OBSTRUCTIVE UROPATHY, RENAL FAILURE, AND SEPSIS

IN THE NEONATE - A SURGICAL EMERGENCY

CURTIS A. SHELDON, M.D.

RICARDO GONZALEZ, M.D.

S. MICHAEL MAUER, M.D.

ELWIN E. FRALEY, M.D.

From the Departments of Urologic Surgery and Pediatrics, University of Minnesota Hospitals, Minneapolis, Minnesota

ABSTRACT - Two infants who had obstructive uropathy accompanied by renal failure and sepsis are reported herein. Diagnostic and therapeutic techniques used to treat this type of surgical emergency are discussed in the order they were performed, as follows: (1) resuscitation for severe fluid and electrolyte disturbances; (2) gathering of cultures and initiation of antibiotic therapy; (3) the decision of whether or not dialysis is required, as well as when and how diagnostic evaluation should proceed; (4) the decision of whether further dialysis is necessary or whether correction of obstructive uropathy can begin; and (5) the choice of the best operative procedure for this indi- vidual. This article emphasizes the necessity for a multidisciplinary team approach to these patients.

Infants with acute renal failure secondary to obstruction and sepsis have a good prognosis (in contrast to the infant with acute renal failure secondary to other medical problems). ’ It is crit- ical to identify obstruction compounded by ad- vanced renal failure and sepsis because early aggressive therapy is mandatory. Treatment of these infants is illustrated by the 2 cases re- ported herein.

Case Reports

Case 1

An eight-week-old, 4,300-Gm. male was ad- mitted with severe dehydration, hypotension, hypothermia, and palpably enlarged kidneys and bladder. His blood urea nitrogen (BUN) was 113 mg./dl. and serum creatinine was 3.5 mg./lOO ml. The serum sodium level was 129 mEq./L., serum potassium 7.5 mEq./L., pH 7.31 with a serum bicarbonate of less than 10 mEq./L., and white blood cell count was 27,000

__-- Read at the North Central Section, American Urological Association, Phoenix, October 14, 1979.

per mm. 3 with a marked left shift. Urinalysis re- vealed packed leukocytes, white blood cell casts, and hematuria. He was given sodium polystyrene sulfonate cation-exchange resin (Kayexalate) enemas, and a central venous catheter was placed by internal jugular venous cutdown to administer and monitor fluids and to provide blood access for single-needle hemodialysis. 2 After appropriate cultures were obtained, parenteral ampicillin and gentamicin treatment was begun.

The child received his first hemodialysis treatment within six hours after admission. Methods of infant hemodialysis described previ- ously2 which consider carefully the choice of dialyzer and blood lines, calculation of blood flow rate, accurate weight monitoring, tempera- ture regulation, and monitoring of vital signs were used. Initial hemodialysis was complicated by severe metabolic acidosis which required the administration of 58 mEq. of sodium bicarbo- nate during the course of this four-hour treat- ment. The infant’s condition improved after hemodialysis, fluid and antibiotic administra- tion, and correction of acidosis; then, urologic

UROLOGY / NOVEMBER 1980 / VOLUME XVI, NUMBER 5 457

l + U.O. Right Cultuf es :

M U.O. Left

X-X Serum Creat. Blood E. Coli Urine E. Coli Left Pelvis E. Coli Right Pelvis Sterile

Cfeatinhe Clear mce : Date Left Right

POD5 7 3 3mos. 19 19 Current 41 43

I I I I I I I I I 2 4 6 8 10 12 14 16 J 18 I/ 90 Post Operative Day

FIGURE 1. Case 1. Urine outputs and serum creatinine levels after surgery.

investigation was done. Renal tomography re- vealed enlarged kidneys, and voiding cystoure- thrography showed a large trabeculated bladder with diverticula and posterior urethral valves, but no vesicoureteral reflux.

Following a second hemodialysis treatment and after the infant was stable, bilateral opera- tive nephrostomies were performed. Urine from the left renal pelvis was purulent while the urine from the right side was clear. Although the gross appearance of the kidneys was normal, a renal biopsy revealed peripheral cystic dysplasia.

There was prompt diuresis and gradual,*reso- lution of the renal failure following surgery. Es- cherichia coli was cultured from the, blood, bladder, and left renal pelvis (Fig. I), and, am- picillin therapy, to which this organism was sen- sitive, was continued. Postoperative nephros- tograms showed bilateral tortuous dilated ureters with adequate drainage. Fulguration of the posterior urethral valves and removal of the nephrostomy tubes were done when the patient was thirteen months of age. Despite normal growth and development and normal renal func- tion (creatinine clearance 93 ml./min./1.73 m’), ureteropyelocaliectasis and renal cortical atro- phy continued and, at age three years, the pa- tient underwent successful ureteral shortening, tailoring, and reimplantation. At surgery, the patient appeared to have so-called aperistaltic distal ureters bilaterally.

Case 2

An eight-week-old, 3,410-Gm. female was critically ill when admitted with anemia (hemo- globin 3.9 Cm. /dl.), profound hyponatremia (serum sodium 102 mEq./L.), hyperkalemia (serum potassium 7.5 mEq./L.), acidosis (serum bicarbonate 12 mEq./L.), and uremia (BUN 112 mg./dl.). Serum creatinine was 4.2 mg./dl. and; although hypothermic (94.6” F., rectally), and lethargic, she was not in shock. There was a palpable left flank and suprapubic mass. Ure- thral catheterization yielded purulent urine. The white blood cell count was 22,000 per mm.3 with a marked left shift. A central venous cathe- ter was inserted, and fluid and antibiotic treat- ments (ampicillin and gentamicin) were begun. Within six hours after admission, she underwent her first hemodialysis treatment as outlined previously. After her first three-hour treatment, serum sodium was 122 mEq. and serum potassium was 4.5 mEq./L. Her hemoglobin, with transfusion of packed red blood cells through hemodialysis, was 11.6 Gm./dl. Neph- rosonography showed bilateral hydronephrosis, bilateral ureterectasis, and massive splenomeg- aly (the left flank mass). A cystogram revealed a large, trabeculated bladder with a defect of filling in the bladder base which was an ectopic ureterocele.

Following these studies, a second four-hour hemodialysis treatment was performed which

458 UROLOGY i NOVEMBER1980 i VOLUMEXVI, NUMBER5

0-o U.O. Right

o----OU.O. Left Cultures :

Blood - citrobacter E. Coli enterococcus

Urine - citrobacter E. Coli

Right Pelvis - citrobacter

bacteroides

Left Pelvis

- E.Coli

Creatinine at discharge 0.5

2 4 6 8 IO 12 14 16 18 20 Post Operative Day

FIGURE 2. ,Case 2. Urine outputs and serum creatinine levels for twenty days after surgery.

corrected the serum sodium to 135 mEq./L. and the BUN and serum creatinine to 31 and 1.4 mg./dl., respectively. After correction of the anemia, electrolyte imbalance, uremia, and hypothermia, cystourethroscopy was performed, and a large prolapsing ureterocele obstructing the bladder outlet was found. Next, under the same anesthesia, bilateral nephrostomies were done, at which time massive ureteral dilatation was noted. There were multiple small cysts in the right kidney, while the left renal cortex seemed normal. Cultures from the urine and blood grew multiple organisms (Fig. 2). Follow- ing the initial surgery, total renal function im- proved (Fig. 2) but the right kidney never de- veloped significant function as judged by urine output from the nephrostomy tube. Biopsy of the right kidney demonstrated severe periph- eral cystic dysplasia and xanthogranulomatous pyelonephrosis (Fig. 3). The left kidney showed normal histologic development and severe acute pyelonephritis. A right nephrostogram (Fig. 4) showed a tortuous dilated ureter terminating in a ureterocele. Three weeks later, she under- went a right nephroureterectomy. The left neph- rostomy tube was removed, and she was dis- charged with a serum creatinine of 0.5 mg./dl. By six months of age, she had doubled in weight and her development was normal.

Comment Obstructive uropathy complicated by sepsis

and acute renal insufficiency is a life-threatening condition in infants, and these patients require a carefully planned multidisciplinary diagnostic and therapeutic approach if they are to be saved. We discuss five steps for diagnosis and treatment in what we believe is the order of their priority.

First, fluid disturbances and electrolyte and acid base problems must be counteracted. The fluid balance in babies with these problems may demand early treatment with blood or protein solutions to combat shock. The placement of a central venous catheter allows rapid administra- tion of these blood products, monitoring of central venous pressure, access for hemodialysis and, therefore, it is essential that this procedure be performed early.

Hyperkalemia probably is the most significant electrolyte abnormality in these patients. The treatment of hyperkalemia, as described by others3a4 consists of glucose and insulin infu- sion, calcium or bicarbonate infusion, and sodium polystyrene sulfonate cation-exchange resin therapy. However, the infusion of fluids to treat hyperkalemia may worsen or precipitate severe pulmonary edema, leaving dialysis as the only option.

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FIGURE 3. Case 2. Low, intermediate, and high-power photomicrographs revealing cystic dysplasia and pyelonephritis in right kidney jhematonylin and eosin).

460 UROLOGY / NOVEMBER1980 / VOLUMEXVI, NUMBER5

It is beyond the scope of this article to dis- cuss, in detail, the treatment of hypernatremia or hyponatremia in uremic infants. However, suffice it to say that if a hyponatremic patient is having seizures, emergency administration of sodium may be necessary; the condition is most easily corrected by dialysis. Hypernatremia can complicate hemodialysis in uremic patients by increasing the risk of disequilibrium syndrome5 and requires special precaution. 2

Second, appropriate cultures should be gathered, followed by rapid institution of antibi- otic therapy. Babies localize infection poorly and therefore urine, blood, and spinal fluid samples are necessary. Clearly, extension of in- fection into the central nervous system would suggest the selection of antibiotics that more easily penetrate the blood brain barrier. Initial antibiotic therapy should include coverage for relatively resistant gram-negative infections. Antibiotic dose should be tailored to the renal function of the patient.6

Third, the decision must be made, following the aforementioned steps, as to whether the infant is ready for diagnostic studies of the un- derlying nephrologic disorder or if further stabilization by dialysis is necessary. Indications for immediate hemodialysis, preempting even initial urologic diagnostic evaluation, include severe pulmonary edema, life-threatening hyperkalemia, or advanced uremia. Volume overload, which would be aggravated by other necessary treatments such as those for hyper- kalemia, bicarbonate administration for serous acidosis, calcium infusion for symptomatic hypocalcemia, and blood for correction of severe anemia would also lead toward early dialysis. Administration of hypertonic radiographic con- trast material is safest after hypervolemia or hyperosmolality has been corrected.

The choice of hemodialysis over peritoneal dialysis depends primarily on the expertise of the institution caring for the baby. Where ex- tensive experience in infant hemodialysis exists, it is our view that this procedure, offering more rapid control of fluid and electrolyte disorders, correction of uremia, and increased safety in blood transfusion is preferable. The major drawback of hemodialysis, the risk of the dis- equilibrium syndrome from overly rapid correc- tion of hyperosmolality, can be overcome.2 Peritoneal dialysis has the advantage of simplic- ity but is relatively slow, may technically fail in babies, and has the risk of producing respiratory compromise in infants about to undergo anes-

thesia and surgery. Two cautionary notes re- garding peritoneal dialysis in these infants should be made: (1) In obstructive uropathy, great care must be taken to avoid injuring the enlarged bladder upon peritoneal dialysis cathe- ter insertion. We believe a Tenckhoff catheter7 inserted under local anesthesia is safest. (2) Large quantities of intra-abdominal fluid can cause compression of the inferior vena cava and give the misleading impression of caval throm- bosis if cavography is done from a femoral vein contrast injection.

The differential diagnosis of acute renal fail- ure in an infant with enlarged kidneys may be classically divided as follows:

I. Prerenal Passive congestion

II. Renal Renal vein thrombosis Renal cystic disease Renal cortical or papillary necrosis Acute tubular necrosis Renal artery occlusion Hemolytic uremic syndrome Glomerulonephritis Pyelonephritis

III. Postrenal Posterior urethral valves Anterior urethral valves, strictures, etc. Congenital bladder neck contracture Neurogenic bladder Hydrometrocolpos Ureteropelvic junction obstruction Ureterocele Primary obstructive megaureter Ectopic ureter

IV. Combined However, this distinction in the septic child may be much more difficult. Obstructive uropathy involving the bladder outlet may obvi- ously create renal failure, as may upper tract le- sions occurring bilaterally or involving a single functioning renal-ureteral unit. A prolapsing or ectopic ureterocele may cause bilateral obstruc- tion. Sepsis of nonurologic cause and sepsis associated with unilateral obstructive uropathy may be accompanied by dehydration, prerenal azotemia, acute tubular or cortical necrosis, and renal vein thrombosis with secondary azotemia. These factors, compounded with the lack of uni- form success of radiography in demonstrating hydronephrosis as well as the occasional confu- sion of nephromegaly with splenomegaly sec- ondary to sepsis, demonstrate the importance of a systematic approach to diagnostic evaluation.

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The appropriate diagnostic evaluation can be evolved by considering the major anatomic fea- tures necessary to provide the diagnosis and di- rect the surgical approach. The final anatomic diagnosis may not always be appreciated prior to surgery, but in all cases the appropriate initial procedure should be determined. The necessary anatomic points to investigate include the pres- ence or absence of hydronephrosis, vesico- ureteral reflux, intravesical filling defects, blad- der outlet obstruction, and viable renal paren- chyma.

Often intravenous pyelography is not helpful and may even be dangerous in the presence of hyperosmolality. Hydronephrosis can be dem- onstrated by renal tomography or sonography. Sonography offers the additional advantages of distinguishing hydronephrosis from splenomeg- aly, and identifying ureterectasis and extravesi- cal pelvic masses. Hydronephrosis is the key feature of renal failure and secondary to obstruc- tive uropathy. The voiding cystourethrogram demonstrates reflux, intravesical filling defects, and bladder outlet obstruction. Cystourethros- copy and retrograde pyelography, when possi- ble, can be extremely helpful in revealing obstruction or confirming the presence of free drainage. In some cases a dysplastic, cystic, or even hydronephrotic renal-ureteral segment will not be visible or will appear normal on to- mography and ultrasound studies. Finally, po- tentially functional renal parenchyma can be ac- cessed only by direct surgical exploration and renal biopsy.

Fourth, the decision must be made, once the diagnostic evaluation is complete, whether ini- tial or further dialysis is required prior to surgi- cal drainage. Our criteria for deciding that the uremic infant is ready for surgery include (1) normal or near normal fluid balance, (2) normal sodium, potassium, and calcium levels, (3) com- plete correction of acidosis, (4) BUN less than 75 mg./dl., (5) h emoglobin at least 10 Gm./dl., and (6) normal or near normal coagulation pa- rameters. The surgical situation of a hypoxic in- fant with pulmonary edema accompanied by acidosis and hyperkalemia, who is hypoventi- lated or requires a large transfusion of low-pH, high-potassium bank blood and in whom a car- diac arrest develops from hyperkalemia, is bet- ter avoided than treated.

Finally, once the diagnosis is known, a ra- tional approach to surgery is possible. Each renal-ureteral unit must be considered inde- pendently. During the eighteen to twenty-

four-hour period of evaluation dialysis, bladder drainage by catheter is maintained. A child with renal failure, urosepsis, and an obstructive le- sion at the bladder outlet level, demonstrated by voiding cystourethrogram, who has enlarged kidneys on tomography or hydronephrosis on ultrasound analysis, can undergo surgical explo- ration and nephrostomy tube drainage. There are only two exceptions: a ureteropelvic junc- tion obstruction, for which we favor a primary, intubated, pyeloplasty with nephrostomy drain- age; and total reflux with complete drainage on postdrainage films, in which case surgical drain- age may not be necessary or may be accom- plished by a vesicostomy. Occasionally, severe inflammation of the renal pelvis makes a pri- mary pyeloplasty impossible. If bladder outlet obstruction cannot b,e demonstrated by voiding cystourethrography, cystourethroscopy and ret- rograde pyelography should be performed. They may disclose an outlet obstruction or obstructive upper tract pathology.

The rationale for supravesical drainage in upper tract lesions is obvious. In the case of lower tract obstruction, secondary upper tract obstruction at the ureterovesical junction or re- sulting from a large, kinked, static volume ure- ter may occur. In addition, multiple primary obstructive lesions may coexist. These anatomic details may not be fully delineated preopera- tively, and the most conservative drainage pro- cedures include nephrostomy, pyelostomy, and high cutaneous ureterostomy. Which of these three procedures to use depends on the indi- vidual patient, but we prefer nephrostomy drainage. Its advantages include ease of renal exploration and renal biopsy as well as maximal proximal drainage and nonoperative reversibil- ity. Disadvantages include the chronic persist- ent infection associated with intubation, the difficulties of maintenance, and the risk of the tube falling out. Cutaneous ureterostomy is often complicated by stenosis, and postoperative reconstruction is difficult following this proce- dure, occasionally requiring multiple opera- tions.8’g Pyelostomy may be difficult and require operative reversal. Another viable alternative which should be considered and may be applic- able in some circumstances is percutaneous nephrostomy. The advantages of this procedure include the speed with which it can be per- formed as well as the ability to avoid general anesthesia. A potential complication is extrava- sation of purulent urine; in our second case, the urine had such a high viscosity that a smaller

462 UROLOGY / NOVEMBER 1980 / VOLUME XVI, NUMBER 5

caliber catheter may not have provided ade- quate drainage. In addition, gross inspection and renal biopsy are not achieved. For these reasons and because the surgeon can count on only one chance to achieve adequate drainage in such desperately ill infants, we still prefer open surgical drainage.

The approach outlined varies considerably from our approach to the uninfected infant. In the case of lower tract obstruction, an initial trial of catheter drainage would be attempted to determine the necessity of upper tract drainage, as indicated by resolution of azotemia and diuresis. We favor early complete reconstruc- tion in these infants when possible.

Once the nephrostomies are in place and in- fection is resolved, the split renal function, urine outputs, and open renal biopsy results will predict the functional capacity of each renal unit. Nephrostograms will outline the presence or absence of upper tract obstruction. These data will then indicate reconstruction or neph- roureterectomy to be the best choice. Again, these results and the nephrostomy coverage will most often allow for only one further reconstruc- tive procedure.

Conclusion

The essence of this article is that the desper- ately ill infant with obstructive uropathy, uremia, and sepsis can be treated effectively with excellent results. However, it is critical that all aspects of management be considered carefully and that rapid institution of appropri-

ate medical, diagnostic, and surgical inter- ventions be coordinated. The close interaction of a team of urologic surgeons, pediatricians, and pediatric nephrologists, so important in the care of these babies, appears to indicate that the infant’s treatment should be done at an institu- tion where the requisite people and facilities are readily available.

Department of Urologic Surgery Box 394, Mayo

University of Minnesota Hospitals Minneapolis, Minnesota 55455

(DR. GONZALEZ)

References

1. Hodson EM, Kjellstrand CM, and Mauer SM: Acute renal failure in infants and children: outcome of 53 patients requiring hemodialysis treatment, T. Pediatr. 93: 756 (1978).

2. Mauer SM, and Lynch RE: Hemodialysis techniques for in- fants and children, Pediatr. Clin. North Am. 23: 843 (1976).

3. Lynch RE, and Mauer SM: Neonatal acute renal failure, in Moss AJ (Ed): Pediatrics Update, New York, Elsevier-North Hol- land Publishing Co., 1979, pp. 39-53.

4. Trainin EB, and Spit&r A: Treatment of acute renal failure, in Edelmann CM, lr (Ed): Pediatric Kidnev Disease. Boston. Lit- tle, Brown and Co.“, I978, vol. 1, chap. 33:

5. Arieff AI, Massry SG, Barrientos A, and Kleeman CR: Brain water and electrolyte metabolism in uremia: effects of slow and rapid hemodialysis, Kidney Int. 4: 177 (1973).

6. Bennett WM, Singer I, and Coggins Cl: A guide to drug therapy in renal failure,JAMA 230: 1544 (1974). I

7. Tenckhoff T, and Schechter H: A bacteriolozicallv safe peritoneal access hevice, Trans. Am. Sot. Artif. Inter.-&g& 14: 181 (1968).

8. Hendren WH: Complications of ureterostomy, J. Ural. 120: 269 (1978).

9. Pinto MH, Markland C, and Fraley EE: Posterior urethral valves managed by cutaneous ureterostomy with subsequent ure- teral reconstruction, ibid. 119: 696 (1978).

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