Clinical Phenotyping in the Prediction of Pediatric Acute Kidney Injury

Thesis (Master's)--University of Washington, 2016-06

Clinical and functional outcomes of acute lower extremity compartment syndrome at a Major Trauma Hospital

Background: Acute lower extremity compartment syndrome (CS) is a condition that untreated causes irreversible nerve and muscle ischemia. Treatment by decompression fasciotomy without delay prevents permanent disability. The use of intracompartmental pressure (iCP) measurement in uncertain situations aids in diagnosis of severe leg pain. As an infrequent complication of lower extremity trauma, consequences of CS include chronic pain, nerve injury, and contractures. The purpose of this study was to observe the clinical and functional outcomes for patients with lower extremity CS after fasciotomy. Methods: Retrospective chart analysis for patients with a discharge diagnosis of CS was performed. Physical demographics, employment status, activity at time of injury, injury severity score, fracture types, pain scores, hours to fasciotomy, iCP, serum creatine kinase levels, wound treatment regimen, length of hospital stay, and discharge facility were collected. Lower extremity neurologic examination, pain scores, orthopedic complications, and employment status at 30 days and 12 months after discharge were noted. Results: One hundred twenty‑four patients were enrolled in this study. One hundred and eight patients were assessed at 12 months. Eighty‑one percent were male. Motorized vehicles caused 51% of injuries in males. Forty‑one percent of injuries were tibia fractures. Acute kidney injury occurred in 2.4%. Mean peak serum creatine kinase levels were 58,600 units/ml. Gauze dressing was used in 78.9% of nonfracture patients and negative pressure wound vacuum therapy in 78.2% of fracture patients. About 21.6% of patients with CS had prior surgery. Nearly 12.9% of patients required leg amputation. Around 81.8% of amputees were male. Sixty‑seven percent of amputees had associated vascular injuries. Foot numbness occurred in 20.5% of patients and drop foot palsy in 18.2%. Osteomyelitis developed in 10.2% of patients and fracture nonunion in 6.8%. About 14.7% of patients underwent further orthopedic surgery. At long‑term follow‑up, 10.2% of patients reported moderate lower extremity pain and 69.2% had returned to work. Conclusion: Escalation in leg pain and changes in sensation are the cardinal signs for CS rather than reliance on assessing for firm compartments and pressures. The severity of nerve injury worsens with the delay in performing fasciotomy. Standardized diagnostic protocols and wound treatment strategies will result in improved outcomes from this complication.

Propofol infusion syndrome in a super morbidly obese patient (BMI = 75)

Propofol infusion syndrome (PRIS) is a rare but often fatal complication as a result of large doses of propofol infusion (4–5 mg/kg/hr) for a prolonged period (>48 h). It has been reported in both children and adults. Besides large doses of propofol infusion, the risk factors include young age, acute neurological injury, low carbohydrate and high fat intake, exogenous administration of corticosteroid and catecholamine, critical illness, and inborn errors of mitochondrial fatty acid oxidation. PRIS manifestation include presence of metabolic acidosis with a base deficit of more than 10 mmol/l at least on one occasion, rhabdomyolysis or myoglobinuria, acute renal failure, sudden onset of bradycardia resistant to treatment, myocardial failure, and lipemic plasma. The pathophysiology of PRIS may be either direct mitochondrial respiratory chain inhibition or impaired mitochondrial fatty acid metabolism mediated by propofol. We report a case of supermorbidly obese patient who received propofol infusion by total body weight instead of actual body weight and developed PRIS.

Development and regeneration of neuronal circuits in the vertebrate retina

Thesis (Ph.D.)--University of Washington, 2016-08