosine gfr fx
Decreases renin release and afferrent vasoconstriction, dec renal bf
Auto reg range for ribs and gfr
Map 80-200
Myogenic mechanism of gfr auto reg
Inc bp- reflex afferrent vasoconstriction. Dec bp opposite fx
Conditions when auto reg is severely reduced
Sepsis, ARF, CPB
How prostaglandins work
Oppose actions of ang II, sns, and adh. Renal vasodilation, inc na and h20 excretion
CRF: when long term dialysis req.
Creat >3 gfr <30
Anemia in CRF: downside to EPO therapy. Hct and hgb goals
Can cause or exacerbate htn. Hct 36-40% hgb 12 females 13 males
Coagulopathies in CRF can be related w what? 4
Desmopressin, EPO, cryo, and estrogen
BP goal in crf
<130/85
AKI: creat, creat clearance, and urine produc
> 0.5, 50% decrease, <400 ml/day or no urine
AKI: pre renal
Dec bp to kidneys from CHF, hypotension, or low blood vol
AKI intra renal
Severe ischemia, nephrotoxic exposure, parenchymal disease
AKI post renal
Obstruction of urinary collecting system
When to reduce doses of drugs cleared unchanged by kidneys
Gfr <50 ml/min
What can prolong NMB in renal failure
Lyte imbalance, aminoglycosides, diuretics, immunosuppresants, mg antacids
Nml levels for gfr
Bun 5-10, creat 0.5-1, cr cl 110-150
Nml levels for renal tubular function
Sp gravity 1.003-1.03, osmolariy urine 38-1400
Nml bun/cr ratio, when it indications pre renal issue
10:1. >20:1
When bun indicative of dec gfr. When cr cl estimates gfr
> 50/ <25 ml/min
Periop oliguria: urine volume, how to tell its pre renal
<0.5 ml/kg/hr. Urinary na <40, osmolarity >400, urine to plasma osmolarity >1.8
How to determine periop oliguria intrarenal
Urinary na >40, osm 250-300, urine to plasma osm <1.1
Where to avoid ivs in dialysis pt
Non dominant arm and upper portion of dominant arm
What kinds of drugs does dialysis clear
Low weight, <90% protein bound, water soluble
How to tx dialysate hypersensitivity
Ethylene oxide or polyacrylonitrile
