Pyelonephritis: clinical approach
文摘
科学
2024-07-26 07:00
澳大利亚
If you would like to view past exciting content, please click on the following link.Acute pyelonephritis is an upper urinary tract infection that typically occurs when bacteria, most commonly E. coli, ascend from the lower urinary tract areas like the urethra and bladder, through the ureters into the kidneys. Depending on the patient’s clinical presentation, acute pyelonephritis may be categorized as either complicated or uncomplicated. Complicated pyelonephritis is seen in patients with structural or functional urinary tract abnormalities such as a neurogenic bladder or urinary obstruction due to nephrolithiasis, or in those with specific host risk factors including immunosuppression, advanced age, or being male. Uncomplicated pyelonephritis, however, occurs in patients without any anatomical urinary tract abnormalities or specific host risk factors.Should you suspect acute pyelonephritis, an initial ABCDE assessment is crucial to determine patient stability. In unstable patients, signs of sepsis or shock such as tachycardia and hypotension may be evident; it’s critical to manage their airway, breathing, and circulation, establish IV access, provide supplemental oxygen, and monitor vital signs continuously.Returning to the ABCDE assessment, once the patient is stabilized, a focused history and physical examination should be conducted. Commonly, patients may report symptoms such as fever, chills, malaise, flank pain, nausea and vomiting, and occasionally dysuria. The physical examination might show findings like elevated body temperature, hypotension, tachycardia, tenderness at the costovertebral angle and flank, and abdominal tenderness.At this stage, pyelonephritis should be suspected, prompting the ordering of laboratory tests including a CBC, CMP, urinalysis, and urine cultures. The CBC typically shows leukocytosis with a left shift, and the CMP may indicate elevated BUN and creatinine levels suggesting renal insufficiency. Generally, the urinalysis reveals pyuria, bacteriuria, and possibly hematuria, nitrates, leukocyte esterase, and WBC casts.With these results, a confident diagnosis of acute pyelonephritis can be made. The next decision is whether hospitalization is necessary. Outpatient management is suitable for those who can tolerate oral intake, follow the treatment plan, and do not have complicating conditions such as diabetes, renal insufficiency, a history of nephrolithiasis, or urinary tract anatomical abnormalities.For eligible patients, medical therapy should begin with oral hydration and empiric antibiotics. Due to rising fluoroquinolone resistance, a parenteral antibiotic like cephalosporin should be administered initially, followed by an oral fluoroquinolone such as ciprofloxacin.Following this, it's important to review culture results, which should identify the pathogen within a few days and allow for tailoring of antibiotic therapy. A response to treatment is expected within 72 hours; if the patient improves, the treatment is deemed effective. If there is no improvement, this suggests a failure of outpatient therapy, raising suspicion for complicated pyelonephritis, and necessitating hospital admission for inpatient management.Inpatient management targets those unable to tolerate oral intake, those who have failed outpatient treatment, those likely not to adhere to the treatment plan, or those with coexisting conditions requiring more intensive care. Such cases have a higher risk of complications like obstruction and abscess formation.While awaiting culture results, initiate medical therapy with IV hydration and empiric IV antibiotics, such as ceftriaxone or piperacillin-tazobactam, monitoring the patient's response closely. If the patient shows improvement and the response to treatment is adequate, arrangements can be made for them to complete their treatment on an outpatient basis, either by continuing IV antibiotic administration or by transitioning to oral antibiotics.If there is no clinical improvement after 72 hours of IV antibiotics, it is advisable to proceed with imaging studies to identify any underlying causes, which may include nephrolithiasis, anatomical abnormalities, or obstructive conditions like malignancy or abscess. CT scans are typically utilized for this purpose, with findings in pyelonephritis potentially showing decreased cortical enhancement and surrounding perinephric stranding indicative of an obstruction, such as a renal stone. These cases are categorized as complicated pyelonephritis.For these individuals, antibiotic treatment should be tailored based on culture results, and consultation with the appropriate surgical team may be necessary. Ultrasound is an alternative imaging method, particularly useful in patients with contraindications to CT, such as pregnancy, or in situations where CT is unavailable.Conversely, if renal ultrasound and CT scans do not show abnormalities, this strongly suggests uncomplicated pyelonephritis. Treatment should be adjusted based on culture results and the patient's response. If they are improving, they may be able to complete treatment as an outpatient. However, if there is no improvement or the patient's condition worsens, complicated pyelonephritis should be suspected, necessitating a reevaluation of the treatment approach, which may include repeating urine cultures and further imaging. In some cases, consultation with a surgical team may be required.Here's an important clinical note: Not all instances of complicated pyelonephritis are detectable through imaging. Pyelonephritis that is associated with sepsis or septic shock should be treated as complicated, requiring aggressive management with broad-spectrum antibiotics. Additionally, while urinary tract infections are more common in biologically female individuals, their occurrence in biologically male individuals is inherently considered complicated, warranting a thorough urological evaluation.1. **Initial Assessment:** Conduct an ABCDE assessment for suspected acute pyelonephritis. Stabilize the airway, breathing, and circulation in unstable patients, and ensure IV access, supplemental oxygen (if necessary), and continuous vital sign monitoring.2. **Stable Patients:** In stable individuals, proceed with lab orders including CBC, CMP, urinalysis, and urine cultures to guide diagnosis.3. **Hospitalization Decision:** Determine if hospitalization is needed based on the patient’s ability to tolerate oral intake, adhere to the treatment plan, and absence of complicating coexisting conditions.4. **Outpatient Management:** For those suitable for outpatient care (suspected uncomplicated pyelonephritis), start oral hydration and empiric antibiotics. Tailor antibiotics once culture results are available, monitoring the patient's response. If the patient improves, continue the current antibiotics regimen. If not, suspect complicated pyelonephritis and proceed with hospital admission.5. **Inpatient Management:** Begin empiric therapy with IV hydration and antibiotics for patients who fail outpatient treatment, cannot tolerate oral intake, may not adhere to the treatment plan, or have coexisting conditions.6. **Further Assessment:** If there is no clinical improvement after 72 hours, perform an ultrasound or CT to investigate potential complications such as obstruction, anatomical abnormalities, or abscesses.7. **Complicated Pyelonephritis:** If imaging reveals complications, tailor antibiotics based on culture results and consult with the surgery team.8. **Continuous Evaluation:** For normal imaging results suggesting uncomplicated pyelonephritis, again tailor the antibiotics per culture findings. If the patient is improving, consider completing the treatment on an outpatient basis, transitioning from IV to oral antibiotics if possible. If improvement is not observed, suspect undiagnosed complicated pyelonephritis, repeat urine cultures and imaging, and potentially consult the surgical team for further intervention. - - - - - - - END - - - - - - -
作者：Joy，
澳洲最佳高校非首席脑科学科学家/博导，
德国精英大学非精英医学博士，
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