Prophylactic total gastrectomy for familial gastric cancer

BACKGROUND

An autosomal dominant syndrome of diffuse gastric cancer has been reported with germline mutations in the E-cadherin (CDH1) gene and has been identified in approximately 14 families and 50 individuals worldwide. Penetrance of the gene is 70% to 80%, and the average age of onset of gastric cancer is 37 years. These characteristics have led to the consideration of prophylactic total gastrectomy in family members with CDH1 mutations.

METHODS

We report here the first use of prophylactic gastrectomy in 6 asymptomatic members of 2 families (2 males, 4 females; ages 22, 27, 28, 35, 39, and 40) based on family pedigree and genetic analysis. Total gastrectomy was performed via an upper midline incision, and reconstruction of the gastrointestinal tract was done via a Roux-en-Y esophagojejunostomy. Complete removal of all gastric mucosa was documented intraoperatively, and confirmation was made that only esophageal mucosa remained at the proximal specimen margin.

RESULTS

The gastric specimens appeared normal, and the results of routine pathologic examination were negative for cancer. All specimens from patients who tested positive for E-cadherin mutations were subjected to a research protocol of microscopic sectioning in which 150 to 250 tissue blocks were examined. All of these patients had microscopic foci of cancer, often at multiple sites, with overlying normal gastric mucosa.

CONCLUSIONS

E-cadherin gene mutations in association with familial gastric cancer is a new disease for which prophylactic surgery must be considered. The morbidity of this operation is much higher than that for other genetic diseases, but the alternative is a mortality risk of more than 80% at a young age.

Early gastric cancer in young, asymptomatic carriers of germ-line E-cadherin mutations

BACKGROUND

Germ-line truncating mutations in the E-cadherin (CDH1) gene have been found in families with hereditary diffuse gastric cancer. These families are characterized by a highly penetrant susceptibility to diffuse gastric cancer with an autosomal dominant pattern of inheritance, predominantly in young persons. We describe genetic screening, surgical management, and pathological findings in young persons with truncating mutations in CDH1 from two unrelated families with hereditary diffuse gastric cancer.

METHODS

Mutation-specific predictive genetic testing was performed by polymerase-chain-reaction amplification, followed by restriction-enzyme digestion and DNA sequencing in Family 1 and by heteroduplex analysis in Family 2. A total gastrectomy was performed prophylactically in five carriers of mutations who were between 22 and 40 years old. In each case, the entire mucosa of the stomach was extensively sampled for microscopical analysis.

RESULTS

Superficial infiltrates of malignant signet-ring cells were identified in the surgical samples from all five persons who underwent gastrectomy. These early diffuse gastric cancers were multifocal in three of the five cases, and in one person infiltrates of malignant signet-ring cells were present in 65 of the 140 tissue blocks analyzed, representing in aggregate less than 2 percent of the gastric mucosa.

CONCLUSIONS

We recommend genetic counseling and consideration of prophylactic gastrectomy in young, asymptomatic carriers of germ-line truncating CDH1 mutations who belong to families with highly penetrant hereditary diffuse gastric cancer.

Surgical management of radiation injury of the small and large intestine

The following principles should be observed during operations for radiation injuries of the small and large intestine: 1) The objective of operation is modest: to relieve symptoms. 2) Only healthy bowel, which was outside the radiation field, should be anastomosed. 3) Isolated small intestinal injuries should be resected or bypassed, and extensive dissection should be avoided. 4) Colorectal injuries should be treated by diverting descending colostomy, with or without resection of the diseased bowel.

An objective analysis of process errors in trauma resuscitations

OBJECTIVE

A computer-based system to apply trauma resuscitation protocols to patients with penetrating thoracoabdominal trauma was previously validated for 97 consecutive patients at a Level 1 trauma center by a panel of the trauma attendings and further refined by a panel of national trauma experts. The purpose of this article is to describe how this system is now used to objectively critique the actual care given to those patients for process errors in reasoning, independent of outcome.

METHODS

A chronological narrative of the care of each patient was presented to the computer program. The actual care was compared with the validated computer protocols at each decision point and differences were classified by a predetermined scoring system from 0 to 100, based on the potential impact on outcome, as critical/noncritical/no errors of commission, omission, or procedure selection.

RESULTS

Errors in reasoning occurred in 100% of the 97 cases studied, averaging 11.9/case. Errors of omission were more prevalent than errors of commission (2. 4 errors/case vs 1.2) and were of greater severity (19.4/error vs 5. 1). The largest number of errors involved the failure to record, and perhaps observe, beside information relevant to the reasoning process, an average of 7.4 missing items/patient. Only 2 of the 10 adverse outcomes were judged to be potentially related to errors of reasoning.

CONCLUSIONS

Process errors in reasoning were ubiquitous, occurring in every case, although they were infrequently judged to be potentially related to an adverse outcome. Errors of omission were assessed to be more severe. The most common error was failure to consider, or document, available relevant information in the selection of appropriate care.

Familial gastric cancer: overview and guidelines for management

Families with autosomal dominant inherited predisposition to gastric cancer have been described. More recently, germline E-cadherin/CDH1 mutations have been identified in hereditary diffuse gastric cancer kindred. The need to have protocols to manage and counsel these families in the clinic led a group of geneticists, gastroenterologists, surgeons, oncologists, pathologists, and molecular biologists to convene a workshop to produce consensus statements and guidelines for familial gastric cancer. Review of the available cancer pathology from people belonging to families with documented germline E-cadherin/CDH1 mutations confirmed that the gastric cancers were all of the diffuse type. Criteria to define the different types of familial gastric cancer syndromes were agreed. Foremost among these criteria was that review of histopathology should be part of the evaluation of any family with aggregation of gastric cancer cases. Guidelines for genetic testing and counselling in hereditary diffuse gastric cancer were produced. Finally, a proposed strategy for clinical management in families with high penetrance autosomal dominant predisposition to gastric cancer was defined.

Prediction of outcome in intensive care unit trauma patients: a multicenter study of Acute Physiology and Chronic Health Evaluation (APACHE), Trauma and Injury Severity Score (TRISS), and a 24-hour intensive care unit (ICU) point system

OBJECTIVE

To conduct a multicenter study to validate the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) II system, APACHE III system, Trauma and Injury Severity Score (TRISS) methodology, and a 24-hour intensive care unit (ICU) point system for prediction of mortality in ICU trauma patient admissions.

METHODS

The study population consisted of retrospectively identified, consecutive ICU trauma admissions (n = 2,414) from six Level I trauma centers. Probabilities of death were calculated by using logistic regression analysis. The predictive power of each system was evaluated by using decision matrix analysis to compare observed and predicted outcomes with a decision criterion of 0.50 for risk of hospital death. The Youden Index (YI) was used to compare the proportion of patients correctly classified by each system. Measures of model calibration were based on goodness-of-fit testing (Hosmer-Lemeshow statistic less than 15.5) and model discrimination were based on the area under the receiver operating characteristic curve (AUC).

RESULTS

Overall, APACHE II (sensitivity, 38%; specificity, 99%; YI, 37%; H-L statistic, 92.6; AUC, 0.87) and TRISS (sensitivity, 52%; specificity, 94%; YI, 46%; H-L statistic, 228.1; AUC, 0.82) were poor predictors of aggregate mortality, because they did not meet the acceptable thresholds for both model calibration and discrimination. APACHE III (sensitivity, 60%; specificity, 98%; YI, 58%; H-L statistic, 7.0; AUC, 0.89) was comparable to the 24-hour ICU point system (sensitivity, 51%; specificity, 98%; YI, 50%; H-L statistic, 14.7; AUC, 0.89) with both systems showing strong agreement between the observed and predicted outcomes based on acceptable thresholds for both model calibration and discrimination. The APACHE III system significantly improved upon APACHE II for estimating risk of death in ICU trauma patients (p < 0.001). Compared with the overall performance, for the subset of patients with nonoperative head trauma, the percentage correctly classified was decreased to 46% for APACHE II; increased to 71% for APACHE III (p < 0.001 vs. APACHE II); increased to 59% for TRISS; and increased to 62% for 24-hour ICU points. For operative head trauma, the percentage correctly classified was increased to 60% for APACHE II; increased to 61% for APACHE III; decreased to 43% for TRISS (p < 0.004 vs. APACHE III); and increased to 54% for 24-hour ICU points. For patients without head injuries, all of the systems were unreliable and considerably underestimated the risk of death. The percentage of nonoperative and operative patients without head trauma who were correctly classified was decreased, respectively, to 26% and 30% for APACHE II; 33% and 29% for APACHE III; 33% and 19% for TRISS; 20% and 23% for 24-hour ICU points.

CONCLUSION

For the overall estimation of aggregate ICU mortality, the APACHE III system was the most reliable; however, performance was most accurate for subsets of patients with head trauma. The 24-hour ICU point system also demonstrated acceptable overall performance with improved performance for patients with head trauma. Overall, APACHE II and TRISS did not meet acceptable thresholds of performance. When estimating ICU mortality for subsets of patients without head trauma, none of these systems had an acceptable level of performance. Further multicenter studies aimed at developing better outcome prediction models for patients without head injuries are warranted, which would allow trauma care providers to set uniform standards for judging institutional performance.

Comparison of mammographically guided breast biopsy techniques

OBJECTIVE

To determine which mammographically guided breast biopsy technique is the most efficient in making a diagnosis in women with suspicious mammograms.

SUMMARY BACKGROUND DATA

Mammographically guided biopsy techniques include stereotactic 14-gauge core-needle biopsy (SC bx), stereotactic 11-gauge suction-assisted core biopsy (Mammotome [Mbx]), stereotactic coring excisional biopsy (Advanced Breast Biopsy Instrument [ABBI]), and wire-localized biopsy (WL bx). Controversy exists over which technique is best.

METHODS

All patients undergoing any one of these biopsy methods over a 15-month period were reviewed, totaling 245 SC bx, 107 Mbx, 104 ABBI, and 520 WL bx. Information obtained included technical success, pathology, discordant pathology, and need for open biopsy.

RESULTS

Technical success was achieved in 94.3% of SC bx, 96.4% of Mbx, 92.5% of ABBI, and 98.7% of WL bx. The sensitivity and specificity were 87.5% and 98.6% for SC bx, 87.5% and 100% for Mbx, and 100% and 100% for ABBI. Discordant results or need for a repeat biopsy occurred in 25.7% of SC bx, 23.2% of Mbx, and 7.5% of ABBI biopsies. In 63.6% of ABBI and 50.9% of WL bx, positive margins required reexcision; of the cases with positive margins, 71.4% of ABBI and 70.4% of WL bx had residual tumor in the definitive treatment specimen.

CONCLUSION

Although sensitivities and specificities of SC bx and Mbx are good, 20% to 25% of patients will require an open biopsy because a definitive diagnosis could not be reached. This does not occur with the ABBI excisional biopsy specimen. The positive margin rates and residual tumor rates are comparable between the ABBI and WL bx. The ABBI avoids operating room and reexcision costs; therefore, in appropriately selected patients, this appears to be the most efficient method of biopsy.

Racial differences in the presentation and surgical management of breast cancer

BACKGROUND

African American women are seen with more advanced breast cancers, are less likely to be treated with breast-conserving surgery, and generally have poorer prognoses than white women. There are a myriad of potential causes for these phenomena. The purpose of this study was to measure racial differences in the surgical treatment of breast cancer among women with comparable health care access and delivery.

METHODS

The Breast Cancer Registry of the Department of Surgery at Henry Ford Hospital was accessed for all patients between January 1, 1990, and December 31, 1997 for whom data on race, tumor characteristics, stage, and treatment specifics were available. Socioeconomic information was collected with use of 1990 census block data. Proportions of women who received each treatment were compared for African Americans and whites with use of the relative risk (RR) and 95% confidence intervals (CI). We used multiple logistic regression to obtain estimates of the relative risk, controlling for potential confounding factors.

RESULTS

Of the 1699 patients in the database, 1250 had sufficient information for analysis. A total of 8.7% of African American women were diagnosed with late-stage disease (i.e., stage III or IV) compared with 7.9% of whites. Nevertheless, African American women had a lower frequency of stage I disease (30.5% vs 36.2%) and a higher frequency of stage II disease (36.8% vs 31.4%). Overall and adjusted risk estimates for age, tumor stage, marital status, median income, and type of insurance revealed no substantive or statistically significant differences between African American and white patients. The adjusted RR for local excision was 1.39 (95% CI 0.78 to 2.49), for lumpectomy and axillary dissection RR 0.92 (95% CI 0.66 to 1.29), for simple mastectomy RR 0.84 (95% CI 0.41 to 1.72), and for modified radical mastectomy RR 1.00 (95% CI 0.73 to 1.36).

CONCLUSIONS

In this setting of equal access to health care, African American women still have higher frequencies of stage II disease, although the frequencies for late-stage disease are similar. Nevertheless, no surgical differences were found in this population, even after the effects of socioeconomic indicators and stage at diagnosis were controlled for Survival differences between African American and white women are unlikely to be explained by differences in treatment.

Epidemiology of injuries by needles and other sharp instruments. Minimizing sharp injuries in gynecologic and obstetric operations

Surgical and obstetric HCWs and epidemiologists will benefit from working together to describe the frequency and circumstances of percutaneous injuries in operating and delivery rooms. Rates of percutaneous injury vary among institutions, and attending and resident surgeons are among those at greatest risk for injury. Gynecologic surgery appears to have one of the highest rates of injury of the surgical specialties, and rates of injury vary by procedure within a given specialty. Suture needles cause the majority of injuries. Certain actions such as holding tissue while suturing or cutting are associated with a higher risk of injury. Many percutaneous injuries appear to be preventable. Epidemiologic data can be used to develop strategies based on the industrial hygiene model to reduce the incidence of percutaneous injury and to collect and disseminate data on the efficacy of new preventive measures. Potentially safer instruments and suture needles, technique modification strategies, and personal protective equipment such as cut-resistant gloves and finger protective strips are now available. Scientific assessment is needed of these and other new measures to determine whether they will decrease the risk of percutaneous injury, be acceptable to users, be cost effective, and avoid adverse consequences to patients or HCWs.

Are universal precautions realistic?

In concluding whether universal precautions are necessary, it certainly appears that we need something to reduce the significant problem of HIV transmission to health-care providers. As occupational risk goes, it exceeds the occupational risk of a number of other high-risk professions. Unfortunately, we do not know if universal precautions are effective. We also do not know the true compliance rate in use of universal precautions, nor whether they have an impact on transmission even if effectively used. What are the alternatives? They are not great, but some have not been adequately explored or implemented. Re-engineering around needle use in the hospital is clearly the most likely area to produce concrete results, because needlesticks are overwhelmingly the greatest source of infection, but this has not been encouraged to the degree it could be, even with systems already developed. Universal testing does not appear to be a viable alternative, for numerous reasons already discussed. Finally, are universal precautions more important for other pathogens than HIV? I would say yes. Hepatitis B, hepatitis C, and nosocomial infections are more important both as public health issues and as health-care provider prevention issues. If universal precautions are effective in reducing any of these, they are worthwhile.

Cytogenetic analysis of thyroid tumors after cryopreservation

Current cytogenetic evaluation of solid tumors is performed on fresh tissue specimens requiring on-call tissue culture facilities. The application of cryopreservation to tumor samples prior to cytogenetic analysis allows collection of tumors to a desired sample size. We evaluated methods of cryopreservation for their effects on growth potential from 11 benign thyroids and one papillary thyroid cancer. Mitotic indices and thyroglobulin expression applying imunocytology were analyzed. Compared to fresh tumors, the revived tumor samples showed unaltered thyroglobulin expression. A statistically significant (p < 0.004) prolongation to develop mitotic activity occurred in samples received after the freezing of dispase digested tissues, but not in samples frozen as thinly cut pieces. In addition, the data show that cytogenetic analysis at the 400-band level can be achieved in cryopreserved thyroid tissues.

Effect of interferon gamma on infection-related death in patients with severe injuries. A randomized, double-blind, placebo-controlled trial

OBJECTIVE

To assess the efficacy of interferon gamma in reducing infection and death in patients sustaining severe injury.

DESIGN

Multicenter, randomized, double-blind, placebo-controlled trial with observation for 60 days and until discharge for patients with major infection on day 60.

SETTING

Nine university-affiliated level 1 trauma centers.

PATIENTS

Four hundred sixteen patients with severe injuries, assessed by Injury Severity Score and degree of contamination.

INTERVENTION

Recombinant human interferon gamma, 100 micrograms, was administered subcutaneously once daily for 21 days (or until patient discharge if prior to 21 days) as an adjunct to standard antibiotic and supportive therapy.

MAIN OUTCOME MEASURES

Incidence of major infection, death related to infection, and death.

RESULTS

Infection rates were similar in both treatment groups; however, patients treated with interferon gamma experienced fewer deaths related to infection (seven [3%] vs 18 [9%]; P = .008) and fewer overall deaths (21 [10%] vs 30 [14%]; P = .17). While 12 early deaths (days 1 through 7) occurred in each treatment group, late death occurred in 18 placebo-treated patients and nine in interferon gamma-treated patients. The results were dominated by findings at one center, which had the highest enrollment and higher infection and death rates. Statistical analysis did not eliminate the possibility of an unidentified imbalance between arms as an explanation for the results.

CONCLUSION

Further evaluation is required to determine the validity of the observed reduction in infection-related deaths in patients treated with interferon gamma.

Prevention of venous thromboembolism in trauma patients

Trauma patients are at risk for thromboembolic complications, but effective methods of prophylaxis have not been established for this heterogenous population. In this prospective trial, 400 trauma patients were assigned to one of three groups, depending upon their injuries, and randomized within each group to a treatment mode: Group I: sequential gradient pneumatic leg compression (SCD), low-dose subcutaneous heparin (H), or control (C); Group II: H or C; Group III: SCD or C. Venous duplex ultrasound examinations were performed on admission and weekly thereafter. Of the 251 patients who completed the study, 15 (6%) developed lower extremity venous thrombosis and two additional patients developed pulmonary embolism (one fatal). Significant risk factors associated with the development of thromboembolism included immobilization > 3 days, age 30 years or older, and the presence of pelvic or lower extremity fractures. In patients with neurotrauma who cannot receive heparin (Group III), the SCD was more effective than control in preventing DVT (p = 0.057). Neither H nor SCD appeared to offer protection for the other groups of trauma patients, but surveillance with ultrasound examinations allowed for prompt recognition and treatment of occult deep vein thrombosis.

The effects of adrenergic agents on oxygen delivery and oxygen consumption in normal dogs

This study measured changes in whole body Do2 and Vo2 caused by the administration of exogenous adrenergic agents given at physiologically relevant doses. Using 25-kg nonseptic dogs, we calculated Do2 and directly measured Vo2 in six groups (saline control, colloid fluid challenge, dopamine, dobutamine, norepinephrine, and epinephrine). The dogs were anesthetized with isoflurane, paralyzed, and maintained at a minimum baseline temperature of 37 degrees C. Measurements were taken at six time points: baseline, after each of four successively larger doses of drug, and after a recovery period. Our results demonstrated no significant changes in Vo2 in either the saline control or colloid challenge groups over the 6-hour experiment despite marked increases in cardiac output and oxygen delivery during colloid challenge. At the maximum dose used, adrenergic agents increased Vo2 by the following: dopamine, 56%; dobutamine, 51%; norepinephrine, 43%; epinephrine, 61%. We conclude that adrenergic agents cause a significant increase in whole body Vo2 at moderate doses in normal dogs.

Changes in oxygen consumption relative to oxygen delivery in endotoxemic dogs given adrenergic agents

Adrenergic agents (AAs) have been used in critically ill patients to increase oxygen delivery (DO2). Associated parallel increases in oxygen consumption (VO2) have been noted and are thought to represent improved tissue oxygen utilization at supraphysiologic levels of DO2. We hypothesize that the increase in VO2 associated with the use of AAs in septic animals is secondary to direct, obligate, metabolic effects of the agents themselves. In this study, mongrel dogs were anesthetised, paralyzed, and had minimum temperature maintained on a warming blanket. Pulmonary and systemic hemodynamics were monitored. DO2 was calculated, while VO2 was measured directly with a metabolic cart. All dogs were given an Escherichia coli challenge and a colloid fluid resuscitation. Two hours after the onset of endotoxemia, baseline values were obtained, followed by four progressively larger doses of saline, dobutamine, or dopamine. At each dose there was a 40-min stabilization period and a 20-min measurement of hemodynamics and VO2. Data were analyzed using analysis of variance with a Scheffe's S test. P values of < 0.05 were considered significant. The control group slowly decreased VO2 during the 6-hr experiment to 73% of baseline. Dobutamine increased VO2 to 119% of baseline (31% above control) and dopamine to 111% of baseline (28% over control). We conclude that adrenergic agents cause a significant increase in whole body VO2 at moderate doses in septic dogs. It is likely, therefore, that the "pathologic" relationship between VO2 and DO2 described in critically ill patients is partially due to the direct metabolic effects of AAs.

The role of duplex ultrasound arterial imaging in patients with penetrating extremity trauma

OBJECTIVE

To investigate the role of color-flow duplex ultrasound vascular imaging in screening patients for potential arterial injuries following penetrating trauma of the extremities.

DESIGN

In this prospective study, patients with penetrating trauma in proximity to major peripheral vessels but without signs of arterial injury underwent color-flow duplex imaging. Patients with abnormal color-flow duplex examination results were then studied with angiography, and the results of the two studies were compared. In patients who presented with signs of arterial injury, immediate operative exploration and/or angiography was performed.

SETTING

An urban trauma center.

PATIENTS

Patients entering the trauma center with penetrating trauma between April 1991 and December 1992.

RESULTS

Seventy-seven patients with 86 extremity injuries were initially screened with color-flow duplex imaging. Four patients had positive study results, and all injuries were confirmed with angiography (100% true positive). No missed arterial injuries were detected in clinical follow-up.

CONCLUSIONS

Color-flow duplex imaging reliably detects occult arterial injuries and may also have a role in following up minor injuries treated without surgery.

Can adult trauma surgeons care for injured children?

Large urban trauma centers care for injured children as well as adults in many areas of the country, but the quality of care in these hospitals has not been evaluated versus that available at pediatric trauma centers. The recent validation of TRISS methodology in pediatric populations allowed us to evaluate the quality of pediatric trauma care being provided in a level I trauma center treating injured patients of all ages. We reviewed the records of 353 injured children (aged 0-17 years) who were admitted to our trauma center over a 30-month period for the following data: demographics, mechanism of injury, initial physiologic status (RTS), surgical procedures required, need for intensive care, nature and severity of the injuries (ISS), and outcome. TRISS analysis allowed us to compare our population with the Major Trauma Outcome Study. Only two of the 21 total deaths (overall mortality, 6%) were unexpected, and there were seven unexpected survivors. One hundred twenty-one patients underwent emergency surgical procedures and 63 required admission to the intensive care unit. The Z scores ranged from +0.32 for the children aged less than 2 years to +3.98 for the older age group (14-17 years). We conclude that the quality of care for pediatric trauma patients admitted to trauma centers that care for patients of all ages compares favorably with national standards. In most areas of the country, improvements in pediatric trauma care will likely come from addressing the special needs of injured children in general trauma centers rather than from developing separate pediatric facilities.

The Surgical Infection Society's policy on human immunodeficiency virus and hepatitis B and C infection. The Ad Hoc Committee on Acquired Immunodeficiency Syndrome and Hepatitis

The Ad Hoc Committee on Acquired Immunodeficiency Syndrome and Hepatitis of The Surgical Infection Society has outlined its policy regarding three deadly blood-borne viral infections. The risk of transmission of these microbes, the role of preoperative testing, the problem of the human immunodeficiency virus-infected surgeon, and conduct in the operating room are discussed.

Relationship between skin fluorescence and blood flow in normal and in chronically ischemic subjects dosed with fluorescein

To elucidate parameters diagnostic of chronic ischemia, the fluorescence of skin on the foot, leg, arm, and forehead of six chronically ischemic patients and six normal subjects injected with fluorescein was measured serially using a surface-measurement fluorometer (dermofluorometer). Simultaneously collected plasma samples were assayed spectrofluorometrically for unmetabolized fluorescein. The time courses of plasma fluorescein content and dermofluorometer readings were jointly analyzed by combining a standard pharmacokinetic model, a model predicting skin site from plasma concentrations of fluorescein, and a model predicting the dermofluorometer response to those skin concentrations. Fluorescein plasma clearance (0.22 +/- 0.06 versus 0.46 +/- 0.20 L/h/kg) in ischemic patients was only half, and half-life was double (2.4 +/- 1.0 versus 1.3 +/- 0.3 h) those in normal subjects, with volume of distribution (Vdss = 0.46 L/kg) being similar. Despite the ischemia diagnosis for all patients involving claudication of the lower extremities, patients could be distinguished statistically from normal subjects on the basis of fluorescence readings taken on the arm, but not those using the foot or leg. The rate constant describing flux of fluorescein from the arm skin site in patients was only half that in normal subjects, and the peak reading on the arm occurred at 42 +/- 14 min after fluorescein injection in patients, but at only 15 +/- 6 min in normal subjects. Lack of discrimination between subject groups via leg and foot readings may be due to several physiologic and/or experimental factors, including the need to take skin surface readings much earlier than previously recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Independence of intrapericardial right and left ventricular performance in septic pulmonary hypertension

To study the effect of septic pulmonary hypertension on right/left ventricular intrapericardial interactions thirteen trauma patients, seven septic and six non-septic controls, were compared. Ventricular volumes were derived from first-pass or gated equilibrium radionuclide angiocardiography, and related to body surface area. Systemic and pulmonary pressures were measured invasively. Pulmonary arterial pressure was significantly increased in the sepsis group. Although right ventricular end-diastolic volumes were higher in sepsis, left ventricular end-diastolic volumes were not decreased. In terms of intrapericardial right/left ventricular interactions these results indicate that the right and left ventricles operate independently in septic pulmonary hypertension.

Iodinated contrast media effects on extravascular lung water, central blood volume, and cardiac output in humans

Intravascular contrast media produce pulmonary edema in one rat model, but not in dogs or pigs. In humans, pulmonary edema after contrast media is rarely diagnosed, but subclinical edema could be more frequent than believed previously. Therefore, the authors prospectively studied the effects of diatrizoate (n = 5) and ioxaglate (n = 5) on extravascular lung water, central blood volume, and cardiac output in ten patients undergoing routine radiographic procedures. Variables were measured by thermal-dye dilution before and every 5 minutes after completion of the procedure for four repetitions. Extravascular lung water and central blood volume did not change significantly, indicating that pulmonary edema or pulmonary congestion did not occur. Cardiac output was elevated by 10.6% immediately after the procedure, but returned to baseline during the 10 following minutes. The authors conclude from this preliminary study in a small number of patients that intraarterial contrast media (less than 1.5 g/kg body weight of iodine) did not produce pulmonary edema or pulmonary congestion, even at a subclinical level.

Post-traumatic changes in, and effect of colloid osmotic pressure on the distribution of body water

The aim of this study was to define the post-traumatic changes in body fluid compartments and to evaluate the effect of plasma colloid osmotic pressure (COP) on the partitioning of body fluid between these compartments. Forty-two measurements of plasma volume (green dye), extracellular volume (bromine), and total body water (deuterium) were done in ten traumatized patients (mean Injury Severity Score, ISS, = 34) and 23 similar control studies were done in eight healthy volunteers who were in stable fluid balance. Interstitial volume, intracellular volume, and blood volume were calculated from measured fluid spaces and hematocrit; COP was directly measured. Studies in volunteers on consecutive days indicated good reproducibility, with coefficients of variation equal to 3.5% for COP, 6.3% for plasma volume, 4.5% for extracellular volume, and 4.9% for total body water. COP values extended over the entire range seen clinically, from 10 to 30 mmHg. Interstitial volume was increased by 55% in patients, but intracellular volume was decreased by 10%. We conclude (1) that posttraumatic peripheral edema resulting from hemodilution is located in the interstitial compartment, with no intracellular space expansion; and (2) that interstitial volume, but not intracellular volume, is closely related to plasma COP.

Appendicitis: continuing diagnostic challenge

Recognition of appendicitis depends on an understanding of the underlying pathophysiology and anatomy that shape the clinical presentation. Knowledge of the clinical symptoms and signs that distinguish between appendicitis and competing diagnoses enables the clinician to differentiate appendicitis from other pathologies. Variations in anatomy, pathophysiology, symptoms, and signs are described for adult men, ovulating women, pregnant women, children, the elderly, and immunocompromised patients.

The role of pulmonary lymphatics in the clearance of hydrostatic pulmonary edema

Pulmonary lymphatics are believed to play a major role in preventing the formation of pulmonary edema, but their role in clearance of established edema has not been defined. To measure the lymphatic contribution to the clearance of acute hydrostatic pulmonary edema, a lung lymph fistula was established in 16 anesthetized sheep. Pulmonary edema was induced by a rapid volume infusion of Ringer's lactate (six animals) or homologous plasma (six animals). Four control animals received no fluid. Simultaneous measurements of lymph flow and extravascular lung water (EVLW) were made. Data were analyzed for the resolution phase of pulmonary edema. The contribution of the pulmonary lymphatics to resolution was expressed as a percentage of total lung water resolved. Resolution rates for crystalloid and plasma infusion groups were 3.8 +/- 2.4 cc/kg/hr and 2.7 +/- 1.0 cc/kg/hr, respectively. There was no statistically significant difference between the groups in terms of EVLW increases or resolution rates. Net measured pulmonary lymph flow during the resolution phase of pulmonary edema was 0.33 +/- 0.18 cc/kg/hr and 0.39 +/- 0.20 and accounted for only 8.8 and 14.6% of resolved pulmonary edema in these respective groups. These data suggest the pulmonary lymphatic drainage plays a very minor role in the clearance of acute hydrostatic edema. The lungs appear to be capable of resolving as much as 40% per hour of increased extravascular lung water produced under these circumstances.

Regional trauma system design: critical concepts

Regional trauma system implementation is proceeding in a number of areas of the United States in response to a demonstrated need for improved trauma care to prevent unnecessary death. The critical questions underlying the design of such systems and the current state of knowledge and opinion regarding each of them have been defined and these provide a framework for system planning. Additional data are badly needed in several areas to provide a more rational basis for system configuration. It is hoped that systems currently being implemented will include appropriate data elements in their trauma registries to answer the remaining questions in succeeding years.

Acute appendicitis: high-resolution real-time US findings

High-resolution, real-time ultrasonography (US) with graded compression was used to evaluate 90 patients with clinically suspected acute appendicitis. US visualization of a noncompressible appendix was the primary criterion for a diagnosis of acute appendicitis. The overall sensitivity was 89%, the specificity was 95%, and the accuracy was 93%. When the results in women were analyzed separately (n = 49), the overall accuracy was 96%. Several important limitations of US scanning were encountered. There were three false-positive examinations in patients with a sonographically visible appendix whose symptoms spontaneously resolved. Another patient had a normal compressible appendix with a thin (2-mm), symmetric wall surrounded by ascites. There were three nondiagnostic studies (3%) due to inability to compress the cecum and right lower quadrant adequately because of exquisite tenderness (two patients) or massive ascites (one patient). When interpreted in light of the clinical examination, sonography should significantly reduce the rate of false-negative appendectomies, particularly in women.

Prehospital intravenous fluid therapy: physiologic computer modelling

A computer model incorporating known behavior of the cardiovascular system and intravascular:interstitial fluid exchange was designed which allowed bleeding rate, IV infusion rate, and prehospital care times to be independently specified. All possible circumstances were examined. The model shows that IV's are potentially of benefit only when all of the following occur: 1) the bleeding rate is initially 25-100 ml/min, 2) the prehospital time exceeds 30 minutes, and 3) the IV infusion rate is approximately equal to the bleeding rate. IV infusions therefore appear of little benefit in the usual urban environment and have a sharply limited role overall. The possibility of pulmonary edema from fluid overload in nonhypovolemic patients, and reluctance of field personnel to infuse fluid at the rates necessary to produce benefit raise further questions about realistic benefit of IV's in all but the most rural systems.

Necrotizing amebic colitis: a frequently fatal complication

Acute necrotizing amebic colitis is an uncommon but life threatening development with a high mortality rate, even when properly diagnosed and treated. We report six cases of acute necrotizing amebic colitis, none of which were diagnosed preoperatively. At operation, five of the six patients had friable, necrotic, and gangrenous colon. A right hemicolectomy with ileostomy was performed in two patients and a subtotal colectomy with ileostomy was performed in four patients. Five of the six patients died within 4 weeks of operation. The sole survivor was the patient who had received metronidazole preoperatively. Only after histologic examination of the surgical specimen was the diagnosis made in all cases. If the diagnosis can be made preoperatively and antiamebic therapy instituted, surgical resection may decrease the high mortality rate of this disease.

Initial assessment and resuscitation

It has been estimated that one fourth to one third of the deaths from trauma could be prevented by more effective initial care. The majority of traumatized patients who present to the emergency department do not have life-threatening injuries and may be assessed in an orderly manner. Roughly 10 per cent of patients will have life-threatening injuries, however, and speed in assessment, diagnosis, and therapy is crucial to their survival.

The prehospital use of external counterpressure: does MAST make a difference?

Military anti-shock trousers (MAST) have achieved widespread civilian usage because of reported effectiveness in treating hypovolemic shock. The literature, however, consists of either case reports or series in which no controls were evaluated. No published reports exist which compare similar groups of patients treated with and without MAST in the pre-hospital setting. We reviewed the paramedic and emergency department records of 226 patients sustaining moderate to severe trauma who were transported to San Francisco General Hospital by paramedics over a 15 month period. MAST usage during this period was approximately random as a result of logistical and training constraints. For analysis, patients were divided into two groups: those in whom MAST was applied and inflated during transport and those in whom it was not used. Paramedic interventions other than MAST were similar in both groups. Trauma Scores (TS), and blood pressure index (greater than 90 = 4, 70-89 = 3, 50-69 = 2, 0-49 = 1, no pulse = 0), were calculated for initial field observations and initial emergency room evaluation after hospital arrival. Patients with isolated head injury were excluded. The average change in TS and BP index (E.R.--field value) was calculated for MAST and non-MAST groups of patients. Mortality and total field times were also evaluated. Average TS and BP index increased slightly in both groups. Use of MAST produced no significant improvement in trauma score, BP index, or mortality over non-MAST patients. There was no demonstrable field benefit of MAST in fully arrested patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Digital cutaneous fluorometry: correlation between blood flow and fluorescence

Central to the use of fluorescein in vascular diagnosis is the requirement that the intensity of evoked fluorescence be proportional to blood flow. With the introduction of the digital dermofluorometer, a device that quantitates cutaneous fluorescence, establishment of this relationship has become possible. After experimentally producing measured reductions in the distal aortic flow of eight rabbits, the ratio of fluorescence in the flow-restricted and unrestricted areas was obtained by measuring hind- and forelimb fluorescence. At any time between 20 and 60 minutes following a bolus injection of sodium fluorescein (1 mg/kg body weight), there was a significant linear relationship (p less than 0.05, r greater than 0.75) between residual aortic flow and the ratio of hind-/forelimb fluorescence. Simultaneously obtained plasma fluorescein concentrations decayed rapidly by first-order kinetics with a half-life of 12.5 minutes, regardless of the degree of distal aortic occlusion. The time course of the rise and fall of cutaneous fluorescence was slower than that of the plasma fluorescein concentration, proving that interstitial rather than intravascular fluorescein was responsible for the measured fluorescence. We conclude that the intensity of tissue fluorescence is linearly related to blood flow and that conclusions regarding perfusion may be drawn from relative fluorescence at any time between 20 and 60 minutes following a bolus injection of fluorescein. Furthermore, the passage of fluorescein into the interstitium is dependent on a time-limited diffusion process, which along with flow, establishes the time to peak and the absolute amplitude of the tissue fluorescence curve.

Morphologic and physiologic correlates of increased extravascular lung water

The thermal-green dye indicator dilution method for measuring extravascular lung water (EVLW) has been extensively validated against gravimetric EVLW, but no reports to date have correlated in vivo EVLW with pulmonary physiologic parameters or postmortem lung morphologic findings. A predetermined level of hydrostatic edema was created in 12 swine by the variable inflation of a left atrial Foley balloon. EVLW, arterial and mixed venous blood gases, and mixed expired gases were before balloon inflation and periodically throughout the experiment. The animals were killed by rapid excision of the lungs, which were then reinflated and frozen in liquid nitrogen. Postmortem morphometrics were performed by photographing random sections of the lungs while still frozen. A blinded observer measured perivascular cuff width, interlobular septal width, and percent of alveoli flooded on each section. Perivascular cuff width:vessel diameter ratio correlated linearly with EVLW (r2 = 0.76; p less than 0.0001) and increased 25% for each 5 ml/kg of EVLW. Alveolar flooding did not begin until EVLW had doubled from normal to 11.4 ml/kg but then increased linearly with EVLW, reaching 60% flooding at 21 ml/kg. Increase in shunt fraction correlated linearly with increases in EVLW (r2 = 0.76; p less than 0.001) and increased approximately 10% for each EVLW increment of 5.0 ml/kg. We conclude that in vivo EVLW measurements correspond closely to more conventional morphologic and physiologic measurements and sensitively detect all levels of pulmonary edema from minimal perivascular cuffing to fulminant alveolar flooding.

Crystalloid resuscitation of patients with pulmonary contusion

One hundred nine patients with the diagnosis of pulmonary contusion were studied retrospectively. Thirteen deaths were respiratory related (12 percent of patients). All of the patients were quickly resuscitated with crystalloid solutions as necessary to restore perfusion to normal. Twenty-eight of the most severely injured patients, all of whom were intubated and ventilated and in whom serial PaO2 and total protein determinations were available, were examined for the relationship between crystalloid induced hemodilution as measured by the plasma colloid oncotic pressure and oxygenation as measured by the PaO2/FiO2 ratio. When survivors and nonsurvivors were analyzed by group, both individually and collectively, no correlation was found between oxygenation and oncotic pressure. Survivors and nonsurvivors exhibited similar post-traumatic courses in the PaO2/FiO2 ratios with differences not becoming significant until the eleventh day after injury. We conclude that contusion is not a progressive lesion unless pneumonia supervenes and that pulmonary dysfunction after contusion is unrelated to hemodilution.

Pulmonary extravascular fluid accumulation following intracranial injury

Previous investigations have reported an 11 to 71% incidence of pulmonary edema following CNS injury, based on post-mortem examinations. No premortem assessment to date has been made of the frequency and severity of in vivo pulmonary fluid accumulation following acute head injury. The thermal green dye technique was used to objectively determine extravascular lung water (EVLW) in 18 comatose patients with severe acute intracranial injuries resulting from trauma or spontaneous subarachnoid hemorrhage. Patients with aspiration, lung contusion, or pneumonia were excluded from the study. Control values for EVLW were obtained on admission from a group of 13 traumatized patients without head injury or evidence of pulmonary disease or injury. Intracranial injury patients who had EVLW values greater than two standard deviations above the control group mean were considered to have pulmonary edema. The incidence of pulmonary edema in this series was 50% (9/18). Extravascular lung water was determined post mortem in five patients using the gravimetric method of Pearce. The results suggest that pulmonary edema is a distinct clinical event occurring frequently after acute intracranial injury. Edema appears to be mediated by increased pulmonary microvascular permeability, and is not primarily dependent on postinjury changes in intracranial pressure or pulmonary vascular pressures.

Effect of inhalation injury on lung water accumulation

Fourteen thermally injured patients with severe inhalation injury were sequentially studied with the thermal-green dye double indicator dilution technique of extravascular lung water (EVLW) measurement. Eight females and six males (average age, 49 years, and average thermal burn, 37% body surface) were studied for 2-31 days postinjury. All were burned in a closed space, had facial burns, soot in their sputum, and a mean carboxyhemoglobin level of 30%. Nine patients died, six of sepsis, one each of acute renal failure, hepatorenal syndrome, and anoxic brain damage. Mean EVLW on admission was 7.0 +/- 2.9 ml/kg and remained normal in the five survivors and in the patients dying of acute renal failure and anoxic brain damage. Six patients had increases in EVLW, caused by altered pulmonary capillary permeability in five and by elevation of hydrostatic pressures in one patient (hepatorenal death). Of the five patients with permeability edema, one appeared to result from a direct early effect of inhalation injury resulting in an EVLW of 13.3 ml/kg on admission. The other four patients had EVLW increases after the onset of sepsis, resulting in a mean EVLW of 23.2 +/0- 7.2 ml/kg at death (p less than 0.01). Seventy-one per cent of all patients developed pneumonia, which appears to have caused an EVLW increase in one patient; the other EVLW increases were caused by systemic sepsis. In our present study of 14 patients with definite severe inhalation injury only one had an early increase in EVLW directly related to the inhalation injury, an early effect on capillary permeability presumably caused by direct chemical toxicity of inhaled gases. The remaining four cases of permeability edema occurred 4-24 days postinjury and resulted from burn wound or pulmonary sepsis. We thus conclude that increases in EVLW after thermal and inhalational injury are primarily caused by systemic or pulmonary sepsis, and have a delayed onset. Early increases in EVLW may be a result of the chemical toxicity of inhaled gases but are very uncommon, moderate in degree, and are seen only with the severest cases of inhalation injury.

Surface quantification of injected fluorescein as a predictor of flap viability

In a laboratory model, quantitative skin-surface fluorescence has been used to reliably measure skin perfusion in ischemic random flaps and to predict viability. The method is reproducible and allows investigators to sequentially monitor soft-tissue perfusion using a fluorescent indicator. It is superior to the conventional fluorescein test (Wood's lamp method), which allows only a single subjective assessment within a 24-hour period.

A single indicator technique to estimate extravascular lung water

An estimate of extravascular thermal volume (EVTV) calculated from a single thermal indicator (SI) sampled in the pulmonary artery and the femoral artery was compared with direct gravimetric measurements of extravascular lung water (EVLW) on 47 dogs and with simultaneous double indicator (DI) dilution measurements made on 62 dogs and 38 humans with heat as the diffusible indicator and green dye as the intravascular indicator. For the gravimetric measurements the relation was EVTV(SI) = 1.00 EVLW(grav) + 61 ml r = 0.91. When compared with double indicator dilution measurements, the results were EVTV(SI) = 1.10 EVTV(DI) + 17 ml r = 0.94 for dogs and EVTV(SI) = 0.89 EVTV(DI) + 66 ml r = 0.97 for humans. A total of 1880 measurements were made over a range of EVTV(DI) from 70 to 2150 ml. The single indicator measurements of EVTV agrees with the double indicator measurements of EVTV and with the direct gravimetric measurements of EVLW and can be performed with standard catheters and without the withdrawal of blood.

Determinants of pulmonary interstitial fluid accumulation after trauma

We have sequentially measured the daily extravascular lung water (EVLW) changes in 16 severely traumatized patients to better define the principal etiologic factors causing post-traumatic interstitial fluid accumulation and subsequent respiratory failure. We found that severe hemorrhagic shock (mean initial BP = 40 mm Hg), massive transfusion (12.7 liters of blood), and crystalloid resuscitation with resulting hemodilution of plasma colloid osmotic pressure (PCOP) (PCOP less than or equal to 15 mmHg) do not cause EVLW accumulation. Post-traumatic elevations in EVLW were seen after lung contusion (average EVLW = 15.3 +/- 2.5 ml/kg), sepsis (average EVLW = 17.1 +/- 2.9 ml/kg) and cardiac failure (EVLW = 15.3 +/- 0.3 ml/kg). Severe hemorrhagic shock, massive transfusion, and crystalloid resuscitation with resulting hemodilution of plasma colloid oncotic pressure do not cause EVLW accumulation. Post-traumatic elevations in EVLW are seen after lung contusion, sepsis, and cardiac failure. We conclude that after trauma elevations in capillary hydrostatic pressure and capillary permeability alterations resulting from lung contusion or sepsis are the primary determinants of interstitial fluid accumulation.

Measurement of extravascular renal water by the thermal dye indicator dilution technique

Simple mechanical swelling of the renal parenchyma against an unyielding renal capsule may be responsible in part for the development of oliguria and acute tubular necrosis. However, until now, renal swelling was difficult to measure, except by postmortem gravimetric techniques. A new in vivo technique, the thermal dye double indicator dilution technique, was used to assess renal swelling by measuring extravascular renal water. Ice cold indocyanine green dye solution was injected rapidly into the renal artery of 5 mongrel dogs, and the thermal dilution and dye dilution curves were recorded simultaneously by means of a thermistor catheter in the renal vein. The curves were corrected for the response time of the measuring systems, then the extravascular renal water was compared (renal blood flow multiplied by the difference in mean transit times of the thermal dilution and dye dilution curves). The results were compared to the gravimetrically determined extravascular renal water. A high correlation was found to exist between the thermal dye dilution method and the gravimetric method (r = 0.92, X = 0.65 Y + 19.8, p less than 0.05). These preliminary results are encouraging and warrant further trials, inasmuch as this technique would allow the sequential in vivo measurement of renal edema. It is therefore feasible to quantitate the effect of clinical insults, such as hypovolemic shock or sepsis, on the kidney, and to assess the value of different therapeutic interventions. A small body of evidence attempts to relate the role of simple mechanical swelling of the kidney to the pathogenesis of acute renal failure.