CASE STUDY 1

Patient A is a woman, 50 years of age, who was admitted to the emergency department after a motor vehicle accident. She incurred massive abdominal injuries and was transported to the emergency department unconscious and hypotensive upon arrival. She was receiving 35% O₂ via oxygen mask. Her respiratory rate was 28 breaths per minute, and lung sounds were clear bilaterally. She had a sinus tachycardia with a heart rate of 150 beats per minute. Her blood pressure was 80/45 mm Hg. The patient had a 40 pack-year history of cigarette smoking and had been taking medications to control hypertension.

She was transported via stretcher to radiology for a computed tomography scan, which revealed bleeding in the peritoneum. She was taken immediately to surgery. Following surgery, she was taken to the ICU. Three liters of lactated Ringer's solution had been infused in surgery. Estimated blood loss was 2,500 cc, and she received 6 units of whole blood in surgery. Despite fluid resuscitation, the patient was hypotensive during much of the surgical procedure. To assess fluid management, a pulmonary artery catheter was placed while in surgery. A variety of data was obtained upon arrival to the surgical ICU.

Patient A was hemodynamically stable following surgery. She awakened slowly and was able to be extubated and put on a 40% O₂ mask.

Three days after surgery, the patient's level of consciousness began to deteriorate. She was obtunded and only awoke when her name was called. Her skin was warm to touch and appeared flushed, and she had 4+ bounding pulses.

Urine output was 15 cc per hour for the last three hours. Cultures of sputum, urine, and blood were obtained. Antibiotic therapy was initiated.

1. Identify the term that best describes Patient A's condition at the present moment.

Sepsis is caused by bacteria, viruses, or fungi in the blood. It is a clinical continuum ranging from bacteremia through septicemia to septic shock. Patient A is presently displaying signs of septicemia. Her blood pressure and cardiac output are within an acceptable range. Chemical mediators are being released and causing the physiologic changes.

On the 5th post-operative day, Patient A's blood pressure dropped to 84/58 mm Hg; her respirations were 32 breaths per minute, heart rate was 130 beats per minute, and temperature was 97°F. Despite 3000 cc fluid resuscitation, Patient A's condition continued to deteriorate. She was re-intubated and connected to a ventilator.

1. List the risk factors applicable to Patient A's case.

2. Patient A is in what stage of septic shock? Describe the symptoms to support your answer.

Patient A is in the hypodynamic (cold) phase of septic shock. This phase is characterized by decreased cardiac output, increased SVR, hypotension, and inadequate tissue perfusion.

3. What are some of the causative organisms associated with sepsis in a post-operative, hospitalized patient?

On post-operative day 8, Patient A's skin was cool and cyanotic, and mottling was noted in the extremities. She responded only to painful stimuli.

1. Patient A's temperature is 95.6°F. Is this to be expected in the hypodynamic phase and why?

Yes. Hypothermia is common during the hypodynamic phase. Metabolic and myocardial activity are greatly reduced.

2. What is the physiologic cause of increased SVR in the hypodynamic phase?

In the hypodynamic phase, SVR is caused by decreased cardiac output and elevated serum lactate levels.

3. What management would be appropriate in this phase?

Afterload reduction and myocardial support are of great importance at this point. Before the use of vasodilators, cautious fluid administration with hemodynamic monitoring is essential to provide normovolemia as the vascular capacitance increases. If fluid resuscitation proves unsuccessful, the use of vasodilators in combination with a positive inotrope may be attempted.

Patient A died on the 10th post-operative day due to the complications of septic shock: renal failure and hepatic failure complicated by DIC and ARDS.