Volatile capture technology in sustainable anaesthetic practice: a narrative review.

Anaesthetic practice contributes to climate change. Volatile capture technology, typically based on adsorption to a carbon- or silica-based substrate, has the potential to mitigate some of the harmful effects of using halogenated hydrocarbons. Anaesthetists have a professional responsibility to use anaesthetic agents which offer the greatest safety and clinical benefit with the lowest financial cost and environmental impacts. Inhalational anaesthetics should be used at an appropriate concentration with a minimal fresh gas flow via a circle system to minimise unnecessary waste. Once practice efficiencies have been maximised, only then should technical solutions such as volatile capture be employed. In this narrative review, we focus on the available literature relating to volatile capture technology, obtained via a targeted literature search and through contacting manufacturers and researchers. We found six studies focusing on the Blue-Zone Technologies Deltasorb®, SageTech Medical SID and Baxter/ZeoSys CONTRAfluran™ volatile capture systems. Though laboratory analyses of available systems suggest that > 95% in vitro mass transfer is possible for all three systems, the in vivo results for capture efficiency vary from 25% to 73%. Currently, there is no financial incentive for healthcare organisations to capture waste anaesthetic gases, and so the value of volatile capture technology requires quantification. System-level organisations, such as Greener NHS, are best positioned to commission such evaluations and make policy decisions to guide investment. Further research using volatile capture technology in real-world settings is necessary and we highlight some priority research questions to improve our understanding of the utility of this group of technologies.

Percutaneous pinning for treating distal radial fractures in adults.

BACKGROUND: Fracture of the distal radius is a common clinical problem. A key method of surgical fixation is percutaneous pinning, involving the insertion of wires through the skin to stabilise the fracture. OBJECTIVES: To evaluate the evidence from randomised controlled trials for the use of percutaneous pinning for fractures of the distal radius in adults. SEARCH STRATEGY: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (September 2006), the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and other databases, conference proceedings and reference lists of articles. No language restrictions were applied. SELECTION CRITERIA: Randomised or quasi-randomised controlled clinical trials involving adults with a fracture of the distal radius, which compared percutaneous pinning with conservative treatment, or different aspects of percutaneous pinning. DATA COLLECTION AND ANALYSIS: Two authors independently assessed and extracted data from the included trials. Some pooling of data was undertaken for one comparison. MAIN RESULTS: Thirteen trials, involving 940 generally older adults with dorsally displaced and potentially or evidently unstable distal radial fractures, were included. Methodological weaknesses among these trials included lack of allocation concealment and inadequate outcome assessment. Factors affecting the applicability of trial evidence included inconsistent fracture classification, variations in outcome assessment and incomplete reporting. Six heterogeneous trials compared percutaneous pinning with plaster cast immobilisation. Across-fracture pinning, used in five trials, was associated with improved anatomical outcome and generally minor complications. There was some indication of similar or improved function in the pinning group. One quasi-randomised trial found an excess of complications after Kapandji pinning. Three trials compared different methods of pinning. Two trials found a higher incidence of complications after Kapandji fixation compared with two methods of across-fracture fixation. The third trial provided inadequate evidence for modified Kapandji fixation versus Willenegger fixation. Two small trials comparing biodegradable pins versus metal pins found a significant excess of complications associated with biodegradable material. Two small trials compared plaster cast immobilisation for one week versus for six weeks after surgery. One trial found duration of immobilisation after trans-styloid fixation did not have a significant effect on outcome. More complications occurred in the early mobilisation group after Kapandji pinning in the second trial. AUTHORS' CONCLUSIONS: Though there is some evidence to support its use, the precise role and methods of percutaneous pinning are not established. The higher rates of complications with Kapandji pinning and biodegradable materials casts some doubt on their general use.

The use of recombinant activated factor VII in the control of haemorrhage following blunt pelvic trauma.

This article reports two cases of severe blunt pelvic trauma associated with road traffic accidents, where the patients developed significant bleeding and haemodynamic instability, poorly responsive to conventional management. Both patients required massive transfusion of blood products with a resultant dilutional coagulopathy. In each case, a single dose of recombinant activated factor VII (rFVIIa) was used to achieve haemostatic control, with a subsequent decrease in blood product requirements and improvement in haemoglobin concentration and clotting profile.

Interventions for treating mallet finger injuries.

BACKGROUND: Mallet finger, also called drop or baseball finger, is where the end of a finger cannot be actively straightened out due to injury of the extensor tendon mechanism. Treatment commonly involves splintage of the finger for six or more weeks. Less frequently, surgical fixation is used to correct the deformity. OBJECTIVES: To examine the evidence for the relative effectiveness of different methods of treating mallet finger injuries. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group trials register (November 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2004), MEDLINE (1966 to February week 2 2004), EMBASE (1988 to 2004 week 8), other databases, reference lists of articles and various conference proceedings. SELECTION CRITERIA: Randomised or quasi-randomised clinical trials evaluating different interventions, including no intervention, for treating mallet finger injuries. DATA COLLECTION AND ANALYSIS: Two reviewers independently performed study selection, quality assessment and data extraction. Study authors were contacted for additional information. MAIN RESULTS: Four trials were included. These involved a total of 278, mainly adult, participants with 283 mallet finger injuries. All four trials were methodologically flawed, including inadequate outcome assessment. Three trials compared different types of finger splints versus a standard Stack splint. One trial found a lower incidence of treatment failure in participants treated with a perforated custom-made splint. One trial found there were fewer complications in participants treated with a padded aluminium-alloy malleable finger splint; however, the incidence of treatment failure was similar in the two treatment groups. One trial evaluating the Abouna splint found a similar incidence of treatment failure in the two groups. However, the Abouna splint often needed replacing due to disintegration of its rubber cover and rusting of the exposed wires and was also less popular with participants. The fourth trial found no statistically significant differences between participants whose mallet finger was treated with Kirschner wire fixation and those with a Pryor and Howard splint. Similar numbers had complications in the two groups. REVIEWERS' CONCLUSIONS: There was insufficient evidence from comparisons tested within randomised trials to establish the relative effectiveness of different, either custom-made or off-the-shelf, finger splints used for treating mallet finger injury. There was a useful reminder that splints used for prolonged immobilisation should be robust enough for everyday use, and of the central importance of patient adherence to instructions for splint use. There was insufficient evidence to determine when surgery is indicated.

Interobserver variations in intra-articular evaluation during arthroscopy of the knee.

We carried out a prospective study in order to establish to what extent the intra-articular evaluation undertaken during arthroscopy of the knee differed between surgeons. Two senior specialist registrars and a consultant orthopaedic surgeon with a special interest in knee surgery were involved. A total of 78 knee arthroscopies (78 patients) was studied. Arthroscopy was first carried out by the trainee and then by the senior author (ACWH). The intra-articular evaluation during the arthroscopy was recorded independently by a third person in the operating theatre. Data were collected to record variations in examination under anaesthesia, the morphology and pathology of the menisci and anterior cruciate ligament and the state of the articular surfaces. The overall interobserver variation was 20% in all categories. We question the published results of intra-articular evaluation during knee arthroscopy when surgeons of different levels of experience are involved in a single study.

Withdrawal of mycophenolate mofetil in stable renal transplant recipients.

BACKGROUND: Mycophenolate mofetil (MMF) has been demonstrated to decrease episodes of acute rejection in renal transplant recipients during the first year after transplantation. The utility of MMF after 1 year is less clear. METHODS: Forty-five stable renal transplant recipients on maintenance therapy of cyclosporine microemulsion, MMF, and prednisone had MMF withdrawn at approximately 1 year after transplantation. A matching concurrent group of 45 stable renal transplant recipients served as the case control group. RESULTS: Two of 45 patients in the MMF withdrawal group suffered an acute rejection episode as opposed to 1 of 45 in the control group. Both patients who rejected in the withdrawal group had adequate cyclosporine levels and had no recent decrease in prednisone dose. There was no evidence of an increased incidence of proteinuria or increased creatinine levels in the MMF withdrawal group. CONCLUSION: In general, withdrawal of MMF in stable renal transplant recipients is well tolerated. No increased risk of rejection could be demonstrated in this patient group. A larger study will be needed to confirm our result.

Infectious complications in geriatric renal transplant patients: comparison of two immunosuppressive protocols.

BACKGROUND: It has been well documented that a regimen of mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisone (Pred) reduces the incidence of acute rejection in renal transplant recipients, as compared with previous regimens based on azathioprine (AZA), CsA, and Pred. In the general renal transplant patient population, immunosuppressive regimens that include MMF are usually well tolerated. It is not clear whether this holds true for older transplant recipients, who may be more susceptible to complications from the greater immunosuppression conferred by MMF. METHODS: We retrospectively analyzed our geriatric renal transplant population (age >60 years, 1990-1998) and compared a cohort of 46 patients treated with AZA, Pred, and CsA to a cohort of 45 patients treated with MMF, Pred, and CsA. RESULTS: There were no significant differences between the groups with regard to pretransplantation demographics. Patient and graft survival during the first year was not significantly different between the groups. During the first year of follow-up, we observed 27 infections requiring hospitalization in 15 patients in the MMF-treated group as compared with 10 infections in 7 patients in the AZA-treated group. A Cox proportional hazard model accounting for the above mentioned covariates isolated MMF versus AZA as a significant risk factor for the occurrence of serious infectious events (all: P<0.01; cytomegalovirus, fungal: P<0.01). CONCLUSION: We conclude that an immunosuppressive regimen of MMF, CsA, and Pred seems to be correlated with an increased incidence of infectious adverse events as compared with AZA, CsA, and Pred in elderly patients.

The effect of body mass index on long-term renal allograft survival.

BACKGROUND: A number of factors have been implicated in decreasing long-term renal graft survival. Factors such as living versus cadaveric donor status, acute rejection, and HLA matching have been studied in detail. Mild obesity defined as a body mass index (BMI) of >25 has been found to have a deleterious effect on a number of physiologic processes. We studied the effect of a BMI >25 on long-term renal transplantation outcome. METHODS: A total of 405 patients who underwent transplantation at Saint Barnabas Medical Center from 1990 to 1997 were evaluated. All known variables impacting on long-term graft function were collected. Multivariate analysis utilizing the Cox-proportional hazard model and Kaplan-Meier actuarial survival were applied to these risk factors. RESULTS: BMI >25 was isolated as an independent risk factor for both decreased graft survival and patient survival (relative risk 2.0 for each). Cadaveric donor status, acute rejection, and use of azathioprine versus mycophenolate mofetil were the only other significant risk factors. CONCLUSIONS: Mild obesity before transplantation has a negative impact on long-term renal graft and patient survival.

Pathogenesis of diffuse intimal thickening (DIT) in non-human primate thoracic aortas.

The pathogenesis of diffuse intimal thickening (DIT) is not well understood. In animals, it is positively correlated with size, and with the exception of the pig, is thought to involve the proximal more than the distal portions of vessels. DIT is often not visible grossly, so that it's study requires extensive microscopic sampling of tissue. Review of previous studies in animals suggests that microscopic sampling may not have been sufficient to determine exactly where DIT occurs throughout the entire length of a vessel. The present study is a longitudinal step-serial section examination of the entire descending thoracic aorta from 12 adult non-human primates of varying size and species and with varying degrees of DIT as determined previously by more limited cross-section techniques. The findings indicate that DIT is not more pronounced in the proximal versus the distal segments of the vessel, and is not correlated with branch orifices. Review of the literature suggests that DIT may not be a single process, but may vary in pathogenesis from vessel to vessel and from species to species.