1.      Introduction

Emphysematous pyelonephritis is a severe necrotising infection of the renal parenchyma by gas producing gram negative bacteria. It is often a complication acute pyelonephritis in patients with diabetes mellitus, mostly women.[1,2]. However, it is also a manifestation in patients withobstructive uropathy[3].We present a case of emphysematous pyelonephritis where not only diabetes mellitus, but the presence of obstruction in the renal collecting systemplayed an important role in the clinical presentation.

2.      Case Repor

A 72-year-old male a known case of Type 2 diabetes mellitus, hypertension and chronic kidney disease on conservative management presented to us with high grade fever with chills, abdominal pain, vomiting, reduced urine output and drowsiness of 3 days duration. He was a known case of chronic kidney disease on conservative management. 6 months back he was admitted with similar symptoms at a different hospital and was told to have urinary tract infection then.His CT scan of the abdomen then revealed anupper ureteric stricture of the left kidney and shrunken hydronephrotic right kidney Figure 1a

He was managed successfully with antibiotics and temporary haemodialysis. After that his serum creatinine hovered around 4-4.5 mg/dl and was managed conservatively. A diagnosis ofgenitourinary tuberculosis was made, and he took ant tuberculous therapy for 6 months.At our hospital he was found to be febrile, hypotensive and in altered sensoriumHis abdominal examination revealed extensive crepitus over the right flank, inguinal region and scrotum. His initial laboratory investigations are detailed in (Table 1).

His blood glucose control was reasonable, and he was not on any antidiabeticmedications. His computed tomography of the abdomen showed aright perinephric collection andair in the right renal pole (Figure 2).

A diagnosis of right emphysematous pyelonephritis with sepsis was made.He wasstarted on intravenous antibiotics and reinitiated on haemodialysis. An urgent urology consult was sought, and he underwent an emergency right ureteric DJ stenting and percutaneous drainage of the perinephric/scrotalcollection.He continued to make steady progress and his abdominal drains were removed on the eighth postoperative day. He received intravenous antibiotics for fourteen days.At no point of time during his hospital stay he required any antidiabetic medications for his blood glucose control. At discharge he was afebrile and hemodynamically stable. 3 months on follow up he is on continuous bladder drainage and thrice weekly maintenance haemodialysis through a left jugular permcath.

3.      Discussion

Emphysematous pyelonephritis was first described in 1898 and since then it has been considered to be a rare clinical manifestation. However, with increasing incidence of diabetes mellitus this disease is being increasingly recognised in our clinical practice [4].In a caseseries Fatima et al have shown that 20-30 % of Indian patients present with extensive gas formation(CT gradeIII/IV) and have sepsis and multiorgan dysfunction as initial clinical presentation [5]. Similar findings were also reported in another case series from North India [6].All these patients (100%) hadhyperglycemia. Hyperglycemia and infection with gas producing(mixed acid fermenting) bacteria are considered to be important elements in the development of emphysematous pyelonephritis[7].Besides hyperglycemia,local tissue ischemia is an important pathophysiological factor which perpetuates the infection. Ureteral obstruction, which is the second most common predisposing factor,[8] can also cause local tissue ischemia which can further exacerbatetissue destruction.Obstruction relatedinadequate removal of gas from the affected renal parenchyma further aggravates the clinical presentation [9]. Besides ischemia, immune deficiency secondary to long standing chronic kidney disease,also plays a contributory role.We believe obstruction and long-standing kidney disease had an important synergistic role to play in our case who presented with extensive subcutaneous and scrotal emphysema. Not only early drainage of the perinephric collection [10,11], as is the standard of care, but also attention to the obstructed renal collecting system lead to a favourable outcome in our patient.A recent case series also highlighted the importance of upper tract obstruction as an important predisposing factor in the development of emphysematous pyelonephritis.In this report only one out of five (20%) had diabetes mellitus,whereas 60% (3/5) had upper tract obstruction[12]. Our case illustrates an important point of the synergistic role of various predisposing factors besides hyperglycemia which contributes to serious complications in a patient with emphysematous pyelonephritis. Attaining normoglycemia is an important goal of therapy, but early evaluation and treatment of an obstructed urinary tract is also important.

Figure 1a: Left hydronephrotic kidney with upper ureteric stricture and right hydronephrotic kidney.

His bladder was grossly thick walled and shrunken (Figure 1b).

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Figure 1b: Grossly thick walled and shrunken bladder.

Figure 2:Right posterior perinephric collection with air pockets. Air in ureter, periureteric and in anterior perinephric space.

The air in the right kidney extended upto the retroperitoneal space, anterior abdominal wall, scrotal sac and the soft tissues of the right thigh(Figure 3).

Figure 3: Air in right perinephric space, retroperitoneum air, air in anterior abdominal wall, soft tissues of thigh, right scrotal sac.

Table 1: Initial Laboratory Findings.

1.       Tang HJ, Li CM, Yen MY, Chen YS, Wann SR, et al. (2001) Clinical characteristics of emphysematous pyelonephritis. J Microbiol Immunol Infec34:125-130.

2.       Pontin AR, Barnes RD, Joffe J, Kahn D (1995) Emphysematous pyelonephritis in diabetic patients. Br J Urol 75:71-74.

3.       Kelly HA and MacCullum WG (1898) Pneumaturia. JAMA 31:375-381.

4.       Patel C, Anandh U, Shah A, Malghan R (2015) Emphysematous pyelonephritis presenting asa sonologically absent kidney.Saudi J Kidney Dis transpl 26:764-768.

5.       Fatima R, Jha R, Muthukrishnan J, Gude D, Nath V, et al. (2013) Emphysematous pyelonephritis: A single center study. Indian J Nephrol23:119-124.

6.       Misgar RA, Mubarik I, Wani AI, Bashir MI, Ramzan M, et al. (2016) Emphysematous pyelonephritis: A 10-year experience with 26 cases.Indian J Endocrinol Metab20:475-480.

7.       Turney JH (2000) Renal conservationfor gas-forming infections.The Lancet 335:770-771.

8.       Ubee SS, McGlynn L, Fordham M (2011) Emphysematous pyelonephritis.BJU International 107:1474-1478.

9.       Aswathaman K, Gopalkrishnan G, Gnanraj L, Chacko K, Kekre NS, et al. (2008) Emphysematous pyelonephritis: outcome of conservative management. Urology 71:1007-1009.

10.    Sharma PK, Sharma R, Vijay MK, Tiwari P, Goel A, et al. (2013) Emphysematous pyelonephritis: Our experience with conservative management in 14 cases. Urol Ann5:157-162.

11.    Pontin A and Barnes D (2009) Current management of emphysematous pyelonephritis.Nature reviews Urology6:272-279.

12.    Arsene C, Saste A, Arul S, Mestrovich J, Kammo R, et al. (2014) A case series of emphysematous pyelonephritis. Case Rep Med2014:587926.