Persistent Infection. Generally, intravenous hydration and antimicrobial therapy are followed by stepwise defervescence of approximately 1°F per day. With persistent spiking fever or lack of clinical improvement by 48 to 72 hours, urinary tract obstruction, another complication, or both are considered. In these women, renal sonography is recommended to search for obstruction, which is manifest by abnormal ureteral or pyelo caliceal dilatation (Seidman, 1998). Although most women with continuing infection have no evidence of obstruction, some are found to have calculi. Although renal sonography will detect hydronephrosis, stones are not always seen in preg nancy (Butler, 2000; Maikranz, 1987). If stones are strongly suspected despite a nondiagnostic sonographic examination, a plain abdominal radiograph will identiy nearly 90 percent.
Another option is the modified one-shot intravenous pyelo injection-which usually provides adequate imaging (Butler, 2000).
In some women, MR imaging may disclose the cause of persistent infection (Spencer, 2004). Even without urinary obstruction, persistent infection can be due to an intrarenal or perinephric abscess or phlegmon (Cox, 1988; Rai, 2012).
Obstruction relief is important, and one method is cystoscopic placement of a double-J ureteral stent (Rodriguez, 1988).
Because these stents are usually left in place until after deliv ery, they frequently become encrusted and require replacement.
We have found that percutaneous nephrostomy is preferable because the stents are more easily replaced. Finally, surgical removal of stones may be required in some women (p. 1030).
Outpatient Management. This is sometimes done for non pregnant women with uncomplicated pyelonephritis (Hooton, 2012). Outpatient management was described in 92 pregnant axone, two 1-g doses 24 hours apart (Wing, 1999). After this, only a third of the group was considered suitable for outpatient therapy, and these women were randomly assigned either to discharge home and oral antimicrobials or to continued hospi talization with intravenous therapy. A third of the outpatient management group was unable to adhere to the treatment regi men and required readmission. his suggests that outpatient management is applicable to very few gravidas.
Recurrent urinary tract infection-either covert or symptomatic-develops in 30 to 40 percent of women following completion of pyelonephritis treatment (Cunningham, 1973). Unless other measures are taken to ensure urine sterility, nitrofurantoin, 100 mg orally at bedtime given for the remainder of the pregnancy, reduces bacteriuria recurrence (Van Dorsten, 1987).
Vesicoureteral reflux in early childhood can cause recurrent urinary tract infections, and subsequent chronic interstitial nephritis is attributed to chronic pyelonephritis. Moreover, high-pressure sterile reflux impairs normal renal growth. Combined, this leads to patchy interstitial scarring, tubular atrophy, and loss of nephron mass and is termed relux nephropathy. In some casesespecially those with staghorn calculi-xanthogranulomatous pyelonephritis causes suppurative destruction of renal tissue. In adults, long-term complications of chronic pyelonephritis include hypertension, which may be severe (Beck, 2015; Diamond,a2012).