NEPHROLITHIASIS

 

Etiology:

  1. This can be 2ry  to Ca+, P, Oxalate, Cystine, Urate, Urea-Splitting organisms (sturvite stones),  medications (Crixivan), high protein diet (such as Atkins diet).

S & S:

  1. Severe, acute abdominal/flank pain commonly radiating to the groin. Pain intermittent and colicky.
     
  2. Pt cannot find comfortable position.
     
  3. N/V/anorexia are commonly found. Fever is not common  and if present it signifies infected stone.

DX:

  1. UA = commonly shows RBC i.e. microscopic hematuria (in 85% of cases). If pH is >7.6 this  may indicate presence of  sturvite stones.
     
  2. SMA = to r/o renal  failure, to r/o metabolic abnormality ( Ca, P, Urate), to r/o  Hyperchloremic metabolic acidosis with hypoK suggesting  RTA. The SMA is also useful to document BUN/Cr and assure normal kidney function. Abnormal BUN/Cr may dictate different approach to the treatment of kidney stone.
     
  3. IVP = obtained if BUN/Cr are WNL, no iodine or shellfish allergy (not an absolute contraindication) and if pt is not on glucophage. The later is a contraindication  for any  IV contrast study.
     
  4. Spiral CT without contrast: in many centers is preferred since it is faster, has no complications and there is no need to wait  for BUN/Cr. Crixivan  stones are radiolucent in 70%  of  CT scans.
    Radiographic studies are needed to r/o hydronephrosis.
  5. The important differential of hematuria in geriatric patient in ER is AAA that in 30% of cases can present with hematuria and flank pain. Also embolic events to renal artery, especially in pts with arrhythmia, are important in ddx.
     
  6. An obstructive pylonephritis is a surgical emergency, requiring placement of  nephrostomy  tube.

Treatment:

  1. Morphine titrated to pain. Avoid NSAIDs.
     
  2. IVF NS @ 250cc/hr
     
  3. Admit if:
      1. Intractable pain, N/V
      2. Infection documented by UA or C+S
      3. Solitary obstructing kidney.
      4. RF (­BUN/Cr)
      5. Inability to visualize obstructed kidney 
      6. 2d visit within 24hrs
         
  4. DC home (if above not present) with pain medications such as Tylenol #3, PO fluids, f/u with GU and  RTER if fever or ­ in pain. It must be explained to patient the importance of  f/u with GU since hematuria may be S&S of CA.

 

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