Evaluation of surface disinfection methods to inactivate the beta coronavirus Murine Hepatitis Virus.

The list of EPA-approved disinfectants for coronavirus features many products for use on hard, non-porous materials. There are significantly fewer products registered for use on porous materials. Further, many common, high-touch surfaces fall in between non-porous materials such as glass and porous materials such as soft fabrics. The objective of this study was to assess the efficacy of selected commercially available disinfectant products against coronaviruses on common, high-touch surfaces. Four disinfectants (Clorox Total 360, Bleach solution, Vital Oxide, and Peroxide Multi-Surface Cleaner) were evaluated against Murine Hepatitis Virus A59 (MHV) as a surrogate coronavirus for SARS-CoV-2. MHV in cell culture medium was inoculated onto four materials: stainless steel, latex-painted drywall tape, Styrene Butadiene rubber (rubber), and bus seat fabric. Immediately (T0) or 2-hr (T2) post-inoculation, disinfectants were applied by trigger-pull or electrostatic sprayer and either held for recommended contact times (Spray only) or immediately wiped (Spray and Wipe). Recovered infectious MHV was quantified by median tissue culture infectious dose assay. Bleach solution, Clorox Total 360, and Vital Oxide were all effective (>3-log10 reduction or complete kill of infectious virus) with both the Spray Only and Spray and Wipe methods on stainless steel, rubber, and painted drywall tape when used at recommended contact times at both T0 and T2 hr. Multi-Surface Cleaner unexpectedly showed limited efficacy against MHV on stainless steel within the recommended contact time; however, it showed increased (2.3 times greater efficacy) when used in the Spray and Wipe method compared to Spray Only. The only products to achieve a 3-log10 reduction on fabric were Vital Oxide and Clorox Total 360; however, the efficacy of Vital Oxide against MHV on fabric was reduced to below 3-log10 when applied by an electrostatic sprayer compared to a trigger-pull sprayer. This study highlights the importance of considering the material, product, and application method when developing a disinfection strategy for coronaviruses on high-touch surfaces.

Outcome After Fenestrated and Branched Repair of Aortic Aneurysms-Device Failures Predict Reintervention Rates.

BACKGROUND: Previous reports have indicated endovascular repair to be safe and effective in the treatment of complex aortic aneurysms. The endovascular technology evolves rapidly, and continuous evaluation of F/B-EVAR results is critical to detect failing techniques. Our aim was to analyze the outcome after endovascular repair of complex abdominal aortic and thoracoabdominal aneurysms. METHODS: Single-center, retrospective cohort study, of all F/B-EVAR from August 2009 to December 2018. Primary outcomes were branch instability and freedom from reinterventions at 2 years. Secondary outcomes were major adverse events and all-cause mortality at 30 and 90 days. RESULTS: A total of 72 consecutive patients were included, 55 with a complex abdominal aortic aneurysm (AAA) and 17 with a thoracoabdominal aortic aneurysm (TAAA). Two patients were operated on for rupture. A total of 219 vessels were stented through fenestrations (n = 163) or branches (n = 56). Median follow-up was 24 months (IQR 4-24). Fractured bridging stent graft was the most common cause for reintervention, n = 6. All fractures were in vessels stented with first generation BeGrafts, (6/41 BeGraft vs 0/61 other stents, P < 0.01). Freedom from reinterventions at 2 years was 75% and 35%, in the complex AAA and TAAA groups, respectively (P = 0.04) and excluding BeGrafts 79% (cAAA) and 66% (TAAA). The most common major adverse event was spinal cord ischemia (SCI), in total 8.3% with either transient (2.8%) or permanent (5.6%) deficit. Elective mortality at 30 days was 1.4% (1/70) and at 90 days was 2.9% (2/70). CONCLUSIONS: The rate of branch instability and reintervention was high, with a clear relation to fractured first-generation BeGrafts. Mortality and major adverse event rates were low. Long-term close surveillance of bridging stent graft performance is crucial, and the endovascular community should strive to find ways to report failing materials at an early stage to avoid potentially serious complications.

Near Infrared Spectroscopy as a Predictor for Shunt Requirement During Carotid Endarterectomy.

OBJECTIVE/BACKGROUND: Near infrared spectroscopy (NIRS) continuously monitors regional cerebral oxygenation (rSO2) in the frontal lobes. This method may be used in patients during carotid endarterectomy to indicate the need for shunting. The aim of the study was to evaluate the value of NIRS in determining the need for selective shunting during CEA. A secondary aim was to compare NIRS with stump pressure. METHODS: Between January 2013 and October 2016, 185 patients from two vascular units, undergoing CEA under local anaesthesia were prospectively included. All patients gave informed consent to participate; there were no exclusion criteria. A Foresight® oximeter was used for rSO2 measurement, which was compared with stump pressure. Receiver operating characteristic curve analysis was used to identify optimal cutoff points, and sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Twenty patients (10.8%) developed neurological symptoms during clamping. Mean stump pressure was lower in the group that developed neurological symptoms than in the group who did not (34 ± 19 mmHg vs. 55 ± 17 mmHg [p < . 01]). Corresponding NIRS results for the decrease in rSO2 on the ipsilateral side was 15 ± 7% versus 4 ± 6% (p < .01). Using stump pressure ≤50 mmHg as cutoff value for predicting symptoms, the sensitivity was 85% (95% confidence interval [CI] 64-95) and specificity 54% (95% CI 46-61). With a relative decrease in NIRS saturation (ΔrSO2) of 9%, sensitivity was 95% (95% CI 76-99), and specificity 81% (95% CI 74-86) to predict ischaemic symptoms during carotid clamping. Neurological deterioration during carotid clamping was detected in one patient with a relative decrease in rSO2 of <9% compared with three patients with a stump pressure >50 mmHg. CONCLUSION: NIRS allows continuous non-invasive monitoring of cerebral oxygenation during CEA, with high sensitivity and acceptable specificity in predicting cerebral ischaemia and the need for shunting, which makes it an attractive alternative to stump pressure.

Peri-procedural Risk with Urgent Carotid Artery Stenting: A Population based Swedvasc Study.

OBJECTIVES: Current European Society for Vascular Surgery guidelines recommend that patients with a symptomatic carotid stenosis should be operated on within 14 days of onset of symptoms. Recent reports indicate that carotid endarterectomy (CEA) within 2 days of a neurological event may be associated with a higher peri-procedural risk of stroke. Whether urgent carotid artery stenting (CAS) carries a similar high risk is unclear. The aim of this study was to analyze if urgent CAS increases the peri-procedural risks. METHODS: Retrospective analysis of all CAS registered in Swedvasc, a validated nationwide registry, between January 1, 2005, and March 20, 2014. Only symptomatic patients treated for a stenosis of the internal carotid artery were included. Patients were categorized according to time from index event to surgery; 0-2 days, 3-7 days, 8-14 days, and 15-180 days. Primary outcome was 30 day combined stroke and death rate. RESULTS: 323 patients underwent CAS for symptomatic carotid artery stenosis. The demographic and clinical data were similar in the groups. No procedure related complications or deaths were observed in the urgent CAS group. The 30 day combined stroke and death rate did not differ significantly between the groups; zero of 13 (0%; 95% CI 0-26.6) in the group treated 0-2 days versus four of 85 (4.7%; 95% CI 1.5-11.9), at 3-7 days, five of 80 (6.3%; 95% CI 2.4-14.1) at 8-14 days, and six of 145 (4.1%; 95% CI 1.7-8.9) for the patients treated at 15-180 days (p = .757). Stroke and death were not more frequent for patients treated within 1 week compared with after 1 week: 4 out of 98 (4.1%; 95% CI 1.3-9.0) versus 11/225 (4.9%; 95% CI 2.7-8.6) (p = .751). CONCLUSIONS: In this national registry study, CAS performed within 1 week of the onset of a neurologic event was not associated with an additional risk of a peri-operative complication compared with those treated subsequently.

Reasons for non-participation in population-based abdominal aortic aneurysm screening.

BACKGROUND: A population-based screening programme for abdominal aortic aneurysm (AAA) started in 2010 in Stockholm County, Sweden. This present study used individual data from Sweden's extensive healthcare registries to identify the reasons for non-participation in the AAA screening programme. METHODS: All 65-year-old men in Stockholm are invited to screening for AAA; this study included all men invited from July 2010 to July 2012. Participants and non-participants were compared for socioeconomic factors, travel distance to the examination centre and healthcare use. The influence of these factors on participation was analysed using univariable and multivariable logistic regression models. RESULTS: The participation rate for AAA screening was 77·6 per cent (18 876 of 24 319 men invited). The prevalence of AAA (aortic diameter more than 2·9 cm) among participants was 1·4 per cent. The most important reasons for non-participation in the multivariable regression analyses were: recent immigration (within 5 years) (odds ratio (OR) 3·25, 95 per cent confidence interval 1·94 to 5·47), low income (OR 2·76, 2·46 to 3·10), marital status single or divorced (OR 2·23, 2·08 to 2·39), low level of education (OR 1·28, 1·16 to 1·40) and long travel distance (OR 1·23, 1·10 to 1·37). Non-participants had a higher incidence of stroke (4·5 versus 2·8 per cent; P < 0·001) and chronic pulmonary disease (2·9 versus 1·3 per cent; P < 0·001). Daily smoking was more common in residential areas where the participation rate for AAA screening was low. CONCLUSION: Efforts to improve participation in AAA screening should target the groups with low income, a low level of education and immigrants. The higher morbidity in the non-participant group, together with a higher rate of smoking, make it probable that this group also has a high risk of AAA.

Low post-operative mortality after surgery on patients with screening-detected abdominal aortic aneurysms: a Swedvasc registry study.

OBJECTIVES: Screening for abdominal aortic aneurysms (AAAs) substantially reduces aneurysm-related mortality in men and is increasing worldwide. This cohort study compares post-operative mortality and complications in men with screening-detected vs. non-screening-detected AAAs. METHODS: Data were extracted from the Swedish National Registry for Vascular Surgery (Swedvasc) for all screening-detected men treated for AAA (n = 350) and age-matched controls treated for non-screening-detected AAA (n = 350). RESULTS: There were no differences in baseline characteristics besides age, which was lower in the screening-detected group than in the non-screening-detected group (median 66 vs. 68, p < .001). Open repair was used more frequently than endovascular aortic repair (EVAR) in patients with screening-detected AAAs than in non-screening-detected controls (56% vs. 45% p = .005). No differences in major post-operative complications at 30 days were observed between the groups. In patients treated with open repair there were no differences in 30-day, 90-day or 1-year mortality in screening-detected patients compared to non-screening-detected controls (1.0% vs. 3.2% p = .25, 2.1% vs. 4.5% p = .23, 4.1% vs. 5.8% p = .61). None of the patients treated with EVAR in either group died within 30 days. The 90-day mortality after EVAR was lower in patients with screening-detected AAA than in those with non-screening-detected AAAs (0.0% vs. 3.1%, p = .04). No difference in the 1-year mortality was detected in the EVAR-patients between the two groups (1.4% vs. 4.7%, p = .12). CONCLUSIONS: The contemporary post-operative mortality after AAA surgery was low in this national audit of patients with screening-detected AAAs and age-matched controls. Patients with screening-detected AAAs have the same frequency of complications at 30 days as patients with non-screening-detected AAA. This study gives further support to national screening programs for the detection of AAA in men.

Outcome after 7 years of carotid artery stenting and endarterectomy in Sweden - single centre and national results.

OBJECTIVES: The aim was internal vascular centre quality-control measures to compare single-centre results with the national perspective, as well as analysing the Swedish results from carotid artery stenting (CAS) and comparing a relatively high-volume single centre with the Swedish Vascular Registry (Swedvasc) data. The second aim was to compare CAS and carotid artery endarterectomy (CEA) outcomes for the same 7-year period. DESIGN: Retrospective review of a single high-volume centre (Södersjukhuset (SÖS)) (approximately 30 CAS year(-1) approximately 90 CEA year(-1)) versus Swedvasc National data. MATERIALS AND METHODS: All consecutive selective patients treated with CAS at SÖS for a stenosis of the internal carotid artery (n = 208) or CEA (n = 552) between 2004 and 2011 were compared with all patients in Swedvasc registered for CAS (n = 258) and CEA (n = 6474). Primary outcome was 30-day frequency of stroke or death. Secondary outcome was stroke/death/acute myocardial infarction (AMI). RESULTS: The 30-day frequency of any stroke or death after CAS at SÖS compared to the national data was 2.9% and 7.4%, respectively (P = 0.04). The 30-day AMI/stroke/death frequency was 3.4% and 9.5%, respectively (P = 0.01). After CEA during the same time period, the Swedvasc national data had a 4.4% frequency of 30-day stroke and death and 5.8% for AMI/stroke/death. CONCLUSIONS: CAS is not as safe as CEA from a national perspective but our results indicate that a single centre can achieve acceptable results with CAS.

Scandinavian, Siberian, and Arctic Ocean Glaciation: Effect of Holocene Atmospheric CO2 Variations.

A computer model of coupled ice sheet-ice shelf behavior was used to evaluate whether observed changes in atmospheric CO(2) concentration could have caused the advance and retreat of Pleistocene ice sheets in the Eurasian Arctic. For CO(2) concentrations below a threshold of approximately 250 parts per million, an extensive marine-based ice sheet covering Scandinavia, the Barents, Kara, and East Siberian seas, and parts of the Arctic Ocean developed in the model simulations. In the simulations, climatic warming associated with the Holocene rise of atmospheric CO(2) was sufficient to collapse this widespread glaciation and restore present-day ice conditions.

Instrumental neutron activation analyses of lunar specimens.

Ten Apollo 11 specimnens were divided into 24 samtples. Sodillim contents of 8 diverse specimens clluster tightly abolit 0.3 percent. Plagioclase separated from sample 10044 contains aboltt 1.09 percent Na; barium is not enriched in the plagioclase separate. Contents of the rare earths are strikingly high, and relative abtmndances resemble those of calcium-rich achondrites or abyssal basalts but are depleted in Eu by factors of 2 to 3 and in La by about 20 percent. The plagioclase separate is enriched in Eu and pyroxenes (and opaqtte minerals are Eu-depleted. Fine fractions of 10044 are abotit 20 to 40 percent richer in most rare earths (50 percent for Eu) than coarse fractions, probably becaitse of the presence of small grains in which rare earths are mnarkedly concentrated. "Microgabbro" 10045 is imnpoverished, relative to the soil, in rare eartlhs and Hf. Ratios by mass of Zr to Hf are comlparatively low. Abttndances of Mn, Co, Fe, Sc and Cr stiggest systematic differences between igneous rocks on one hanid and breccias and "soil" on the other. Fromn the Co abuindances, no more than about 3 percent of the present "soil" can consist of chondritic mleteorite conitamination.

The efficacy of a smoking cessation programme in patients undergoing elective surgery: a randomised clinical trial.

It is known that smokers constitute an important risk group of patients undergoing surgery. It is unknown how smoking cessation intervention initiated 4 weeks prior to elective surgery affects the probability of permanent cessation. We randomly assigned 117 patients, scheduled to undergo elective orthopaedic and general surgery, to smoking cessation intervention and control group. The intervention group underwent a programme initiated, on average, 4 weeks prior to surgery with weekly meetings or telephone counselling and were provided with free nicotine replacement therapy (NRT). The control group received standard care. As a result, 20/55 (36%) patients the intervention group vs 1/62 (2%) in the control group became completely abstinent throughout the peri-operative period (p < 0.001). After 1 year, those in the intervention group was most likely to be abstinent (18/55 (33%) vs 9/62 (15%) of the controls (p = 0.03). Level of nicotine dependence and obesity seemed to be a predictor of long-term abstinence (p = 0.02).

Impact of body mass index and tobacco smoking on outcome after open appendicectomy.

BACKGROUND: The effect of body mass index (BMI) and smoking on the risk of perforated appendix and postoperative complications in patients undergoing open appendicectomy for acute appendicitis was studied. METHODS: Record linkage was used to identify 6676 male construction workers who underwent open appendicectomy for acute appendicitis between 1971 and 2004. Multivariable binomial logistic regression analyses were performed. RESULTS: After adjustment for age, calendar period and BMI, smoking was significantly associated with an increased risk of perforated appendicitis (PA) (P = 0.004). The relative risk was 1.29 (95 per cent confidence interval 1.11 to 1.50) among current smokers with more than 10 pack-years of tobacco use. In patients with non-perforated appendicitis (NPA), the relative risk of overall postoperative complications was significantly associated with BMI (P < 0.001), and was 2.60 (1.71 to 3.95) in obese patients and 1.51 (1.03 to 2.22) in current smokers with more than 10 pack-years of tobacco use. In patients with PA, overweight, obesity and smoking status were not associated with an increased risk of overall postoperative complications. CONCLUSION: Perforation due to acute appendicitis was associated with current tobacco smoking. A BMI of 27.5 kg/m(2) or more and current smoking were associated with overall postoperative complications in patients with NPA.

Dual roles for Spt5 in pre-mRNA processing and transcription elongation revealed by identification of Spt5-associated proteins.

During transcription elongation, eukaryotic RNA polymerase II (Pol II) must contend with the barrier presented by nucleosomes. The conserved Spt4-Spt5 complex has been proposed to regulate elongation through nucleosomes by Pol II. To help define the mechanism of Spt5 function, we have characterized proteins that coimmunopurify with Spt5. Among these are the general elongation factors TFIIF and TFIIS as well as Spt6 and FACT, factors thought to regulate elongation through nucleosomes. Spt5 also coimmunopurified with the mRNA capping enzyme and cap methyltransferase, and spt4 and spt5 mutations displayed genetic interactions with mutations in capping enzyme genes. Additionally, we found that spt4 and spt5 mutations lead to accumulation of unspliced pre-mRNA. Spt5 also copurified with several previously unstudied proteins; we demonstrate that one of these is encoded by a new member of the SPT gene family. Finally, by immunoprecipitating these factors we found evidence that Spt5 participates in at least three Pol II complexes. These observations provide new evidence of roles for Spt4-Spt5 in pre-mRNA processing and transcription elongation.

The effect of tobacco consumption and body mass index on complications and hospital stay after inguinal hernia surgery.

BACKGROUND: The extent to which lifestyle factors such as tobacco consumption and obesity affect the outcome after inguinal hernia surgery has been poorly studied. This study was undertaken to assess the effect of smoking, smokeless tobacco consumption and obesity on postoperative complications after inguinal hernia surgery. The second aim was to evaluate the effect of tobacco consumption and obesity on the length of hospital stay. METHODS: A cohort of 12,697 Swedish construction workers with prospectively collected exposure data on tobacco consumption and body mass index (BMI) from 1968 onward were linked to the Swedish inpatient register. Information on inguinal hernia procedures was collected from the inpatient register. Any postoperative complication occurring within 30 days was registered. In addition to this, the length of hospitalization was calculated. The risk of postoperative complications due to tobacco exposure and BMI was estimated using a multiple logistic regression model and the length of hospital stay was estimated in a multiple linear regression model. RESULTS: After adjusting for the other covariates in the multivariate analysis, current smokers had a 34% (OR 1.34, 95% CI 1.04, 1.72) increased risk of postoperative complications compared to never smokers. Use of "Swedish oral moist snuff" (snus) and pack-years of tobacco smoking were not found to be significantly associated with an increased risk of postoperative complications. BMI was found to be significantly associated with an increased risk of postoperative complications (P = 0.04). This effect was mediated by the underweighted group (OR 2.94; 95% CI 1.15, 7.51). In a multivariable model, increased BMI was also found to be significantly associated with an increased mean length of hospital stay (P < 0.001). There was no statistically significant association between smoking or using snus, and the mean length of hospitalization after adjusting for the other covariates in the model. CONCLUSION: Smoking increases the risk of postoperative complications even in minor surgery such as inguinal hernia procedures. Obesity increases hospitalization after inguinal hernia surgery. The Swedish version of oral moist tobacco, snus, does not seem to affect the complication rate after hernia surgery at all.

Ofloxacin otic drops vs neomycin-polymyxin B otic drops as prophylaxis against early postoperative tympanostomy tube otorrhea.

OBJECTIVES: To evaluate the incidence of tympanostomy tube (TT) sequelae, tube otorrhea, and tube obstruction immediately postoperatively in patients receiving TT for otitis media and to compare patients receiving postoperative otic drops with controls. DESIGN: Blinded randomized control trial. SETTING: A tertiary pediatric otolaryngology practice. SUBJECTS: The study population comprised 306 patients undergoing TT placement. INTERVENTIONS: The 306 patients were enrolled into the following 3 groups: (1) those receiving no postoperative otic drop prophylaxis (control group), (2) those receiving ofloxacin otic drops (FLOX group), and (3) those receiving neomycin sulfate-polymyxin B sulfate-hydrocortisone otic drops (COS group). RESULTS: Overall otorrhea rates postoperatively were 14.9% for the control group, 8.1% for the FLOX group, and 5.5% for the COS group. When controlling for disease severity, the rate of otorrhea was significantly higher for the control group than for both the FLOX (P = .04) and COS (P = .01) groups. Nonpatent, plugged, tube rates were added to otorrhea rates for a TT failure analysis postoperatively. The control group demonstrated a significantly greater failure rate (29.9%) than both the FLOX (12.1%) and COS (7.7%) groups. The only differences between the patients in the 2 groups receiving drops were that ofloxacin was more well liked by patients (P = .04) and caused less pain (P = .004). CONCLUSIONS: Nonpatency and otorrhea are the most frequent sequelae immediately following TT placement. Few studies have compared different treatment regimens in a randomized controlled trial. These results demonstrate that otic drops clearly provide benefit postoperatively in preventing TT plugging and otorrhea but primarily in patients who have middle ear fluid at the time of TT placement. In addition, consideration of drop choice should be based on patient tolerance and medication safety profiles.

Genetic interactions of Spt4-Spt5 and TFIIS with the RNA polymerase II CTD and CTD modifying enzymes in Saccharomyces cerevisiae.

Genetic and biochemical studies have identified many factors thought to be important for transcription elongation. We investigated relationships between three classes of these factors: (1) transcription elongation factors Spt4-Spt5, TFIIS, and Spt16; (2) the C-terminal heptapeptide repeat domain (CTD) of RNA polymerase II; and (3) protein kinases that phosphorylate the CTD and a phosphatase that dephosphorylates it. We observe that spt4 and spt5 mutations cause strong synthetic phenotypes in combination with mutations that shorten or alter the composition of the CTD; affect the Kin28, Bur1, or Ctk1 CTD kinases; and affect the CTD phosphatase Fcp1. We show that Spt5 co-immunoprecipitates with RNA polymerase II that has either a hyper- or a hypophosphorylated CTD. Furthermore, mutation of the CTD or of CTD modifying enzymes does not affect the ability of Spt5 to bind RNA polymerase II. We find a similar set of genetic interactions between the CTD, CTD modifying enzymes, and TFIIS. In contrast, an spt16 mutation did not show these interactions. These results suggest that the CTD plays a key role in modulating elongation in vivo and that at least a subset of elongation factors are dependent upon the CTD for their normal function.

Comparison of caregiver otitis media risk factor knowledge in suburban and urban primary care environments.

OBJECTIVE: There are many risk factors for otitis media. Some of these, such as passive tobacco smoke exposure and childcare arrangements; have the potential to be modified. The purpose of this study is to assess caregiver knowledge deficits about risk factors associated with otitis media and their willingness to modify behaviors associated with those risks. RESEARCH DESIGN AND METHODS: This study is a prospective survey study investigating knowledge deficits of parents or guardians of children ages 6-36 months about the risk factors of otitis media. The patients were consecutively drawn from a suburban and an urban pediatric practice. Any difference in survey results between these two groups was also assessed. Participants completed a survey of 21 questions with content including demographic and OM risk factor data. RESULTS: A total of 401 caregivers completed surveys, with 213 from an urban pediatric practice and 188 from a suburban practice. There was a significant difference in the ethnic distributions of the two populations. The suburban population had a significantly greater family history of ear infections, number of ear infections in the past 12 months, and number of previous ventilation tubes placed. The urban population had a significantly greater number of smokers in the household and decreased knowledge about day care as a risk for OM. The urban population's question responses suggested a greater willingness to change day care arrangements to reduce the risk of otitis media. CONCLUSIONS: Both populations demonstrated knowledge deficits regarding risk factors associated with OM and both populations exhibited willingness to modify behaviors to reduce risk. These findings demonstrate that there are opportunities for improving education regarding OM risk factors and that this education could potentially reduce risk for OM and in turn reduce the incidence of OM in children.

Role of hyaline membrane disease in production of later childhood lung abnormalities.

Between 1961 and 1970, 177 survivors of hyaline membrane disease have been followed clinically and roentgenologically for a minimum of three years to determine the long-term pulmonary outcome. Of these, 153 have been seen for at least six years and 61, for 11 years or more. A total of 175 batteries of pulmonary function tests have been performed on 129 children at age 7 and/or 11 years, Final roentgenograms showed fibrosis in 12 instances, and these changes were positively correlated with the severity of the initial disease, the use of a positive pressure respirator (but not negative pressure respirator), time on the respirator, and length of time in O2, but not high O2 concentrations. Residual symptoms in the first years of life were also correlated with positive pressure respirator use, length of use, and with secondary infection. Pulmonary function tests showed minimal abnormalities in 12 children when last seen. None of these children had a history of exercise intolerance or chronic respiratory symptoms. The ultimate pulmonary history of this population of patients is unknown, but overt childhood lung disease following hyaline membrane disease is not a frequent occurrence.

Improved survival accounts for most, but not all, of the increase in bronchopulmonary dysplasia.

The incidence of bronchopulmonary dysplasia (BPD) increased from 10.6% in 1976 through 1980, to 21.7% (1981 through 1985), and to 32.9% (1986 through 1990) in very low birth weight neonates (1500 g or less) admitted to the Vanderbilt Neonatal Intensive Care Unit, while there was a concurrent decline in incidence of neonatal death (NEOD) during the same periods (26.4%, 18.3%, and 15.9%, respectively). Population changes in risk factors (birth weight, sex, race, location of birth, gestational age, diagnosis of hyaline membrane disease, and 5-minute Apgar score) over time do not account for this increase. To estimate the proportion of the increase in BPD attributable to the concurrent decline in NEOD during these periods, separate logistic regression models for NEOD and BPD were calculated from patients born during 1976 through 1985. These results were used to predict the expected number of cases of NEOD and BPD during 1986 through 1990, assuming that the adjusted incidence of NEOD and BPD remained constant from 1976 through 1985, to 1986 through 1990. The increase in the combined outcome, NEOD/BPD, over the three time periods (34.2%, 36.1%, and 43.5%) remained statistically significant after adjustment for the risk factors listed above. During 1986 through 1990, the predicted number of NEOD was 83 more than the number observed, while the predicted number with BPD was 115 less than the number observed. If all 83 averted cases of NEOD during 1986 through 1990 had developed BPD, then 83 (72%) of the 115 excess cases of BPD could be attributed to averted NEOD. The approximate 95% confidence interval for this estimate was 58% to 87%.(ABSTRACT TRUNCATED AT 250 WORDS)

Origin of cardiac-related thoracic electrical impedance variations in lambs.

Cardiac-related deflections in thoracic electrical impedance have been thought to correlate sufficiently well with cardiac stroke volume to be used as the basis for a noninvasive estimation of cardiac output. To determine more precisely the physiological origin of the impedance deflection (DZ), we regarded right ventricular stroke volume (SVa) as the sum of two components: 1) that part of SVa responsible for the transient increment in pulmonary blood volume within a cardiac cycle, SVa-v and 2) the remaining part of SVa, (SVa-SVa-v). SVa-v was measured in lambs by integration of the difference between pulmonary arterial and pulmonary venous flow. SVa and its components were varied experimentally by opening and closing an aorticocaval shunt or by inflating and deflating a cuff implanted around the pulmonary artery. DZ was measured using a tetrapolar disk electrode system. Multivariate linear regression analysis revealed that SVa-v had a significant positive effect on DZ, and, at the same time, (SVa-SVa-v) had a significant negative effect on DZ. In the pulmonary artery occluder model, the positive effect of SVa-v dominated the opposing negative effect of (SVa - SVa-v) so that the net effect of SVa on DZ was positive and significant. In the aorticocaval shunt model, these effects opposed each other to the extent that there was no significant correlation between SVa and DZ. These results shed new light on the physiological origin of DZ. They also demonstrate that use of DZ to measure acute changes in cardiac output may yield misleading results. Changes or the lack of changes in thoracic electrical impedance do not necessarily reflect cardiac output status.