Nomogram to predict perioperative blood transfusion for hepatopancreaticobiliary and colorectal surgery.

BACKGROUND: Predictive tools assessing risk of transfusion have not been evaluated extensively among patients undergoing complex gastrointestinal surgery. In this study preoperative variables associated with blood transfusion were incorporated into a nomogram to predict transfusion following hepatopancreaticobiliary (HPB) or colorectal surgery. METHODS: A nomogram to predict receipt of perioperative transfusion was developed using a cohort of patients who underwent HPB or colorectal surgery between January 2009 and December 2014. The discriminatory ability of the nomogram was tested using the area under the receiver operating characteristic (ROC) curve and internal validation performed via bootstrap resampling. RESULTS: Among 4961 patients undergoing either a HPB (56·3 per cent) or colorectal (43·7 per cent) resection, a total of 1549 received at least 1 unit of packed red blood cells, giving a perioperative transfusion rate of 31·2 per cent. On multivariable analysis, age 65 years and over (odds ratio (OR) 1·52), race (versus white: black, OR 1·58; Asian, OR 1·86), preoperative haemoglobin 8·0 g/dl or less (versus over 12·0 g/dl: OR 26·79), preoperative international normalized ratio more than 1·2 (OR 2·44), Charlson co-morbidity index score over 3 (OR 1·86) and procedure type (versus colonic surgery: major hepatectomy, OR 1·71; other pancreatectomy, OR 2·12; rectal surgery, OR 1·39; duodenopancreatectomy, OR 2·65) were associated with a significantly higher risk of transfusion and were included in the nomogram. A nomogram was constructed to predict transfusion using these seven variables. Discrimination and calibration of the nomogram revealed good predictive abilities (area under ROC curve 0·756). CONCLUSION: The nomogram predicted blood transfusion in major HPB and colorectal surgery.

Development and validation of the Australian Aboriginal racial identity and self-esteem survey for 8-12 year old children (IRISE_C).

INTRODUCTION: In Australia, there is little empirical research of the racial identity of Indigenous children and youth as the majority of the current literature focuses on adults. Furthermore, there are no instruments developed with cultural appropriateness when exploring the identity and self-esteem of the Australian Aboriginal population, especially children. The IRISE_C (Racial Identity and Self-Esteem of children) inventory was developed to explore the elements of racial identity and self-esteem of urban, rural and regional Aboriginal children. This paper describes the development and validation of the IRISE_C instrument with over 250 Aboriginal children aged 8 to 12 years. METHODS: A pilot of the IRISE C instrument was combined with individual interviews and was undertaken with 35 urban Aboriginal children aged 8-12 years. An exploratory factor analysis was performed to refine the survey and reduce redundant items in readiness for the main study. In the main study, the IRISE C was employed to 229 Aboriginal children aged 6-13 years across three sites (rural, regional and urban) in Western Australia. An exploratory factor analysis using Principal axis factoring was used to assess the fit of items and survey structure. A confirmatory factor analysis was then employed using LISREL (diagonally weighted least squares) to assess factor structures across domains. Internal consistency and reliability of subscales were assessed using Cronbach's co-efficient alpha. RESULTS: The pilot testing identified two key concepts - children's knowledge of issues related to their racial identity, and the importance, or salience, that they attach to these issues. In the main study, factor analyses showed two clear factors relating to: Aboriginal culture and traditions; and a sense of belonging to an Aboriginal community. Principal Axis Factoring of the Knowledge items supported a 2-factor solution, which explained 38.7% of variance. Factor One (Aboriginal culture) had a Cronbach's alpha of 0.835; Factor 2 (racial identity) had a Cronbach's alpha of 0.800, thus demonstrating high internal reliability of the scales. CONCLUSION: The IRISE_C has been shown to be a valid instrument useful of exploring the development of racial identity of Australian Aboriginal children across the 8-12 year old age range and across urban, rural and regional geographical locations.

Detection of a novel reassortant epizootic hemorrhagic disease virus (EHDV) in the USA containing RNA segments derived from both exotic (EHDV-6) and endemic (EHDV-2) serotypes.

Epizootic hemorrhagic disease virus (EHDV) is a Culicoides-transmitted orbivirus that infects domestic and wild ruminants and is provisionally thought to be distributed throughout Africa, North America, Australia, East Asia and the Middle East. Historically, of the seven proposed serotypes of EHDV, only EHDV-1 and EHDV-2 have been reported from North America. In 2006, EHDV isolates were recovered from moribund or dead white-tailed deer (Odocoileus virginianus) in Indiana and Illinois that could not be identified as either EHDV-1 or EHDV-2 by virus neutralization tests or by serotype-specific RT-PCR. Additional serological and genetic testing identified the isolates as EHDV-6, a serotype that, although originally described from Australia, has recently been recognized as an emerging pathogen of cattle in Morocco, Algeria and Turkey. In 2007 and 2008, EHDV-6 was isolated again from white-tailed deer, this time in Missouri, Kansas and Texas, suggesting that the virus is capable of overwintering and that it may become, or already is, endemic in a geographically widespread region of the USA. Genetic characterization of the virus indicates that it is a reassortant, such that the outer capsid proteins determining serotype specificity (VP2 and VP5) are derived from exotic EHDV-6, whilst the remaining structural and non-structural proteins are apparently obtained from indigenous EHDV-2 (Alberta).

Eruption prediction aided by electronic tiltmeter data at mount st. Helens.

Telemetry from electronic tiltmeters in the crater at Mount St. Helens contributed to accurate predictions of all six effusive eruptions from June 1981 to August 1982. Tilting of the crater floor began several weeks before each eruption, accelerated sharply for several days, and then abruptly changed direction a few minutes to days before extrusion began. Each episode of uplift was caused by the intrusion of magma into the lava dome from a shallow source, causing the dome to inflate and eventually rupture. Release of magma pressure and increased surface loading by magma added to the dome combined to cause subsidence just prior to extrusion.

A Rapid Field-Deployable Reverse Transcription-Insulated Isothermal Polymerase Chain Reaction Assay for Sensitive and Specific Detection of Bluetongue Virus.

Bluetongue is a non-contagious, haemorrhagic, Culicoides-borne disease of ruminants. The causative agent, bluetongue virus (BTV), is a member of the Orbivirus genus of the Reoviridae family. So far, 26 BTV serotypes have been identified worldwide. The global distribution of bluetongue has been expanding, and rapid detection of BTV, preferably in the field, is critical for timely implementation of animal movement restrictions and vector control measures. To date, many laboratory-based, molecular assays for detection of BTV have been developed. These methods require the samples to be shipped to a central laboratory with sophisticated instruments and highly skilled technicians to perform the assays, conduct analyses and interpret the results. Here, we report the development and evaluation of a rapid, portable, user-friendly, pan-BTV reverse transcription-insulated isothermal polymerase chain reaction (RT-iiPCR) assay that can potentially be used in low-resource field conditions. The total length of the assay was <60 min, and at the end of the assay, the results were automatically displayed as '+' or '-' without the need for data interpretation. The RT-iiPCR assay detected 36 BTV isolates and two in vitro transcribed RNA samples representing all 26 BTV serotypes. The assay did not cross-react with other animal viruses tested, including two closely related orbiviruses. The analytical sensitivity of the assay was as low as nine copies of in vitro transcribed double-stranded BTV RNA. Analysis of BTV-infected whole blood samples showed that the BTV RT-iiPCR assay was as sensitive as real-time RT-PCR. The assay can potentially be used for rapid screening of animals for BTV in routine diagnostics and for monitoring bluetongue outbreaks both in ruminants and in Culicoides vectors in the field and in the laboratory.

Incidence and outcomes of ventral hernia repair after robotic retropubic prostatectomy: A retrospective cohort of 570 consecutive cases.

BACKGROUND: Robotic retropubic prostatectomy (RRP) has become one of the most commonly performed robotic procedures in the United States. Ventral hernia (VH) has been increasingly recognized as an important complication after laparoscopic procedures, in general. However, data related to VH after robotic procedures is relatively scarce, especially after RRP. With increasing popularity of RRP, the purpose of this study was to look at the incidence of VH and outcomes of ventral hernia repair (VHR) after RRP. METHODS: All patients who underwent RRP at a single institution between January 2012 and June 2014 were studied retrospectively using electronic medical records. RESULTS: A total of 570 patients underwent RRP, of which 33 (5.8%) developed VH during the study period. Fourteen (42%) patients were obese and five (15%) had diabetes. One patient (3%) had a surgical site infection after RRP and two (6%) patients were on immunomodulators/steroids. Median duration to develop VH after RRP was 12 (1-25) months. Out of the 33 patients with VH, ten (33%) underwent VHR; five laparoscopic and five open. Median size of hernia defect and mesh used was 25 (1-144) cm2 and 181 (15-285) cm2, respectively. Median length of hospital stay and follow up was 0 (0-4) days and 12 (1-14) months, respectively. One patient who had initial VHR done at an outside institution had a recurrence. Thirty-two (97%) patients were alive at their last follow up. One patient died secondary to progression of prostate cancer. There was no significant 30 day morbidity (surgical site infection, fascial dehiscence, pneumonia, acute kidney injury, myocardial infarction). Of patients who decided non-operative management of VH (n = 23, 67%), none developed a complication requiring emergent surgical intervention. CONCLUSION: The incidence of VH after RRP is likely underreported in prior studies. Repair, either laparoscopic or open, is safe and effective in experienced hands. Patients who decide on watchful waiting can be followed with minimal risk of incarceration/strangulation. Further studies are needed to analyze the extraction techniques after RRP and correlate with incidence of VH.

The difficult gall bladder: Outcomes following laparoscopic cholecystectomy and the need for open conversion.

INTRODUCTION: Surgery for the difficult gallbladder (DGB) is associated with increased risk compared to more routine laparoscopic cholecystectomies (LC). Laparoscopic "damage control" methods including cholecystostomy, fundus-down approach and subtotal cholecystectomy (SC) have been proposed to avoid conversion to open. We hypothesized that a Total LC (TLC) for DBG can be completed safely with an acceptably low conversion rate. MATERIAL AND METHODS: All patients that underwent LC from January 2005-June 2015 were retrospectively reviewed. Cases met criteria for DGB if they were necrotic/gangrenous, involved Mirizzi syndrome, had extensive adhesions, were converted to open, lasted more than 120 min, had prior tube cholecystostomy or known GB perforation. RESULTS: A total of 2212 patients underwent LC during the study time period, of which 351 (15.8%) met criteria for DGB. Of these cases, 213 (60.7%) were admitted from the emergency department and 67 (19.1%) underwent urgent/emergent cholecystectomy (within 24 h). Additionally 18 (5.1%) had pre-operative tube cholecystostomies. Seventy patients (19.9%) were converted to open. Indications for conversion included severe inflammation/adhesion (n = 31, 46.3%), difficult anatomy (n = 14, 20.9%) and bleeding (n = 6, 9.0%). Predictors for conversion included urgent/emergent intervention (OR, 0.80; 95% CI 0.351-0.881, p = 0.032), previous abdominal surgery (OR, 2.18; 95% CI, 1.181-4.035, p = 0.013) and necrotic/gangrenous cholecystitis (OR, 1.92; 95% CI, 1.356-4.044, p = 0.033). Comparing the TLC and the conversion groups, mean operative time and length of hospital stay were significantly different; 147 ± 47 min vs 185 ± 71 min; p < 0.005 and 3 ± 2 days vs 5 ± 3 days; p = 0.011, respectively. There was no significant difference in postoperative hemorrhage, subhepatic collection, cystic duct leak, wound infection, reoperation and 30 day mortality. There was no bile duct injury in either group. CONCLUSION: Total laparoscopic cholecystectomy can be safely performed in difficult gallbladder situations with a lower conversion rate than previously reported. Possible predictors of conversion include urgency, necrotic gallbladder and history of prior abdominal surgeries. For patients converted to open, similar morbidity and mortality can be expected.

Bcl-2 accelerates multistep prostate carcinogenesis in vivo.

The impact of bcl-2 proto-oncogene expression on the pathogenesis and progression of prostate cancer was examined in a transgenic mouse model. Probasin-bcl-2 transgenic mice were crossed with TRAMP (TRansgenic Adenocarcinoma Mouse Prostate) mice that express the SV40 early genes (T/t antigens) under probasin control. Prostate size, cell proliferation, apoptosis, and the incidence and latency of tumor formation were evaluated. The double transgenic, probasin-bcl-2 X TRAMP F1 (BxT) mice exhibited an increase in the wet weight of the prostate. This was associated with an increase in proliferation, attributable to T/t antigens, and a decrease in apoptosis attributable to bcl-2. The latency to tumor formation was also decreased in the BxT mice compared to the TRAMP mice. The incidence of metastases was identical in both the TRAMP and BxT mice. Lastly, the incidence of hormone-independent prostate cancer was reduced in the BxT mice compared to the TRAMP mice. Together, these results demonstrate that bcl-2 can facilitate multistep prostate carcinogenesis in vivo.

The impact of bcl-2 expression and bax deficiency on prostate homeostasis in vivo.

Prostatic glandular epithelial cells undergo apoptosis in response to androgen-deprivation. The molecular determinants of androgen-responsiveness in these cells are incompletely understood. Recent evidence suggests that bcl-2 gene family members may be important in this context. We used the probasin promoter to target a human bcl-2 transgene specifically to the prostate in order to assess its impact on conferring resistance to androgen withdrawal in, otherwise sensitive, prostatic glandular epithelial cells in vivo. We examined the contribution of bax to mediating androgen-responsiveness in prostatic glandular epithelial cells using bax knockout mice. The histologic appearance of the prostates from probasin-bcl-2 transgenic mice or bax-/- mice did not differ from those of control littermates. There was no evidence of hyperplastic or neoplastic growth. There was no difference between probasin bcl-2 transgenic mice, bax-/- mice, and control littermates in steady-state levels of apoptosis. Following castration our findings suggest that both bax and bcl-2 may each contribute to the androgen-responsiveness of prostatic glandular epithelial cells. It is apparent from these results, however, that bax is not required to mediate cell death in prostatic glandular epithelial cells following castration. A comparison between the apoptotic indices in the ventral prostate from the probasin-bcl-2 and bax-/- mice following castration suggests that the presence of bcl-2 may be a more important indicator of androgen-sensitivity than a deficiency of bax.

Challenging a surgical dictum: results from a 10-year experience on the safety of open inguinal herniorrhaphy in patients on chronic warfarin therapy.

BACKGROUND: Previous reports document the safety of open inguinal herniorrhaphy in patients on chronic warfarin therapy; however, the practice remains controversial. This study is a 10-year update of our experience. METHODS: A retrospective review of 1,839 consecutive patients undergoing open inguinal hernia repair was conducted from 2000 to 2010. All patients on chronic warfarin therapy were included. Three groups: continuation (CW), discontinuation (DW) and case-matched control (C) not on warfarin therapy were compared for operative details and postoperative complications. RESULTS: One hundred and fifty-eight patients were on chronic warfarin therapy. Of these, 40 patients (25%) continued on warfarin during the perioperative period (CW). Average preoperative international normalized ratio (INR) was 2.15 ± 0.76 for CW and 1.38 ± 0.42 for DW, p < 0.001. Mean operative times were equivalent between all three groups (88 min CW vs. 85 min DW vs. 79 min C, p = 0.518). Although CW patients experienced higher incidences of both hematoma and urinary retention overall, no statistically significant differences in complication rates were seen between the three groups (hematoma = 10 vs. 8% DW vs. 5% C, p = 0.703; urinary retention = 15 vs. 10% DW vs. 8% C, p = 0.541). Comparing patients by INR, there were no statistically different postoperative complication rates, particularly for hematoma (8% INR <2 vs. 9.5% INR = 2-3 vs. 20% INR >3, p = 0.65). CONCLUSION: Maintenance of warfarin therapy during the perioperative period for open inguinal herniorrhaphy results in equivalent operative times and postoperative complications as discontinuation.

Factor VIIa and the extracellular domains of human tissue factor form a compact complex: a study by X-ray and neutron solution scattering.

The four-domain structure of human factor VIIa and the two-domain structure of tissue factor form a tight complex to initiate blood coagulation. By solution scattering, the mean X-ray and neutron radii of gyration RG (which determine macro-molecular elongation) were found to be 3.25 nm, 2.13 nm and 3.14 nm (+/- 0.13 nm) for factor VIIa, the extracellular region of tissue factor and their complex in that order. The mean cross-sectional radii of gyration RXS were 1.33 nm, 0.56 nm and 1.42 nm (+/- 0.13 nm) in that order. The mean lengths were 10.3 nm, 7.7 nm and 10.2 nm in that order. The data show that, in solution, the free proteins have extended domain structures, and the complex is formed by a compact side-by-side alignment of the two proteins along their long axes. The high binding affinity of tissue factor for factor VIIa may thus be accounted for by the occurrence of many intermolecular contacts in the complex.

Factor Xa and thrombin, but not factor VIIa, elicit specific cellular responses in dermal fibroblasts.

UNLABELLED: Coagulation factors (F)VIIa, FXa and thrombin are implicated in cellular responses in vascular, mesenchymal and inflammatory cells. Fibroblasts are the most abundant cells in connective tissue, and damage to blood vessels places coagulation factors in contact with these and other cell types. OBJECTIVES: To investigate cellular responses of primary dermal fibroblasts to FVIIa, FXa and thrombin by following changes in expression of candidate proteins: monocyte chemotactic protein-1 (MCP-1), interleukin-8 (IL-8), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF), and to determine the expression of receptors implicated in signaling by these coagulation factors. METHODS: Steady-state mRNA levels were quantified by RNase protection assay, and protein secretion by ELISA. PAR gene expression was assessed by ribonuclease protection assay and conventional and quantitative reverse-transcription-polymerase chain reaction. RESULTS: FVIIa did not induce the candidate genes. In contrast, FXa and thrombin induced MCP-1 mRNA and protein secretion strongly, IL-8 moderately, and IL-6 weakly. Neither FXa nor thrombin induced VEGF mRNA or protein secretion, although FXa induced VEGF protein secretion in lung fibroblasts. Comparison of the presence of candidate receptors in the two fibroblast subtypes demonstrated higher levels of PAR-1 and PAR-3 in lung fibroblasts relative to their dermal counterparts and the additional expression of PAR-2. CONCLUSIONS: FXa and thrombin induce expression of MCP-1, IL-8 and IL-6, and distribution and expression of PARs on dermal fibroblasts is reduced relative to their lung counterparts. Tissue origin may influence the cellular response of fibroblasts to coagulation proteases.

The effect of induced atherosclerosis on the synthesis of elastin in chick aortic tissue.

Atherosclerosis was induced in growing chickens by the administration of a diet containing elevated levels of cholesterol and vitamin D3. The effect of this diet on the accumulation of insoluble elastin and the synthesis of soluble and insoluble elastin in the thoracic aortas of these animals was measured. Although the diet resulted in significant increases in levels of cholesterol, 25-OH vitamin D3 and calcium in plasma, increased levels of cholesterol and calcium in aortic tissue, and histological evidence of aortic lipid deposition, there were no detectable differences between experimental and control animals in either the rate or the time course of accumulation of total insoluble elastin in the thoracic aorta, or in the rate and time course of synthesis of soluble and insoluble elastin. These data suggest that, at least in this model, any effect of atherosclerosis on aortic elastin production must be either small or so localized as to be not measurable by the methods used.

Development of a head and neck companion module for the quality of life-radiation therapy instrument (QOL-RTI)

PURPOSE/OBJECTIVE: A review of available head and neck quality of life (QOL) instruments reveals them to inadequately address important radiation related side effects, or to be too cumbersome for routine use. The purpose of this study was to develop a head and neck disease specific module as a companion to the previously developed quality of life - radiation therapy instrument (QOL-RTI). The goal was to create a more complete, yet concise, head and neck site-specific module geared toward patients receiving radiation therapy for head and neck cancer. METHODS AND MATERIALS: This exploratory study included 34 consecutive patients undergoing definitive radiotherapy over a 6-7 week course (60-79.8 Gy). We developed and administered a 14-item questionnaire to all eligible patients treated with radiotherapy for head and neck cancer who were not already registered in another research study assessing quality of life (e.g., RTOG). During the treatment period, the QOL-RTI general tool and the head and neck (H&N) module were administered as follows: at baseline, at week four (for test-retest), and at the end of the treatment period. For validation purposes the QOL-RTI/H&N was compared to the functional assessment cancer tool head and neck (FACT-H&N) questionnaire. The FACT-H&N was administered one time at week 4, on the same day as the QOL-RTI/H&N. This report includes the treatment phase of the study (during the course of radiation). RESULTS: Mean age was 62 years (range 40-75). Internal consistency of the module was satisfactory (Chronbach's alpha = 0.85). Test-retest yielded a correlation coefficient of 0.90 (p < 0.001). Concurrent validity, established by comparing the module to the FACT/H&N , yielded a correlation coefficient of 0.85. Significant changes in quality of life scores during a course of radiation was noted for both general quality of life tool and the site specific module. For the head and neck module, the difference in the mean baseline (7.17) and end of treatment scores (4.20) was 2.94, or 42% change (p < 0.0001). A smaller, yet still significant, difference in scores was seen in the general QOL tool (22 % change, p = 0.001). Item analysis of the module revealed statistically significant (p < 0.05) worsening in quality of life scores in the following areas: pain in throat, swallowing difficulty (meat/bread and liquids), changes in mucous and saliva, changes in taste, difficulty chewing, trouble with coughing, and speech difficulties. Items that were not significant were pain in the mouth, and appearance. CONCLUSION: These initial results suggest that the H&N companion module to the QOL-RTI is a valid and reliable tool that is responsive to changes in QOL during a course of H&N radiation therapy. This tool differs from existing H&N tools by including specific assessments of mucous, saliva, taste, cough, and local pain in a concise format. Significant changes in QOL scores were noted in all of these items. Evaluation of the tool in the post-treatment period (follow-up) is ongoing.

Can costs be measured and predicted by modeling within a cooperative clinical trials group? Economic methodologic pilot studies of the radiation therapy oncology group (RTOG) studies 90-03 and 91-04.

PURPOSE: To (1) measure radiation therapy costs for patients in randomized controlled clinical trials, (2) compare measured costs to modeling predictions, (3) examine cost distributions, and (4) assess feasibility of collecting economic data within a cooperative group. METHODS: The Radiation Therapy Oncology Group conducted economic pilot studies for two Phase III studies that compared fractionation patterns. Expected quantities of Current Procedural Terminology (CPT) codes and relative value units (RVU) were modeled. Institutions retrospectively provided procedure codes, quantities, and components, which were converted to RVUs used for Medicare payments. Cases were included if the radiation therapy quality control review judged them to have been treated per protocol or with minor variation. Cases were excluded if economic quality review found incomplete economic data. RESULTS: The median and mean RVUs were within the range predicted by the model for all arms of one study and above the predicted range for the other study. CONCLUSION: The model predicted resource use well for patients who completed treatment per protocol. Actual economic data can be collected for critical cost items. Some institutions experienced difficulty collecting retrospective data, and prospective collection of data is likely to allow wider participation in future Radiation Therapy Oncology Group economic studies.

Factor VIII S373L: mutation at P1' site confers thrombin cleavage resistance, causing mild haemophilia A.

A novel CRM+ mutation, factor VIII position 373 serine to leucine substitution (FVIII 373-Leu) was identified during a survey of Factor VIII (FVIII) mutations. We have purified the variant protein from the patient's plasma in order to allow further characterisation of the molecule. The CRM+ plasma contained 120% Factor VIII antigen (FVIII:Ag) and 6% Factor VIII coagulant activity (FVIII:C). After purification the mutant FVIII was subjected to thrombin proteolysis, and was thereby activated 5.6-fold compared with 7-fold for wild type molecule. Subsequently, spontaneous inactivation of the mutant was much slower than noted for wild type FVIII. Western blot analysis using monoclonal antibodies demonstrated that thrombin cleavage of FVIII 373-Leu at positions 740 and 1689 were normal but that cleavage at position 372 was completely absent. Crystallographic coordinates of the active site of thrombin complexed to fibrinopeptide A were used to explore possible mechanistic reasons for the failure of thrombin to cleave the mutant FVIII at position 372. Steric hindrance between the mutant side chain and the side chain of the P1 residue was apparent. We conclude that the functional defect of FVIII 373-Leu results from the inability of thrombin to cleave the mutant at position 372-373, and propose that this is due to steric hindrance by the side chain of leucine 373, preventing correct formation of the enzyme substrate complex.

Comparison of pressure and flow triggering systems during continuous positive airway pressure.

STUDY OBJECTIVE: Compare the inspiratory work of breathing (WOBI) during pressure triggering (PT), and flow triggering (FT) using two microprocessor ventilators. DESIGN: A randomized, crossover comparison of triggering strategies and ventilators used. SETTING: Surgical intensive care unit. PATIENTS: Ten patients recovering from acute respiratory failure (eight men, two women; mean age, 48 +/- 12 years) breathing on continuous positive airway pressure (CPAP) of 5 cm H2O were studied. INTERVENTIONS: Patients were randomly assigned to either receive 5 cm H2O CPAP via one of two units (Hamilton Veolar or Puritan Bennett 7200ae) using either PT or FT. Each patient had 30-min trials using the following: (1) Veolar FT; (2) Veolar PT; (3) 7200ae FT; and (4) 7200ae FT. MEASUREMENTS AND RESULTS: During each trial period, work of breathing (WOB) and pressure time product (PTP) were measured using a respiratory monitor (Bi-core CP-100). All patients were placed in semi-Fowler position and esophageal balloons were inserted and their position confirmed using the occlusion technique. Continuous measurements of peak negative pressure during inspiration, tidal volume (VT), minute ventilation (VE), respiratory frequency (f) were accomplished with a flow transducer at the proximal airway. FT with the 7200ae was superior to PT as measured by both the WOB (0.58 +/- 0.3 vs 0.84 +/- 0.2 J/L, p < 0.01) and PTP (148 +/- 50 vs 206 +/- 41 cm H2O/s/min, p, 0.05). FT with the Veolar was also superior to PT with respect to the WOB (0.53 +/- 0.2 vs 0.93 +/- 0.2 J/L, p < 0.01) and PTP (140 +/- 39 vs 229 +/- 46 cm H2O/s/min, p < 0.05). CONCLUSION: FT reduces the WOB compared with PT, regardless of the ventilator used. The reduction in WOB during FT is related to improved responsiveness and changes in the posttrigger phase.

Humidification in the intensive care unit. Prospective study of a new protocol utilizing heated humidification and a hygroscopic condenser humidifier.

STUDY OBJECTIVE: Determine the utility of a proposed algorithm in allowing safe, efficient humidification in mechanically ventilated patients using both a hygroscopic condenser humidifier (HCH) and heated humidifier (HH). DESIGN: A prospective study using an algorithm to chose humidification devices based on physical examination and sputum characteristics. SETTING: All patients admitted to the surgical ICU. PATIENTS: One hundred twenty consecutive patients requiring mechanical ventilation (MV) were studied. INTERVENTIONS: Patients were examined by the attending respiratory care practitioner and given either an HCH or HH. If patients demonstrated any of the following--thick or tenacious secretions, core temperature < 32 degrees C, or bloody secretions--they were given an HH. All others used an HCH. If any of the above conditions occurred during HCH use, the patient was given an HH. MEASUREMENTS AND RESULTS: Duration of ventilation, incidence of nosocomial pneumonia, ventilator circuit colonization, and mortality were determined for patients in each group. Cost of humidification devices, number of suctioning procedures per day, and volume of saline solution instilled were also recorded. Initially, 27 percent (32/120) of patients used an HH and 73 percent (88/120) used an HCH. During the study, ten patients required changing to an HH during HCH use. Patients in the HH group were more likely to have preexisting lung disease and had a longer duration of ventilation (83 +/- 21 h) and higher mortality (21 percent). Patients in the HCH group were more likely to be postoperative, had shorter durations of ventilation (38 +/- 14 h), and lower mortality (9 percent). There was no difference in the incidence of nosocomial pneumonia between the two groups (9 percent vs 6 percent) and endotracheal tube occlusion did not occur in either group. Circuit colonization was common in the HH group (64 percent) but rate in the HCH group (5 percent). Cost per day was significantly less for the HCH group ($4 vs $19.80). Patients who required a change from HCH to HH did so at a mean of 5 days. CONCLUSION: The proposed algorithm resulted in cost-efficient and safe application of humidification devices in patients in the surgical ICU.

The addition of sighs during pressure support ventilation. Is there a benefit?

The purpose of this study was to determine if sigh breaths delivered during pressure support ventilation (PSV) were beneficial in maintaining arterial oxygenation (PaO2) and pulmonary mechanics. Ten patients being weaned from mechanical ventilation in the PSV mode were studied. All patients were ventilated for 4 h without sighs, 4 h with sighs, and again for 4 h without sighs. During each 4-h period, continuous measurements of ventilatory volumes and airway pressures were accomplished. At the end of each 4-h period, an arterial blood gas determination was obtained. There were no statistically significant differences in any of the measured variables during the different periods of ventilation. We conclude that the sigh breath is of no benefit during PSV.

Limited effects of prostaglandin inhibitors in Escherichia coli sepsis.

Responses to bacteremia include fever, leukocytosis, elaboration of acute-phase proteins, hypoferremia, and increased protein catabolism. To evaluate the role of prostaglandins in the mediation of these responses, the effects of intravenous ibuprofen (12.5 mg/kg X dose) were studied in eight dogs infused with live Escherichia coli. Thirteen dogs served as noninfected controls. Two of the eight animals that received ibuprofen died during the study, whereas all control animals with sepsis survived. Prostaglandin inhibition prevented the rise in temperature resulting from sepsis, while alterations in white cell count, C-reactive protein, and serum iron levels were unaffected. In addition, protein catabolism appeared to be similar in both groups. This minimal metabolic effect coupled with observed renal side effects makes the use of nonsteroidal, anti-inflammatory agents in sepsis of questionable benefit.