infection - Nursing Case Study

Pathophysiology

• Primary mechanism: Invasion and colonization - Pathogens enter the body through various routes (inhalation, ingestion, or skin breaches) and attach to host cells. They then multiply and produce toxins, causing cell and tissue damage.

• Secondary mechanism: Immune response - The body reacts to the infection by activating the immune system. The inflammatory response recruits white blood cells to the site of infection. These cells engulf pathogens and release chemicals to kill them. This response can result in fever, redness, swelling, and pain.

• Key complication: Sepsis - If the infection is not contained, it can spread through the bloodstream, leading to sepsis. This severe reaction involves widespread inflammation, which can cause organ dysfunction and, if not treated promptly, can be fatal.

Patient Profile

Demographics:

48 years old, male, construction worker

History:

• Key past medical history: Type 2 Diabetes, Hypertension

• Current medications: Metformin, Lisinopril

• Allergies: Penicillin

Current Presentation:

• Chief complaint: Fever, persistent cough, difficulty breathing

• Key symptoms: High fever, productive cough with yellow/green phlegm, shortness of breath, fatigue, body ache

• Vital signs: Temperature 101.5°F, Heart rate 110 bpm, Respiratory rate 22 breaths per minute, Blood pressure 145/95 mmHg, Oxygen saturation 90% on room air.

Section 1

Change in Patient Status:

Overnight, the patient's condition deteriorates. His fever spikes to 103°F and his respiratory rate increases to 28 breaths per minute. Oxygen saturation drops to 86% on room air, indicating worsening respiratory function. His blood pressure also increases, now consistently measuring at 155/100 mmHg. The patient becomes increasingly fatigued and confused, suggesting possible decreased oxygenation to the brain.

In response to these changes, the nurse increases the frequency of vital signs monitoring to every 2 hours. The healthcare team is concerned about the possibility of sepsis due to the patient's increased fever, tachycardia, and tachypnea. Blood cultures are drawn and sent to the lab for analysis, and the patient is started empirically on broad-spectrum antibiotics, due to his allergy to penicillin. The patient's blood glucose levels are also checked regularly, as his diabetes could complicate his body's ability to fight off the infection. The healthcare team must remain vigilant and prepared to escalate care if the patient's condition continues to worsen.

Section 2

Change in Patient Status:

By the next morning, the patient's condition has further declined. His fever rises to 105°F and his respiratory rate climbs to 35 breaths per minute. Oxygen saturation plummets to 80% on room air, suggesting severe respiratory distress. Blood pressure continues to elevate, with readings now averaging around 160/105 mmHg. The patient appears dazed and lethargic, with decreased responsiveness to stimuli. His skin feels cool to touch and is clammy, indicating possible shock.

The nurse initiates supplemental oxygen therapy at 4 L/min via nasal cannula to improve oxygenation, and notifies the healthcare team about the patient's deteriorating condition. The team requests a STAT chest X-ray to rule out possible pneumonia and orders a complete blood count (CBC) and metabolic panel to assess for organ dysfunction. Given the escalating fever and worsening vital signs, the patient is transferred to the intensive care unit (ICU) for closer monitoring and management. The healthcare team is gravely concerned about the potential for septic shock and acute respiratory distress syndrome (ARDS), both life-threatening conditions.

Section 3

New Diagnostic Results:

The chest X-ray results reveal diffuse bilateral infiltrates, characteristic of ARDS. The CBC report shows a high white blood cell count of 20,000 cells/mm3, indicative of a severe infection. The metabolic panel shows elevated levels of blood urea nitrogen (BUN) at 30 mg/dL and creatinine at 2.0 mg/dL, suggesting potential renal impairment. His liver enzymes are also elevated with an alanine aminotransferase (ALT) of 200 U/L and an aspartate aminotransferase (AST) of 250 U/L, indicating possible liver dysfunction. The lactate level is also high at 4 mmol/L, which suggests tissue hypoxia and possible sepsis.

These findings significantly suggest multi-organ dysfunction, possibly due to severe sepsis. The healthcare team initiates broad-spectrum antibiotics, while awaiting results of blood cultures to identify the causative pathogen. The nurse continues to monitor the patient closely, particularly his oxygenation status and hemodynamic stability, while preparing for possible intubation and mechanical ventilation, given the severity of the patient's ARDS. The nurse also starts fluid resuscitation as per the sepsis protocol to manage potential septic shock. The healthcare team also prepares to initiate renal replacement therapy, given the patient's worsening renal function. The team's immediate goal is to stabilize the patient's condition, while identifying the underlying cause of his severe illness.

Section 4

Change in Patient Status:

Over the next few hours, the patient's condition continues to deteriorate. He becomes increasingly dyspneic, with an oxygen saturation that drops to 88% on a high-flow nasal cannula at 15 L/min. His blood pressure also drops to 90/50 mmHg, and his heart rate increases to 120 beats per minute. Despite aggressive fluid resuscitation, the patient's urine output remains less than 30 mL/hr, reflecting ongoing renal impairment. The patient also seems to be becoming increasingly confused and lethargic, which suggests possible encephalopathy secondary to the severe sepsis.

The patient's worsening hypoxia, hypotension, tachycardia, decreased urine output, and altered mental status indicate a progression towards septic shock and multi-organ failure. The nurse immediately informs the healthcare team of these changes. The intensivist decides to proceed with intubation and mechanical ventilation to better manage the patient's respiratory failure. The team also starts vasopressor therapy to support the patient's blood pressure and organ perfusion. The nephrologist also recommends initiating continuous renal replacement therapy (CRRT) given the ongoing oliguria and rising creatinine. The team continues to work on identifying the underlying pathogen causing the sepsis to adjust the antibiotic therapy accordingly. The healthcare team's goal remains to stabilize the patient's condition and prevent further deterioration.

Section 5

Change in Patient Status:

By the next day, the patient's condition has not improved as hoped. His blood pressure remains unstable, fluctuating between 85/45 mmHg and 95/60 mmHg despite the ongoing vasopressor therapy. His heart rate continues to be elevated, remaining in the range of 115 to 125 beats per minute. The patient's oxygen saturation levels remain persistently low at around 88-90%, even with the mechanical ventilation. The CRRT has resulted in some improvement in the patient's urine output, increasing to around 40 mL/hr, but his serum creatinine level is still high at 3.2 mg/dL, indicating persistent renal impairment.

New Diagnostic Results:

A blood culture drawn two days ago has finally yielded results. The laboratory reports the presence of gram-negative bacilli, which is suggestive of a severe bacterial infection. Sensitivity testing indicates that the bacteria are resistant to the initial broad-spectrum antibiotics that were administered, which explains the patient's lack of response to the treatment. The intensivist decides to switch the patient's antibiotic therapy to a regimen that includes meropenem and gentamicin, both of which the bacteria are sensitive to according to the sensitivity report. The team is hopeful that the change in antibiotic therapy will help control the infection, stabilize the patient's condition, and prevent further organ damage.