Cardiac complications associated with goal-directed therapy in high-risk surgical patients: a meta-analysis

Patients with limited cardiopulmonary reserve are at risk of mortality and morbidity after major surgery. Augmentation of oxygen delivery index (DO2I) with i.v. fluids and inotropes (goal-directed therapy, GDT) has been shown to reduce postoperative mortality and morbidity in high-risk patients. Concerns regarding cardiac complications associated with fluid challenges and inotropes may prevent clinicians from performing GDT in patients who need it most. We hypothesized that GDT is not associated with an increased risk of cardiac complications in high-risk, non-cardiac surgical patients. We performed a systematic search of Medline, Embase, and CENTRAL databases for randomized controlled trials (RCTs) of GDT in high-risk surgical patients. Studies including cardiac surgery, trauma, and paediatric surgery were excluded. We reviewed the rates of all cardiac complications, arrhythmias, myocardial ischaemia, and acute pulmonary oedema. Meta-analyses were performed using RevMan software. Data are presented as odds ratios (ORs), [95% confidence intervals (CIs)], and P-values. Twenty-two RCTs including 2129 patients reported cardiac complications. GDT was associated with a reduction in total cardiovascular (CVS) complications [OR=0.54, (0.38-0.76), P=0.0005] and arrhythmias [OR=0.54, (0.35-0.85), P=0.007]. GDT was not associated with an increase in acute pulmonary oedema [OR=0.69, (0.43-1.10), P=0.12] or myocardial ischaemia [OR=0.70, (0.38-1.28), P=0.25]. Subgroup analysis revealed the benefit is most pronounced in patients receiving fluid and inotrope therapy to achieve a supranormal DO2I, with the use of minimally invasive cardiac output monitors. Treatment of high-risk surgical patients GDT is not associated with an increased risk of cardiac complications; GDT with fluids and inotropes to optimize DO2I during early GDT reduces postoperative CVS complications.

Hard two-body photodisintegration of 3He

We have measured cross sections for the γ(3)He → pd reaction at photon energies of 0.4-1.4 GeV and a center-of-mass angle of 90°. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

Clinical review: Goal-directed therapy-what is the evidence in surgical patients? The effect on different risk groups

Patients with limited cardiac reserve are less likely to survive and develop more complications following major surgery. By augmenting oxygen delivery index (DO₂I) with a combination of intravenous fluids and inotropes (goal directed therapy (GDT)), postoperative mortality and morbidity of high-risk patients may be reduced. However, although most studies suggest that GDT may improve outcome in high-risk surgical patients, it is still not widely practiced. We set out to test the hypothesis that GDT results in greatest benefit in terms of mortality and morbidity in patients with the highest risk of mortality and have undertaken a systematic review of the current literature to see if this is correct. We performed a systematic search of Medline, Embase and CENTRAL databases for randomized controlled trials (RCTs) and reviews of GDT in surgical patients. To minimize heterogeneity we excluded studies involving cardiac, trauma, and paediatric surgery. Extremely high risk, high risk and intermediate risks of mortality were defined as >20%, 5 to 20% and <5% mortality rates in the control arms of the trials, respectively. Meta analyses were performed and Forest plots drawn using RevMan software. Data are presented as odd ratios (OR; 95% confidence intervals (CI), and P-values). A total of 32 RCTs including 2,808 patients were reviewed. All studies reported mortality. Five studies (including 300 patients) were excluded from assessment of complication rates as the number of patients with complications was not reported. The mortality benefit of GDT was confined to the extremely high-risk group (OR = 0.20, 95% CI 0.09 to 0.41; P < 0.0001). Complication rates were reduced in all subgroups (OR = 0.45, 95% CI 0.34 to 0.60; P < 0.00001). The morbidity benefit was greatest amongst patients in the extremely high-risk subgroup (OR = 0.27, 95% CI 0.15 to 0.51; P < 0.0001), followed by the intermediate risk subgroup (OR = 0.43, 95% CI 0.27 to 0.67; P = 0.0002), and the high-risk subgroup (OR 0.56, 95% CI 0.36 to 0.89; P = 0.01). Despite heterogeneity in trial quality and design, we found GDT to be beneficial in all high-risk patients undergoing major surgery. The mortality benefit of GDT was confined to the subgroup of patients at extremely high risk of death. The reduction of complication rates was seen across all subgroups of GDT patients.

[The school child with ADHD]

Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most frequent psychiatric disorders at school age. The core symptoms of hyperactivity, impulsivity and inattention emerge before the age of seven and are associated with severe impairment of the child's everyday functioning (family, school, leisure time). Seventy percent of the affected children show at least one comorbid psychiatric condition or learning disorder/academic impairment. ADHD is one of the most widely investigated disorders in child and adolescent psychiatry. A multitude of imaging (fMRI) and genetic studies comparing children with ADHD and typically developing children have provided clear evidence for the neurobiological foundation of ADHD. Nevertheless, environmental, familial and academic factors play an important role with regard to the persistence and severity of the disorder. Treatment should be preferentially multimodal, with interventions targeting the child, the parents, and, if possible, the teacher. Society with its specific requirements and constraints, and also school, are not well adjusted for children that are different, hyperactive and easily distracted. However, many of these children also have resources. When fascinated by a task, they may show persistence and commitment.

Medical emergencies: pulmonary embolism and acute severe asthma

In this, the second of two articles covering specific medical emergencies, we discuss the definitions, epidemiology, pathophysiology, acute and chronic management of pulmonary embolus and acute severe asthma.

Measurement of exclusive π(0) electroproduction structure functions and their relationship to transverse generalized parton distributions

Exclusive π(0) electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in Q(2), x(B), t, and ϕ(π), in the Q(2) range from 1.0 to 4.6  GeV(2), -t up to 2  GeV(2), and x(B) from 0.1 to 0.58. Structure functions σ(T)+ϵσ(L), σ(TT), and σ(LT) were extracted as functions of t for each of 17 combinations of Q(2) and x(B). The data were compared directly with two handbag-based calculations including both longitudinal and transversity generalized parton distributions (GPDs). Inclusion of only longitudinal GPDs very strongly underestimates σ(T)+ϵσ(L) and fails to account for σ(TT) and σ(LT), while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity-flip and helicity nonflip processes. The results confirm that exclusive π(0) electroproduction offers direct experimental access to the transversity GPDs.

The rate, risk factors and cost of surgical site infections in primary breast surgery

Although breast surgery involving clean wounds is expected to be associated with a low risk of surgi-cal site infection (SSI) and minimal associated costs, estimates of infection could be affected by intensity of case finding and choice of follow-up methods. A broad range of post-discharge follow-up methods is more likely to estimate true SSI rates and costs. This prospective systematic study used 30 day surveillance with active data collection methods to identify the rate and cost of surgical site infection in patients having primary breast surgery. Ten per cent of patients (16/159) had a surgical site infection. The additional average cost of treating each infected patient was £1443. Hierarchical sequential regression identified high body mass index, operations lasting more than two hours and smoking as significant independent risk factors.

A pseudo-Rumsfeldian approach to pleural effusions in mechanically ventilated patients

Pleural effusions are common in mechanically ventilated patients but what is their significance and how should we manage them? What do we know? What don't we know? What didn't we know we knew? How should we resolve the unknowns?

Autism spectrum features in Smith-Magenis syndrome

Smith-Magenis syndrome (SMS; OMIM 182290) is a neurodevelopmental disorder characterized by a well-defined pattern of anomalies. The majority of cases are due to a common deletion in chromosome 17p11.2 that includes the RAI1 gene. In children with SMS, autistic-like behaviors and symptoms start to emerge around 18 months of age. This study included 26 individuals (15 females and 11 males), with a confirmed deletion (del 17p11.2). Parents/caregivers were asked to complete the Social Responsiveness Scale (SRS) and the Social Communication Questionnaire (SCQ) both current and lifetime versions. The results suggest that 90% of the sample had SRS scores consistent with autism spectrum disorders. Moreover, females showed more impairment in total T-scores (P = 0.02), in the social cognition (P = 0.01) and autistic mannerisms (P = 0.002) subscales. The SCQ scores are consistent to show that a majority of individuals may meet criteria for autism spectrum disorders at some point in their lifetime. These results suggest that SMS needs to be considered in the differential diagnosis of autism spectrum disorders but also that therapeutic interventions for autism are likely to benefit individuals with SMS. The mechanisms by which the deletion of RAI1 and contiguous genes cause psychopathology remain unknown but they provide a solid starting point for further studies of gene-brain-behavior interactions in SMS and autism spectrum disorders.

A case of hepatitis C virus transmission acquired through sharing a haemodialysis machine

Hepatitis C virus (HCV) infection is a significant problem among haemodialysis populations worldwide. 'Horizontal' cross-infection between patients can occur, predominately through direct environmental transmission of the virus. Current guidelines thus recommend universal barrier precautions, however they do not suggest using dedicated machines for HCV-positive patients to prevent the 'sequential' transmission of virus to those who subsequently use that machine. We report a case where sequential HCV transmission occurred from a patient of low HCV infectivity with no identifiable machine fault. We suggest that current guidelines should be reviewed to encourage the use of dedicated haemodialysis machines for HCV-positive patients.

Measurement of single- and double-spin asymmetries in deep inelastic pion electroproduction with a longitudinally polarized target

We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ϕ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

Underwater-seal nasogastric tube drainage to relieve gastric distension caused by air swallowing

Air swallowing can occur as a psychogenic phenomenon, because of abnormal anatomy, or during non-invasive positive pressure ventilation. Gross distension of the stomach with air can have severe consequences for the respiratory and gastrointestinal systems. We report the case of a 62-year-old man with severe dynamic hyperinflation due to chronic obstructive pulmonary disease, who developed respiratory failure requiring intubation a few hours after radical prostatectomy. Following a percutaneous tracheostomy and weaning of sedation on day six, his abdomen began to enlarge progressively. X-rays revealed massive gastric distension due to air swallowing, which continued despite all efforts to optimise therapy. The use of an underwater seal drainage system on a nasogastric tube improved ventilation and ultimately aided weaning from mechanical support.

Tensor correlations measured in 3He(e,e' pp)n

We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum p(tot). For pair relative momenta between 0.3 and 0.5  GeV/c, the ratio is very small at low p(tot) and rises to approximately 0.5 at large p(tot). This shows the dominance of tensor over central correlations at this relative momentum.

Absorption of the ω and ϕ mesons in nuclei

Because of their long lifetimes, the ω and ϕ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.

Considerations and proposals for the management of patients after prolonged intensive care unit admission

The majority of patients admitted to the intensive care unit (ICU) have a short stay of only a few days. However a small but significant number require prolonged intensive care. This is typically due to persisting, and sometimes complex, medical/surgical problems. Discharge of such ICU patients requires a comprehensive, multidisciplinary, verbal and written handover to the receiving ward team. As with any acutely ill adult in hospital, post-ICU patients should be carefully monitored with 'track and trigger' systems such as the Early Warning Score. Those with unexpected physiological deterioration should be promptly reviewed by senior clinicians and/or medical emergency/critical care outreach teams and considered for ICU re-admission where appropriate. Patients who have received prolonged organ support in the ICU are often affected by a number of specific medical problems such as ventilatory insufficiency, cardiac dysfunction, kidney injury, nutritional deficiency, ICU acquired weakness, and brain injury. They also frequently experience physical disability and psychosocial problems including delirium, anxiety, depression, post-traumatic stress disorder, cognitive dysfunction, and disturbed sleep. Structured rehabilitation programmes for post-ICU patients, tailored to individual needs, should be commenced on the ICU and continued through to and beyond hospital discharge. Care bundles, which are widely used on the ICU, are groups of interventions employed to optimise treatments or minimise complication rates. They may be additionally useful in the post-ICU ward setting by prompting clinicians to focus on, and address, commonly occurring medical and psychosocial problems in these patients.

Variation in the biological properties of HIV-1 R5 envelopes: implications of envelope structure, transmission and pathogenesis

HIV-1 R5 viruses predominantly use CCR5 as a coreceptor to infect CD4(+) T cells and macrophages. While R5 viruses generally infect CD4(+) T cells, research over the past few years has demonstrated that they vary extensively in their capacity to infect macrophages. Thus, R5 variants that are highly macrophage tropic have been detected in late disease and are prominent in brain tissue of subjects with neurological complications. Other R5 variants that are less sensitive to CCR5 antagonists and use CCR5 differently have also been identified in late disease. These latter variants have faster replication kinetics and may contribute to CD4 T-cell depletion. In addition, R5 viruses are highly variable in many other properties, including sensitivity to neutralizing antibodies and inhibitors that block HIV-1 entry into cells. Here, we review what is currently known about how HIV-1 R5 viruses vary in cell tropism and other properties, and discuss the implications of this variation on transmission, pathogenesis, therapy and vaccines.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190  GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1  GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66  GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0))  MeV/c2 and a width of (269±21(-64)(+42))  MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

Macroscopic and microscopic changes in incinerated deciduous teeth

Teeth are amongst the most resilient elements of the human skeleton and are thus often utilized in routine forensic investigation involving the identification of unknown remains. Teeth exposed to thermal stress have the potential to not only aid in identification, but also in understanding the circumstances surrounding the fire. Children are twice as likely to become victims of house fire because of an inability to safely evacuate from areas of danger. The literature demonstrates, however, that research on the effects of incineration on teeth is mostly restricted to the permanent dentition. The apparent lack of knowledge on the effects of incineration on deciduous teeth thus necessitates further research in this area. To this end, this study aimed to relate colour changes that occur post heating with fragility to aid in proper handling of samples in a forensic scenario and to determine the possibility of identifying incineration temperature based on tooth condition. Teeth are amongst the most resilient elements of the human skeleton and are thus often utilized in routine forensic investigation involving the identification of unknown remains. Teeth exposed to thermal stress have the potential to not only aid in identification, but also in understanding the circumstances surrounding the fire. Children are twice as likely to become victims of house fire because of an inability to safely evacuate from areas of danger. The literature demonstrates, however, that research on the effects of incineration on teeth is mostly restricted to the permanent dentition. The apparent lack of knowledge on the effects of incineration on deciduous teeth thus necessitates further research in this area. To this end, this study aimed to relate colour changes that occur post heating with fragility to aid in proper handling of samples in a forensic scenario and to determine the possibility of identifying incineration temperature based on tooth condition. A total of 90 deciduous teeth, extracted as a part of routine clinical treatment, were exposed to temperatures ranging from 100°C to 1100°C for 30 minutes using a laboratory Gallenkamp oven. Unheated deciduous teeth were used as controls for the project. Post-incineration the teeth were analyzed under a stereomicroscope and SEM to assess the morphological changes. A colorimetric assessment was also undertaken to evaluate colour changes due to thermal stress. It was possible to identify incineration temperature based on tooth condition when the colour changes, stereomicroscopic findings and SEM images were utilized collectively. It was concluded that thermally induced changes in primary teeth occur at lower temperatures in comparison to the permanent teeth. It was also established that post-incineration deciduous teeth are fragile and show a tendency to fragment after minimal exposure to thermal stress.

Recently published papers: changing bandwagons, innovations and questioning dogma

This issue's Recently published papers commentary considers the popular and muddy waters of glycaemic control, stops briefly to ponder the incidence of pulmonary embolus in acute exacerbations of chronic obstructive pulmonary disease, promotes novel studies in the areas of traumatic brain injury and extracorporeal circuits, and rounds off with a potentially dogma-challenging study in cardiac arrest.

OSETI with STACEE: a search for nanosecond optical transients from nearby stars

We have used the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) high-energy gamma-ray detector to look for fast blue-green laser pulses from the vicinity of 187 stars. The STACEE detector offers unprecedented light-collecting capability for the detection of nanosecond pulses from such lasers. We estimate STACEE's sensitivity to be approximately 10 photons/m(2) at a wavelength of 420 nm. The stars have been chosen because their characteristics are such that they may harbor habitable planets, and they are relatively close to Earth. Each star was observed for 10 minutes, and we found no evidence for laser pulses in any of the data sets. Key Words: Search for extraterrestrial intelligence-Optical search for extraterrestrial intelligence-Interstellar communication-Laser.

Recently published papers: more about EGDT, experimental therapies and some inconvenient truths

This issue's recently published papers concentrates on early goal directed therapy, starting with new data from the original study through to new studies that may have a major bearing on the treatment of septic shock in years to come. A timely reminder about talking, walking and teaching clinical medicine completes the roundup.

Recently published papers: a little less ventilation, a little more oxygen please?

Recent papers discussed include two large, multicentre, high-positive end-expiratory pressure trials in acute lung injury and reflects upon the usefulness of such trial designs. Further papers considered include the emerging story of β₂-agonists for pulmonary oedema, highlights the newly described, iatrogenic demon, of ventilator-induced diaphragm injury, promotes the addition of B-type natriuretic peptide testing to the prediction of extubation success, and muses again over the oxygen debate.