NU656 Unit 4 Septic Shock From an Empyema Example

The Antibiotic Was Right and the Pus Was Still There: A Sepsis Case Analysis of Septic Shock From an Empyema in a 64-Year-Old Man

[Student Name]

Purdue University Global

NU656: AGACNP Critical Care Management

Unit 4 Sepsis Case Analysis

[Instructor Name]

[Date]

The patient is composite; times, values and doses are bracketed.

Timeline

The case is laid out by day and then by clock time on the day he deteriorated, because the argument depends on what was visible to the team before the shock and not only after it.

1. [Day 1]. Admitted from home with right lower lobe pneumonia; ceftriaxone and azithromycin started.

2. [Day 3]. Still febrile to [38.9] C; chest radiograph shows a small right effusion blunting the costophrenic angle; antibiotics broadened to piperacillin-tazobactam.

3. [Day 5]. Fever continues; white count [18,400]; the effusion is larger on the repeat film. No sample is taken.

4. [Day 7], [10:30]. Confused; mean arterial pressure [58] mmHg; lactate [3.8] mmol/L; rapid response called.

5. [10:45]. Two sets of blood cultures; [2] liters of balanced crystalloid over the next hour.

6. [11:50]. Mean pressure [60] after fluids; norepinephrine started through a new central line.

7. [12:30]. Bedside ultrasound: large right effusion with septations.

8. [13:40]. Diagnostic tap: frank pus, pH [6.9], glucose [22] mg/dL, Gram stain with gram-positive cocci in chains.

9. [15:10]. Chest tube placed; [900] mL of pus drained.

10. [Day 8]. Intrapleural alteplase and DNase started.

11. [Day 9]. Off norepinephrine; lactate [1.4].

Scoring the Organ Failure

The Sepsis-3 task force moved the diagnosis away from inflammatory criteria and toward failing organs: a patient with infection has sepsis when the SOFA score has risen by 2 or more points above that patient's baseline (Singer et al., 2016). He had no known chronic organ disease, so his baseline is taken as zero. At [11:50] on [Day 7] the six systems scored as follows.

1. Respiration: PaO2 to FiO2 ratio [230], 2 points.

2. Coagulation: platelets [118,000], 1 point.

3. Liver: bilirubin [1.4] mg/dL, 1 point.

4. Cardiovascular: norepinephrine at [0.12] mcg/kg per minute, 3 points.

5. Central nervous system: Glasgow Coma Scale [13], 1 point.

6. Renal: creatinine [1.6] mg/dL, 1 point.

Total SOFA [9], a rise of [9] from baseline. Sepsis is confirmed with room to spare.

Septic shock is a subset with two further criteria that must both be present: a vasopressor needed to keep the mean pressure at 65 mmHg or above despite adequate fluid, and a serum lactate above 2 mmol/L (Singer et al., 2016). He met the first at [11:50], after [2] liters, and the second on the lactate drawn at [10:30]. By the consensus definition, then, he was in septic shock from [11:50], a state the same paper links to hospital mortality above 40 percent.

The Initial Response

The response on [Day 7] followed the Surviving Sepsis Campaign guidance closely: blood cultures before antibiotics were changed, fluid, a vasopressor for a mean pressure below 65 after fluid, and reassessment of the antimicrobial plan (Evans et al., 2021). Norepinephrine as the first vasopressor matches the guideline. The team considered whether a resistant organism had been missed and added vancomycin at [12:00], on the reasoning that a patient getting worse on piperacillin-tazobactam might have methicillin-resistant Staphylococcus aureus.

That reasoning was defensible, and adding a drug did no harm in the short term. The analysis argues, however, that it answered the wrong question. The organism was not the problem; the location of the infection was.

The Argument: Source Control

The guideline asks clinicians to identify, rapidly, any anatomic source of infection that needs control, and to carry out that control as soon as it is medically and logistically practical (Evans et al., 2021). Six days of appropriate antibiotics had not worked because the antibiotics could not reach the infection; a collection of pus has no blood supply of its own. The effusion was visible on [Day 3] and larger on [Day 5], yet it was not sampled until the patient was already in shock.

British Thoracic Society guidance on pleural infection advises sampling a pleural effusion in any patient with pneumonia and ongoing sepsis, and draining it by chest tube when the fluid is frankly purulent, when organisms are seen on Gram stain or culture, or when the pleural fluid pH is below 7.2 (Davies et al., 2010). The fluid obtained on [Day 7] met all three criteria. A tap on [Day 3] might have found a simple parapneumonic effusion; a tap on [Day 5], with the fever unbroken and the collection growing, would very probably have found an infected one and led to drainage before the patient's pressure fell.

The strongest evidence for the argument comes from what happened next. After drainage he improved within [48] hours on the same beta-lactam he had been receiving since [Day 3]. His lactate fell from [3.8] to [1.4] and norepinephrine was weaned off by [Day 9]. Nothing about his antimicrobial coverage had changed except the addition of vancomycin, which the cultures later showed he did not need.

Completing Source Control

Nine hundred milliliters drained through the tube, but ultrasound on [Day 8] still showed loculated pus in the lower chest. In the MIST2 trial, combined intrapleural tissue plasminogen activator and DNase improved radiographic drainage and reduced referral for surgery, from 16 percent with placebo to 4 percent, while either agent alone did not outperform placebo (Rahman et al., 2011). The combination was given twice daily for [three] days, the tube was flushed on schedule, and thoracic surgery reviewed him on [Day 8] so that video-assisted surgery could follow quickly if drainage stalled. A repeat scan on [Day 11] showed only a thin residual rim, and the tube was removed on [Day 12].

Antibiotic Choice, Revisited

Streptococcus intermedius grew from the pleural fluid; the blood cultures stayed negative. This organism belongs to the anginosus group, which is known for forming abscesses and empyema, a detail that supports the view that the problem was a collection from the start. With the source drained, antibiotics were narrowed to ceftriaxone with metronidazole for anaerobic cover, and vancomycin was stopped on [Day 9]. The planned course was [four to six] weeks, with the final length guided by his imaging and inflammatory markers at a clinic visit.

What the Case Teaches

When a patient with sepsis does not improve on antibiotics that cover the likely organism, the first question should be whether there is a collection that needs draining, not which antibiotic to add. In this case the effusion was visible on two radiographs before the shock, and the analysis names the missed opportunity plainly: nobody asked the source question at the [Day 3] and [Day 5] reviews, because each review asked only whether the drug was right.

Two practical changes follow for the unit. First, any effusion in a patient with pneumonia who remains febrile after [48 to 72] hours of treatment should be sampled under ultrasound, with pH, glucose, Gram stain and culture sent together. Second, the daily review template for patients on antibiotics should carry a line that asks whether a drainable source has been looked for, so that the question is prompted rather than remembered.

References

Davies, H. E., Davies, R. J. O., Davies, C. W. H., & BTS Pleural Disease Guideline Group. (2010). Management of pleural infection in adults: British Thoracic Society pleural disease guideline 2010. Thorax, 65(Suppl. 2), ii41-ii53. https://doi.org/10.1136/thx.2010.137000

Evans, L., Rhodes, A., Alhazzani, W., Antonelli, M., Coopersmith, C. M., French, C., Machado, F. R., Mcintyre, L., Ostermann, M., Prescott, H. C., Schorr, C., Simpson, S., Wiersinga, W. J., Alshamsi, F., Angus, D. C., Arabi, Y., Azevedo, L., Beale, R., Beilman, G., . . . Levy, M. (2021). Surviving sepsis campaign: International guidelines for management of sepsis and septic shock 2021. Critical Care Medicine, 49(11), e1063-e1143. https://doi.org/10.1097/CCM.0000000000005337

Rahman, N. M., Maskell, N. A., West, A., Teoh, R., Arnold, A., Mackinlay, C., Peckham, D., Davies, C. W. H., Ali, N., Kinnear, W., Bentley, A., Kahan, B. C., Wrightson, J. M., Davies, H. E., Hooper, C. E., Lee, Y. C. G., Hedley, E. L., Crosthwaite, N., Choo, L., . . . Davies, R. J. O. (2011). Intrapleural use of tissue plasminogen activator and DNase in pleural infection. New England Journal of Medicine, 365(6), 518-526. https://doi.org/10.1056/NEJMoa1012740

Singer, M., Deutschman, C. S., Seymour, C. W., Shankar-Hari, M., Annane, D., Bauer, M., Bellomo, R., Bernard, G. R., Chiche, J.-D., Coopersmith, C. M., Hotchkiss, R. S., Levy, M. M., Marshall, J. C., Martin, G. S., Opal, S. M., Rubenfeld, G. D., van der Poll, T., Vincent, J.-L., & Angus, D. C. (2016). The third international consensus definitions for sepsis and septic shock (Sepsis-3). JAMA, 315(8), 801-810. https://doi.org/10.1001/jama.2016.0287