1
Q
The _________ pressure gradient forces glomerular filtration
A
hydrostatic
2
Q
___% of renal plasma flow is filtered into Bowman’s capsule; hemodynamic factors contribute to the filtration rate
A
20%
3
Q
What are the main parts of the kidney?
A
4
Q
What are the main parts of the nephron?
A
5
Q
Glomerular Filtration Rate (GFR) affected by renal artery pressure other autoregulation factors of GFR such as…
A
- vasoreactive (myogenic) reflex of afferent arteriole
- tubuloglomerular feedback (TGF)
- angiotensin II-mediated vasoconstriction of the efferent arteriole
6
Q
What is the effect of the vasoreactive (myogenic) reflex of afferent arteriole?
A
causes dilatation or constriction of the afferent arteriole to maintain stable glomerular pressure in response to variations in systole
7
Q
Where are the macula densa cells located in the nephron?
A
distal/ascending limb of loop
8
Q
What is the effect of the tubuloglomerular feedback (TGF)?
A
causes dilatation or constriction of the afferent arteriole to maintain stable glomerular pressure in response to solute concentration changes detected by the macula densa cells in the distal/ascending Loop of Henle
9
Q
What hormone allows for constriction where the arrows are pointing?
A
angiotensin II
10
Q
What is the function of the kidney?
A
- Water regulation
- Electrolyte regulation
- Extracellular volume/pressure regulation
- Acid-base homeostasis
- Endocrine/metabolic
— Kinins
— Erythropoietin
— Phosphate
— Vitamin D
— Renin - Blood plasma filtration
— Glucose and amino acid reabsorption
— Calcium and phosphate regulation - Excretion of metabolic waste
- Urine production
- Prostaglandin production
— regulate tubular and hemodynamic transport
— possibly fibroblast production in an immune response
11
Q
What is acute renal failure (ARF)?
also called acute kidney injury (AKI)
A
- A condition in which the kidneys suddenly can’t filter waste from the blood.
- Uremia results from the cumulative effects of renal failure, retention of excretory products, and interference with metabolic and endocrine function
12
Q
How fast is the onset of acute renal failure (ARF)?
A
- develops rapidly over a few hours or days
- It may be fatal
13
Q
Who is acute renal failure (ARF) common in?
A
most common in those who are critically ill and already hospitalized
14
Q
What are the symptoms of acute renal failure (ARF)?
A
- decreased urinary output
- swelling due to fluid retention
- nausea
- fatigue
- shortness of breath.
- sometimes symptoms may be subtle or may not appear at all
15
Q
What are the causes of acute renal failure (ARF)?
A
- Pre-renal
- Intrinsic Renal
- Post-renal
16
Q
What are the causes of prerenal ARF?
A
17
Q
What are the medications that can lead to prerenal ARF?
A
- ACE-I: monopril, captopril, enalapril
- ARB: angiotensin receptor blocker, (Diovan, Cozaar, Benicar)
- NSAIDs:Indomethacin
- PPI: proton pump inhibitors Prilosec, Prevacid & Nexium
- TTP-HUS, thrombotic thrombocytopenic purpura-hemolytic-uremic syndrome
18
Q
What are the causes of intrinsic ARF?
A
19
Q
What are the causes of postrenal ARF?
A
20
Q
What are the treatments for acute renal failure (ARF)?
A
- address the underlying cause
- cardiology and hepatology consultation
- fluids
- medication
21
Q
What are the causes of chronic kidney disease?
A
- Chronic Glomerulonephritis
- Systemic Lupus Erythematosus
- Neoplasms
- Polycystic kidney disease
- AIDS nephropathy
- Diabetic nephropathy
- Etc. (many others)
22
Q
What are the risk factors for chronic kidney disease?
A
- Age (≥60 years of age)
- Smoking
- Obesity
- HTN
— poorly controlled - Diabetes
— 40-50% of patients with type 2 DM will develop CKD - Nephrotoxins/Drugs
- Infections
- Low birthweight
- Chronic Inflammation
23
Q
What is the pathogenesis for diabetic kidney disease?
A
- nephron hypertrophy and/or nephron loss
- glomerular filtration impairment
- renal fibrosis
24
Q
What is the glomerular filtration rate (GFR) in those with chronic kidney disease?
A
<60 ml/min/1.73 m2
25
Diagnosis and Classification of CKD are based on...
GFR and albuminuria/proteinuria
26
End-Stage Renal Disease (ESRD) has a GFR of...
<15 ml/min/1.73 m2
27
What is the treatment for End-Stage Renal Disease (ESRD)?
Requires kidney replacement therapy (hemodialysis, transplantation)
28
What are the stages of chronic kidney disease?
29
What threshold of GFR is "normal"?
90 or higher
30
What GFR is stage 4 chronic kidney disease (severe loss of kidney function)?
29-15
31
What are the possible complications of chronic kidney disease?
I. Fluid and electrolyte imbalance
II. Hypertension
III. Cardiovascular Disease
IV. Endocrine dysfunction
V. Anemia
VI. Hyperuricemia (uric acid) and Uremia (urea)
VII. Dyslipidemia
VIII. Metabolic acidosis
IX. Mineral bone disorder (MBD)
32
What are the issues involving fluid and electrolyte imbalance in chronic kidney disease?
* Dysregulation of Na+, K+, and H2O reabsorption
* Hyperkalemia
* Edema
33
What are the issues involving hypertension in chronic kidney disease?
* RAS activation
* Aldosterone and catecholamine activation
* Hypervolemia
34
What are the issues involving anemia in chronic kidney disease?
* Decreased Epo and RBC survival
* Impaired iron absorption, blood loss
* Normocytic, normochromic anemia
35
What are the issues involving dyslipidemia in chronic kidney disease?
* Dysregulated metabolism of lipid and uremic toxin-mediated lipid alterations
* Atherosclerosis
36
What are the issues involving metabolic acidosis in chronic kidney disease?
* Decreased excretion of NH4+
* Decreased absorption of H+ and HCO3-
37
What are the issues involving mineral bone disorder (MBD) in chronic kidney disease?
* Decreased vitamin D levels
* Dysregulation of Ca2+ and PO4-3
* Increased PTH and FGF23 levels
* Renal Osteodystrophy, secondary hyperparathyroidism
* Calciphylaxis – extraosseous calcifications
➢Blood vessels of dermis & subcutaneous fat
38
What is the level of HbA1c for a person with controlled DM and chronic kidney disease?
<8%
39
What is the BP for a person with controlled HTN and chronic kidney disease?
<140/90 mm Hg
* Cardioselective beta-blocker
* Diuretics
* ACE inhibitor
* ARB
* Calcium channel blocker
40
What is the LDL for a person with controlled diabetes and chronic kidney disease?
LDL <100mg/d
41
What is the range of BMI for a person with controlled diabetes and chronic kidney disease?
BMI 18.5 -24.9 kg/m2
42
What is the oral manifestation for chronic kidney disease?
- Xerostomia/dry mouth
- Halitosis
- Dysgeusia (metallic taste)
- Infections
--- Opportunistic
--- Periodontal
--- Odontogenic
--- Salivary
- Enamel defects
--- Children
- Uremic stomatitis (rare)
--- BUN (blood urea nitrogen) >55 mg/dl
- Petechiae and ecchymosis
- Osteodystrophy
43
What is osteodystrophy?
* Lack of hydroxylation of 25(OH)D to 1,25(OH)2D which takes place in the kidneys
* Causes lack of Ca+ absorption from intestines
* Stimulates parathormone secretion and Ca+ loss from bone
* Inhibits bone mineralization
44
What causes osteodystrophy?
* Loss of lamina dura
* Demineralization (“ground-glass”)
* Expansile radiolucencies (CGCG, brown tumor)
* Wide trabeculae
* Loss of cortication
* Sclerosis
45
What does this patient with renal osteodystrophy show?
ground glass trabeculation
| more blurry trabeculae due to calcium loss
46
What are the two modalities for filtering the blood?
- Hemodialysis (venous access)
- Peritoneal dialysi
47
What does filtering the blood do?
removes uremic toxins; initiated in ESRD
48
What are the features of hemodialysis (venous access)?
* Arteriovenous fistula
* Ateriovenous graft
* Central venous catheter (special, short-term)
* Machine filters blood
* Heparin is typically used
* Every 2-3 days (three/week) ; 3-4 hours/session
* Risk of infectious disease – Hep B; Hep C
* Induces fatigue and dizziness
49
What are the features of peritoneal dialysis?
* Hypertonic solution in peritoneal cavity
* Peritoneal membrane used for exchange
* 3-5x/day or overnight
50
Dental treatment planned for the
day ______ hemodialysis
AFTER
51
What type of matching is required for kidney transplant?
* ABO matching
* HLA matching
* > 5- year life expectancy
* Can be from live (better) or deceased donor
--- Related mismatched donor (3/6 match) is better than deceased donor
52
What are the absolute contraindications for kidney transplants?
* AIDS
* Active hepatitis
53
What are the different types of rejection with kidney transplant?
* Activated cytotoxic T cells (direct)
* Alloantibodies (direct)
* Delayed type hypersensitivity – arteriosclerosis of transplant (indirect)
54
What are the induction (prevent acute rejection) immunosuppressants for a kidney transplant?
* Antithymocuyte globulin
* Alemtuzumab (anti-CD52)
55
What are the maintenance immunosuppressants for a kidney transplant?
* Azathioprine
--- Antimetabolite
--- Inhibits DNA and/or RNA synthesis
* Mycophenolate mofetil
--- Similar to azathioprine
--- Less bone marrow suppression
* Steroids
--- Low doses, adjunct
* Calcineurin inhibitors
* mTOR inhibitors (mTORi)
* Belatacept
56
What are important adverse effects for taking immunosuppressants for a kidney transplant?
Cytopenias (bone marrow suppression)
- Bleeding
▪ Severe thrombocytopenia <50K
- Susceptibility to infection
▪ Severe leukopenia/neutropenia
--- WBC <2000
--- ANC <500
Increased risk of developing skin and hematologic cancers
57
What are the oral adverse effects of taking immunosupression for a kidney transplant?
* Gingival hyperplasia (cyclosporine)
* Aphthous-like ulcers (mTORi)
58
How do you determine the level of renal impairment and disease control?
* BP – Avoid arm with AV shunt when measuring BP
* GFR
* BUN
* Creatinine clearance
* Serum creatinine
* Electrolytes
59
How do you assess the risk of bleeding with renal impairment when doing dentistry?
* Patients can be at risk for both bleeding and thrombosis
* Quantitative and qualitative platelet impairment
➢ Platelet count
➢ PT-INR
➢ PTT
* Hemostatic measures as necessary
* Be aware of signs and symptoms of thrombosis
* Referral to a specialized center as necessary
60
How do you decide if a patient with renal impairment needs antibodies?
* Advanced uremia → decreased immune function
* Treat infections aggressively
* If invasive procedures in patients with stage 4 (severe) or end-stage renal disease → consult physician about need for antibiotics
* Antibiotic prophylaxis IS NOT routinely necessary for peritoneal dialysis
* Antibiotic prophylaxis may be necessary for patients with a synthetic AV graft
* Antibiotic prophylaxis is necessary in hemodialysis patients if performing incision and drainage
61
What drugs do you need to be careful with for patients with renal impairement?
- Caution with nephrotoxic drugs (acyclovir, NSAIDs, aspirin, aminoglycosides, tetracycline)
- Caution with opioids
- Caution with benzodiazepines
- Caution with antibiotics (amoxicillin, cephalexin, azithromycin)
62
What are the goals of pre-transplant dental clearance?
Remove active foci of infection and limit potential foci of infection (think 6 months)
* Treat active foci of infection
--- SRP
--- Endodontic treatment
--- Restorations
* Extract teeth with questionable (even if in your opinion minimally)/poor prognosis
* Assess caries risk and need for adjuncts (fluoride)
* Educate patient on importance of maintaining good homecare, diet and professional maintenance
63
Defer elective treatment within first ___ months post-transplant
6
| Emergency care only – consider specialized center
64
What do you need to survey for post kidney transplant?
* Opportunistic infections (odontogenic, candidiasis, aspergillosis, HSV, OHL, CMV)
* Toxicities/side effects of systemic treatment
* Cancer
65
