Surgical history
In 1997, the patient underwent successful open-heart surgery (aortic stenosis repair). In preparation for the surgery, the patient was receiving oral danazol (200 mg, three times a day). He was also given one dose of 1500 units IV pdC1-INH concentrate preoperatively (his weight was approximately 78 kg). The patient was satisfied with the outcome and his quality of life was substantially improved.
In 2000, the patient required emergency surgery due to an extensive ascending aorta aneurysm dissection. Surgery lasting 12 hours was carried out to replace the ascending aorta. At the time of operation, he was receiving oral stanozolol (4 mg, four times a day), as the surgeon chose to prescribe stanozolol over danazol. This higher than normal dosing was only prescribed for 1 week in preparation for the emergency surgery (4–6 mg/day is the norm). Stanozolol was reduced to 12 mg daily after about 1 month and then tapered down to 4 mg daily shortly after that. The operation had a successful outcome. Postoperatively, he had an abdominal HAE attack and was treated with 1500 units of IV pdC1-INH concentrate.
Surgical complications
In 2004, the patient was admitted for a scheduled aortic aneurysm repair. He was receiving oral danazol (200 mg, twice daily) as stanozolol had been removed from the market at this time. However, the procedure was cancelled as complications arose 3 days before the scheduled surgery; hence, no prophylactic C1-INH had been provided.
In preparation for the surgery, the patient’s anticoagulation was bridged from long-term warfarin to heparin. Three days into his heparin protocol, the patient complained of left flank pain and severe abdominal pain. On physical examination, the patient was agitated, disoriented, pale, and peripherally cold. His vital signs consisted of a temperature (temp) of 35.2°C, heart rate (HR) of 91 beats per minutes (bpm), blood pressure (BP) of 70/40 mm Hg, and respiratory rate (RR) of 26 breaths/min. Laboratory results revealed low hemoglobin at 43 g/L (was 118 g/L 2 days prior), low hematocrit of 0.24, leukocytosis at 22 × 109/L, hyperglycemia at 8.6 mmol/L, and acute renal failure with creatinine (Cr) at 290 umol/L (up from 64 umol/L 5 days earlier) and zero urine output. Resuscitation interventions included discontinuation of heparin, sedation with propofol, intubation, mechanical ventilation (FiO2 = 0.40, PEEP = 10), and renal replacement therapy (RRT). Red blood cells, IV fluids, norepinephrine (vasopressor), and pdC1-INH concentrate (2000 units) were also administered. An abdominal computed tomography (CT) scan showed a massive retroperitoneal hemorrhage, slight intraperitoneal bleeding, and moderate ascites. Ascites was clinically confirmed the following morning as the patient had asymmetric abdomen distention and tautness in the right and left upper quadrants with rebound tenderness and guarding in the right lower quadrant. His abdominal girth at this time was 106 cm. The care team had the clinical impression that the patient had an HAE abdominal crisis precipitated by a spontaneous retroperitoneal bleed followed by the development of ascites, hypovolemic shock, and acute renal failure. Repeat CT scan revealed the retroperitoneal hematoma was stable, organized, and contained.
Two days later, the patient contracted hospital-acquired pneumonia (subsequently shown to be caused by Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa).
A chest x-ray (CXR) showed extensive bilateral pneumonia. The patient was treated with different antibiotics (ciprofloxacin, piperacillin/tazobactam, vancomycin, metronidazole, cloxacillin, rifampin, and tobramycin) over the next few weeks in attempts to clear up the bacterial infection.
Simultaneously with regard to renal function, the patient was diagnosed with ischemic acute tubular necrosis. Renal function improved for a short time following the initial RRT with Cr trending down to 124 umol/L, but 7 days after the initial bleed, renal function deteriorated again with Cr rising to 139 umol/L, most likely due to increasing sepsis as the patient developed a temp of 40.4°C, HR of 138 bpm, BP of 115/50 mmHg, RR of 27 breaths/min, and leukocytosis of 30.3 × 109/L. This second round of acute kidney injury necessitated reinitiating RRT 2 days later, as Cr reached 322 umol/L. Three days later, the patient’s ascites, which had begun to resolve, started to increase again in the absence of new bleed (according to a CT scan). The next day, dialysis became clinically indicated. In addition to worsening kidney function, the patient showed signs of hypoxemic respiratory failure with mild oxygen desaturation (93–97%) despite being on a bi-level ventilator. Two days later, the respiratory failure required a tracheotomy for assisted ventilation. His active pneumonia was implicated as the suspected source of the severe sepsis. However, the care team’s differential diagnosis for the hypoxemic respiratory failure consisted of extensive nosocomial pneumonia, severe sepsis from the pneumonia, ARDS, or a combination of the three. Discerning between the three processes was a challenge because they were highly interrelated. Severe pneumonia and sepsis can cause ARDS while severe sepsis and ARDS can lead to multisystem dysfunction. Furthermore, severe pneumonia and ARDS share similar symptoms, signs, and radiographic findings (i.e. the patient’s CXR showed bilateral patchy infiltrates which could be due either to pneumonia or alveolar pulmonary edema). Over the course of the following weeks, the patient continued to experience renal failure requiring dialysis up to 4 times a week.
Despite 2 months of optimal intensive care unit (ICU) interventions including renal dialysis, assisted ventilation, antibiotic therapy, blood transfusions, daily danazol (200 mg), and very conservative intermittent pdC1-INH concentrate, the patient remained in critical condition and the decision to terminate his life was considered. Given a lack of clinical and hemodynamic response to ongoing conventional treatment, a decision was made to administer daily pdC1-INH concentrate as a trial to see if the multi-organ failure and ascites would be alleviated with better control the patient’s HAE via C1-INH replacement. An IV infusion of pdC1-INH concentrate (1000 units) was administered for 21 days (total: 21000 units).
Within 48 hours of daily pdC1-INH concentrate infusion, renal function improved (improved urine output and stabilization of Cr levels). After 4 more days, Cr values started decreasing. Eventually, abdominal ascites and pneumonia clinically resolved as well. The care team successfully weaned him off the respirator. The patient regained his full strength after further reconditioning and returned home 4 months after being admitted for aortic aneurysm repair.