Matthew S. Slater

Rhabdomyolysis and myoglobinuric renal failure in trauma and surgical patients : A review

The Old Testament contains the oldest written description of rhabdomyolysis. As the Israelites wandered the desert, they encountered a quail migration and gathered birds to dry and store. Consuming large numbers of quail the people were stricken with “. . . a very great plague . . .” (Numbers 11:33). Ouzounellis postulates that quail consumption produces rhabdomyolysis and myoglobinuric renal failure. The mechanism is apparently analogous to the sensitivity of certain individuals with glucose-6phosphatase deficiency who develop hemolysis after fava bean ingestion. Studies of rhabdomyolysis were published in the German literature in the late 1800s. In 1911 MeyerBetz described a clinical syndrome consisting of dark brown urine, muscle pain, and weakness. Bywaters and Beall reported on the clinical association between crush injury, dark urine, shock, and renal failure in casualties who were crushed beneath fallen masonry for extended periods during the bombing of London during World War II (Fig. 1). Myoglobin present in the urine of these patients was responsible for the dark urinary pigmentation. Recently, casualties with rhabdomyolysis have been generated in large numbers by catastrophes such as mine collapse, train accidents, and seismic events. In the United States rhabdomyolysis is commonly diagnosed in intoxicated patients subjected to prolonged muscle compression as they lay motionless and in patients with seizure disorders. Less frequently, surgeons treat patients who develop rhabdomyolysis after crush or other traumatic injury to skeletal muscle. Renal failure is a well-documented sequellae of rhabdomyolysis. In recent reports, the risk of acute renal failure after rhabdomyolysis ranges from 4% to 33%. Rhabdomyolysis is responsible for 5–7% of all cases of acute renal failure in the United States.

Crush injury and rhabdomyolysis

Crush injuries resulting in traumatic rhabdomyolysis are an important cause of acute renal failure. Ischemia reperfusion is the main mechanism of muscle injury. Intravascular volume depletion and renal hypoperfusion, combined with myoglobinuria, result in renal dysfunction. The infusion of intravenous fluids before extrication or soon after injury may lessen the severity of the crush syndrome. Serum CK levels can be used to screen patients with crush injuries to determine injury severity. Once intravascular volume has been stabilized, and the presence of urine flow has been confirmed, a forced mannitol-alkaline diuresis for prophylaxis against hyperkalemia and acute renal failure should be instituted. If an extremity compartment syndrome is suspected, one should have a low threshold for checking the intracompartmental pressures. Further studies are needed to demonstrate if any treatment regimen is truly superior to early, aggressive crystalloid infusion.

Does neoadjuvant chemoradiation downstage esophageal carcinoma

BACKGROUND Neoadjuvant chemoradiotherapy is administered to patients with esophageal carcinoma with the belief that this will both downstage the tumor and improve survival. Endoscopic ultrasound (EUS) is currently the most accurate method of staging esophageal cancer for tumor (T) and lymph node (N) status. Because both EUS and neoadjuvant therapy for esophageal carcinoma are relatively new, there are few data examining the relationship between EUS stage and histological stage (the stage after resection) in patients receiving neoadjuvant therapy. METHODS To determine the effect of neoadjuvant chemoradiotherapy on T and N stage as determined by EUS, we retrospectively compared two groups of patients with esophageal cancer staged by EUS. One group (33 patients) underwent neoadjuvant therapy (Walsh protocol: 5-fluorouracil, cisplatin, and 4000 rads of external beam radiation) followed by resection. The second group (22 patients), a control group, underwent resection without neoadjuvant therapy. We then compared histological stage to determine if there was a downstaging in the patients receiving neoadjuvant therapy. Survival was evaluated as well. RESULTS EUS accurately predicted histologic stage. In the control group EUS overestimated T stage in 3 of 22 (13%), underestimated N stage in 2 of 22 (9%), and overestimated N stage in 2 of 22 (9%) of patients. Preoperative radiochemotherapy downstaged (preoperative EUS stage versus pathologic specimen) 12 of 33 (36%) of patients whereas only 1 of 22 (5%) of patients in the control group was downstaged. Complete response (no tumor found in the surgical specimen) was observed in 5 of 33 (15%) of patients receiving radiochemotherapy. Survival was prolonged significantly in patients receiving radiochemotherapy: 20.6 months versus 9.6 months for those (stage II or III) patients not receiving radiochemotherapy (P <0.01). Operative time, operative blood loss, and length of stay were not significantly different between groups. Perioperative mortality was higher in the radiochemotherapy group (13%) compared with the no radiochemotherapy group (5%) but did not achieve statistical significance. CONCLUSIONS EUS accurately stages esophageal carcinoma. Neoadjuvant radiochemotherapy downstages esophageal carcinoma for T and N status. In our nonrandomized study, neoadjuvant therapy conferred a significant survival advantage. Operative risk appears to be increased in patients receiving neoadjuvant radiochemotherapy prior to esophagectomy.

Improved quality and cost-effectiveness of coronary artery bypass grafting in the United States from 1988 to 2005

OBJECTIVE This study was undertaken to assess the impact of increasing patient complexity and health care cost on coronary artery bypass grafting quality and cost-effectiveness in the United States over an 18-year period. METHODS A retrospective study was carried out utilizing the Nationwide Inpatient Sample to track the characteristics and outcomes of 5,549,700 patients having isolated coronary artery bypass grafting in the United States from 1988 to 2005. Expected mortality, risk-adjusted mortality, and hospital charges were tracked over this period. RESULTS The prevalence of congestive heart failure, pulmonary disease, diabetes, and acute myocardial infarction increased significantly over the study period. Expected mortality increased from 2.57% to 3.66%, reflecting the increasing patient comorbidity burden (P < .0001). Despite this, coronary artery bypass grafting outcomes improved, leading to a decrease in risk-adjusted mortality from 6.20% to 2.12% (P < .0001). Furthermore, when hospital charges were corrected for medical care inflation, hospital charges declined significantly, from

Operative stabilization of a flail chest six years after injury

26,210 in 1988 to

Impact of Single-Ventricle Physiology on Death After Heart Transplantation in Adults With Congenital Heart Disease

19,196 in 2005 (1988 dollars, P < .0001). CONCLUSIONS Coronary artery bypass grafting surgery is being performed on an increasingly complex, high-risk patient population in the United States. Despite this challenge, risk-adjusted operative mortality has progressively declined. Moreover, hospital charges for coronary artery bypass grafting in relation to other medical care services have been reduced. These findings reflect improved quality and cost-effectiveness of coronary artery bypass grafting in the United States. Ongoing efforts directed at quality improvement should address the risks associated with comorbidities that increasingly accompany the diagnosis of coronary artery disease in patients having coronary artery bypass grafting.

Mechanical Circulatory Support Pathways That Maximize Post-Heart Transplant Survival

We report a case of operative stabilization of an incompetent upper chest wall 6 years following flail chest. The indications for stabilization were chronic pain and dyspnea associated with rib malunion and loss of hemithorax volume. At operation, multiple pseudoarthroses were encountered and partial resection of ribs three and four was required. Malleable plates were used to bridge the gaps created by the resection and were secured in place with sternal wire. The patient reported a dramatic relief of symptoms and, at 18 months postoperatively, continues to work full-time on his cattle ranch essentially pain-free.

Pulmonary Artery Sarcoma Mimicking Massive Pulmonary Embolus: A Case Report

BACKGROUND Prevalence of univentricular (1V) anatomy over time and whether 1V anatomy is associated with early death after heart transplant (HTx) among recipients with adult congenital heart disease (ACHD) is unknown. We investigated changes in case-mix over time, 1V vs biventricular (2V) status, and the effect of 1V anatomy on death after HTx among ACHD recipients. METHODS The Nationwide Inpatient Sample (NIS) was used to identify ACHD HTx recipients in the United States aged 14 years or older from 1993 to 2007, divided into era 1 (1993 to 2000) and era 2 (2001 to 2007). In-hospital death was compared among recipients with 1V and 2V anatomy. Multivariable determinants associated with an increased risk of in-hospital death were sought with logistic regression models. RESULTS From a national estimate of 509 ACHD recipients, 143 were 1V and 366 were 2V. Overall, 1V in-hospital mortality (23%) was higher than for 2V (8%; p<0.001) and remained associated with in-hospital death after adjustment for other factors (odds ratio, 3.9; 95% confidence interval, 1.29 to 11.74; p=0.02). All 1V diagnoses had higher mortality than all 2V diagnoses. Despite minor fluctuations, the proportion of 1V patients did not increase over time (era 1, 36%; era 2, 30%; p=0.46). CONCLUSIONS Overall case-mix of ACHD recipients (1V vs 2V) has not changed over time. Initial 1V anatomy increases post-HTx death among ACHD recipients, whereas 2V patients have mortality rates similar to non-CHD recipients. National and international transplant registries should include specific CHD diagnoses because this factor plays such a large role in determining early outcomes.

Recurrent Pulmonary Artery Sarcoma

BACKGROUND Heart transplant (HTx) recipients reach transplantation through increasing numbers of support pathways, including transition from one pathway to another. Outcomes of patients successfully bridged with various support pathways are unknown. We sought to identify mechanical circulatory support pathways that maximize survival after HTx. METHODS A supplemented United Network Organ Sharing Dataset tracked status 1 HTx outcomes from 2000 to 2010. Recipients were grouped based on support pathway before HTx, including those transitioning from one pathway to another. Multivariable factors for time-related death were sought using Cox proportional hazard regression models. RESULTS We identified 13,250 status 1 HTx recipients. Initial support pathways were inotropes (n = 7,607), left ventricular assist device (LVAD [n = 4,034]), intraaortic balloon pump (n = 729), biventricular assist device (n = 521), extracorporeal membrane oxygenation (ECMO [n = 316]), and right ventricular assist device (n = 43). Multivariable analysis demonstrated that LVAD use conferred a survival advantage (hazard ratio [HR] 0.71; p < 0.001), whereas all other support pathways, including inotropes (HR 1.1; p = 0.02), right ventricular assist device (HR 1.9; p = 0.01), and ECMO (HR 2.2; p < 0.001) increased the risk of post-HTx death. Support pathway transition (both escalation and reduction) occurred in 2,175 patients. Patients who transitioned from either ECMO or biventricular assist device support at listing to LVAD-only support at HTx had improved post-HTx survival that was comparable to patients who had LVAD-only therapy throughout their course (p = 0.74). CONCLUSIONS The LVAD supported HTx recipients have better posttransplant survival than patients after all other mechanical support pathways. Survival after HTx is optimized when ECMO or biventricular assist device support can be transitioned to LVAD-only support. Our findings should aid clinical decision making and inform organ allocation policy development intended to maximize societal benefits of HTx.

Genetics, Pregnancy, and Aortic Degeneration

Intimal sarcomas of the pulmonary artery are rare tumors that are often difficult to distinguish from pulmonary thromboembolic disease, complicating accurate diagnosis and timely therapy. We report the case of a gentleman with a primary pulmonary artery sarcoma who presented with a massive pulmonary embolism and complete right ventricular outflow tract obstruction. The patients condition was successfully managed with urgent pulmonary artery thromboendarterectomy, pulmonary valve replacement, and tricuspid valve annuloplasty.