uti - Nursing Case Study
Pathophysiology
• Primary mechanism: Urinary Tract Infections (UTIs) most commonly result from bacterial invasion, particularly by Escherichia coli, which ascend the urethra to colonize the bladder, causing inflammation and symptoms like dysuria and frequent urination.
• Secondary mechanism: The bacteria's ability to adhere to the uroepithelium via fimbriae facilitates persistent infection and evasion of the host's immune response, leading to a continued inflammatory cycle and potential progression to the kidneys.
• Key complication: If untreated, UTIs can ascend to the kidneys, causing pyelonephritis, which is characterized by fever, flank pain, and potential risk of systemic infection (sepsis), requiring prompt intervention to prevent renal damage.
Patient Profile
Demographics:
32-year-old female, office manager
History:
• Key past medical history: Recurrent urinary tract infections, hypertension
• Current medications: Lisinopril, cranberry supplements
• Allergies: Penicillin
Current Presentation:
• Chief complaint: Severe lower abdominal pain
• Key symptoms: Burning sensation during urination, increased frequency and urgency, fever, chills, flank pain
• Vital signs: Temperature 101.3°F, heart rate 110 bpm, blood pressure 145/92 mmHg, respiratory rate 20 breaths per minute
Section 1
During the initial assessment, the clinical team noted that the patient appeared visibly uncomfortable, with her hand placed protectively over her lower abdomen. On physical examination, there was notable tenderness upon palpation of the suprapubic region, and the patient reported exacerbated pain with pressure. Additionally, flank tenderness was elicited upon percussion, suggesting possible renal involvement. Upon further questioning, the patient mentioned having experienced similar symptoms in the past but noted that the pain and discomfort were more intense this time, coupled with a persistent fever.
Given the patient's clinical presentation and past medical history of recurrent UTIs, the healthcare provider ordered a urinalysis and urine culture to identify the causative organism and determine antibiotic sensitivity, given her penicillin allergy. The urinalysis revealed cloudy urine with significant leukocyte esterase and nitrites, indicating a bacterial infection. Microscopic analysis showed abundant white blood cells and occasional red blood cells, further supporting a diagnosis of a complicated urinary tract infection. Blood tests showed elevated white blood cell count and C-reactive protein levels, indicative of a systemic inflammatory response.
Recognizing the potential complication of pyelonephritis, the clinical team decided to initiate intravenous antibiotics, opting for a broad-spectrum agent to cover gram-negative bacteria, while awaiting culture results. The patient's vital signs continued to be closely monitored, as her elevated temperature and heart rate were concerning for potential progression to sepsis. This careful monitoring and prompt intervention were critical to prevent further complications, such as acute kidney injury or systemic infection, which could significantly impact the patient's recovery and overall health.
Section 2
As the clinical team continued to monitor the patient, they observed that her condition showed signs of improvement initially, with a slight reduction in fever and a decrease in flank pain after 24 hours of intravenous antibiotic therapy. However, by the second day of treatment, the patient's condition began to deteriorate unexpectedly. Her temperature spiked to 39.5°C (103.1°F), and she became increasingly tachycardic, with a heart rate rising to 120 beats per minute. Additionally, her blood pressure dropped to 90/60 mmHg, raising concerns about the development of septic shock. The patient also reported new onset of nausea and vomiting, coupled with increased fatigue, suggesting a worsening systemic infection.
Given these alarming changes in the patient's status, the clinical team promptly reassessed her condition. A repeat urinalysis and blood cultures were ordered to evaluate the effectiveness of the current antibiotic regimen and to check for any new or resistant pathogens. The repeat urinalysis still showed significant bacteriuria and pyuria, consistent with ongoing infection. Blood cultures revealed the growth of a multi-drug resistant organism, necessitating a change in the antibiotic regimen. The decision was made to switch to a more targeted antibiotic, specifically effective against the identified pathogen, and to initiate aggressive fluid resuscitation to address her hypotension.
These developments required a coordinated response from the healthcare team, emphasizing the importance of vigilant monitoring and timely interventions to prevent further complications. The patient's care plan was adjusted to include more frequent vital sign checks, continuous cardiovascular monitoring, and regular assessments of renal function to detect any early signs of acute kidney injury. This comprehensive approach aimed to stabilize the patient and prevent the progression of sepsis, thereby facilitating her recovery and minimizing the risk of long-term complications.
Section 3
As the clinical team implemented the revised care plan, they continuously monitored the patient's vital signs and response to the new antibiotic therapy. Within the first 12 hours of intervention, the patient's heart rate showed a slight improvement, decreasing to 110 beats per minute, while her blood pressure remained concerning at 92/58 mmHg despite aggressive fluid resuscitation. The patient's temperature, however, remained elevated at 38.9°C (102°F), indicating persistent infection and an ongoing inflammatory response.
Lab results from the repeat blood cultures confirmed the presence of a resistant strain of Escherichia coli, which was known for causing severe urinary tract infections and had shown susceptibility to only a limited class of antibiotics. The team also noted a rising creatinine level of 1.9 mg/dL, up from 1.1 mg/dL at admission, suggesting the onset of acute kidney injury likely due to both the systemic infection and the hypotensive episodes. Urine output was closely monitored, revealing oliguria with output decreasing to 20 mL/hr, further indicating compromised renal function.
Despite the change in antibiotic therapy and fluid management, the patient began to exhibit signs of mental status changes, becoming more lethargic and disoriented. This altered mental status prompted an urgent evaluation for potential central nervous system involvement or worsening sepsis. The clinical team prioritized a head CT scan to rule out any neurological complications and prepared for the possibility of escalating to intensive care support if the patient's condition failed to stabilize. These developments underscored the critical need for continuous reevaluation and adaptation of the treatment plan to address both the immediate and potential systemic complications of the infection.
Section 4
As the patient's condition continued to evolve, the clinical team received the results from the head CT scan, which fortunately showed no acute intracranial abnormalities. However, the neurologist on call was consulted due to the persistent altered mental status, and it was suggested that the mental changes were likely related to the systemic effects of sepsis and possible uremic encephalopathy, given the rising creatinine levels. The nephrology team was also brought in to assess the worsening renal function, which was now a critical concern. The increasing creatinine level and decreasing urine output suggested that the patient's kidneys were under significant stress, possibly progressing towards acute tubular necrosis if not addressed promptly.
In light of these findings, the clinical team decided to initiate renal replacement therapy via continuous venovenous hemofiltration (CVVH) to support kidney function and manage fluid overload while also considering the possibility of adjusting the antibiotic regimen to optimize therapeutic levels, especially given the resistant strain of E. coli. To improve the patient's hemodynamic status and support organ perfusion, vasopressor support was initiated with a low-dose norepinephrine infusion, as the blood pressure remained borderline low at 88/55 mmHg despite continued fluid resuscitation.
As the team implemented these interventions, they closely monitored the patient's response, specifically looking for stabilization in vital signs, improved mental status, and increased urine output. The next few hours were critical in determining the effectiveness of the new management strategies. The multidisciplinary approach was crucial, with the team remaining vigilant for any further complications, such as worsening sepsis, potential multi-organ dysfunction, or new signs of infection spread. This stage of the patient's journey highlighted the importance of dynamic clinical reasoning and the need for swift adaptation of the care plan to mitigate the developing complications effectively.
Section 5
As the clinical team monitored the patient closely following the initiation of continuous venovenous hemofiltration (CVVH) and vasopressor support, they observed a gradual stabilization of the patient's hemodynamic status. Over the next few hours, the blood pressure showed a modest improvement, rising to 95/60 mmHg, and the heart rate stabilized around 100 beats per minute. However, despite these encouraging signs, the patient's mental status remained significantly altered, with only minimal improvement noted. This prompted further evaluation of potential contributing factors, including metabolic imbalances and medication effects.
New diagnostic results revealed a slight improvement in renal function, with serum creatinine levels decreasing from 3.2 mg/dL to 2.9 mg/dL, though urine output remained low at 15 mL/hour. Blood urea nitrogen (BUN) levels also showed a marginal decrease, suggesting that the CVVH was beginning to mitigate some of the metabolic disturbances. However, a repeat complete blood count (CBC) indicated persistent leukocytosis with a white blood cell (WBC) count of 18,000/mm³, and inflammatory markers such as C-reactive protein (CRP) remained elevated, pointing to ongoing systemic inflammation.
Given the persistence of altered mental status and new lab findings, the team considered the likelihood of ongoing sepsis and began evaluating for potential sources of infection that might not have been addressed. A repeat urinalysis indicated persistent bacteriuria, and blood cultures drawn earlier returned positive for E. coli with extended-spectrum beta-lactamase (ESBL) resistance. These findings highlighted the need for an urgent review of the antibiotic regimen to ensure coverage of resistant organisms. The infectious disease specialist recommended switching to a carbapenem to better target the resistant strain. This adjustment, along with continued supportive care, was crucial to prevent further deterioration and address the underlying infection effectively.