Exercise decreases plasma antioxidant capacity and increases urinary isoprostanes of IPF patients.

We tested whether markers of systemic oxidant stress were detectable in 29 typical IPF patients, and whether these increased after low level exercise. We obtained resting plasma for measurement of amino terminal pro brain natriuretic peptide (NT-proBNP), and plasma and urine samples for isoprostanes and total nitrite. Total antioxidant capacity (TAC) was measured in plasma, and H(2)O(2) was measured in urine. Subjects exercised at ˜50 W on a semi recumbent bicycle until limited by dyspnea. Samples were obtained immediately after exercise for measurement of the same variables. Plasma and urine samples were also obtained at rest from 6 normal individuals over 40 years of age solely to establish comparison values for NT-proBNP, nitrite, H(2)O(2) and TAC assays. Plasma NT-proBNP was high at rest and after exercise, suggesting pulmonary arterial hypertension. IPF patients' resting NT-proBNP concentrations apparently exceeded those of normal controls. IPF plasma isoprostanes at rest exceeded the normals. IPF urine isoprostanes increased significantly after exercise (P = 0.047 by signed rank test); and, plasma TAC decreased significantly after exercise (P < 0.001 by signed rank test). Neither plasma nor urine nitrite changed significantly after exercise. H(2)O(2) concentration was quite high after exercise in some IPF subjects' urine. IPF patients demonstrate systemic oxidant stress at rest detectable as increased isoprostanes in the circulation. An increase in urine isoprostanes and a decrease in plasma TAC after exercise suggest that reactive oxygen species (ROS) are produced during low level exercise done by IPF patients.

Race and ethnicity impact on the maximum proliferative response in peripheral blood lymphocytes from HIV-seropositive individuals.

The effects of race and ethnicity on immunological function have not been fully studied in patients infected with HIV-1. To study such differences, 54 patients on virally suppressive highly active antiretroviral therapy (HAART) with CD4 counts >200 cells/microL had their peripheral blood lymphocytes (PBL) evaluated for response to recall antigen. Significant differences were found in the maximum responses for PBL from black individuals compared with those from white individuals, and the differences were highly significant when responses for African-Americans were compared with those for white-Hispanics. These findings support work delineating ethnicity and race as significant variables to be taken into account when looking at vaccination strategies and responsiveness to therapeutic pharmacological interventions.

Effects of level and degree of spinal cord injury on male orgasm.

DESIGN: Controlled, laboratory-based analysis. OBJECTIVE: To determine the impact of spinal cord injuries (SCIs) on the ability to achieve male orgasm. SETTING: US academic medical center. METHODS: A laboratory-based analysis of the ability of 45 men with SCIs and 16 able-bodied control subjects to achieve orgasm coupled with a detailed neurologic examination, history and physical examination, and administration of the International Index of Erectile Function. RESULTS: Men with SCIs were less likely than controls to achieve orgasm. Mean latency to orgasm, blood pressure and heart rates at orgasm were not significantly different between controls and SCI subjects. Men with incomplete SCIs were more likely to achieve orgasm than those with complete SCIs. A disconnect was noted between the presence of orgasm and the presence of ejaculation. Men with complete lower motor neuron dysfunction affecting their sacral segments were less likely to achieve orgasm than men with any other patterns of SCI. CONCLUSION: These results document the ability of men with complete SCIs to achieve orgasm. Characteristics of orgasm in men with SCIs as compared to able-bodied subjects are similar. Although orgasm and ejaculation are more likely to occur together, a number of men with SCIs achieve orgasm without ejaculation. Further research should explore the possibility of retraining ejaculatory and orgasmic responses in men with SCIs.

Acute and chronic disability among U.S. farmers and pesticide applicators: the National Health Interview Survey (NHIS).

The National Health Interview Survey (NHIS) is a multipurpose household survey of the U.S. civilian non-institutionalized population conducted annually since 1957. From 1986 to 1994, over 450,000 U.S. workers, age 18 years and older, participated in a probability sampling of the entire non-institutionalized U.S. population; variables collected included a range of measures of acute and chronic disability. The objective of the present study was to assess predictors of health status, and acute and chronic disability for farmers and pesticide applicators (pesticide-exposed workers) compared to all other U.S. workers using the 1986-1994 NHIS. After adjustment for sample weights and design effects using SUDAAN, several measures of acute and chronic disability and health status were modeled with multiple logistic regression. Farmers (n = 9576) were significantly older compared to all other U.S. workers (n = 453,219) and pesticide applicators (n = 180). Farmers and pesticide applicators had a higher proportion of males, whites, and Hispanics and were less educated. After adjusting for age, gender, race-ethnicity, and education, compared to all other workers, farmers were significantly less likely to report acute and chronic disability and health conditions, while pesticide applicators were more likely to report chronic disability, health conditions, and poor health. Given the cross-sectional nature of the data and the significant job demands of farming, both leading to a relative healthy worker effect, the present results indicate that at any point in time, farmers report less acute and chronic disability, compared to other U.S. workers, whereas pesticide applicators report similar or poorer health.

The use of cell salvage during radical retropubic prostatectomy: does it influence cancer recurrence?

OBJECTIVE: To assess whether there is a difference in the biochemical recurrence rate in patients who had radical retropubic prostatectomy (RRP) with or without cell salvage transfusion. PATIENTS AND METHODS: The records of 769 consecutive patients undergoing RRP between 1992 and 1998 were retrospectively reviewed. Patients having adjuvant hormonal treatment, postoperative external beam radiotherapy, or a follow-up of < 1 year were excluded from the analysis. The remaining 408 patients were categorized into three groups: 87 who received cell-salvaged blood using a commercial cell saver; 264 receiving only autologous transfusion; and 57 with no transfusion. Disease recurrence was defined as a prostate-specific antigen (PSA) level of> 0.2 ng/mL. Bivariate and multivariate logistic regression analyses were used to assess and compare the risk of cancer recurrence in the three groups. Covariates used in the multivariate analyses included Gleason score, preoperative PSA level, seminal vesicle involvement and surgical margins. RESULTS: The mean (range) follow-up was 40.2 (12-104) months; there were no significant differences among the groups in initial PSA level and Gleason score. In the multivariate logistic regression analysis, the initial PSA, Gleason score, seminal vesicle involvement and surgical margins, but not transfusion group, were independent predictors of recurrence. CONCLUSION: Cell salvage during RRP does not influence the recurrence of prostate cancer. Cell salvage is a safe method of transfusion during RRP.

Serum citrulline and rejection in small bowel transplantation: a preliminary report.

BACKGROUND: There is no known serum marker for intestinal rejection. Serum concentrations of the amino acid citrulline arise almost exclusively from the intestinal mucosa. We examined the impact of acute cellular rejection (ACR) of intestinal allografts on serum citrulline levels. METHODS: Citrulline concentrations were assayed in serum samples of healthy volunteers (n=6) and seven patients who underwent small bowel transplants (SBTx). Trends in mean citrulline concentrations versus degree of ACR were assessed by matching posttransplantation citrulline concentrations with patients' grade of ACR at time of serum collection. Rejection was confirmed by biopsy and graded by following standardized criteria. An additional patient had citrulline concentrations determined for 31 sequential specimens 3-60 days posttransplant. RESULTS: Mean citrulline concentrations in controls were significantly higher than posttransplantation samples at any rejection grade. Mean concentrations declined significantly as rejection severity increased. The overall downward trend was statistically significant (P<0.05). In sequential measurements, citrulline levels increased significantly over time with declining severity of rejection. The increase in mean citrulline concentration between posttransplant days 3-16 and 52-60 was significant (P<0.01). CONCLUSIONS: Serum citrulline levels decline with increasing grade of ACR and may be a useful serum marker for intestinal rejection.

Safety and efficacy of topical mitomycin C in myringotomy patency.

OBJECTIVE: To develop an alternative method for prolonged middle ear ventilation using topical mitomycin C. STUDY DESIGN AND SETTING: Twenty guinea pigs with normal ears had bilateral myringotomies performed using the argon laser. After myringotomy, either mitomycin C (0.4 mg/mL) or saline pledgets were applied topically. Monitoring consisted of otomicroscopy and distortion-product otoacoustic emissions. RESULTS: Before myringotomy, all tympanic membranes were intact, and distortion-product otoacoustic emissions were measurable. After myringotomy, none (0%) of the saline-treated myringotomies were patent at day 7 as compared with 100% of the mitomycin C-treated myringotomies. At day 42, 10 (52.6%) of 19 mitomycin-treated myringotomies remained patent and 4 (28.6%) of 14 were patent at 131 days. Five (13.1%) ears developed purulent otorrhea; 3 were mitomycin C-treated and 2 were treated with saline solution.- Distortion-product otoacoustic emissions testing did not document any evidence of ototoxicity. CONCLUSION: Topical mitomycin C appears to be safe and effective at prolonging the duration of myringotomy patency in the guinea pig. SIGNIFICANCE: Mitomycin C may be useful as an adjunct for preventing myringotomy closure.

Uncorrected binocular distance visual impairment in U.S. Hispanic children and adolescents.

PURPOSE: To assess and compare uncorrected binocular distance visual impairment rates in U.S. Hispanic children and adolescents. METHODS: Data from the Hispanic Health and Nutrition Examination Survey, 1982-1984, were analyzed for 6-19 year-old Cuban-Americans (n = 317), Mexican-Americans (n = 2519), and Puerto Ricans (n = 988). Visual acuity was assessed using Sloan Letters or Landolt Rings. RESULTS: Prevalence rates of uncorrected binocular distance visual impairment (20/30 or worse) were 15.5%, 14.9%, and 23.6% for Cuban-Americans, Mexican-Americans, and Puerto Ricans, respectively. After adjusting for age and gender, the differences between Puerto Ricans and both Cuban-Americans and Mexican-Americans were significant (p < 0.05). Children 6-12 years of age had lower visual impairment rates than 13-19 year-old adolescents. Girls had higher age-adjusted visual impairment rates than boys; these gender differences were statistically significant among Mexican-Americans (OR = 1.6, 95% CI = 1.1, 2.2) and Puerto Ricans (OR = 1.7, 95% CI = 1.2, 2.4). CONCLUSIONS: Among Hispanics, Puerto Rican children and adolescents have the highest prevalence rate of uncorrected binocular distance visual impairment; older age and female gender are associated with higher rates of uncorrected visual impairment.

Prevalence of usual-corrected distance visual acuity impairment in Hispanic and non-Hispanic children and adolescents.

Data from the Hispanic Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey I were analysed to determine the prevalence of visual acuity impairment among US Hispanics and non-Hispanics aged 6-19 years. The prevalence of 20/30 or worse distance visual acuity with usual or habitual correction ranged from 10.8% in non-Hispanic whites to 19.1% in Puerto Ricans. Puerto Rican boys aged 13-19 years had significantly greater rates of moderate or greater impairment (20/70 or worse) than 6-12-year-old Puerto Rican boys (5.7% vs. 0.7%). The prevalence of visual impairment was generally greater in girls than in boys. Assessment and comparison of refractive error and eye disease prevalence rates are necessary in future studies to determine factors influencing prevalence of visual acuity impairment in children.

Comparison of two antibiotic regimens in the treatment of perforated appendicitis in pediatric patients.

BACKGROUND AND PURPOSE: An increased incidence of post-surgical infectious complications in children admitted with a diagnosis of perforated appendicitis led to development of a disease-specific antibiogram and modification of our post-operative antibiotic regimen. METHODS: A historical control group comprised of 32 pediatric patients receiving ampicillin, gentamicin, and clindamycin (group AGC) was compared to a cohort of 32 children receiving ticarcillin/clavulanate plus gentamicin (group TG). The surgical procedure, peri-operative management, and inclusion, exclusion and discharge criteria were the same for each group. Outcome measures including length of stay, time to defervesce, incidence of infectious complications, and clinical failures to the antibiotic regimen were compared. RESULTS: The groups were similar with respect to gender, age, weight, surgical time, pre-operative leukocytes, and number of intra-operative bacterial isolates cultured per patient. Length of stay was 10.1 days in group TG and 12.5 days for group AGC (p = 0.0197). The number of clinical failures was reduced from 9 (28.1%) to 2 (6.3%) in group TG (p = 0.02). The time to defervesce was decreased by 1.4 days, and the number of infectious complications was reduced to 2.5-fold in group TG patients. CONCLUSIONS: Ticarcillin/clavulanate plus gentamicin was clinically more effective than ampicillin, gentamicin, and clindamycin combination therapy in the management of perforated appendicitis in our pediatric population.

Expression of GLUT-1 glucose transporter in borderline and malignant epithelial tumors of the ovary.

OBJECTIVE: Cancer cells have increased rates of glucose metabolism when compared to normal cells. One of the mechanisms proposed for the accelerated glucose use in malignant cells is the overexpression of glucose transporters. In this study we evaluated the expression of the GLUT-1 glucose transporter in borderline and malignant epithelial neoplasms of the ovary. METHODS: Histologic sections of tumor tissues from 21 borderline and 82 malignant epithelial neoplasms of the ovary were stained for GLUT-1 using polyclonal GLUT-1 antibody (Dako, Carpinteria, CA) and the labeled streptavidin biotin procedure. DAB was used as chromagen and tissues were counterstained with hematoxylin. RESULTS: Normal ovarian surface epithelial cells were either negative or weakly positive. Of the 82 carcinomas, 81 (98.8%) were positive for GLUT-1. The staining intensity was significantly associated with the grade of tumor (P = 0.001). Of the 21 borderline neoplasms, 20 (95.2%) were positive for GLUT-1. Carcinomas had a significantly stronger stain than borderline tumors (P = 0.0001). The intensity of the stain was also stronger in serous carcinomas compared to other subtypes (P = 0. 0001). Positive cells demonstrated a cytoplasmic membrane staining that was more intense in tumor cells farther away from blood supply. CONCLUSION: Overexpression of the GLUT-1 transporter is associated with the histology and grade of the tumors. Our findings show a progressive increase in the expression of the GLUT-1 transporter from the borderline tumor to the high-grade carcinomas. These data suggest that the expression of this transporter may be closely related to the malignant transformation of epithelial ovarian tumors.

Effect of prenatal zidovudine on disease progression in perinatally HIV-1-infected infants.

OBJECTIVE: To determine the influence of prenatal zidovudine (ZDV) prophylaxis on the course of HIV- 1 infection in children by comparing the clinical outcome of infants born to HIV- 1-seropositive mothers who did versus those who did not receive ZDV during pregnancy. METHODS: Medical records of HIV-1-seropositive mothers and their infants were reviewed retrospectively. Participants were divided according to maternal ZDV use: no ZDV (n = 152); ZDV (n = 139). The main outcome measure was rapid disease progression (RPD) in the infant, defined as occurrence of a category C disease or AIDS-related death before 18 months of age. RESULTS: HIV vertical transmission rates were significantly different (no ZDV versus ZDV: 22.3% versus 12.2%; p = .034). Among infected infants, the RPD rate was 29.4% in the no ZDV group compared with 70.6% in the ZDV group (p = .012), and prematurity was significantly associated with a higher risk of RPD (p = .027). CONCLUSIONS: The rate of RPD was significantly higher among perinatally infected infants born to HIV-infected mothers treated with ZDV than among infected infants born to untreated mothers. The decreased proportion of infected infants with nonrapid disease progression in the former group might be related to the ability of ZDV to block intrapartum transmission preferentially and also to nonrapid disease progression resulting from intrapartum transmission.

Severe perineal lacerations during vaginal delivery: the University of Miami experience.

OBJECTIVE: After childbirth-related third- or fourth-degree perineal lacerations, the estimated incidence of wound disruption, fecal incontinence, or fistula ranges from 1% to 10%. Risk factors associated with severe laceration were analyzed at a single large teaching institution. STUDY DESIGN: This study consisted of an analysis of data from the delivery database of Jackson Memorial Hospital, University of Miami, from 1989 through 1995. Included were vaginal deliveries for which complete information was available on maternal age, parity, ethnicity (white, black, or Hispanic), birth weight, episiotomy versus no episiotomy, type of episiotomy, and delivery (normal spontaneous, vacuum, or forceps). Multiple gestations, cases of shoulder dystocia, cesarean deliveries, patients with a history of cesarean delivery, and babies weighing <500 g at birth were excluded from this study. Both univariate and multivariate analyses were performed with variables such as maternal age, race, birth weight, type of episiotomy if any, and type of vaginal delivery. RESULTS: Among the 71,959 women who were delivered at our institution during the 7-year study period, 50,210 met the inclusion criteria. Through time there had been a decline in the use of episiotomy in general and of midline episiotomy in particular. The annual total number of deliveries also decreased. The episiotomy procedure per se and the type of episiotomy as well as birth weight, assisted vaginal delivery, and older maternal age were identified as independent risk factors associated with third- and fourth-degree perineal lacerations. CONCLUSION: Although episiotomy is an important risk factor for severe lacerations after vaginal delivery, there are other significant independent risk factors, such as maternal age, birth weight, and assisted vaginal delivery, that should be considered in counseling and making decisions regarding delivery modality. Older patients who are being delivered of a first child are at higher risk for severe laceration. Midline episiotomy and assisted vaginal delivery should therefore be avoided in this population whenever possible, especially in the presence of a large baby.

Perinatal outcome of twin pregnancies with one structurally affected fetus: a case-control study.

OBJECTIVE: To determine whether one structurally affected fetus of a twin pregnancy further increases the risk of preterm delivery and to compare perinatal morbidity and mortality in these pregnancies with twin gestations with structurally normal fetuses. STUDY DESIGN: The cases (n = 25) included all twin gestations diagnosed from 1991 to 1994 with a sonographically detected fetal anomaly and a structurally normal co-twin delivered after 24 completed weeks' gestation. The control group consisted of 547 twin gestations delivered during the study period with no sonographically detected structural anomalies in either twin. RESULTS: Compared with controls, pregnancies with a single anomalous fetus (cases) delivered at a significantly lower gestational age (mean +/- SD: 34.0 +/- 3.2 weeks versus 35.6 +/- 3.2 weeks; p = 0.019) and had a significantly increased preterm delivery rate (76.0% vs 55.4%; p = 0.042). There was no significant difference in the incidence of intraventricular hemorrhage or respiratory distress syndrome, yet the perinatal mortality (80.0/1000 vs 6.4/1000; p = 0.000) and the average nursery stay (45.5 +/- 43.3 days versus 17.0 +/- 24.0 days; p = 0.003) were significantly increased for cases compared with controls. In addition, a significantly greater birth weight discordancy (> or = 30%) was seen in cases compared with controls (32.0% versus 9.1%; p = 0.002). The normal co-twin did not show any significant difference in the perinatal outcome variables studied when compared with controls. CONCLUSION: Compared with structurally normal twin pairs, twin gestations with a single anomalous fetus are at a significantly increased risk for preterm delivery. In addition, the anomalous fetus, but not the structurally normal co-twin, has a significantly increased mortality rate and a longer nursery stay. Finally, despite the increased risk for preterm delivery in twin pregnancies with one anomalous fetus, it is the nature of the anomaly itself that dictates the perinatal outcome.

Octreotide scintigraphy for the detection of paragangliomas.

Paragangliomas are neuroendocrine tumors located primarily in the head and neck region, but they can also occur at other sites. Confirming the preoperative diagnosis and detecting synchronous tumors may be difficult in some patients. Octreotide is a somatostatin analog that, when coupled to a radioisotope, produces a scintigraphic image of tumors expressing somatostatin type 2 receptors. Paragangliomas, like many neuroendocrine tumors, have been found to have a high density of somatostatin type 2 receptors on the cell surface. This study compared the results of preoperative octreotide scintigraphy with the histopathology in 21 patients who underwent surgery for presumed head and neck paragangliomas. Octreotide scan findings were positive in 16 patients with paragangliomas and negative in 3 patients with other pathology. One false-positive and 1 false-negative result were obtained. Thus, this test had an accuracy of 90%, a sensitivity of 94%, and a specificity of 75%. Previously unidentified synchronous tumors were identified in 5 patients. On the basis of this series of patients, octreotide scintigraphy appears to be a reliable test to detect paragangliomas and may be quite helpful in preoperative planning.

Gram-negative bacillary bacteremia in human immunodeficiency virus type 1-infected children.

BACKGROUND: HIV-infected children are particularly susceptible to serious bacterial infections including Gram-negative bacillary bacteremia (GNB). However, the information available on GNB in these children is limited. METHODS: Retrospective review of hospital charts of HIV-infected children with GNB diagnosed between 1980 and 1997. The association between bacteremic episodes, degree of immunosuppression, HIV severity, medical treatment and clinical outcome was assessed. RESULTS: Of 680 HIV-infected children, 72 (10.6%) had 95 episodes of GNB. Statistical analyses were restricted to data from the first episode. The mean age (+/-SD) at diagnosis of GNB was 2.5 +/- 2.7 years (median, 1.6). The predominant organisms were Pseudomonas aeruginosa (26.4%), nontyphoidal Salmonella (15.3%), Escherichia coli (15.3%) and Haemophilus influenzae (12.5%). The relative frequency, per 5-year interval, of P. aeruginosa bacteremia steadily increased from 13% during 1980 through 1984 to 56% during 1995 through 1997. There were no cases of H. influenzae bacteremia after January 1, 1990. Eighty percent of GNB developed in children with AIDS and 72.2% developed in those with severe immunosuppression. Hypogamma-globulinemia and neutropenia were present in only 4.9 and 10.4% of first episodes, respectively. The overall case-fatality rate of GNB was 43.0%, and in children younger than 12 months it was 54.2%. CONCLUSIONS: A diagnosis of AIDS and/or severe immunosuppression was associated with increased risk of GNB, especially among younger children. Because of the high mortality of GNB, a broad spectrum antimicrobial therapy that effectively covers these organisms should be promptly instituted when bacteremia is suspected in HIV-infected children.

Prevalence of usual-corrected binocular distance visual acuity impairment in Hispanic and non-Hispanic adults.

OBJECTIVES: The purpose of this study was to perform comparative analyses of the population-based prevalence of usual-corrected binocular distance visual acuity impairment among Hispanics and non-Hispanics in the United States. METHODS: Data from the Hispanic Health and Nutrition Examination Survey (HHANES), 1982-1984, and the National Health and Nutrition Examination Augmentation Survey I (NHANES I-A), 1974-1975, were analyzed to investigate the epidemiology of usual-corrected binocular distance acuity in adults 25 to 74 years of age among Cuban-Americans (N=396), Mexican-Americans (N=1,381), Puerto Ricans (N=513), African-Americans (N=250), and non-Hispanic white Americans (N=2, 660). Binocular distance acuity was assessed using Sloan Letters or Landolt Rings with the participants wearing their corrective lenses, if any. RESULTS: Prevalences of 20/50 or worse usual-corrected binocular distance acuity were 3.5%, 4.6%, and 6.6% for Cuban-Americans, Mexican-Americans, and Puerto Ricans, respectively, in the HHANES; and 7.7% and 4.1% for African-Americans and non-Hispanic whites, respectively, in the NHANES I-A. Within the HHANES, after adjustment for gender and age, Puerto Rican adults were found to have a significantly higher prevalence of visual impairment (20/50 or worse) and were significantly less likely to become unimpaired with usual correction than Cuban-American adults. Within the NHANES I-A, African-Americans were found to have a higher prevalence of visual impairment (20/50 or worse) and were significantly less likely to become unimpaired with usual correction than non-Hispanic whites. Higher prevalences of visual impairment (20/50 or worse) were associated with increasing age for all ethnic groups. After controlling for age, odds of usual-corrected visual impairment (20/50 or worse) were significantly higher in women than in men for Cuban-Americans and Mexican-Americans (odds ratios: 4.5 and 2.6, respectively). CONCLUSIONS: The results from this study suggest that compared to other Hispanic groups and non-Hispanic whites, Puerto Rican and African-American adults may not be receiving similar eye care services and/or may have more severe eye diseases.

Smoking and joint replacement: resource consumption and short-term outcome.

Smoking has been shown to increase morbidity and mortality in surgical procedures. Microvascular and trauma surgeons have documented the adverse effect of smoking in the healing of skin flaps and increased complication rates in the treatment of nonunions. In addition, spine surgeons have shown the adverse effects of smoking in fusion rates. The objective of this study was to assess the effects of smoking on the incidence of short term complications, resource consumption, and length of hospital stay of patients undergoing arthroplasty of the hip and knee. Two hundred two patients who underwent joint replacement surgery were evaluated. A smoking history was assessed for all patients. The number of packs multiplied by the number of years as a smoker were calculated. Operative and anesthesia time and medical severity of illness were documented on all patients. Short term outcome was assessed using hospital charges, length of stay, inhospital consults, and the presence and number of complications during the acute hospitalization. One hundred forty-one primary and 61 revision procedures were done. The mean age of the patients was 66.07 years. Sixty-one percent of the patients had osteoarthritis, 3.9% had rheumatoid arthritis, 4.9% had osteonecrosis, 28% had a failed total knee or hip arthroplasty and 2% had a periprosthetic fracture. There were 25 patients who smoked and 177 patients who did not smoke. For patients who currently smoke, the mean number of packs of cigarettes smoked per day multiplied by the number of years as a smoker was 28.3. The average length of stay in the hospital was 5.1 days and the average hospital charges were $31,315. Patients who smoked were younger and had fewer comorbidities than patients who did not smoke. However, patients who smoked were found to have statistically longer surgical time and higher charges adjusted for age, procedure, and surgeon than patients who did not smoke. Patients who smoked also had longer anesthesia times. A history of smoking is obtained easily on all patients. Preoperative screening for nicotine use can predict operative time and health resource consumption. The exact reasons why patients who smoked had higher hospital charges remain elusive. Probable reasons include higher degree of operative complexity (orthopaedic severity of illness). In addition patients who smoked previously also had better short term outcome than patients who currently smoke. This indicates the importance of smoking abstinence before joint replacement surgery and other surgical procedures. Regardless of the exact causes, it is more expensive to treat patients who smoke. Contracting for orthopaedic care should include a history of smoking.

Proportional assist ventilation in low birth weight infants with acute respiratory disease: A comparison to assist/control and conventional mechanical ventilation.

OBJECTIVES: To compare the physiologic efficacy and safety aspects of proportional assist (PA), assist/control (A/C), and intermittent mandatory ventilation (IMV) in very low birth weight infants with acute respiratory illness and to test the hypothesis that ventilatory pressure requirements are lower and arterial oxygenation is improved during PA when compared with IMV or A/C at an equivalent inspired oxygen fraction. STUDY DESIGN: Randomized, 3-period, crossover design. METHODS: Thirty-six infants were stratified by birth weight (600 to 750, 751 to 900, and 901 to 1200 g) and exposed to consecutive 45-minute epochs of the 3 modalities in a sequence chosen at random. Tidal volumes of 4 to 6 mL/kg were targeted during A/C and IMV. The IMV rate was matched to the rate during an A/C test period. PA was adjusted to unload the resistance of the endotracheal tube and the disease-related increase in lung elastic recoil. RESULTS: Compared with A/C and IMV, PA maintained similar arterial oxygenation with lower airway and transpulmonary pressures (15% to 44% reduction depending on the index variable). The oxygenation index decreased by 28% during PA. No adverse events were observed. The number and severity of apneic episodes and periods of arterial oxygen desaturations were similar with the 3 modes. Similar results were obtained within each birth weight subgroup. CONCLUSIONS: PA safely maintains gas exchange with smaller transpulmonary pressure changes compared with A/C and IMV. It may therefore offer a way of reducing the incidence of chronic lung disease in low birth weight infants.