A Case of Pyelonephritis: A Medical Student Clinical Pearl
Natasha Glover
MUN Medicine, CC4
Class of 2022
Reviewed by Dr. Paul VanHoutte
Copyedited by Dr. Mandy Peach
Case
Ms. X, a 23 year old mother of 2 presents to the Emergency Department with a 3 day history of left flank pain and vomiting. She describes the pain as sharp, constant, and worse with touch. Her boyfriend observed her sweating and shivering the night before. She has also experienced a loss of appetite, having been unable to keep any food or liquids “down”. In the ED waiting room, she vomits and describes bright red “streaks” mixed with the vomitus.
2 weeks prior to her visit, she describes having dysuria and suprapubic pressure. She has a history of frequent UTIs, so she took an old bottle of unfinished amoxicillin from a previous diagnosis of cystitis and took the remaining 3 pills over the course of the 3 days. Reports that dysuria and pressure subsided afterwards.
PMHx:
Frequent UTIs
Medications:
No prescription medications
Social:
Smokes marijuana daily
No EtOH consumption
No other recreational drug use
1 month ago became sexually active with a new partner, reports that partner was tested prior to beginning their sexual relationship
Physical Exam:
HR 112 BP 132/88 T 37.8 RR 18 SpO2 97%
Appears in mild discomfort. No respiratory distress. Oriented to person, place, and time. Dry oral mucosa. Skin tenting. No facial edema.
Mild tachycardia, otherwise normal cardiac exam. Equal breath sounds to the bases, no adventitious sounds. Abdomen was non-distended, soft, moderate tenderness in the LUQ and LLQ, no rebound tenderness, no masses, no evidence of hepatosplenomegaly. Tenderness at the left flank.
Peripheral pulses present, equal, capillary refill <2s . No peripheral edema.
Differential Diagnosis:
- Pyelonephritis
- Renal colic
- Ectopic pregnancy
- Gonorrhea/chlamydia infection
- Nephrotic syndrome
- Splenic flexure syndrome
Urinalysis:
Leukocyte esterase 25
Blood casts 50
Protein 20
HCG negative
Culture: E.coli positive (reported after 24 hours in lab)
Labs:
Sodium 140
Potassium 4.2
Chloride 108
Creatinine 274
Hgb 135
HCT 0.450
LKC 23.7
PLT 281
CRP 506.3
Lipase 8
Bedside renal U/S unable to detect any hydronephrosis.
A CT is ordered to rule out infected renal stone.
Left kidney is markedly larger than the right kidney. Stranding around the left kidney. No evidence of obstruction, hydronephrosis or hydroureter.
Assessment:
This patient is mildly hypovolemic. She also has a new AKI, likely pre-renal as the result of NSAID use and volume depletion. She has a left sided pyelonephritis given her recent history of cystitis (likely suboptimally treated by the use of old remaining antibiotics for a previous UTI), left flank pain with costovertebral tenderness and various abnormal lab findings
Imaging rules out obstructive causes and other complicating factors. As a result, she requires fluid resuscitation, pain management, nausea/vomiting management, IV antibiotics, and admission to the hospitalist unit.
Let’s Break it Down; Assessment of Acute Kidney Injury:
Pathogenesis of Pyelonephritis:
The majority of pyelonephritis cases are the result of lower genitourinary infections that travel up through the ureters and into the kidneys. Other sources of infection occur through hematogenous spread, which is most often seen in chronically ill and immunocompromised patients. Additionally, metastatic manifestations of fungal and staphylococcus may spread distantly from the skin. Escherichia coli is the most common pathogen observed in cases of pyelonephritis.
Treatment of pyelonephritis is highly dependent on whether or not it is classified as a complicated UTI or an uncomplicated UTI.
Complications:
-Higher mortality among elderly, immunocompromised patients, and those who develop septic shock
-A small number of individuals, particularly those with structural abnormalities, complex renal obstructions, congenital anomalies, develop chronic pyelonephritis. Chronic pyelonephritis is characterized by nonspecific symptoms as well as histologic findings of lymphoplasmacytic infiltrates, thyroidization, tubulointerstitial scarring, glomerulosclerosis, and fibrosis. It accounts for approximately 20% of end-stage kidney disease.
Figure 2: Chronic pyelonephritis with focal and segmental glomerulosclerosis with periglomerular fibrosis (Jones silver stain) from the National Kidney Foundation
Management for Ms. X:
Ceftriaxone 1mg IV q24h because she was systemically unwell
Fluid resuscitation with normal saline
Pain management with acetaminophen 975 PO QID and morphine 5mg SC q3h PRN
Nausea and vomiting management with ondansetron (Zofran) 8mg IV q8h PRN
Admit to hospitalist for further monitoring and management
References:
1. Hooton, T., Gupta K. Acute complicated urinary tract infection (including pyelonephritis) in
adults. UpToDate. https://www.uptodate.com/contents/acute-complicated-urinary
-tract-infection-including-pyelonephritis-in-adults. Published 2021. Accessed July 14,
2021.
2. Buonaiuto VA, Marquez I, De Toro I, et al. Clinical and epidemiological features and
prognosis of complicated pyelonephritis: a prospective observational single
hospital-based study. BMC Infect Dis. 2014;14(1):639. doi:10.1186/s12879-014-0639-4
3. Fogo AB, Lusco MA, Najafian B, Alpers CE. AJKD Atlas of Renal Pathology: Chronic
Pyelonephritis. Am J Kidney Dis. 2016;68(4):e23-e25. doi:10.1053/j.ajkd.2016.08.001
4. Khanna R. Clinical presentation & management of glomerular diseases: hematuria,
nephritic & nephrotic syndrome. Mo Med. 2011;108(1):33-36.
http://www.ncbi.nlm.nih.gov/pubmed/21462608. Accessed July 14, 2021.
6. NB Provincial Health Authorities Anti-Infective Stewardship Committee. Treatment of adult
urinary tract infections. 2021. doi:10.1002/14651858.CD003237.pub2
7. Rahman M, Shad F, Smith MC. Acute kidney injury: A guide to diagnosis and management.
Am Fam Physician. 1970;86(7):631-639. https://www.aafp.org/afp/2012/1001/
p631.html. Accessed July 14, 2021.
8. Scheid DC. Diagnosis and Management of Acute Pyelonephritis in Adults. Vol 71.
American Academy of Family Physicians; 1970. https://www.aafp.org/afp/
2005/0301/p933.html. Accessed July 12, 2021.