Post on 11-Jul-2015
Biochemical Alterations and
Mechanism for Changes in Urinary
pH,
Sodium,
Potassium,
Calcium
and
Phosphorous
in Patients of Acute PoliomyelitisBy: Samyek Napit
Roll No. 66
NAIHS-COM, KTM
Urinary pH
Normal pH of urine: 4.6 – 8
Average pH = 6 In poliomyelitis(spinal, bulbar,
bulbospinal), pH of the urine drops
below average values
Hence, acidic
Mechanism of alteration of
Urine pH:
Tightness of intercoastal muscles, failure
of diaphragm muscles, hypoventilation
due to depression of respiratory centers
Retention of CO2 in blood
Respiratory Acidosis
• Acidity of the blood
• more H+ ions are excreted in the urine
ALSO,
Other factors responsible for increasing
the pH:-
1. High phosphate level (excreted as
NaH2PO4 )
2. High NH4+ being secreted
K+ levels in urine
Normal level of K+
( on a regular diet ) 25 to 125 mEq/
liter per day
In acute poliomyelitis:
Rise in K+ until the serum K+ is low
Destruction of tissues
Discharge of intracellular deposit of K+
into the extracellular fluid
Blood is brought to the kidney
In Kidney, K+ is conserved via Potassium-Hydrogen exchanger
BUT, K+ levels are too high
Result: Potassium concentration in
urine is high
Poliomyelitis
• Bulbar
Blood Pressur
e
• Increase
K+ or Na+
• More conservation
Na+ Levels in Urine
Normal Values
40-220 mEq/liter/day
BUT,
Varies with diet and level of
aldosterone hormone
In Acute Poliomyelitis
Marked drop in excretion of Na+ via
urine (however, Na+ is lost via extra-
renal channels)
But depends on the hydration of the
patient
In case of poliomyelitis, the serum Na+ is
elevated only slightly
Blood reaching the kidney is only slightly
elevated in Na+ level
Furthermore, the Na+ is conserved by the
kidney by using Na+-H+ exchanger
RESULT: Na+ excretion is low
Ca++ Levels in Urine
Normal
On normal diet = 100-300 mg/day
On calcium low diet= 50-150 mg/day
In Poliomyelitis:
gradual increase in Ca++ level
Changes in Calcium level and
Phosphorous level Acute Poliomyelitis is at times
accompanied by paralysis(flaccid)
Disuse of the part (esp. limbs)
Loss of balance between the
osteoblastic and osteoclastic activity
Demineralization
Left:X-Ray of pelvis and femur on the first month of onset of
disease
Right:X-ray of pelvis and femur after the six months of illness
Left:X-Ray of tibiae on the first month of onset of disease
Right:X-ray of tibiae after the two months of illness
Increase in serum Ca++ and PO4-
Other causes for Ca++
-Hypoalbuminemia
Increased excretion of Ca++ and PO4- in
urine
High levels of Ca++ can lead to renal stones, Nephrocalcinosis
Loss of Ca++ and PO4-leads to loss of
flexibility of bone(loss of water via hydroxyapatite) and osteoporosis
Further complications of Poliomyelitis
Knowing about the levels of Na+, K+
,Ca++, PO4-can help in learning about
the stage of the disease
References:
Nelson’s Textbook of Pediatrics, 19th Edition
THANK
YOU!