The effect of ACGME duty hour restrictions on operative continuity of care.

Resident work restrictions limit participation in operations that address problems created by a prior operation, because complications occur at any time. We compared resident and attending surgeon staffing of operative complications. We reviewed all complications that required a second operation reported at our Morbidity and Mortality Conference over 1 year, noting surgeons present, their postgraduate year level, and call shift. Comparisons were done using chi2. Of 142 cases, 39 involved a second operation. The same attending surgeon was present for both in 79 per cent of cases, whereas the same resident was present in only 44 per cent (P = 0.002). Postgraduate year 4 to 5 were less likely to be present for second operations than attendings (48% vs 87%, P = 0.011). Resident shift (day, night float, and weekend) was known in 32 cases. When the first operation occurred during day hours, attendings and residents were equally likely to be present at the second (55% and 45%, P = 0.16). When original operations took place during night float or weekend shifts, residents were less likely to be present (33%) than attendings (83%) at second operations (P = 0.036). Duty hour restrictions interfere with operative continuity of care. Reoperations should be exempted from duty hour restrictions.

Three-year results of mandated work hour restrictions: attending and resident perspectives and effects in a community hospital.

In response to the Accreditation Council of Graduate Medical Education mandated resident work hour restrictions, our residency program used a night float system in 2003. We undertook a survey of attending staff and residents to assess its effects on patient care and resident education. An anonymous survey was administered to attending staff and residents 1 year and 3 years after work hour restrictions took effect. The areas of disagreement include: beneficial effect on education (residents vs faculty: in 2004, 87% vs 22%, respectively, P = 0.02; in 2006, 71% vs 22%, P = 0.03); beneficial effect on patient care (in 2004, 53% vs 10%, P = 0.03); and compromised continuity of care (in 2004, 27% vs 70%, P = 0.04; in 2006, 7% vs 89%, P = 0.0002). One area of agreement was that residents' quality of life had improved. Both disagreed that more errors were being made and that work hour restrictions should be mandated on practicing surgeons. Attending staff and residents have deeply held opinions regarding the effects of work hour restrictions. This reflects a continuing dissatisfaction with providing patient care and educating residents under a set of requirements that solely addresses resident sleepiness and fatigue.

Mammography as screening for coronary artery disease.

Coronary artery disease (CAD) is the leading cause of death in American women. Screening mammograms are recommended for women starting at age 40 for the early detection of breast cancer. An additional benefit of this routine screening tool may be to detect breast arterial calcifications (BAC) as a possible sign of CAD. The purpose of this study was to determine further the relationship between mammographically detected BAC and CAD. The medical records of 44 women who had undergone coronary artery bypass grafting at our institution over 5 years were reviewed. These mammograms were examined for evidence of BAC. For all women included in the study, 18 of 44 (41%) had evidence of BAC on screening mammogram. This was statistically significant (P < 0.0001) compared with the prevalence of BAC reported in the general population in previous studies. Most were also overweight (61.1%), had hypertension (88.8%), and hypercholesterolemia (55.5%). This is the first study to look at the direct correlation between patients with known CAD requiring revascularization and BAC. Perhaps women with BAC seen on screening mammography should undergo further workup for CAD, with the potential benefit of early intervention.

Impedance cardiography: can it replace thermodilution and the pulmonary artery catheter?

Clinical assessment of cardiac output (CO) is inaccurate, yet the use of the pulmonary artery catheter (PAC) for thermodilution (TD) measurement of CO (CO(TD)) has declined significantly. Can noninvasive impedance cardiography (ICG) now be used to measure CO (CO(ICG)) in place of CO(TD)? A literature review of recent CO(ICG) correlations with CO(TD) (r = 0.73-0.92) were similar to ours, r = 0.81. A search for conditions interfering with CO(ICG) revealed no serious problems with patient position, cardiac or pulmonary assist devices, "wet lungs," body mass index > or = 30, or age > or = 70 years. A prospective randomized study was initiated beginning with a record of physician assessment of CO as high, normal, or low; concordance was 57%. Data from ICG was revealed only in the study group, resulting in a 49 per cent change in treatment compared with 29 per cent in the control group. Length of stay was shorter in the study than the control group in the intensive care unit (2.4 +/- 8.8 vs 3.3 +/- 7.3 days) and on the floor (9.8 +/- 10.6 vs 15.7 +/- 19.0 days). In conclusion, ICG is comparable with TD, is easily, accurately, and safely performed, enhances clinical assessment of CO, and improves care in hemodynamically compromised patients.

Accelerated migration and proliferation of smooth muscle cells cultured from neointima induced by a vena cava filter.

Formation of a neointima is associated with grafted artery or vein, angioplasty, and stent and inferior vena cava filter (IVCF) implantation. Contributing to the neointima is a population of vascular smooth muscle cells (SMC) that migrates from media and subsequently proliferates within intima. The purpose of this present study was to culture SMC from normal vessel wall and from neointima and to compare migration and growth of these cells. Neointima was stimulated in the vena cava of pigs by placement of an IVCF for 30 days. Tissue was taken from the thickened wall between the struts and from a normal segment of the IVCF. After removal of the endothelium and adventitia, explants were placed in culture dishes and were observed for the migration of cells. Immunoassay for smooth muscle alpha-actin was used to identify cell origin. Proliferation was determined by cell counting. The cell cycle regulator cyclin D1 was detected by Western blot analysis. SMC phenotype was confirmed by positive immunostaining for smooth muscle alpha-actin. Cells migrated from the neointimal explants (NI-SMC) more rapidly than cells from explants of normal media (NM-SMC). Proliferation of NI-SMC was also more rapid than NM-SMC with or without exogenous mitogens. NI-SMC expressed more cyclin D1 than NM-SMC. Injury to the vena cava triggered neointima formation characterized by the expansion of a population of SMC with increased migration and replication compared with SMC from normal regions of the vessel.

Removal of the OptEase retrievable vena cava filter is not feasible after extended time periods because of filter protrusion through the vena cava.

BACKGROUND: Therapeutic and prophylactic vena cava filters (VCFs) are used to prevent pulmonary embolism. Concerns exist over placing a permanent filter in a young trauma patient. Recently, retrievable VCFs have become available. One such filter is the OptEase, which has a recommended time of removal of up to 23 days after insertion. Data supporting this recommendation are sparse. Many trauma patients will need filters for more than 2 weeks, and there are no data evaluating the safety of removal after extended time periods. The purpose of this study was to determine the safety, feasibility, and reaction of the vena cava when removing the OptEase retrievable VCF at different time intervals. METHODS: Twenty Yorkshire cross pigs (80-113 kg) underwent general anesthesia with tiletamine and zolazepam. Filters were placed in the infrarenal vena cava (VC) through the femoral vein under fluoroscopic guidance. Animals were then divided into four groups. In group 1, filters were removed at 14 days; in group 2, at 30 days; in group 3, at 60 days; and in group 4, at 90 days. Removal was attempted using a snare-and-sheath technique through the femoral vein. Animals with successful filter removal were allowed to recover; then, the animals underwent autopsy (gross and microscopic VC examination) 2 months later. Animals with unsuccessful filter removal underwent autopsy immediately after attempted removal. Venacavograms were taken at filter insertion, at removal, and before autopsy to evaluate any VC abnormalities. RESULTS: Successful removal of the filter in all five pigs (100%) was reliably performed only in the 14-day group. In this group, the initial VC transverse diameter was 19.4 +/- 0.8 mm and was significantly reduced to 9.8 +/- 1.1 mm (p < 0.05) immediately after removal. Sixty days later, before autopsy, VC diameter had increased to 15.3 +/- 1.9 mm, which was significantly larger than at removal (p < 0.05) but not different from the initial value. In the 30-day group, removal was successful in only one of five animals. Although removal was successful in the one pig, autopsy at 2 months postremoval revealed total occlusion of the VC. Filters could not be removed from 60- and 90-day groups. At autopsy, the VCF struts were embedded or protruded through the VC wall. Microscopic examination of the VC revealed significant scarring underneath and between the struts. CONCLUSION: Removal of the retrievable OptEase VCF may be successfully performed up to 14 days after insertion. Strut protrusion through the VC wall prohibited successful and safe removal at extended time intervals.

Cardiopulmonary assessment: is improvement needed?

Clinical parameters alone have repeatedly been proven unreliable in assessing cardiopulmonary status, especially in hemodynamically unstable patients. To learn if we had a diagnostic problem in our hospital, we compared physician assessment of cardiac index (CI) and thoracic fluid content (TFC) to values obtained using impedance cardiography (ICG). We selected the newest available ICG monitor, the BioZ, which employs this noninvasive technology. For CI measurements we have shown it to be equivalent to thermodilution and to be more reproducible (variability: 6.3% vs. 24.7%). Physician assessment of CI and TFC (high, normal, or low) was compared to the BioZ monitor's results in 186 patients, considered to be hemodynamically unstable, from the emergency room, the intensive care units, and the floors. Normal values were defined for CI (2.5-4.2 L/min m(2)) and for TFC (males: 30-50 kohm(-1) and females: 21-37 kohm(-1)). The concordance between physician assessment and the BioZ was 51% for CI with Kappa of 0.14 and 58% for TFC with Kappa of 0.19. Attendings did slightly better than the surgical residents with CI (52% vs. 48%) but slightly worse with TFC (57% vs. 61%). The potentially serious conditions of low CI and high TFC were misdiagnosed 42% and 46% of the time, respectively, by all physicians. Analysis of the data revealed that physician use of clinically available objective hemodynamic data, such as heart rate, blood pressure, and pulse pressure index, would not have been helpful. Furthermore, assistance from the pulmonary artery catheter (PAC) is often not available in our hospital, which has experienced a 90% decrease in its utilization over the past six years. Considering the increasing acuity of our aging patient population, accurate assessment of cardiopulmonary status is needed. The use of ICG could be a valuable addition to the physician's armamentarium.

TFC (thoracic fluid content): a new parameter for assessment of changes in chest fluid volume.

Clinical assessment of cardiac status can be difficult and incomplete without an assessment of fluid volume status, especially of the lungs. Now, a new parameter is available, thoracic fluid content (TFC). It is an indicator of total fluid volume, both intracellular and extracellular. Because it is measured noninvasively using impedance cardiography (ICG), it could be a welcome addition to the physician's assessment. An evaluation of TFC was performed beginning with 1) an examination of chest impedance (Z) as an accurate means of following fluid changes, 2) the relationship of TFC to Z using both loop and spot electrodes, and 3) clinical applications of TFC. In 1) 12 dogs, Z was superior (r = 0.935, P < 0.006) to 10 traditional hemodynamic and gas transfer parameters in trending a lactated Ringer's infusion; 2) a plastic model, changes in TFC values derived from Z measurements using both loop and spot electrodes were virtually identical and paralleled infused saline (r = 0.999, P < 0.001); 3) the clinical setting, TFC trended fluid changes well. From these results, we conclude that TFC is a reliable measurement of chest fluid status and of changes in that fluid. Along with cardiac index (CI), also provided by the ICG monitor, TFC can be very helpful to the clinician.

The natural history of untreated penetrating diaphragm injury: an animal model.

BACKGROUND: Surgical repair of diaphragm injuries is rather straightforward, but diagnosis can be difficult. The natural history of diaphragm injury is quite controversial. Undoubtedly, many diaphragmatic injuries are missed at the initial evaluation. Some theories state that diaphragm injuries do not heal, and that all eventually lead to herniation. Current theories regarding uniform herniation of all diaphragm injuries are not supported by animal models. The authors developed a penetrating diaphragm injury model to study the natural history of this injury. METHODS: This study used 48 male Sprague-Dawley rats weighing 300-425 g. During the study, 24 of the rats received a 16-gauge needle puncture of the left diaphragm mimicking a small penetrating wound, whereas 24 of the rats received an injury produced with a 2.7-mm aortic punch, which created a defect comparable to a much larger penetrating wound. Half of the animals in each group were euthanized at 1 month, and the other half at 10 months. This allowed short- and long-term follow-up of the injuries. Gross inspection of the left diaphragm was performed after the animals were sacrificed via a thoracoabdominal incision. All diaphragms then were removed for examination. RESULTS: All the rats experienced perioperative recovery. None of the 24 rats with a 16-gauge needle injury had an injury at 1 month (n = 12) or 10 months (n = 12). No patent injury was noted in the aortic punch injury group (n = 12) sacrificed at 1 month. At 10 months, 1 of 12 animals had a small hepatic herniation through the aortic punch injury. All the injuries displayed adhesions to the underlying left hepatic lobe. CONCLUSIONS: The authors developed a penetrating diaphragm injury model to understand better the natural history of this injury. Spontaneous healing occurred in 98% of the animals. In this animal model, because the left lobe of the liver is present beneath the left diaphragm, healing without herniation usually occurs. A role may exist for nonoperative treatment of human right diaphragm injuries in clinical practice. This animal model may prove useful in further defining future management for these injuries.

Bedside insertion of vena cava filters in the intensive care unit using intravascular ultrasound to locate renal veins.

BACKGROUND: Historically, contrast venography has been used to determine renal vein location and assist with vena cava filter placement. This technique, however, exposes the patient to nephrotoxic contrast and radiation. For trauma patients in the intensive care unit (ICU), inferior vena cava filters should ideally be placed without contrast at the bedside to avoid nephrotoxic agents, radiation, and transport of a critically injured patient to the operating room or x-ray department. Previously, the authors have shown that intravascular ultrasound is a safe and accurate method for locating renal veins and assisting with vena cava filter placement. The purpose of this study was to evaluate bedside vena cava filter placement prospectively using only intravascular ultrasound for imaging. METHODS: Between August 2000 and July 2003, 29 patients met trauma service criteria for prophylactic or therapeutic placement of a vena cava filter. The 7 females and 22 males had a mean age of 51.3 years (range, 20-92 years), a mean height of 177 cm (range, 160-218.4 cm), a mean weight of 101.9 kg (range, 59.1-186.4 kg), and a body mass index of 33 (range, 14.7-56.1). Fifteen patients (55.5%) had a body mass index exceeding 30. The mean Injury Severity Score was 25.4 (range, 12-45). Intravascular ultrasound was the sole imaging method, and no contrast or fluoroscopy was used. All procedures were performed in the ICU by trauma surgeons. Data collection was prospective and included demographics, injuries, vena caval anatomy, length of procedure, complications, and follow-up radiographic confirmation of appropriate deployment. RESULTS: The location of the renal veins and vena cava diameter was imaged in all the patients. Three patients were noted to have accessory renal veins, and no patient had thrombus in the vena cava. The inferior vena cava diameter was less than 28 mm in all the patients, thus allowing standard filters to be deployed. Filter deployment was successful for all the patients. Of the 29 patients, 27 had abdominal computed tomography (CT) during their hospital stay. When the location of the renal veins identified by CT was compared with the level of the filter on abdominal x-ray, the filter tip was found to be at or below the level of the most caudal renal vein in 26 of the 27 patients (96.3%). In one patient, the filter tip was purposely placed 2 to 3 cm above an accessory caudal renal vein, but below the main right and left renal veins. The mean procedure time was 37.7 minutes (range, 12-86 minutes). No complications were associated with filter placement. CONCLUSIONS: Intravascular ultrasound is a safe and effective imaging method that may be used for the bedside placement of vena cava filters in the ICU. This technique avoids the use of nephrotoxic intravenous contrast and eliminates the risk of transporting a critically injured patient to the operating room or x-ray department.

Norepinephrine is a more potent inhibitor of tumor necrosis factor over a range of doses than dopamine.

In the current study, we test the hypothesis that norepinephrine has greater anti-inflammatory effects versus dopamine over a range of doses in a model of lipopolysaccharide (LPS)-stimulated cytokine release in human saphenous vein. Segments of saphenous vein were cut and separated into 1 mm x 1 mm squares and placed into two 24-well plates. These small segments of vessels were incubated in the presence of 20 microg/mL bacterial LPS, alone as a control or with 10x-6, 10x-5, 10x-4, 10x-3 concentration of dopamine or norepinephrine and LPS. The general linear models (GLM) statistical analysis for least squares means and adjustment for multiple comparisons was chosen to analyze the data. Both norepinephrine and dopamine were able to suppress the production of tumor necrosis factor (TNF) in a dose-dependent fashion. Over the range of doses, norepinephrine is a more potent inhibitor of TNF production than dopamine. This is a statistically significant linear trend (P < .0001). Both norepinephrine and dopamine are powerful anti-inflammatory agents. Norepinephrine is a more potent inhibitor of TNF than dopamine.

The first lung transplant.

On the occasion of the 40th anniversary of the first successful human lung transplant performed by Hardy et al., it seems prudent to review the preliminary research, the operative procedure, and the outcome of this significant operation. I have also attempted to establish the primacy of this operation for James Daniel Hardy.

Impact of a surgical oncologist on general surgery residency training program.

BACKGROUND: To assess the impact of adding a surgical oncologist to our faculty we examined the operative experience in our program before and after the addition. METHODS: Operative case numbers reported to the American Board of Surgery over a 10-year period were analyzed. This time period encompassed 5 years before and after the addition of a surgical oncologist to our faculty. All defined category case numbers were examined using t test analysis. Significance was defined as a P value of less than 0.05. RESULTS: The overall caseload increased in the time period after the faculty addition. There was a statistically significant increase in skin/soft tissue, breast, esophagus, small intestine, large intestine, live, spleen, and endocrine cases. No statistical significance was seen in head/neck, stomach, pancreas, and biliary cases. CONCLUSIONS: The addition of a surgical oncologist to our faculty coincides with a statistically significant increase in areas of skin/soft tissue, breast, esophagus, small intestine, large intestine, liver, spleen, and endocrine. Other areas not statistically significant may reflect referral patterns or this particular oncologist's preferences of practice.

Impedance cardiography: the next vital sign technology?

OBJECTIVE: To evaluate the following: (1) the intramethod variability of impedance cardiography (ICG) cardiac output (CO) measurements via the latest generation monitor and thermodilution CO measurements (CO-TDs); (2) the intermethod comparison of ICG CO and CO-TD; and (3) comparisons of the intergeneration ICG CO equation to CO-TD, using the latest ICG CO equation, the ZMARC (CO-ICG), and the predecessor equations for measuring the ICG CO of Kubicek (CO-K), Sramek (CO-S), and Sramek-Bernstein (CO-SB). DESIGN: Prospective study. SETTING: A cardiovascular-thoracic surgery ICU in a community university-affiliated hospital. PATIENTS: Post-coronary artery bypass graft patients (n = 53) in whom 210 pairs of CO measurements were made. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The CO-ICG was determined simultaneously while the nurse was performing the CO-TD. Variability within the monitoring method was better for CO-ICG compared to CO-TD (6.3% vs 24.7%, respectively). The correlation, bias, and precision of the CO-ICG was good compared to CO-TD (r(2) = 0.658; r = 0.811; bias, -0.17 L/min; precision, 1.09 L/min; CO-ICG = 1.00 x CO-TD - 0.17; p < 0.001). A steady improvement in agreement of the previous ICG methodologies compared to CO-TD was observed as follows: (1) CO-K: r(2) = 0.309; r = 0.556; bias, -1.71 L/min; precision, 1.81 L/min; CO-K = 0.78 x CO-TD - 0.45; p < 0.001; (2) CO-S: r(2) = 0.361; r = 0.601; bias, -1.46 L/min; precision, 1.63 L/min; CO-S = 0.80 x CO-TD - 0.36; p < 0.001; and (3) CO-SB: r(2) = 0.469; r = 0.685; bias, -0.77 L/min; precision, 1.69 L/min; CO-SB = 1.03 x CO-TD - 0.95; p < 0.001. The CO-ICG demonstrated the closest agreement to CO-TD. CONCLUSION: The latest ICG technology for determining CO (CO-ICG) is less variable and more reproducible in an intrapatient sense than is CO-TD, it is equivalent to the average accepted CO-TD in post-coronary artery bypass graft patients, and showed marked improvement in agreement with CO-TD compared to measurements made using previous generation ICG CO equations.

Ectopic thyroid.

Primary mediastinal ectopic goiters are very rare. We report a case in which an ectopic goiter with blood supply from the thoracic vessels necessitated a transternal approach for removal, resulting in a favorable outcome.

Champ Lyons: an incomplete life.

The life of Champ Lyons, MD, is presented, with emphasis on his tenure as Chairman of the Department of Surgery of the Medical College of Alabama (University of Alabama in Birmingham School of Medicine) from 1950 until 1965. Before becoming chairman Dr. Lyons, as an esteemed microbiologist, participated in the early use of penicillin in wounded servicemen during World War II. Later in his career, he made many contributions to the emerging disciplines of vascular and cardiac surgery. After a brief illness in 1965, Dr. Lyons expired due to a brain tumor. His relatively brief career and his unanticipated sudden demise have lessened the fame of Dr. Lyons to which he is justly entitled. It is the purpose of this presentation to reawaken the surgical community to the importance of this giant of American surgery.