Screening and treating pre-operative anaemia and suboptimal iron stores in elective colorectal surgery: a cost effectiveness analysis.

Our study investigated whether pre-operative screening and treatment for anaemia and suboptimal iron stores in a patient blood management clinic is cost effective. We used outcome data from a retrospective cohort study comparing colorectal surgery patients admitted pre- and post-implementation of a pre-operative screening programme. We applied propensity score weighting techniques with multivariable regression models to adjust for differences in baseline characteristics between groups. Episode-level hospitalisation costs were sourced from the health service clinical costing data system; the economic evaluation was conducted from a Western Australia Health System perspective. The primary outcome measure was the incremental cost per unit of red cell transfusion avoided. We compared 441 patients screened in the pre-operative anaemia programme with 239 patients not screened; of the patients screened, 180 (40.8%) received intravenous iron for anaemia and suboptimal iron stores. The estimated mean cost of screening and treating pre-operative anaemia was AU$332 (£183; US$231; €204) per screened patient. In the propensity score weighted analysis, screened patients were transfused 52% less red cell units when compared with those not screened (rate ratio = 0.48, 95%CI 0.36-0.63, p < 0.001). The mean difference in total screening, treatment and hospitalisation cost between groups was AU$3776 lower in the group screened (£2080; US$2629; €2325) (95%CI AU$1604-5947, p < 0.001). Screening elective patients pre-operatively for anaemia and suboptimal iron stores reduced the number of red cell units transfused. It also resulted in lower total costs than not screening patients, thus demonstrating cost effectiveness.

Associations of nadir haemoglobin level and red blood cell transfusion with mortality and length of stay in surgical specialties: a retrospective cohort study.

Few studies have investigated if, and how, red cell transfusion and anaemia interact. We analysed 60,955 admissions to three metropolitan hospitals in Western Australia between 2008 and 2017 to determine whether the relationship between red cell transfusion and outcomes in surgical patients differed by lowest (nadir) level of haemoglobin. At levels above 100 g.l-1 , in-hospital, 30-day and 1-year mortality were higher with transfusion, the adjusted odds ratios (ORs) (95%CI) being 8.80 (4.43-17.45) p < 0.001 and 3.68 (1.93-7.02) p < 0.001 and the adjusted hazard ratio (95%CI) being 1.83 (1.28-2.61) p = 0.001, respectively. Likewise, between 90 g.l-1 and 99 g.l-1 , in-hospital, 30-day and 1-year mortality were higher with transfusion, the adjusted odds ratio (95%CI) being 3.76 (2.23-6.34) p < 0.001 and 1.96 (1.23-3.12) p < 0.001 and the adjusted hazard ratio (95%CI) being 1.34 (1.05-1.70) p = 0.017, respectively. Length of stay was longer with transfusion at nadir haemoglobin levels above 100 g.l-1 and in the following ranges: 90-99 g.l-1 , 80-89 g.l-1 , 70-79 g.l-1 and 60-69 g.l-1 , the adjusted rate ratio (95%CI) being 1.38 (1.25-1.53) p < 0.001, 1.18 (1.10-1.27) p < 0.001, 1.17 (1.13-1.22) p < 0.001, 1.07 (1.02-1.12) p = 0.003 and 1.24 (1.13-1.36) p < 0.001, respectively. Mortality was higher with red cell transfusion at haemoglobin levels greater than 90 g.l-1 , whereas at all levels below 90 g.l-1 mortality was not significantly higher or lower. Length of stay was longer with transfusion at nadir haemoglobin levels of 60 g.l-1 or above. Our results suggest that nadir haemoglobin modified the relationship between red cell transfusion and outcomes and adds to the evidence recommending caution before transfusing red cells.

Inhibition of airway hyper-responsiveness by TRPV1 antagonists (SB-705498 and PF-04065463) in the unanaesthetized, ovalbumin-sensitized guinea pig.

BACKGROUND AND PURPOSE Airway sensory nerves play a key role in respiratory cough, dyspnoea, airway hyper-responsiveness (AHR), all fundamental features of airway diseases [asthma and chronic obstructive pulmonary disease (COPD)]. Vagally mediated airway reflexes such as cough, bronchoconstriction and chest tightness originate from stimulation of airway sensory nerve endings. The transient receptor potential vanilloid 1 receptor (TRPV1) is present on peripheral terminals of airway sensory nerves and modulation of its activity represents a potential target for the pharmacological therapy of AHR in airway disease. EXPERIMENTAL APPROACH As guinea pig models can provide some of the essential features of asthma, including AHR, we have established the model with some classical pharmacological agents and examined the effect of the TRPV1 antagonists, SB-705498 and PF-04065463 on AHR to histamine evoked by ovalbumin (OA) in unanaesthetized sensitized guinea pigs restrained in a double chamber plethysmograph. Specific airway conductance (sGaw) derived from the airflow was calculated as a percentage of change from baseline. KEY RESULTS Cetirizine and salbutamol significantly inhibited OA-evoked bronchoconstriction [sGaw area under the curve (AUC): 70 and 78%, respectively]. Atropine, SB-705498 and PF-04065463 significantly inhibited OA-evoked AHR to histamine in unanaesthetized, OA-sensitized guinea pigs (sGaw AUC: 94%, 57% and 73%, respectively). Furthermore, this effect was not related to antagonism of histamine's activity. CONCLUSION AND IMPLICATIONS These data suggest that TRPV1 receptors located on airway sensory nerves are important in the development of AHR and that modulation of TRPV1-receptor activity represents a potential target for the pharmacological therapy of AHR in airway disease.

Obesity and obstetric anaesthesia.

Obesity is increasing in the population as a whole, and especially in the obstetric population, among whom pregnancy-induced physiological changes impact on those already present due to obesity. In particular, changes in the cardiovascular and respiratory systems during pregnancy further alter the physiological effects and comorbidities of obesity. Obese pregnant women are at increased risk of diabetes, hypertensive disorders of pregnancy, ischaemic heart disease, congenital malformations, operative delivery postpartum infection and thromboembolism. Regional analgesia and anaesthesia is usually preferred but may be challenging. Obese pregnant women appear to have increased morbidity and mortality associated with caesarean delivery and general anaesthesia for caesarean delivery in particular, and more anaesthesia-related complications. This article summarises the physiological and pharmacological implications of obesity and pregnancy and describes the issues surrounding the management of these women for labour and delivery.

RNA polymerase interactions with the upstream region of the E. coli tyrT promoter.

The rate of in vivo transcription from the E. coli tRNA and rRNA promoters depends on both cellular growth rate and aminoacid availability. To investigate the molecular mechanisms involved we determined the extent of interaction of RNA polymerase with the promoter of the tyrT stable RNA gene. We show that the enzyme can protect from DNAase I digestion a region of at least 85 bp of the wild-type tyrT promoter and only approximately 62 bp of the lacUV5 mRNA promoter, the protected region extending on the antisense strand to approximately 65 and 42 bp respectively upstream of the transcription startpoint. A mutant tyrT promoter, tyrTp27, is protected more extensively, RNA polymerase interactions extending to at least approximately -130. We propose that these upstream interactions of RNA polymerase perform two functions; activating initiation by polymerase bound at the primary binding site and increasing the concentration of polymerase in the vicinity of the tyrT promoter, thus allowing a high rate of maximal expression and enabling the promoter to be regulated over a wide range of activity.

Association of an S1 nuclease-sensitive structure with short direct repeats 5' of Drosophila heat shock genes.

The potential for a DNA molecule to assume different tertiary structures has been suggested as a possible determinant of transcriptional regulation in eukaryotes. Such forms include cruciforms transitions from B to Z DNA in the same molecule and short unpaired stretches of DNA in an alternating copolymer. All such structures contain regions which are preferentially sensitive to S1 nuclease. We report here an additional class of S1 nuclease sensitive sites associated with short direct repeats of DNA found in the 5' flanking regions of certain Drosophila melanogaster heat shock genes.

PpGpp regulates the binding of two RNA polymerase molecules to the tyrT promoter.

Bacterial promoters differ in the number of RNA polymerase molecules that bind to form a filterable polymerase-promoter complex. We show that two holoenzyme molecules interact with the tyrT promoter, probably as a dimer. This interaction is inhibited by ppGpp. By contrast a single holoenzyme monomer suffices for complex formation at the lacUV5 promoter. We propose that In vivo promoter selection by monomeric and dimeric forms of the enzyme could coordinate the synthesis of stable RNA with that of mRNA and could also account in part for the switch in transcriptional selectivity during the stringent response.