Emphysematous pyelonephritis: Six case reports and review of literature

Table 1 Summary of demographic characteristics and clinical features of cases

Demographic and clinical characteristics of patients and outcomes
Patient	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6
Age, yr	70	81	47	70	62	90
Gender	Female	Female	Female	Male	Female	Female
Past history	DM	HP, AF, lung cancer, puncture and drainage on right side kidney	DM	DM	DM	Anemia
Clinical feature	Left back pain, fever	Right back pain, fever	Right back pain, fever	Fever	Fever and left back pain	Anorexia and abdominal pain
Clinical finding	T 37.5 °C, HR 120 bpm	T 37.9 °C, HR 98 bpm	T 38.4 °C, HR 120 bpm, BP 90/60 mmHg	T 38.4 °C, HR 130 bpm	T 38 °C, HR 120 bpm	T 37.5 °C, HR 92 bpm
Class	IIIb	II	II	I	I	IV
Blood test
WBC (× 109/L)	11.17	19.06	29.41	17.41	15.25	10.25
Absolute neutrophil count (× 109/L)	10.69	16.98	25.24	12.66	13.21	9.22
Hemoglobin (g/L)	81	94	115	101	121	44
Platelets (× 109/L)	129	292	520	105	324	367
CRP (mg/L)	244.90	124	323	318.8	391	124.83
PCT (ng/mL)	4.5	3.43	26.86	5.33	12.82	NA
Albumin (g/L)	26.5	25.5	31	31.2	32.6	30.3
Serum creatinine (μmol/L)	155	79	148	188	72	188
Glucose (mmol/L)	26.7	6.8	28.8	21.7	13.3	4.7
Fibrinogen (mg/dL)	429.1	539.9	489.8	802.4	732	623.7
Other	NA	NA	pH 7.285, AG 20.5 mmol/L, BE 18.1 mmol/L, Lac 1.2 mmol/L, urine acetone bodies, 4+	NA	Unilateral urolithiasis	Bilateral urolithiasis; emphysematous cystitis
Complication	Septic shock, severe pneumonia, right-sided endogenous panophthalmitis, left-sided endogenous endophthalmitis, epilepsy, meningitis stimulation, meningitis	NA	NA	NA	NA	NA
Etiology	Blood culture, puncture fluid culture, sputum culture, urine culture: K. pneumoniae	Parallel puncture fluid culture: K. pneumoniae	Parallel puncture fluid culture: E. coli	Parallel puncture fluid culture: K. pneumoniae	Parallel puncture fluid culture: E. coli	NA
Intervention	PCN and perinephric abscess puncture drainage	PCN and perinephric abscess puncture drainage	PCN and abscess incision and drainage	DJ stenting	PCN	-
LOS	113 d	15 d	39 d	10 d	8 d	-
Outcome	Recovered	Recovered	Recovered	Recovered	Recovered	Died

DM: Diabetes mellitus; HP: Hypertension; AF: Atrial fibrillation; T: Temperature; HR: Heart rate; BP: Blood pressure; WBC: White blood cell; CRP: C-reactive protein; PCT: Procalcitonin; NA: Not available; Klebsiella pneumonia: K. pneumonia; Escherichia coli: E. coli; PCN: Percutaneous nephrostomy; DJ: Double J; LOS: Length of stay (in hospital).

Table 2 Emphysematous pyelonephritis classification systems

Classification	Radiological basis	Class
Wan et al[25]	CT	I: Renal necrosis with presence of gas but no fluid; II: Parenchymal gas associated with fluid in renal parenchyma, perinephric space or collecting system
Huang and Tseng[24]	CT	1: Gas in collecting system only; 2: Gas in the renal parenchyma without extension to extrarenal space; 3A: Extension of gas or abscess to perinephric space; 3B: Extension of gas or abscess to pararenal space; 4: Bilateral EPN or solitary kidney with EPN

CT: Computed tomography; EPN: Emphysematous pyelonephritis.

Table 3 Definition of risk groups

Risk group	Definition
Mild	No septicemia; CT: Emphysematous lesion < 1 cm2 in the kidney, solitary or multiple; Percutaneous drainage is necessary/inapplicable
Moderate	No septicemia; CT: Emphysematous lesion involving equal or less than half of the kidney; Amenable to percutaneous drainage
Severe	Septicemia; CT: Emphysematous lesion involving more than half of the kidney and/or perinephric extension

CT: Computed tomography.