Randomized clinical trial of liposomal bupivacaine transverse abdominis plane block versus intrathecal analgesia in colorectal surgery

Background

Transverse abdominis plane (TAP) block is considered an effective alternative to neuraxial analgesia for abdominal surgery. However, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. This study compared the analgesic efficacy of liposomal bupivacaine TAP block with intrathecal (IT) opioid administration in a multicentre RCT.

Methods

Patients undergoing elective small bowel or colorectal resection were randomized to receive TAP block or a single injection of IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24 and 48 h after surgery. Primary outcomes were mean pain scores and morphine milligram equivalents (MMEs) administered within 48 h after surgery. Secondary outcomes included duration of hospital stay, incidence of postoperative ileus and use of intravenous patient-controlled analgesia.

Results

In total, 209 patients were recruited and 200 completed the trial (TAP 102, IT 98). The TAP group had a 1·6-point greater mean pain score than the IT group at 4 h after surgery, and this difference lasted for 16 h after operation. The TAP group received more MMEs within the first 24 h after surgery than the IT group (median difference in MMEs 10·0, 95 per cent c.i. 3·0 to 20·5). There were no differences in MME use at 24 and 48 h, or with respect to secondary outcomes.

Conclusion

IT opioid administration provided better immediate postoperative pain control than TAP block. Both modalities resulted in low pain scores in patients undergoing elective colorectal surgery and should be considered in multimodal postoperative analgesic plans. Registration number: NCT02356198 ( http://www.clinicaltrials.gov).

Do pre-existing complications affect the failure to rescue quality measures?

BACKGROUND

A project sponsored by the University Health System Consortium has addressed the inaccuracy and high variability across institutions concerning the use of the failure to rescue (FTR) quality indicator defined by the Agency for Healthcare Research and Quality (AHRQ). Results indicated that of the complications identified by the quality indicator, 29.5% were pre-existing upon hospital admission.

OBJECTIVE

The purpose of our study was to investigate the possible bias to FTR measures by including cases of complications that were pre-existing at admission.

METHODS

Hospital discharges between 1 January 1996 and 30 September 2007 were retrospectively gathered from administrative databases. Using definitions outlined by the AHRQ and the National Quality Forum (NQF), FTR rates were calculated. Using present on admission coding, FTR rates were recalculated to differentiate between the rates of pre-existing and that of acquired cases.

RESULTS

Using the AHRQ definition, the overall FTR rate was 11.60%. The FTR rate for patients with pre-existing complications was 8.85%, whereas patients with complications acquired during hospitalisation had an FTR rate of 18.46% (p<0.001). The NQF FTR rate was 9.93%. Pre-existing and acquired FTR rates using the NQF measure were 9.42% and 12.77%, respectively (p<0.001).

CONCLUSIONS

Current definitions of FTR measures meant to identify inhospital complications appear biased by the inclusion of problems at admission. Furthermore, many patients with these complications are excluded from the algorithms. When taking into account the timing of the "complications", these measures can be useful for internal quality control. However, it should be stressed that the usefulness of the measures to compare institutions will be dependent on coding practices of institutions. Validation using chart review may be required.

Medication reconciliation in ambulatory care: attempts at improvement

OBJECTIVE

To enhance overall accuracy of medication lists by providing performance feedback and training to the healthcare team and increasing patient participation in the medication reconciliation process.

METHODS

This prospective study involved patients seen in four academic, ambulatory primary care internal medicine clinics. Before the interventions, baseline data were analysed, assessing completeness, correctness and accuracy of medication documentation in the electronic medical record. Interventions to provide performance feedback and training to the healthcare team, increase patient awareness and participation in the medication reconciliation process were implemented. Immediately after each intervention, a data collection was undertaken to assess the effectiveness of the intervention on the accuracy of individual medications and medication lists.

RESULTS

Completeness of medication lists improved from 20.4% to 50.4% (p<0.001). The incomplete documentation of medication lists was mostly because of lack of frequency (15.4%) and route (8.9%) for individual medications within a medication list. Correctness of medication lists improved from 23.1% to 37.7% (p = 0.087). The incorrectness in a medication list was mostly because of incorrect medications dose. Patient participation in the medication reconciliation process increased from 13.9% to 33% (p<0.001). The medication list accuracy improved from 11.5% to 29% (p = 0.014).

CONCLUSION

In this setting, it was helpful to engage the active participation of all members of the healthcare team and most importantly the patient to improve the accuracy of medication lists.

Screening mammogram utilization in women with diabetes

OBJECTIVE

To determine whether women with diabetes undergo fewer screening mammograms than matched control subjects.

RESEARCH DESIGN AND METHODS

A total of 424 women with diabetes aged 50-75 years who received their primary care from general internists at a large Midwestern multispecialty group practice were retrospectively studied for frequency of mammography from August 1997 to January 2000. Two control subjects without diabetes (n = 845) were matched to each case by age, sex, provider, and date of visit. The main outcome measure was the percentage of subjects undergoing mammography 1 year before and 30 days after an index date, defined as the most recent health care visit after August 1997 and before January 2000.

RESULTS

Analysis by conditional logistic regression demonstrated that women with diabetes had significantly lower rates of mammograms than control subjects (78.1 vs. 84.9%, respectively; odds ratio 0.63, P = 0.002). After adjusting for insurance status and race, women with diabetes continued to have significantly lower rates of mammography (odds ratio 0.70, P = 0.027).

CONCLUSIONS

Women with diabetes were significantly less likely to undergo screening mammography than control subjects. Considering the increasing incidence of diabetes and the equal incidence of malignancy in women with and without diabetes, it would be beneficial to improve breast cancer screening in this population.

Improving hypertension control: a team approach in a primary care setting

BACKGROUND

Blood pressure (BP) control rates in the United States have not improved significantly during the past decade. There has been limited study of improvement efforts focusing on guideline implementation and changes in the model of care to address hypertension.

METHODS

Five physician (MD)/registered nurse (RN)/licensed practical nurse (LPN) teams in a large community practice modified their care model in 1997 to manage hypertensive patients as part of guideline implementation efforts. The other 25 MD teams in the same setting practiced in the usual model, but were exposed to the guideline recommendations. BP control rates of patients in each group were assessed monthly. After nine months of testing the new care model, 10 additional teams adopted the model.

RESULTS

In the pilot group, hypertension control rates showed statistically significant improvement from pre- (33.1%) to postimplementation (49.7%). After adjusting for age, this was significantly greater than the improvement in the control group (p = 0.033). Medication changes were more frequent in the pilot group (32.3%) than in the control group (27.6%); however, the differences were not statistically significant. A longitudinal examination of the hypertension patients in the study showed that improved BP control was sustained for at least 12 months.

DISCUSSION

A change in the model of care for hypertensive patients within a primary care practice resulted in significant, sustainable improvement in BP control rates. These changes are consistent with the chronic care model developed by Wagner; practice redesign appeared to be the most important change.

Improving performance in diabetes care: a multicomponent intervention

CONTEXT

Compliance with recommendations from the American Diabetes Association for management of patients with diabetes is not optimal. Changing physician practice patterns with provider-focused interventions can be difficult. We report results after implementation of a type 2 diabetes mellitus guideline.

OBJECTIVE

To increase the annual rate of microalbumin/urine protein testing, dilated eye examinations, and foot examinations for patients with diabetes and to reduce overall levels of hemoglobin A1c (Hb A1c).

DESIGN

Before-after study.

INTERVENTION

From April 1996 to June 1998, a guideline on type 2 diabetes mellitus was implemented with multicomponent interventions. These included small group educational sessions led by opinion leaders, an electronic version of the guideline, audit with feedback, and enhanced clinical orders support. Medical records of random samples of patients with diabetes were audited for specific diabetes performance measures on a monthly basis. Baseline data were compared with results at the end of the implementation effort.

SETTING

Southeastern Minnesota, excluding Olmsted County.

PARTICIPANTS

Adult patients seen at one practice of 18 general internists.

OUTCOME MEASURES

Outcome measures included Hb A1c values and annual performance of a urine protein test, foot examination, and dilated eye examination.

RESULTS

Gradual, sustained; and statistically significant improvements in the three annual performance measures were observed. Urine protein testing increased from 24% to 66% (P = 0.001), dilated eye examinations increased from 63% to 84% (P = 0.001), and foot examinations increased from 86% to 97% (P = 0.001). Mean Hb A1c values +/- SD also improved from 7.8% +/- 1.0% to 7.1% +/- 0.7% (P < 0.001) in patients who received continuing care for diabetes.

CONCLUSIONS

Statistically significant improvements were observed after continuous improvement efforts were focused on providers in an individual group practice. When used to implement a diabetes guideline, such interventions may improve delivery of services and reduce Hb A1c levels in patients with diabetes.

Busy physicians and preventive services for adults

OBJECTIVE

To study the relationship between overall productivity and the rates at which primary care physicians, in a fee-for-service setting, deliver or prescribe preventive services to adult patients.

PATIENTS AND METHODS

The charts of 452 adult patients treated by 8 family practitioners and 5 internists in a fee-for-service practice setting were randomly selected and abstracted for provision of 10 preventive services over a 27-month period. The percentage of eligible patients screened for each service was correlated with the production of each physician measured in relative value units (RVUs).

RESULTS

The correlation coefficient between RVUs and the aggregate of the 10 services was 0.23 (95% confidence interval [CI], -0.36 to 0.70). The individual correlation coefficients between RVUs and 9 of the 10 preventive services ranged from -0.05 to 0.43. For cervical cancer screening, however, the correlation coefficient was -0.72 (95% CI, -0.91 to -0.24).

CONCLUSION

With the exception of screening for cervical cancer, the data presented in this study do little to support physicians' common belief that lack of time is the reason they are unable to incorporate prevention strategies into their clinical practice.

Traumatic brain injury and time to onset of Alzheimer's disease: a population-based study

Controversy continues as to whether traumatic brain injury is a risk factor for Alzheimer's disease. The authors examined a related hypothesis that among persons with traumatic brain injury who develop Alzheimer's disease, time to onset of the disease is reduced. They used data on all documented episodes of traumatic brain injury that occurred from 1935 to 1984 among Olmsted County, Minnesota, residents. Community-based medical records were used to follow traumatic brain injury cases who were aged 40 years or older at last contact prior to June 1, 1988, for Alzheimer's disease until last contact, death, or June 1, 1988. The test of the hypothesis was restricted to those cases who developed Alzheimer's disease. The expected time to onset of Alzheimer's disease was derived from a life table constructed by using age-of-onset distributions within sex groups for a previously identified cohort of Rochester, Minnesota, Alzheimer's disease incidence cases without a history of head trauma. The authors found that of the 1,283 traumatic brain injury cases followed, 31 developed Alzheimer's disease, a number similar to that expected (standardized incidence ratio = 1.2, 95% confidence interval 0.8-1.7). However, the observed time from traumatic brain injury to Alzheimer's disease was less than the expected time to onset of Alzheimer's disease (median = 10 vs. 18 years, p = 0.015). The results suggest that traumatic brain injury reduces the time to onset of Alzheimer's disease among persons at risk of developing the disease.

Impact of a diabetes electronic management system on the care of patients seen in a subspecialty diabetes clinic

OBJECTIVE

To compare the compliance with diabetes care performance indicators by diabetes specialists using a diabetes electronic management system (DEMS) and by those using the traditional paper medical record.

RESEARCH DESIGN AND METHODS

A DEMS has been gradually introduced into our subspecialty practice for diabetes care. To assess the value of this DEMS as a disease management tool, we completed a retrospective review of the medical records of 82 randomly selected patients attending a subspecialty diabetes clinic (DC) during the first quarter of 1996. Eligible patients were defined by the suggested criteria from the American Diabetes Association Provider Recognition Program. During the first quarter of 1996, approximately one half of the providers began using the DEMS for some but not all of their patient encounters. Neither abstractors nor providers were aware of the intent to examine performance in relationship to use of the DEMS.

RESULTS

Several measures were positively influenced when providers used the DEMS. The number of foot examinations, the number of blood pressure readings, and a weighted criterion score were greater (P < 0.01) for providers using the DEMS. There was evidence, although not statistically significant, for lower mean diastolic blood pressures (P = 0.043) in patients and for number of glycated hemoglobins documented (P = 0.018) by users of the DEMS.

CONCLUSIONS

Performance and documentation of the process of care for patients with diabetes in a subspecialty clinic are greater with the use of a DEMS than with the traditional paper record.

Acute treatment of periodic severe headache: comparison of three outpatient care facilities

We compared treatment of patients with episodic, severe, migraine-vascular headaches in three outpatient settings associated with a major medical center: the Charlton Outpatient Therapy Center (COTC), a dedicated transfusion and injection facility which provides treatment based on physician orders written in advance of the patient's visit; a walk-in Urgent Care Center (UCC); and a traditional hospital emergency trauma unit (ETU). For a 7-month period in 1995, all patient visits for acute migraine headache to the COTC, UCC, and ETU were reviewed. Data collected included the treatment and charges. After the study period, a sample of patients was surveyed regarding their outcome and satisfaction with care at each of the three facilities. During the study period, 15 patients visited the COTC 446 times for the treatment of acute migraine, 80 patients visited the UCC 233 times, and 182 patients visited the ETU 238 times. The average charges per visit were $39.93 for the COTC, $57.28 for the UCC, and $317.71 for the ETU. Average time spent in order to obtain care was 35 minutes in the COTC, 62 minutes in the UCC, and 105 minutes in the ETU. Intramuscular meperidine with either promethazine or hydroxyzine was the most commonly administered treatment in all three settings. Patients treated in the COTC reported greater satisfaction than the patients seen in the UCC or ETU. A dedicated outpatient facility with extended hours of operation and the capability of treating acute headache patients with parenteral medications based on standing orders has provided a community of migraine sufferers with cost-effective care.

Determinants of the autopsy decision: a statistical analysis

Our goal was to use cross-sectional national mortality data to provide a multivariable statistical analysis of the factors that contribute to the decision of whether an autopsy will be performed. The identification of determinants of the autopsy is an important prerequisite for finding cost-effective alternatives for arresting or reversing the decline of autopsy rates in the circumstances in which the autopsy can continue to make a crucial contribution to clinical medicine and public health. The source of the data was 1986 National Center for Health Statistics (Washington, DC) mortality data tapes for Kentucky, Maryland, Minnesota, and Washington for the 1986 calendar year. Separate multiple logistic regressions were conducted on these data on a state-by-state basis, with a total of 139,063 individual mortality records as the unit of analysis. The dependent variable in all models was autopsy (yes/no). Odds ratios for selected explanatory variables were estimated for all four states, and the relative contribution of each explanatory variable was studied in a detailed analysis of one state. In general, the following independent variables had a statistically significant positive relationship with whether an autopsy will be performed: male sex; nonwhite ethnicity; death due to ill-defined or unknown cause; death due to accident, suicide, or homicide; presence of a nationally recognized medical center in the county of death; and death occurring in a standard metropolitan statistical area. In general, the following independent variables had a statistically significant negative relationship with whether an autopsy will be performed: older age at death; higher income level of the decedent; death in a nursing home; death at home; and residency in the county of death. The two most important variables influencing the autopsy decision were age at death (especially old age) and death due to accident, homicide, or suicide.

The Mayo Ventilator-Dependent Rehabilitation Unit: a 5-year experience

OBJECTIVE

To describe the outcomes of 206 patients admitted to the Mayo Ventilator-Dependent Rehabilitation Unit (VDRU) during a 5-year study period.

DESIGN

We analyze the patient data for 1990 through 1994, which had been prospectively entered into a computer database for a cohort of 206 patients who had become ventilator dependent during their current hospitalization.

MATERIAL AND METHODS

Patients in the VDRU were classified into one of six categories that reflected the reasons for ventilator dependence. Ability to be weaned from mechanical ventilation, duration of hospital stay and ventilator dependence, outcome, disposition, demographics, and long-term survival were analyzed. The VDRU patient group was compared for hospital and follow-up outcomes with a group of historical control patients previously described by us.

RESULTS

The Mayo VDRU was established in January 1990. During the first 5 years of its operation, 206 newly ventilator-dependent patients were admitted to the VDRU, 190 (92%) of whom survived to be dismissed; 16 patients (8%) died in the hospital. Of the 190 patients dismissed, 77% were able to return to their homes. Overall, 153 patients were liberated from mechanical ventilation, whereas 37 remained either completely or partially ventilator dependent. Of these 37 patients, 27 (73%) were receiving nocturnal mechanical ventilation only. The 4-year survival was 53%.

CONCLUSION

The Mayo VDRU has been highly successful in liberating newly ventilator-dependent patients from mechanical ventilation. The long-term survival after management in the VDRU has been excellent. In addition, the medical charges for care in the VDRU are less than intensive-care unit charges.

Effect of feedback on resource use and morbidity in hip and knee arthroplasty in an integrated group practice setting

OBJECTIVE

To assess the effect of a structured program of feedback about resource utilization and morbidity on resource consumption and complications in an orthopedic surgical practice.

DESIGN

We prospectively analyzed use and outcomes before and after an intervention (departmental data presentation).

MATERIAL AND METHODS

Feedback on resource utilization and morbidity for 2,820 patients who underwent a primary total hip or knee arthroplasty for a diagnosis of osteoarthritis between Jan. 1, 1990, and Dec. 31, 1992, was provided to members of the orthopedic department of an academic medical center. Data were adjusted for severity of disease.

RESULTS

On reassessment 18 months after the beginning of the feedback program, total charges and length of hospital stay for hip or knee arthroplasty were significantly reduced. Interpractitioner variability was also reduced but not significantly. The feedback process was instrumental in identifying a specific complication--pulmonary embolism after bilateral total knee replacement--which was significantly reduced by addition of warfarin prophylaxis.

CONCLUSION

The intervention was successful in reducing resource use (length of hospital stay) and complications (pulmonary embolism). In addition, total charges for hip and knee arthroplasty declined significantly at a time when medical center charges overall were increasing. Efforts to maintain continuous improvement will primarily focus on the development of critical pathways.

Value of autonomic testing in reflex sympathetic dystrophy

OBJECTIVE

To attempt to characterize reflex sympathetic dystrophy (RSD) and to determine factors that would predict a response to sympathetic block.

DESIGN

We undertook a retrospective analysis on 396 patients with chronic limb pain referred for autonomic testing during a 5-year period.

MATERIAL AND METHODS

Clinical endpoints were relief of pain after sympathetic block and a composite RSD diagnostic probability score, based on the clinical attributes of allodynia, protopathia, swelling, and vasomotor alterations. We compared the results of three autonomic tests--resting sweat output (RSO), resting skin temperature (RST), and quantitative sudomotor axon reflex test (QSART).

RESULTS

Increased RSO predicted the diagnosis of RSD with 94% specificity, and the specificity was 98% when RSO was considered in conjunction with an abnormal QSART result, the best laboratory correlate (P = 0.003) of the clinical diagnosis. Shorter duration of pain correlated with a warmer limb (P < 0.001), even in the absence of RSD. Response to a single sympathetic block did correlate with the diagnosis (P = 0.031) but correlated most significantly with short duration of pain in the arm (P = 0.001) and laboratory findings in the leg, where increased RST (P < 0.001) and QSART (P < 0.001) were near-perfect predictors of response.

CONCLUSION

Sweating abnormalities correlate strongly with the clinical syndrome of RSD, and alterations in RST may be superior to clinical findings in predicting the response to sympathetic block. The findings provide physiologic support for the unproven view of a natural disease progression ("stages"), with better treatment response and a warmer extremity initially. Because certain physiologic trends occur in all patients, general alterations of autonomic function with pain are suggested.

Outcome of patients cared for in a ventilator-dependent unit in a general hospital

We describe our initial experience with the admission of 129 patients for 132 episodes of ventilator-dependence to a self-contained ventilator-dependent unit (VDU) in a general hospital and present a survival comparison between VDU patients and a historic control population from the same institution. Forty-three patients were screened and denied admission to the VDU because long-term ventilator dependence was not felt to be a probable outcome (56%); they were medically unstable, often requiring electrocardiographic monitoring (19%), they had poor rehabilitation potential because of markedly depressed mental status (13%), or they preferred to be treated closer to their homes (12%). Thirteen (9.8%) of the VDU patients died in the hospital compared to 44 (42%) in the historic control group. After exclusion of patients with multiorgan failure (who made up 26% of the control group) and using a proportional hazard model to adjust for group differences in age and disease class, the difference in hospital mortality remained highly significant (p < or = 0.01). Ninety-one of the 119 VDU patients (77%) were ultimately able to return home; 16 (13%) continued to use a ventilator intermittently at night; 26 patients (22%) were permanently placed in nursing homes, all off of the ventilator. Overall, 88% of the 119 patients discharged had been liberated from mechanical ventilation. Ninety-seven (82%) and 86 (72%) remain alive 1 and 2 years after discharge, respectively. Some of the survival benefits may be directly attributed to the VDU. Others reflect a change in treatment philosophy, which was nevertheless reinforced by our VDU experience.

Accuracy of hospital discharge abstracts for identifying stroke

BACKGROUND AND PURPOSE

Much of the available data on stroke occurrence, service use, and cost of care originated with hospital discharge abstracts. This article uses the unique resources of the Rochester Epidemiology Project to estimate the sensitivity and positive predictive value of hospital discharge abstracts for incident stroke.

METHODS

The Rochester Stroke Registry was used to identify all confirmed first strokes (hospitalized and nonhospitalized) among Rochester residents for 1970, 1980, 1984, and 1989 (n = 364). The sensitivity of discharge abstracts was estimated by following these individuals for 12 months after stroke to determine the proportion assigned a discharge diagnosis of cerebrovascular disease (International Classification of Diseases [ICD] codes 430 through 438.9). The positive predictive value of discharge abstracts was assessed by identifying all hospitalizations of Rochester residents with an ICD code of 430-438.9 in 1970, 1980, and 1989 (n = 377). Events were categorized as incident stroke, recurrent stroke, stroke sequelae, or nonstroke after review of the complete community-based medical record by a neurologist.

RESULTS

Only 86% (n = 313) of all first-stroke patients in 1970, 1980, 1984, and 1989 were hospitalized. Of hospitalized patients, only 76% were assigned a principal discharge diagnosis code of 430-438.9. Fatal strokes and those occurring during a hospitalization were less likely to be identified. Among all hospitalizations of Rochester residents in 1970, 1980, and 1989, there were 377 with a principal diagnosis code of 430-438.9. Less than half (n = 177) were determined by the neurologist to be incident stroke; only 60% (n = 225) were either incident or recurrent stroke. Comparison of alternative approaches showed the validity of discharge abstracts was enhanced by increasing the number of diagnoses and excluding codes with poor positive predictive value.

CONCLUSIONS

This study provides previously unavailable estimates of the sensitivity of stroke-coded hospitalizations for a US community. A model for improving the sensitivity and positive predictive value of discharge abstracts is presented.

Microscope-aided pedal bypass is an effective and low-risk operation to salvage the ischemic foot

BACKGROUND

The aim of this study was to determine the current operative risks of the pedal bypass procedure, its durability, and the factors affecting long-term outcome.

METHODS

We prospectively observed 96 patients who consecutively underwent 100 pedal bypasses using autogenous vein grafts for chronic critical ischemia. Of the 100 limbs, 91 had ischemic ulcers or gangrene, and 9 produced rest pain only. Sixty-four patients were diabetic, 21 had renal failure, and 36 had coronary artery disease. Nonreversed saphenous vein grafts were used most frequently (68 translocated, 13 in situ), followed by composite (13) and reversed vein grafts (6). Fifty-two long grafts originated from the iliac or femoral arteries, and 48 short grafts originated from the popliteal or tibial arteries. For the 100 procedures, 102 distal anastomoses were performed--68 to the dorsalis pedis, 8 to the distal posterior tibial, 10 to the common plantar, 2 to the medial plantar, 9 to the lateral plantar, 4 to the lateral tarsal, and 1 to the first dorsal metatarsal arteries--with the aid of an operating microscope.

RESULTS

No patient died during the perioperative period. Two had hemodynamically insignificant myocardial infarctions. Wound complications developed in 12 patients--infection in 7 and hematoma in 5. There were 10 early graft failures, 6 of which could be salvaged, and 96 grafts were patent at dismissal. Mean follow-up was 2.1 years (range 1 month to 6.4 years). Postoperative surveillance identified 33 failed or failing grafts, 16 of which were successfully revised. At 3 years, cumulative primary and secondary patency rates were 60% and 69%, respectively. Factors correlating with increased secondary patency were intraoperative flow rate > or = 50 mL/min (P = 0.004) and diabetes (P < 0.05). Major amputations were performed on 17 limbs. The cumulative foot salvage rate at 3 years was 79%.

CONCLUSION

Pedal bypass is a safe, effective, and durable procedure. It should be considered even for high-risk patients with critical limb ischemia before major amputation is contemplated.

Pseudomyxoma peritonei. Long-term patient survival with an aggressive regional approach

OBJECTIVE

The aims of this study were to analyze the natural history of patients with pseudomyxoma peritonei (PMP), evaluate clinical and pathologic variables as prognostic indicators, and review the authors' experience with different treatments.

SUMMARY BACKGROUND DATA

PMP is an unusual form of intra-abdominal neoplasm that presents with large amounts of extracellular mucin. Diffuse peritoneal spread occurs in most patients with PMP, and distant metastasis is infrequent. Debulking surgery, radiation therapy (radioisotope and external beam), and chemotherapy (both intraperitoneal and systemic) have all been advocated for optional patient management, but the variability of patients studied, the small patient numbers, and the prolonged course of this disease make the evaluation of results difficult.

METHODS

Fifty-six patients were treated for PMP at the Mayo Clinic between 1957 and 1983. The data were collected retrospectively. Univariate (log-rank test) and multivariate (Cox regression model) analyses were performed for disease recurrence and patient survival.

RESULTS

Most patients with PMP had carcinomas of the appendix (52%) or ovary (34%). All gross tumor could be removed only in the 34% of patients with limited disease. Although tumor progression occurred in 76% of patients, the 1-, 5-, and 10-year survival rates were 98%, 53%, and 32%, respectively. Adverse predictors of patient survival included weight loss (p = 0.001), abdominal distention (p = 0.004), use of systemic chemotherapy (p = 0.005), diffuse disease (p = 0.038), and invasion of other organs (p = 0.04). Intraperitoneal chemotherapy (p = 0.009) and radioisotopes (p = 0.0043) both were effective in prolonging the recurrence time of symptomatic PMP.

CONCLUSIONS

Although PMP is an indolent disease, aggressive surgical debulking followed by intraperitoneal radioisotopes and/or chemotherapy should be considered because of the diffuse peritoneal involvement.

Popliteal artery aneurysms: the risk of nonoperative management

To evaluate the risk of nonoperative management of popliteal artery aneurysms (PAAs), a retrospective cohort study of 106 consecutive patients (103 males and 3 females) with PAAs seen between January 1, 1980, and December 31, 1985, was performed. The mean age was 70.5 years (range 50 to 90 years). The 106 patients with 161 PAAs were followed for a mean of 6.7 years (range 3 days to 12.1 years). Follow-up was complete in 91.5% (97/106) of the patients. PAA was confirmed by ultrasonography in 124 limbs (77%), arteriography only in 7 (4.3%), and physical examination only in 32 (19.9%). Fifteen limbs presented with acute symptoms, 52 with chronic symptoms, and 94 were asymptomatic. Five of the 15 limbs with acute symptoms (33%) underwent amputation (4 primary, 1 secondary). PAAs in 23 of the 52 limbs with chronic symptoms were repaired; 2 limbs required amputation (8.7%). Twenty-seven of the 94 asymptomatic limbs were repaired initially; 1 required amputation (3.7%). The remaining 67 asymptomatic limbs were initially managed nonoperatively. Amputation was required in 3 of 67 limbs (4.4%), 1 with acute symptoms and 2 with chronic symptoms, all of which had undergone attempted repair. Symptoms (3 acute, 9 chronic) eventually developed in 12 (17.9%). At least one of three risk factors (size > 2 cm, thrombus, and poor runoff) was initially present in 11 of 12 limbs (91.7%) compared with 9 of 24 control limbs (37.5%) that remained asymptomatic (p < 0.05). Amputation rates in symptomatic patients with PAAs continues to be high. In patients with asymptomatic PAAs, aneurysm size > 2 cm, thrombus, or poor runoff predicted the development of symptoms. PAA patients with any of these factors should undergo elective repair, even asymptomatic patients who have a reasonable chance for long-term survival.

Doppler hemodynamic profiles of 82 clinically and echocardiographically normal tricuspid valve prostheses

BACKGROUND

Normal Doppler hemodynamics for tricuspid prostheses have not been well characterized in a large group of patients. Therefore, we analyzed comprehensive Doppler echocardiographic examinations of 82 patients with tricuspid prostheses that were normal by clinical and two-dimensional echocardiographic examinations to establish the normal hemodynamics of various types and sizes of tricuspid prostheses.

METHODS AND RESULTS

The earliest complete postoperative echocardiographic study from each patient was chosen for analysis. Doppler examinations were analyzed on an off-line station from tapes or Doppler strip charts. Early velocity, atrial velocity, end-diastolic velocity, pressure half-time, and mean gradient were obtained by digitizing tricuspid velocity curves. The incidence of "physiological" tricuspid prosthetic regurgitation was noted. Ten Doppler cycles were measured for each patient, and maximal, minimal, and average measurements were recorded. The mean values +/- SD of early velocity, atrial velocity, end-diastolic velocity, mean gradient, and pressure half-time and incidence of mild prosthetic regurgitation were reported for each type of prosthesis, as were highest Doppler measurements for each valve type. Average pressure half-time was significantly lower for St Jude than for heterograft prostheses (P = .04). There were no significant differences between the valve types for mean gradient, early velocity, or incidence of prosthetic regurgitation. Increasing prosthesis size was associated with lower average pressure half-time for heterograft prostheses (P = .024). Average differences (respiratory- and cycle-length-dependent) between maximal and minimal values for 10 cardiac cycles were established for each prosthesis.

CONCLUSIONS

This study establishes normal ranges for Doppler hemodynamics of various tricuspid prostheses and emphasizes the importance of measuring multiple cycles for each tricuspid prosthesis, regardless of cardiac rhythm.

A 50-year experience of male breast cancer: is outcome changing?

During the period 1933-1983, 124 men (median age 62.5 years, range 33-86 years) were treated for breast carcinoma. Median length of follow-up was 6.7 years and was complete for 93% of patients. Presenting complaints were most frequently a mass (95%) or pain (31%) while physical examination revealed the tumour to be central in 95% of patients with nipple or skin retraction in 36% and associated gynaecomastia in 12%. Twenty-seven per cent of the patients had a positive family history of breast cancer, 6% noted previous breast trauma and 7% had prior chest wall irradiation. Mean tumour size was 2.5 cm, and the pathological stage was 0 in 3%, I in 17%, II in 22%, III in 35%, IV in 11%, and unknown in 12%. Ninety-four per cent were ductal carcinoma. Histological grading of tumours was 2% grade 1, 10% grade 2, 33% grade 3 and 48% grade 4. Ninety-two per cent of patients underwent mastectomy (41% radical, 39% modified radical and 12% simple), while adjuvant irradiation was used in 44% and chemotherapy in 9%. Median disease-free patient survival was 5 years (36% of patients developed tumour recurrence). Median overall patient survival was 6.3 years (57% at 5 years and 31% at 10 years). Tumour size (P < 0.05), pathological stage (P < 0.04), and tumour grade (P = 0.007) were adverse factors for recurrence, while pathological stage (P < 0.02), tumour size (P < 0.03), pain (P < 0.05) and age (P < 0.02) were associated with a decreased survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive evaluation of the lymphatic system with lymphoscintigraphy: a prospective, semiquantitative analysis in 386 extremities

PURPOSE

Lymphoscintigraphy has emerged as the diagnostic test of choice in patients with suspected lymphedema. To assess the lymphatic circulation of 386 extremities in 188 patients, we prospectively recorded a semiquantitative index of lymphatic transport in addition to visual evaluation of lymphoscintigraphy image patterns.

METHODS

Sixty-one male and 127 female patients were studied (mean age 48 years, range 13 to 87 years). Twenty had upper extremity swelling, and 168 had lower extremity swelling. The disease was bilateral in 60 patients. Lymphoscintigraphy was performed by injecting a mean of 503 microCi of technetium 99m-antimony trisulfide colloid subcutaneously into the second interdigital space of the extremity. Time for transport to regional lymph nodes, appearance of lymph vessels and nodes and distribution pattern were scored. These scores were compiled into a modified Kleinhans transport index (TI). To assess the venous circulation, 155 patients underwent evaluation of the venous system by impedance plethysmography, ultrasonography, or contrast venography.

RESULTS

The mean TI (+/- SEM) in 79 asymptomatic extremities was 2.6 +/- 0.5, with 66 (83.5%) demonstrating normal lymphoscintigraphy pattern (TI < 5). Patients with clinical diagnosis of lymphedema (n = 124) had a mean TI of 23.8 +/- 1.5; 81.5% of these were greater than 5. Fifty-six patients (30%) had primary and 68 (36%) had secondary lymphedema. (TI of 26 +/- 3.5 and 22.1 +/- 1.9, respectively, p = NS). Patients without any lymphatic transport (TI of 45) were more likely to have cellulitis in their history (p < 0.05). Contrast lymphangiography in six patients correlated with lymphoscintigraphy. Sixty-four patients (34%) had swelling without lymphedema (venous edema, cardiac edema, lipedema, etc.; TI of 1.9 +/- 0.4, p < 0.001). Of the 41 patients with abnormal venous studies, 18 (44%) had an elevated TI.

CONCLUSIONS

Semiquantitative evaluation of the lymphatic transport with lymphoscintigraphy reliably depicts abnormalities in the lymphatic circulation. Lymphoscintigraphy excluded lymphedema as a cause of leg swelling in one third of our patients.

A study of various tests to detect asymptomatic urinary tract infections in an obstetric population

OBJECTIVE

To compare rapid screening techniques for detecting asymptomatic urinary tract infections (AUTIs) in pregnant women.

DESIGN

Comparison of results of the screening tests of urinalysis, urine dipstick, and Gram's staining with the results of standard urine culture at an initial prenatal visit. In follow-up visits, urine dipstick testing was compared with urinalysis.

SETTING

Departments of Family Medicine and Obstetrics and Gynecology, Mayo Clinic, Rochester, Minn.

PATIENTS

Pregnant women (1047) from the local community were screened for AUTI on initial and follow-up visits.

METHODS

Initial prenatal urine was tested by using urine dipstick testing, urinalysis, Gram's staining, and urine culture. At each follow-up visit, urine specimens were tested by using urine dipstick and urinalysis.

MAIN OUTCOME MEASURES

Sensitivity and specificity, incremental patient costs, and clinical outcomes were used to assess the effectiveness of the techniques.

RESULTS

On initial visits, rapid screening tests for AUTI in pregnant women revealed the following: Gram's staining identified 22 of 24 patients with AUTI (sensitivity, 91.7%; specificity, 89.2%); urine dipstick, 12 of 24 (sensitivity, 50.0%; specificity, 96.9%); and urinalysis with presence of leukocytes, six of 24 (sensitivity, 25.0%; specificity, 99.0%). In follow-up visits, urine dipstick tests detected 19 infections and urinalysis, three (positive predictive value, 5% compared with 3%).

CONCLUSIONS

Urine dipstick testing for nitrites identified half of all patients with urinary tract infections and was superior to urinalysis on follow-up visits. Although Gram's staining is more expensive, it was more accurate for AUTI than urinalysis or urine dipstick test for nitrites. Urinalysis was never the test of choice because it was more expensive and detected fewer positive cultures. Leukocyte measurement correlated poorly with AUTI.

Early and late outcome of surgical repair for small abdominal aortic aneurysms: a population-based analysis

PURPOSE

Whether small abdominal aortic aneurysms (AAAs) (< or = 5 cm in diameter) should be repaired early to enhance late survival remains controversial. Long-term population-based data on the surgical outcome for small AAAs may help to establish practice guidelines until randomized clinical trials are completed.

METHODS

To examine an entire community experience with small AAAs, we conducted a population-based analysis of the recognition, reasons for operation, perioperative mortality rates, and late survival in Olmsted County, Minnesota.

RESULTS

The incidence of recognized small AAAs increased thirtyfold during a 30-year period. The propensity to repair small AAAs also increased during the same period. Eventually one third of small AAAs were repaired. The primary reasons for surgical consultation and operation were presence of the aneurysm (49%), expansion on serial examination (28%), nonspecific abdominal or back symptoms (18%), and excessive patient anxiety about the aneurysm (5%). Community operative mortality rates for small AAAs were low (2.6%) compared with those for large aneurysms (5.5%) (p = 0.65). However, the observed 5-year survival rate for the group undergoing repair of small aneurysms was 62%, which was significantly less than the 83% expected survival for the general population (p < 0.05). Relative survival for the operated small and large aneurysms was similar. The primary cause of death for both groups was myocardial infarction.

CONCLUSIONS

The results of our population-based analysis indicate that early operative results for elective repair of small AAAs are excellent, but late survival remains significantly impaired by coronary heart disease. Consequently, our data question whether early repair of small AAAs will enhance late survival. Until randomized clinical trials on management of small AAAs are completed, most small AAAs should be monitored for expansion and operated on electively when they approach or enter the range of 5 to 6 cm in good-risk patients.

Variations of the arterial anatomy of the foot

Reconstruction of the arteries of the foot in patients with severe chronic arterial occlusive disease has become a routine and valuable procedure. However, it is frequently difficult to select the optimal site for the distal arterial anastomosis. In order to determine the most important anatomic variations of foot arteries and the relationship of the dorsalis pedis artery to crossing tendons, the following study was performed in 30 cadaver limbs of 17 persons (9 men and 8 women). Their mean age at death was 69.8 years (range: 42 to 93 years). Methods to evaluate anatomy included anatomic dissection, arteriography, and preparation of corrosion cast models. The latter was performed by injection of liquid plastic and catalyst into the tibial arteries followed by chemical débridement of the soft tissue of the foot. Photographs of the corrosion cast models were taken at various stages of soft tissue dissolution. The dorsalis pedis artery was absent in 6.7% of the cases, and the arcuate artery was absent in 33%. The dorsalis pedis artery arose from the peroneal artery in 6.7%. The dorsalis pedis artery crossed under the extensor hallucis longus tendon at the ankle in 54%, above the ankle in 43%, but below the ankle in only 3%. Our study suggests that the optimal site for the dorsalis pedis artery anastomosis on the foot is the segment distal to the ankle.

Advanced carotid disease in patients requiring aortic reconstruction

Perioperative stroke is a devastating complication of abdominal aortic operations. Patients requiring aortic reconstruction with advanced carotid occlusive disease pose a particularly challenging management problem regarding timing of operations. All patients (n = 121) undergoing both carotid artery endarterectomy (CEA) and abdominal aortic reconstruction (AAR) within 1 year of each other between 1979 and 1989 were reviewed. The sequence of operation was analyzed to determine its effect on early and late outcome. CEA was the first operation in 99 patients (group I); AAR was performed first in 22 patients (group II). Age, gender, number, types of risk factors, and associated medical problems were similar in both groups. Indications for CEA were: transient ischemic attacks (TIAs), recent ipsilateral stroke, or high-grade asymptomatic carotid artery stenosis exceeding 80%. Indications for aortic operation included: abdominal aortic aneurysm, aortoiliac occlusive disease, and combined aortic and renovascular disease. There were five perioperative strokes, two in group I (2%) and three in group II (14%) (p < 0.04). All strokes occurred after AAR. There were five perioperative deaths (4%), four in group I (4%) and one in group II (5%). Overall survival was significantly greater in group I compared to group II (p < 0.04); 5-year survival was 77% and 51%, respectively. Multivariate analysis demonstrated age, hypertension, and diabetes to adversely affect survival; CEA as the first procedure, however, had a protective effect. Importantly, eight strokes occurred in group I in late follow-up, but only one was ipsilateral to the CEA. We conclude that CEA in selected patients who require AAR is safe, and, when performed prior to abdominal aortic repair, reduces perioperative stroke and may improve long-term survival.

Myocardial revascularization before abdominal aortic aneurysmorrhaphy: effect of coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) has assumed an increasing role in the preoperative preparation of patients with an abdominal aortic aneurysm (AAA). The influence of this modality on perioperative morbidity and long-term outcome has not been substantiated. To determine the effect of PTCA, we analyzed a cohort of 2,452 patients who underwent repair of an AAA between 1980 and 1990 at our institution. We compared the cardiac morbidity, mortality, and survival of patients who had preoperative coronary revascularization by PTCA or coronary artery bypass grafting (CABG). The overall perioperative mortality for the 2,452 patients was 2.9%. Preoperative coronary revascularization was necessary in 100 patients (4.1%)--86 had CABG and 14 had PTCA. Of these 100 patients, 95% had cardiac symptoms. Patients selected for PTCA, in comparison with CABG, had significantly less three-vessel disease but not significant differences in cardiac history or ejection fraction. During the study period, the use of PTCA increased significantly. The perioperative rate of myocardial infarction for patients with prior CABG was 5.8% in comparison with 0% for those with prior PTCA. No hospital deaths occurred in either group. The median interval between coronary revascularization and repair of an AAA was 10 days for PTCA and 68 days for CABG. The 3-year survival was not statistically different between CABG (82.8%) and PTCA (92.3%) groups. The rate of late cardiac events (at 3 years) was 56.5% in the PTCA group and 27.3% in the CABG group. We conclude that PTCA as part of a highly selective approach to coronary revascularization before repair of an AAA minimizes cardiac-related events and death.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimizing technical success of renal revascularization: the impact of intraoperative color-flow duplex ultrasonography

PURPOSE

Technical problems with renal revascularization can be difficult to detect, especially with end points of transaortic renal endarterectomies or anastomosis of bypass grafts to small distal renal arteries. If missed, such technical mishaps may not be recognized until after operation, when the chance for timely renal salvage has often been lost.

METHODS

To evaluate the value of newer color-flow duplex imaging, we performed intraoperative ultrasonography on 35 patients undergoing revascularization of 64 renal arteries, 29 patients undergoing transaortic endarterectomy, and 6 undergoing bypass grafting. Most patients (24/35; 69%) underwent concomitant aortic reconstruction. Ninety-four percent had hypertension, whereas 66% had associated chronic renal insufficiency.

RESULTS

Technical abnormalities prompting operative revision were identified during surgery in 10.9% of reconstructed main renal arteries (7/64). These included two occlusions, three intimal defects, and one extrinsic tissue band after endarterectomy plus one graft anastomotic stenosis. Color-flow imaging revealed all of them. Technical defects were also associated with higher peak-systolic flow velocities (mean 2.62 m/sec; range 2.00 to 3.50 m/sec) than normal-appearing arteries (mean 1.34 m/sec; range 0.40 to 2.50 m/sec) (p = 0.004). Eighty-six percent of the defects (6/7) were immediately correctable. One patient required nephrectomy. Postoperative angiograms revealed two asymptomatic small branch-vessel occlusions (3%). Compared with preoperative levels (p < 0.01), both hypertension and renal insufficiency improved initially. The clinical outcome of patients requiring intraoperative revision did not differ from that of patients undergoing normal intraoperative studies.

CONCLUSION

Intraoperative color-flow duplex detection and surgical correction of technical problems with renal revascularization have enhanced our technical success and been associated with long-term results comparable to those of patients undergoing normal intraoperative studies.

Contribution of a measure of disease complexity (COMPLEX) to prediction of outcome and charges among hospitalized patients

Attention has been focused on the need to adjust hospital reimbursement and outcomes of hospital care for level of illness. Extant measures of disease severity, however, fail to consider the contribution of disease complexity. We developed an easily retrievable measure of disease complexity (COMPLEX) by modifying an existing severity system, computerized Disease Staging. The contribution of COMPLEX (the number of body systems affected with a Disease Staging score of 2 or more) to the prediction of outcome was assessed in two studies: (1) a population-based analysis of readmission and mortality after hospitalization and (2) an analysis of hospital charges among patients who were in an intensive-care unit. The amount of variation in mortality explained by factors included in the Health Care Financing Administration model was significantly improved when COMPLEX was added to the model (adjusted odds ratio per body system, 1.83; 95% confidence interval, 1.61 to 2.08). A significant association was also observed between COMPLEX score and hospital readmission after adjustment for age, sex, case-mix, and disease severity (adjusted odds ratio, 1.31; 95% confidence interval, 1.20 to 1.44). When COMPLEX was added to case-mix and disease severity in a model for predicting hospital charges, the percentage of variation in hospital charges explained by the model increased from 25% to 38%. These findings demonstrate the important contribution of disease complexity to the analysis of outcome of medical care and utilization of resources. Outcome or reimbursement models that do not incorporate disease complexity may negatively affect institutions with a high proportion of patients who have complex conditions.

Influence of complete revascularization on chronic mesenteric ischemia

Complete revascularization for chronic intestinal ischemia is controversial. Fifty-eight patients (119 arteries) underwent mesenteric revascularization between 1981 and 1988. There were 46 women and 12 men (mean age: 63 years). Sixty percent of patients had three-vessel disease. Twenty-one patients underwent concomitant aortic reconstruction. Operative mortality was 10%. Four of the six deaths occurred in patients undergoing aortic surgery. Late graft failure occurred in five patients (10%). Five-year survival for patients with three-vessel involvement who underwent three-vessel repair was 73%, compared with 57% for two-vessel repair and 0% for one-vessel repair (p = NS). Similarly, graft patency in patients with three-vessel disease was highest in those patients who had complete revascularization (90%, 54%, and 0%, respectively) (p = NS). We conclude that increased graft patency and survival in patients with three-vessel disease was most frequent with complete revascularization. Diseased inferior mesenteric arteries should be repaired if feasible. Concomitant aortic operations should be avoided if possible.

Spinal cord injury in experimental thoracic aortic occlusion: investigation of combined methods of protection

The efficacy of combined methods of spinal cord protection during thoracoabdominal aortic reconstruction was evaluated because a recent clinical study failed to substantiate the value of cerebrospinal fluid drainage when used alone in the prevention of paraplegia. The effect of cerebrospinal fluid drainage and aortofemoral shunting were analyzed with regard to neurologic outcome and spinal cord blood flow in a model of thoracic aortic occlusion. In addition, we studied the use of motor-evoked potentials as compared with somatosensory-evoked potentials in monitoring cord perfusion. Thirty-two dogs underwent proximal and distal thoracic aortic occlusion for 60 minutes. The control group (n = 8) underwent thoracic aortic cross-clamping only. Spinal cord protection was used in three groups: cerebrospinal fluid drainage alone (n = 8), aortofemoral shunting alone (n = 8), and cerebrospinal fluid drainage and aortofemoral shunting (n = 8). Neurologic outcome improved in all treatment groups as compared with controls (p less than 0.001). The addition of cerebrospinal fluid drainage to aortofemoral shunting did not further improve neurologic outcome. Spinal cord blood flow measured with microspheres in the lumbar gray matter was significantly higher in the dogs with aortofemoral shunting (+/- cerebrospinal fluid drainage) as compared with those with cerebrospinal fluid drainage alone (p less than 0.05) or the controls (p less than 0.001). Aortofemoral shunting also prevented the development of acidosis and hyperglycemia. Loss or changes in amplitude and latency of motor-evoked potentials did not distinguish between the groups. Loss of somatosensory-evoked potentials had a high sensitivity (92%) but lower specificity (68%) in predicting neurologic injury, whereas loss of motor-evoked potentials had a high specificity (100%) but a very low sensitivity (16%). We conclude that cerebrospinal fluid drainage or aortofemoral shunting significantly improve spinal cord blood flow and neurologic outcome. The greatest increase in spinal cord blood flow was seen with aortofemoral shunting, which also prevented metabolic disturbances of reperfusion. Although the addition of cerebrospinal fluid drainage to aortofemoral shunting was the only group in which no neurologic injury occurred, this group did not have a significant improvement in outcome when compared with aortofemoral shunting alone. Spinal cord ischemia was more accurately detected with somatosensory-evoked potentials when aortofemoral shunting was used, whereas motor-evoked potentials recorded from the spinal cord were not sensitive enough to predict neurologic injury.

Outcomes of patients admitted to a chronic ventilator-dependent unit in an acute-care hospital

The outcomes in 61 patients admitted to a chronic ventilator-dependent unit (CVDU) at Saint Marys Hospital in Rochester, Minnesota, during an 18-month period are summarized. This unit was designed for patients who could not be weaned from mechanical ventilators after repeated attempts. Most patients had been ventilator dependent for more than 21 days, but some patients were admitted to the CVDU after briefer periods if special circumstances suggested that weaning from mechanical ventilation would be difficult. The unit was organized to provide a multidisciplinary approach to the general medical and respiratory management of these patients, including a physiologic evaluation of the respiratory system to determine the actual cause of ventilator dependence and complete medical, nursing, and psychosocial assessments to help adopt a plan of care and weaning from the ventilator. Of the numerous causes for ventilator dependence in this study group, chronic obstructive pulmonary disease was the most frequent underlying diagnosis. Of the 61 patients admitted to the CVDU, 58 survived, and 53 were liberated from the mechanical ventilator. Ultimately, 35 patients were dismissed directly home from the CVDU. Five of these patients required nocturnal mechanical ventilation. An additional eight patients were dismissed home after rehabilitation. After being weaned from mechanical ventilation, 11 patients were eventually transferred to nursing homes, and 3 additional patients were transferred to a local hospital or physical medicine unit. One patient remains in the CVDU. Thus, the CVDU has successfully liberated patients from ventilator dependence. In addition, because of a decreased need for nursing care, the unit has been cost-effective.

Infected femorodistal bypass: is graft removal mandatory?

Infected lower extremity bypass grafts have been associated with high rates of limb loss. Traditionally treatment has included graft excision. To compare aggressive local treatment, without graft removal, with more conventional graft excision, we reviewed 38 consecutive patients with 39 infected lower extremity bypasses treated during the last 10 years. The grafts used were prosthetic in 33 cases, vein in 4, and composite in 2. Median follow-up was 2.7 years. Twenty-eight infected grafts were treated with either complete (14) or partial (14) graft removal. Nine new grafts were placed. Recurrent infection developed in five cases, and two patients died of complications of graft infection. Ten of 20 limbs at risk were lost. Eleven patients with patent bypasses (4 vein, 2 composite, 5 prosthetic) were treated without graft excision. Treatment of five patients in this group included muscle transposition. Five patients were treated with incision and drainage of abscesses, and one had excision of a persistent sinus tract. One patient underwent major amputation 6.3 years after treatment of graft infection. Limb salvage was significantly higher (p = 0.012, log-rank test) than in patients treated with graft excision. One patient died, and no recurrent infections developed; these were not significant differences compared with those having graft excision. We conclude that aggressive local treatment of infected lower extremity bypass grafts, including drainage, debridement, and muscle transposition may treat infection in selected patients without the need for graft removal and with rates of limb salvage superior to those obtained with excisional therapy.

Hospital and posthospital survival in patients mechanically ventilated for more than 29 days

Experience with prolonged mechanical ventilation has improved over recent years. Retrospective analysis of the records of 104 patients older than 16 years of age who were mechanically ventilated for more than 29 days over a 29-month period from May 1986 to October 1988 revealed the following findings. The mean patient age was 66.3 +/- 15.7 years (SD). The mean number of in-hospital ventilator days was 59.9 +/- 36.7 days (range, 29 to 247 days). The mean number of days of oral or nasal endotracheal intubation prior to tracheostomy (96 patients) was 21.5 +/- 14.2 days. The mean length of hospital stay for the 104 patients was 79.9 +/- 45.4 days. The majority of the 104 patients (82.6 percent) were surgical patients. Nine patients left the hospital receiving extended mechanical ventilation. Mortality was highest in multiple organ system failure and lowest among the trauma patients. The total days of mechanical ventilation did not appear to be related to mortality if patients older than 16 years survived for seven days. Postdischarge survival of the 53 of 60 patients who survived and whom we were able to contact was 67 percent at one year and 56 percent at three years.

The role of intravenous fluorescein in the detection of colon ischemia during aortic reconstruction

Intravenous fluorescein is an accurate predictor of small bowel viability, but its effectiveness in assessing colon perfusion during aortic surgery has not been evaluated. Over a 10 year period 186 of 3,306 patients undergoing aortic reconstruction received 500 to 1000 mg of intravenous fluorescein intraoperatively to evaluate colon viability. Prior history of colectomy, hypogastric or mesenteric arterial occlusive disease, or ruptured aneurysm placed these patients at risk to develop ischemic colitis. Patients were operated on for aneurysmal disease (n = 94), occlusive disease (n = 66), or a combination of both (n = 26): 171 exhibited uniform normal perfusion patterns under Wood's lamp illumination, while in 11 it was "patchy." None of these patients developed full-thickness ischemic colitis (observed specificity: 100%). Fluorescence of the rectosigmoid was absent in four patients. One of these patients with a ruptured aneurysm underwent immediate sigmoid resection, while three underwent inferior mesenteric artery reimplantation. The fluorescein pattern subsequently normalized in two patients, but one underwent sigmoid resection for an expanding mesenteric hematoma. The second patient recovered without complications. The final patient continued to show a segmental sigmoid defect and postoperatively developed full-thickness injury requiring sigmoidectomy. During the same period 18 other patients developed transmural colon ischemia from 3,120 aortic reconstructions (0.6%), with a mortality rate of 56%. None had received intraoperative fluorescein. Selective use of intravenous fluorescein may reduce the mortality of ischemic colitis following aortic reconstruction.

The Olmsted County Benchmark Project: primary study findings and potential implications for corporate America

Since 1965, expenditures for medical care in the United States have increased 10-fold. As a result, corporate outlays for health benefits have skyrocketed. Employers have instituted various cost-containment measures based in part on reports of wide variations in rates of utilization and the assumption that unnecessary or inappropriate utilization of medical care contributes to increasing costs. Frequently, however, employers lack adequate means for identifying sources of variation or for evaluating its appropriateness. In this article, we report on a project in which hospital utilization among several US corporate populations was compared with that for a geographically defined benchmark population to assist employers in the assessment of their rates of utilization and expenditures and to identify specific areas that merit further investigation. Our findings illuminate the difficulties in constructing valid rates from medical-care claims data and emphasize potential biases due to problems of comparability between populations. We also address the potential value of such comparison for helping corporations identify areas in which cost-containment efforts may be most effective and yet not jeopardize the quality of medical care.

Acquired conditions: an improvement to hospital discharge abstracts

Selected secondary diagnoses (e.g. pulmonary embolism) may provide an efficient and inexpensive source of data for quality assurance (QA) monitoring if their absence at admission were known. In June 1990 we modified our hospital abstracting methods to classify each diagnosis into categories: (1) present on admission, (2) acquired during hospitalization, or (3) uncertain. Our experience has confirmed the identification and elimination from QA reports of the majority of pre-existing secondary diagnoses. Examples of secondary diagnosis codes acquired or uncertain were acute myocardial infarction 48%, pneumonias 25%, pulmonary emoboli 54% and cerebral vascular accident/hemorrhage 35%. Abstracting time has increased less than 2 min per discharge. A reabstraction study showed 87% agreement (kappa = 0.733, p less than 0.001) between initial collection and blinded reabstraction. The separation of secondary diagnoses into preexisting or acquired can: (1) be reliably undertaken by discharge abstracters; (2) be efficient in adding minimal time; and (3) enhance the validity and usefulness of data and increase physician acceptance.

Late iliac artery aneurysms and occlusive disease after aortic tube grafts for abdominal aortic aneurysm repair. A 35-year experience

Controversy continues over whether patients treated with straight Dacron aortic tube grafts for an abdominal aortic aneurysm remain at significant risk for subsequent development of iliac aneurysm or occlusive disease. To address this issue, the authors performed a population-based analysis of 432 patients who had an abdominal aortic aneurysm diagnosed between 1951 and 1984. Aneurysm repair was performed eventually in 206 patients (48%). To ascertain differences in late development of graft-related complications, iliac aneurysms, and arterial occlusions, the authors compared all tube-graft patients with similar numbers of bifurcated-graft patients matched for age and year of operation. In the tube-graft group, no subsequent clinically evident or autopsy-proven iliac aneurysms or iliac occlusive disease were noted. Over a mean follow-up of 6 years (range, 4 to 18 years), new aortic aneurysms occurred in the proximal aorta in both tube and bifurcated-graft patients (5.0% and 2.5%, respectively). In contrast the cumulative incidence of graft-related complications was higher with a bifurcated prosthesis (12.8%) compared with a straight graft (5.0%) (p = 0.15). These problems generally occurred 5 to 15 years postoperatively and emphasize the need for long-term graft surveillance. The authors conclude that straight tube-grafts for repair of abdominal aortic aneurysms provide excellent late patency with minimal risk of subsequent iliac aneurysm development.

Value and limitations of two-dimensional echocardiography in predicting myocardial infarct size

To investigate the quantitative relations between the severity of regional wall motion abnormalities and segmental infarct size and between the severity of overall left ventricular dysfunction and global infarct size, a clinicopathologic study was undertaken of 30 patients who had a 2-dimensional (2-D) echocardiogram within 7 days before death. The severity of regional wall motion abnormalities was graded for each segment with a 2-D echocardiographic 14-segment model. The severity of global left ventricular dysfunction was calculated as the mean of the visualized regional wall motion scores. On pathologic examination of autopsy specimens, segmental infarct size was estimated as a percentage of the segmental cross-sectional area. The global infarct size was expressed as a percentage of the total left ventricular mass. At the segmental level, regional wall motion score was positively correlated (r = 0.53) with the segmental infarct size. The sensitivity and specificity of detecting infarcted segments by abnormal wall motion scores were 81 and 71%, respectively. All dyskinetic segments revealed infarct size of greater than or equal to 10%. The wall motion score index was positively correlated (r = 0.52) with the global infarct size. The mean global infarct size was 7% for the 8 patients with a wall motion score index of less than 2, which was significantly lower than the mean of 27% for the 22 patients with a wall motion score index of greater than or equal to 2 (p less than 0.001). A 2-D echocardiogram is sensitive and specific in detecting infarcted segments and can be useful in quantitating myocardial damage after myocardial infarction.

Significance of mildly elevated creatine kinase (myocardial band) activity after elective abdominal aortic aneurysmectomy

The clinical significance of mildly elevated creatine kinase (CK) myocardial band (MB) enzyme levels in patients undergoing elective repair of an abdominal aortic aneurysm was evaluated retrospectively in 348 patients. For each patient, preoperative and postoperative electrocardiograms (ECGs) were interpreted blindly for left ventricular hypertrophy, ST segment abnormality, left bundle branch block, right bundle branch block, left axis deviation, atrial fibrillation, T wave abnormality, and Q waves. A total of 107 patients (31%) had postoperative CK-MB elevations of trace or greater; 37 had trace, 35 had 1% to 4%, and 35 had greater than or equal to 5% elevation. There was no difference in survival between those with trace and no CK-MB elevation. Patients with increased CK-MB (greater than or equal to 1%) values were more likely to have ECG abnormalities. The following ECG (either preoperative or postoperative) abnormalities were univariately related to decreased postoperative survival: left ventricular hypertrophy (P less than 0.001), ST segment abnormalities (P less than 0.001), left bundle branch block (P less than 0.001), the combination of right bundle branch block and left axis deviation (P = 0.006), Q wave infarction (P less than 0.001), and atrial fibrillation (P less than 0.001). There were 15 in-hospital deaths, and 333 patients were discharged and followed-up for a median of 4.6 years. There were 97 posthospitalization deaths, 61% of which were due to cardiac causes. Overall survival was associated with the degree of CK-MB elevation; the higher the CK-MB, the worse the survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in elderly hospitalization and readmission rates for a geographically defined population: pre- and post-prospective payment

To address the paucity of patient-level data regarding the effectiveness of Medicare's prospective payment system (PPS), we conducted a population-based study of inpatient hospitalizations among individually identified elderly residents of Olmsted County, Minnesota, 1970-1987. A 4.3% increase in total days of care/1000 population from 2,652/1,000 in 1970 to 2,766/1,000 in 1980 was followed by a 9.8% decline from 1980 to 1987 (2,495/1,000). The decline was due primarily to a 13.4% decrease in mean length stay (9.7 days in 1980 to 8.4 days in 1987). The number of hospitalizations/1,000 Olmsted County elderly in 1980 was already below 1987 U.S. figures and did not exhibit the decline evidenced nationally between 1980 and 1987. A 4.6% decline in the proportion of county residents age 65-74 years who were hospitalized (174/1,000 in 1980 to 166/1,000 in 1987) was offset by an 8.3% increase for persons age greater than or equal to 75 (252/1,000 to 273/1,000) and by a 5.7% increase in the number of hospitalizations per individual hospitalized for persons age 65-74 years (1.34 to 1.42). Using a time-dependent Cox model, which adjusted for differences in patients characteristics between years, there was a significantly higher risk of readmission within 14 days in 1987 vs 1980 (hazard ratio (HR) = 1.33, 95% confidence interval (CI) = 1.05-1.70). The difference between years was no longer evident at 30 or 60 days (HR = 0.84, 95% CI = 0.63-1.11 between 15 and 30 days; HR = 1.12, 95% CI = 0.84-1.49 between 31 and 60 days). This study suggests that initial effects of PPS on utilization may be temporary and that more research is needed to appreciate the impact of cost-containment on patient outcome.

Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up

The perioperative and follow-up results of cardiac operations employing extracorporeal circulation and cold cardioplegic arrest were examined in 191 consecutive patients greater than or equal to 80 years of age having surgery over a 5 year period (1982 to 1986). Most patients had severe preoperative symptoms with functional class III (39.8%) or IV (57.1%) limitation. The overall 30 day postoperative cardiac mortality rate was 15.7%. The total in-hospital mortality rate was 18.8%; the mean postoperative hospital stay was 16.4 +/- 13.3 days. The perioperative mortality rate for elective operations was as follows: coronary artery bypass (5.6%), aortic valve replacement (9.6%), aortic valve replacement with coronary bypass (17.9%) and mitral valve surgery with or without coronary bypass (21.4%). Urgent operations were performed in 39 patients (20.4%) with a total perioperative mortality rate of 35.9%; urgent coronary artery bypass was performed in 26 patients (67%) with an in-hospital mortality rate of 23.1%. Clinical evidence of left ventricular failure, functional class IV symptoms, left ventricular ejection fraction less than 50%, mitral valve repair or replacement for severe mitral regurgitation and urgent operation were associated with an increased perioperative mortality rate. Follow-up study in all 155 patients surviving postoperative hospitalization at 22.6 +/- 14.8 months showed significant improvement in symptom status in all surgical subgroups. There were 18 follow-up deaths (11.6%); 10 were noncardiac. The actuarial survival rate of the entire study group was significantly better than that in age- and gender-matched control subjects (p = 0.037).(ABSTRACT TRUNCATED AT 250 WORDS)

Microvascular pedal bypass for salvage of the severely ischemic limb

Bypass to the pedal arteries was performed with use of the operating microscope and standard microsurgical technique in 37 patients with severe, chronic ischemia of a lower extremity. Twenty-one patients (57%) had three or more cardiovascular risk factors, and 22 (59%) had diabetes. Preoperative arteriography identified a pedal artery suitable for bypass in all but one patient. The greater or lesser saphenous vein was used in all patients, most frequently as a nonreversed, translocated vein graft. An arm vein was used as part of a composite graft in only one patient. No early deaths occurred, and only one patient had a perioperative myocardial infarction. Although five grafts occluded within 30 days, four were successfully revised, and 36 patients had a patent graft at the time of dismissal from the hospital. At 1 year, the primary graft patency rate (patency without revision) was 60.8%, and the secondary patency rate was 68.8%. One early and six late amputations were performed; the cumulative 1-year limb salvage rate was 82.4%. Grafts with an intraoperative flow rate of 50 ml/min or more had a better patency rate than those with a lower flow rate. The presence of diabetes did not adversely affect long-term patency. Of the 34 patients who were alive at the time of this report, 27 (79%) had a functional foot that allowed ambulation, had no rest pain, and had no substantial loss of tissue. Pedal bypass should be considered for critical, chronic ischemia, even if the patient has an increased surgical risk and advanced distal atherosclerotic disease.

Simultaneous bilateral hernia repair. A case against conventional wisdom

The timing of bilateral hernia repair remains controversial. Because of reported high recurrence rates after simultaneous bilateral repair, staged procedures have been suggested. This study determined recurrence and complication rates of unilateral versus simultaneous bilateral repair. Of 659 patients undergoing hernia repair between 1974 and 1980, 333 underwent unilateral repair and 329 had simultaneous bilateral repair. More than 90% of patients were followed until death or a minimum of 60 months (median, 104 months). Perioperative complications were associated with 18% of repairs. More morbidity occurred in the bilateral group. However complication rates for specific events were not significantly different, except for urinary retention, which occurred in 20 patients (6.1%) of the unilateral group and 49 (15%) of the bilateral group (p less than 0.001). Overall 25 recurrences occurred in the unilateral group and 31 in the bilateral group. Recurrence rates at 5 and 9 years were, respectively, 4.8% and 8.8% in the unilateral group and 5.0% and 9.1% in the bilateral group (p = 0.861). These data suggest that simultaneous bilateral inguinal herniorrhaphy does not result in increased rates of most postoperative complications or recurrence when compared with unilateral repair.

Assessment of prediction of mortality by using the APACHE II scoring system in intensive-care units;

Some investigators have suggested that information on quality of care in intensive-care units (ICUs) may be inferred from mortality rates. Specifically, the ratio of actual to predicted hospital mortality (A/P) has been proposed as a valid measure for comparing ICU outcomes when predicted mortality has been derived from data collected during the first 24 hours of ICU therapy with use of a severity scoring tool, APACHE II (acute physiology and chronic health evaluation). We present a comparison of mortality ratios (A/P) in four ICUs under common management, in two hospitals within a single institution. Significant differences in A/P were detected for nonoperative patients (0.99 versus 0.67;P = 0.014) between the two hospitals. This variation was traced to uneven representation of a subset of patients who had chronic health problems related to diseases that necessitated admission to the hematology-oncology or hepatology service. No differences in A/P were seen between the two hospitals for operative patients or for nonoperative patients on services other than hematology-oncology or hepatology. Thus, differences in A/P detected by using the APACHE II system not only may reside in operational factors within the ICU organization but also may be related to weaknesses in the APACHE II model to measure factors intrinsic to the disease process in some patients. We suggest that case-mix must be examined in detail before concluding that differences in A/P are caused by differences in quality of care.

Utilization trends and risk factors for hospitalization in diabetes mellitus

A population-based prevalence cohort of 1,111 residents of Rochester, Minnesota, who had diabetes mellitus on Jan. 1, 1975, was subjected to follow-up assessment for hospitalizations through Dec. 31, 1980. On the basis of these data, hospitalization rates were calculated for various clinical types of diabetes, and a risk factor analysis was done for non-insulin-dependent diabetes mellitus (NIDDM) to identify high-risk persons for subsequent intervention studies. The adjusted incidence density of hospitalization was 141.6 per 1,000 person-years for NIDDM and 331.3 per 1,000 person-years for insulin-dependent diabetes. Although the modeled clinical characteristics accounted for little variability in NIDDM-related hospitalization, age modified by the effect of gender was the strongest risk factor found (multivariate hazard ratios: 1.0 and 1.43, respectively, for male and female patients younger than 65 years old; 1.88 and 1.83, respectively, for male and female patients 65 years old or older); coronary heart disease, diabetic retinopathy, and persistent proteinuria were associated with a 50% increased risk. Although older patients with NIDDM (especially men) are at greatest risk for a first hospitalization, clinical factors alone seem inadequate to account for these hospitalizations. The effect of Medicare's prospective payment systems (PPS) was studied by using a data base for Olmsted County, Minnesota, to determine whether PPS decreased the rate of hospitalizations among patients with diabetes. Among Olmsted County residents 65 years of age or older, the adjusted rate of diabetes-associated hospitalizations decreased from 26.5 per 1,000 person-years in 1980 to 16.7 in 1985, whereas the adjusted rate of all other hospitalizations increased from 259.5 per 1,000 person-years to 261.9. Thus, PPS may have reduced hospitalization rates in elderly patients with diabetes.