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.

The measurement of extravascular lung water by thermal-green dye indicator dilution.

The theory and practice of the thermal-dye indicator-dilution method for measurement of EVLW has been discussed, and all available animal data from our laboratory correlating EVTV and gravimetric EVLW have been presented. The method appears to function well over the entire range of edema seen , and to be minimally dependent on cardiac output. Thermal-indicator loss does not seem to be a significant problem and does not impair the accuracy of this method. Out results are consistent with earlier works in the field in identifying significant differences between the isotopic EVLW methods and the thermal-dye method, and it seems likely that these differences are due to the much greater diffusion rate of the thermal indicator.

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.

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.

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.

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.

Appendicitis. A critical review of diagnosis and treatment in 1,000 cases.

One thousand cases of appendicitis seen from 1963 to 1973 were reviewed. The overall negative appendectomy rate was 20%, but in women between ages 20 and 40 it exceeded 40%. Two thirds of the negative appendectomies were due to nonsurgical lesions. Mesenteric adenitis, gastroenteritis, and abdominal pain of unknown cause accounted for one third of the errors in females and two thirds in males. These diseases were best distinguished from appendicitis on the basis of temperature and white blood cell count. The remainder of the errors in females were due to pelvic inflammatory disease or other gynecologic diagnosis and were best distinguished from appendicitis on the basis of history and physical findings. The rate of perforation was 21% overall. The incidence of wound infection was 8.5%. Use of systemic antibiotics did not affect the wound infection rate.

Incidence and outcome of posttraumatic respiratory failure.

From 1972 through 1975, a total of 6,196 patients were admitted to San Francisco General Hospital Trauma Service, of whom 908 required admission to an intensive care unit and 390 required mechanical ventilation. Duration of mechanical ventilation was one week or less for 76%, two weeks or less for 90%, and four weeks or less for 97%. Survival in patients ventilated seven days or less was 64%, in patients ventilated 8 to 14 days it was 55%, and in patients ventilated 15 to 30 days it was 55%. The mortality for ventilated patients aged 20 to 49 years was 23% while for ventilated patients older than age 60 it was 53%. The average age of ventilated patients was 43. Use of controlled-pressure soft-cuff endotracheal tubes has eliminated tracheal-esophageal fistula and tracheal stenosis as causes of morbidity and mortality. Appropriate ventilator alarms have minimized fatalities due to mechanical equipment failure. Complications related to positive pressure ventilation, such as pneumothorax and subcutaneous emphysema, still occur in 12% to 18% of patients. In our patients who survived the acute respiratory distress syndrome, recovery of lung function was universal, and permanent disability was less than 1%.

Severe chest trauma. Morbidity implication.

Patients who sustain fracture of either the first or second rib have severe injuries usually involving multiple systems. In comparing 71 patients with first rib fractures and 49 patients with second rib fractures, we found morbidity and mortality to be similar. A multidisciplinary approach to management of these patients is described and vigorous diagnostic and therapeutic measures are warranted to promptly determine the extent of injury and minimize the frequency of missed diagnosis.

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.

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.

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.

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.

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.

Prevention of complications from prolonged tracheal intubation.

Eight commercially available soft cuff endotracheal tubes were studied to determine the relationship between inflation pressure distention of the cuff. Although the balloon cuff may be easily distensible in open air, when confined within the trachea small increments in the inflation volume may produce high pressures. This means that continuous external control of cuff pressure is required to prevent ischemia of the tracheal wall. Major tracheal complications in a busy ICU were examined before and after the introduction of a controlled pressure tube. Control of intratracheal cuff pressures decreased major tracheal complications tenfold and eliminated complications specifically related to the cuff.

Epidemiology of trauma deaths.

The records of all 437 persons who died from trauma in San Francisco in 1977 were examined. Sixty-five percent of the sample (285 younger than 50 years, and 119 were between ages 21 and 30. Gunshot wounds (140 or 32 percent) and falls (122 or 28 percent) were the most common causes of injury. Fifty-three percent of the sample were dead at the scene of injury before transport could be accomplished, 7.5 percent died in the emergency room, and 39.5 percent died in the hospital. Fifty-five percent of the 359 patients who died within the first 2 days died from brain injury, while 78 percent of the 55 late deaths were due to sepsis and multiple organ failure. In 10 cases (2 percent), death was due to delayed transport or to errors in diagnosis and treatment and was deemed preventable. The key areas in which advances are necessary in order to reduce the number of trauma deaths are prevention of trauma, more rapid and skilled transport of injured victims, better early management of primary brain injuries, and more effective treatment of the late complications of sepsis and multiple organ failure.

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.

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.

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.

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)