RTA

60 y/o pt presented with Polyuria, polydypsia...only abnormal finding is serum potassium 2.19 and hco3 12 and low ph----------------------------so pt is hving metabolic acidosis and AG is normal....
so two possibilities

1. GI loss
2. RTA

So now have to check Urine PH and Urine AG and Urine K+------------His Urine PH is 5 , UAG positive and urine k+ 30 which is > 25 MEq/l--------------


Type 1 RTA : Decrease H+ secretion from Distal Tubule. Most common cause is Autoimmune disorder Sjogren syndrome
Type 2 RTA: Decrease HCO3 reabsorption from PT .. mcc is multiple myeloma , carbonic anhydrase Inhibitor
Type 4 RTA: Hypoaldosteronism  so increase K+

this pt is having low K+ so obviously this ppt is not hving type 4 RTA....
so differentiate Type 1 vs Type 2 RTA----------give NaHCO3-----------type 1 will response and U HCO3 will be low while in type 2 coz of decreased HCO3 reabsorption ---------urine HCO3 will be high and blood PH also wont have much effect....

Treatment :
type 1: give NaHCO3,  K citrate
Type 2: Give NaHCO3( but wont have much effect coz of abnormal PT), so add  thiazide, K+ citrate
Type 4: give mineralo corticoid----fludrocortisone +/- cortisol , also add diuretic for edema.

Urine Anionic gap

Urine AG  =  Urine (Na  +  K  -  Cl)

measured in normalAG metabolic acidosis..--e.g in  GI loss

The urine AG has a negative value in most patients with a normal AG metabolic acidosis due to the appropriate increase in urinary ammonium in an attempt to excrete the excess acid. Ammonium is an unmeasured cation; as a result, an increase in its excretion as NH4Cl will lead to a rise in the urine Cl concentration and a negative urine AG, usually ranging from -20 to -50 meq/L.

In comparison, patients with renal failure, type 1 (distal) renal tubular acidosis (RTA), or hypoaldosteronism (type 4 RTA) are unable to excrete ammonium normally. As a result, the urine AG will have a positive value .

Urine K+ is also good finding---< 25 meq/L is normal response to GI loss of K+
but if it is > 25 MEq/l with hypokalemia---then suggest RTA type 2

Acidosis discussion

Case: 25 y/o male pt came to ER with altered mental status(AMS)-------
vitals: increased RR, PR and bp150/85
What test You should do in patient with AMS-----do basic metabolic panel(BMP), Urine analyis, Urine Drug screen, ABG.

Na- 139
K- 4
Cl- 102
hco3- 11
BUN 15
Cr 0.8
Glucose 110

ABG----------ph 7.19, Pco2- 24,  po2- 95

Urine drug screen---negative

So this patient is having ph 7.19 which is less then 7.35 so patient is having acidosis----------HCO3( normal 22-26)---11 which is low-----------------so It is metabolic acidosis-----------

Expected decrease in PCO2= 1.2 x ( decrease in HCO3) = 1.2 x  (24-11) = 1.2 x 13 = 16

this pt's PCO2= 24 -----and 40-16= 24------------so this is compensatory respi alkalosis.....

,
Next step is to calculate Anionic Gap= Na - ( HCO3- Cl) = 139- 113= 22
Normal AG = 3 to 12...
so this pt is hving AGmetabolic acisdosis

Causes of Met acidosis--------MUDPILES
this pt has normal S.cr so cant be uremia
normal glucose----so cant be DKA
So next step is t check serum Methanol, Ethanol, blood alcohol, lactic acid, salicylate level....
Blood alcohol , lactic acid and salicylate level normal and plasma osmolar gap is 25 ----so probably ethanol or methanol poisoning....

Management: check ABC, give fomipezol and hemodialysis( because of symptoms) and NaHCO3

Acidosis

Mg correction

Magnesium: normal value= 1.7-2.2 mg/dl

1. Supplement all Mg below 2.0 unless pt has renal failure (around 1.6 is fine, check with resident)

2. For every 0.5 deficit, give 1 g of Mg

3. Magnesium Sulfate 1 g IV (run over 1 hour) or 400mEq MgOxide po BID or TID

ER

1. Pt having Chest Pain- 
#1- Ask nurse for their vitals, if on monitor, ask if they are having EKG changes. Order Stat Cardiac enzymes, EKG, tell nurse to give pt Morphine, NTG, O2. 
#2- GO SEE THE PATIENT NOW!



2. Pt Aggitated/Mental status change- 
#1- Ask the nurse for vitals, Find out if this is baseline, or if this is new,
#2-Go see the patient, Check their meds and see if something you are giving might have caused it,
#3- Check UA (especially in older pts), ABG, Chem 7, #4- Haldol 5mg IV x1 if needed.

K+ correction

Potassium correction....
noraml value= 3.5 to 5 meq/l

Supplement K+ if it is below 3.5 meq/l
in Renal failure pt( look at s. cr...) supplement if k+ below 3.o meq/l

availble forms:
K-Dur 10mEq PO (tablet)
K-Lyte 25mEq PO (liquid): Has a lot of bicarb so if pt is alkolotic give KCl
K-Phos 2 tabs PO
K-Phos 10mmol IV (run over one hour)
Give 10mEq for every 0.1 below 4.0 so if K+ = 3 then give 100 meq
KCl 10mEq IV (run over one hour)

available forms: Potassium chloride (also citrate, acetate, bicarbonate, gluconate)
Adult
IV replacement: 10-40 mEq IV infused over 2-3 h; infusion rate not to exceed 40 mEq/h; may repeat q3-4h prn; modify infusion rate for specific requirements
PO supplementation: 50-100 mEq/d PO divided bid/tid or qd as SR formulation; larger doses may be needed in severe depletion to replenish potassium body storage

Pediatric
Usual dose for potassium replacement: 0.5-1 mEq/kg IV; not to exceed 30-40 mEq/dose
Infusion rate not to exceed 0.3-0.5 mEq/kg/h for noncritical hypokalemia; however, this rate may be inadequate in life-threatening hypokalemia
Infusion rates: >0.5 mEq/kg/h can be delivered but requires ECG monitoring to detect potentially fatal arrhythmia, especially ventricular dysrhythmia, because it can rapidly lead to cardiac arrest
PO supplementation is based on body weight, ranging from 2-4 mEq/kg/d PO in divided doses to avoid gastric distress