Angie Vlahos

Surgical decompression of ductal obstruction in patients with chronic pancreatitis

BACKGROUND Recurrent acute pancreatitis often leads to chronic obstructive ductal disease requiring operative decompression. METHODS From 1983 through 1998, 124 patients with ductal obstruction underwent lateral pancreaticojejunostomy (78 patients), distal pancreatectomy with end-to-side pancreaticojejunostomy (27 patients), distal pancreatectomy with placement of a pancreas with a filleted duct within a jejunal limb (15 patients), or pancreaticoduodenectomy (4 patients). Preoperative symptoms included abdominal and back pain (99%), nausea with vomiting (99%), and diarrhea with weight loss (11%). Associated conditions included hypertension (20%) and diabetes mellitus (12%). Endoscopy in 106 patients demonstrated distal stricture (37%), proximal stricture (36%), pseudocyst (30%), chain of lakes (15%), calcification and debris (19%), and bile duct stricture (8%). RESULTS Two patients died, one of an unrecognized esophageal perforation during intubation and the other of leakage of a 1-layer pancreaticojejunostomy. Thirty-six patients developed 53 complications including intra-abdominal abscess (7 patients) and bleeding requiring reoperation in 1 patient. Pain relief was complete in 61 patients, substantial in 39 patients, moderate in 11 patients, minimal in 8 patients, and nonexistent in 3 patients with multiple stones and narrow duct. Ten patients died, with 6 deaths as a result of pancreatic cancer Two other patients may have died of pancreatic cancer. CONCLUSIONS Lateral pancreaticojejunostomy is the procedure of choice in most patients. Recurrent pancreatitis usually follows alcoholic binges. Long-term follow-up must assess for pancreatic cancer.

The effect of trauma program registry on reported mortality rates.

BACKGROUND This study assesses the relationship that the brand of trauma program registry (TPR) has on mortality rate (MR) in the reports prepared by the American College of Surgeons Committee on Trauma (ACSCOT) trauma center (TC) site surveyors. METHODS Data from 242 ACSCOT adult TC survey reports (88 Level I, 115 Level II, and 39 Level III) were analyzed for annual trauma volume, injury severity score (ISS), MR, and TPR. Six TPR (A through F) were identified; group F was a composite of several infrequently used TPRs. This report focuses on the ISS range 16-24 because of the likelihood that the mean for each TC would be near 20 and MR is high enough so that a difference, if present, could be statistically documented. RESULTS For the total group, MR showed no correlation with TC volume or TC level for ISS 16-24. MR was significantly different according to which TPR was used by the TCs. The MR is less (4.8%) for 14 high volume TCs (over 1200 admits) using TPR A compared with 33 low volume TCs (below 800 admits) using TPR A (6.34%). CONCLUSION The MR for ISS 16-24 in ACSCOT-surveyed TCs differs within subgroups based on type of TPR utilized. This may reflect improper use of the software programs. Enhanced skill in the application of software programs designed to generate ISS scores is essential if meaningful studies on the effects of improved trauma care on MR are to be conducted. Hand scored ISS by trained personnel may circumvent this problem.

Mathematical modeling to define optimum operating room staffing needs for trauma centers.

BACKGROUND Level II trauma centers may be verified (1999, American College of Surgeons Committee on Trauma) with an on-call operating room team if the performance-improvement program shows no adverse outcomes. Using queuing and simulation methodology, this study attempted to add a volume guideline. STUDY DESIGN Data from 72 previously verified trauma centers identified multiple demographic factors, including specific information about the first trauma-related operation that was done between 11:00 PM and 7:00 AM each month for 12 consecutive months. RESULTS The annual admissions averaged 1,477 for 37 Level I trauma centers, 802 for 28 Level II trauma centers, 481 for 4 Level III trauma centers, and 731 for 3 pediatric trauma centers. The annual admissions correlated with the number of operations done between 11:00 PM and 7:00 AM (p < 0.001). These 946 operations were performed by general surgery (39%), neurosurgery (8%), orthopaedic surgery (33%), another specialty (9%), or multiple services (10%). Admission to operation time was within 30 minutes for 12.1% of patients (2.6% for blunt and 24.1% for penetrating injuries). The probability of operation within 30 minutes of arrival varied with the number of admissions and with the percentage of penetrating versus blunt injuries. The likely number of operations from 11:00 PM to 7:00 AM would be 19 for 500 annual admissions, 26 for 750 annual admissions, and 34 for 1,000 annual admissions, with 5.83, 7.98, and 10.13 patients, respectively, going to operation within 30 min. The probability that two rooms would be occupied simultaneously was 0.14 and 0.24 for centers admitting 500 and 1,000 patients, respectively. CONCLUSIONS Trauma centers performing fewer than six operations between 11:00 PM and 7:00 AM per year could conserve resources by using an immediately available on-call team, with responses monitored by the performance-improvement program.

Neurosurgical trauma call: Use of a mathematical simulation program to define manpower needs

Resource criteria for trauma centers (TC) mandate a first plus backup neurosurgeon (NS) coverage, an unnecessary expense for TC treating few neurosurgery patients. This report uses a mathematical modeling system to define optimal NS trauma coverage. Random data from 749 patients treated with emergency neurosurgery operations (OR) within 24 hours of admission at 97 TC were used to create a 1-year profile of admission by month, day, and hour, operation times, and operation duration. These data were entered into a simulation program to define the frequency that a patient needing a NS consult would wait beyond 30 minutes because the NS was in the operating room at a trauma center with one, two, or three neurosurgeons on-call. One thousand iterations were done for each sample size of 25 to 300 patients in 25-patient increments. The probability that a patient could not be seen promptly by one NS in a trauma center operating on 25, 50, 75, or 100 patients per year is 0.23, 0.9, 1.6, and 3.66 patients per year. Fewer than one patient (0.75) per year will wait more than 30 min in a trauma center doing 225 emergency ORs when two neurosurgeons are on-call. One patient in 10 years would wait more than 30 min in a trauma center doing 300 ORs with a third NS on-call. Mathematical modeling of patient data helps define optimal hospital resources. Mandatory NS backup for TC performing fewer than 25 neurosurgery procedures is unneeded.

Inhibition of alpha-smooth muscle actin expression in an in vitro wound healing model by certain antibiotics

OBJECTIVE This study assesses the effects of antimicrobials on wound healing in an in vitro model of chicken flexor tendons in a collagen gel matrix. Two equidistant tendons were bathed in a culture medium for 28 days as fibroblasts (fb) grew from the tendon ends into the collagen gel and migrated toward each other until gap closure. Five groups of 10 paired tendons each included the control and the study groups, which received oxacillin (Ox), clindamycin (Cl), chloramphenicol (Chl), or tetracycline (Tet) in the culture medium to assess their effects on gap closure rate, fb migration, and myofibroblast alpha-smooth muscle (alpha-SM) actin expression. RESULTS Gap closure, by day 27, was 98.5% in the controls compared with 97%, 92%, 89.5%, 21.75% in the Tet, Cl, Ox, and Chl groups. Chl retarded gap closure (p < 0.05). Fb migration was similar for all groups. In the control and Ox groups, myofibroblast expressed actin at day 5. By day 7, fb cells were clearly visible in the control, Ox, and Cl groups, whereas, only light actin was present in the Chl and Tet groups. Actin band densities for the Cl, Ox, Tet, and Chl groups were 78.4%, 62.5%, 61.7% and 26.1%, respectively, of the control group. CONCLUSION These studies suggest that one reason certain antimicrobials impair wound healing, is due to myofibroblast inhibition of alpha-SM actin.

Simulation program for optimal orthopedic call: A modeling system for orthopedic surgical trauma call

This report uses a mathematical modeling system to define optimal orthopedic coverage for trauma centers. Data from 2,325 patients treated with emergency orthopedic operations within 24 hours of admission at 78 randomly sampled and at four totally sampled verified centers were used to create a profile of (1) admission by month, day, and hour; (2) operation times; and (3) operation duration. The reason for operation included (1) open fracture or crush (809 patients); (2) irreducible dislocations (164 patients); (3) fracture with vascular injury (seven patients); (4) dislocation with vascular injury (17 patients); (5) compartment syndrome (11 patients); (6) femoral neck fracture in young patients (36 patients); (7) combination of categories 1 to 6 (70 patients); (8) fracture with multiple injuries (171 patients); and (9) urgent not emergent (1,040 patients). The program defined the frequency that an injured patient needing an orthopedic consult would wait beyond 30 minutes because the orthopedic surgeon was doing a trauma related operation at a center with one or two orthopedic surgeons on call. The probability that a patient cannot be seen promptly by one orthopedic surgeon in a center doing 25, 50, 75, 100, 200, and 300 emergency procedures per year is 0.17, 0.74, 1.6, 3.1, 12.5, and 28 patients per year. When two are on call, 1.3 patients, yearly, will wait more than 30 minutes in a center doing 300 emergency procedures. Thus, mandatory orthopedic backup call for a trauma center performing fewer than 100 emergent trauma procedures within 24 hours is unwarranted.

Effects of physiologic albumin and hespan levels on hepatocytes in vitro.

BACKGROUND Although albumin and hydroxyethyl starch (HES) are routinely used in critically ill, hypoalbuminemic patients, no studies have tested the effect of supplemental albumin and HES on hepatocyte function. METHODS In this study, the effects of these agents were evaluated by using stable, rat hepatocyte cultures in a collagen sandwich configuration. Hepatocyte synthesis of albumin, urea, and intracellular triglycerides was monitored in Dulbeccos modified Eagle medium (supplemented with fetal bovine serum, hydrocortisone, L-proline, gentamycin, and insulin) without supplemental colloid (control cultures) and with supplemental 2% bovine serum albumin (BSA), 4% BSA, 2% HES, or 4% HES. RESULTS The albumin secretion in control cultures rose from 31.03 microg/day per 10(6) cells on day 3 to 154.17 microg/day per 10(6) cells by day 12 and remained constant. In contrast, the level of albumin synthesis in the 2% and 4% BSA groups rose from significantly higher initial values (p < 0.05) of 71.25 microg/day per 10(6) cells and 73.27 microg/day per 10(6) cells, respectively, to 127.61 microg/day per 10(6) cells and 107.95 microg/day per 10(6) cells by day 7, then declined rapidly to 58.98 microg/day per 10(6) cells and 41.28 microg/day per 10(6) cells by day 12 when cell disruption was present. HES also reduced albumin synthesis. The urea genesis in the control groups and in the treatment groups was found to be comparable throughout the study. The BSA supplemented groups accumulated large amounts of intracellular lipid droplets during the experiment. The intracellular triglycerides analysis found the 4% BSA group to be significantly (p < 0.05) higher than the 4% HES. CONCLUSION BSA, added to a collagen sandwich hepatocyte preparation, causes reduced hepatocyte synthesis by day 8, probably a result of intracellular triglyceride accumulation, whereas HES reduces synthesis through unidentified mechanisms.