An assessment of the efficiency of the Glostavent® ventilator

In parts of the world where supplies of oxygen and electricity are erratic, ventilating patients' lungs can be problematic. Should the electricity supply fail, gas driven ventilators have an advantage as they can continue functioning. However, many are extravagant in their requirement for the driving gas. The Glostavent^® ventilator was designed to minimise these requirements. We measured the duration of ventilation achieved by the Glostavent ventilator using an E-size oxygen cylinder at a range of minute volumes, and the inspired oxygen concentration achieved by recycling the driving gas. The period of mechanical ventilation from a single E-size cylinder ranged from 11 h 8 min (SD 4 min) with a minute volume of 7 l.min⁻¹ to 18 h 15 min (SD 7 min) with a minute volume of 3 l.min⁻¹. The mean fractional inspired oxygen concentration achieved by recycling the driving gas without further inspired oxygen supplementation was 0.33. We conclude that the Glostavent ventilator performs as efficiently and cost effectively as predicted.     

Clinical relevance of the B12/N2O interaction A report of a seminar

The interaction of nitrous oxide and vitamin B₁₂ and its implications are not the exclusive territory of any one discipline. The initial discovery was by a chemist but it is of obvious relevance to anaesthetists and intensivists; some complications are neurological others haematological. The interaction provides an extremely important research tool as the first easily available B₁₂-deficient animal model. Finally there are implications for exposure to contaminated atmospheres in hospitals and in industry.     

Laser Resurfacing of the Neck with the Combined CO2/Er:YAG Laser

BACKGROUND: Several clinical studies on laser resurfacing on the neck have yielded variable results with adverse sequelae of hypopigmentation and scarring using the CO2 laser. The Er:YAG laser on the neck resulted in an improved appearance with no adverse sequelae. The combined CO2/Er:YAG laser is a laser that combines a low fluence CO2 laser with the Er:YAG laser in a near simultaneous beam. OBJECTIVE: To study the effects of the CO2/Er:YAG laser on the neck. The decreased nonspecific thermal damage of the CO2/Er:YAG laser should result in decreased postoperative erythema and improved wound healing. METHODS: Eleven patients were treated with the CO2/Er:YAG laser on the neck as well as the face at identical settings. The face was treated with four passes while the neck was treated with two passes. The patients were evaluated for the first 2 weeks then 3-6 months postoperatively. Patients were asked about treatment satisfaction and improvement in skin texture and color using a 25% scale. Skin texture and color, as well as improvement in wrinkling and adverse results were judged by a dermatologist using a 0-4 scale. RESULTS: Moderate improvement was seen in skin color while a higher degree of improvement was seen in skin texture and wrinkling in all 11 patients. No adverse sequelae, including hypopigmentation or scarring, were observed. The majority of patients had a 75-100% improvement in skin texture and color in addition to a 75-100% overall satisfaction rating. CONCLUSIONS: There is a higher degree of overall patient satisfaction, as well as improvement in skin texture and skin color, compared to patients treated with the Er:YAG laser alone. The CO2/Er:YAG laser is a highly effective laser for neck resurfacing with no adverse sequelae to date.     

Comparison of the haemodynamic actions of desflurane/N2O and isoflurane/N2O anaesthesia in vascular surgical patients

Background: The purpose of this study was to compare heart rate and arterial blood pressure response to desflurane/N₂O vs isoflurane/N₂O anaesthesia in a randomised clinical trial performed in patients before vascular surgery.
Methods: To evaluate associated changes in the autonomic nervous system with maintenance of anaesthesia, we used power spectral analysis (PSA) of heart rate and blood pressure and measured plasma catecholamine concentrations. Twenty-five patients whose trachea had been intubated after propofol induction were given either desflurane or isoflurane at 1 and 1.5 MAC in N₂O (60%) in a random manner.
Results: At an anaesthetic depth of up to 1.5 MAC, arterial blood pressure, indices of sympathetic activity derived from PSA, decreased with both anaesthetics, while heart rate and plasma catecholamine concentrations did not significantly change. Plasma renin activity significantly increased at 1.5 MAC anaesthesia in both groups.
Conclusions: We conclude that sympathetic hyperactivity previously reported during desflurane anaesthesia in healthy volunteers is not frequent in clinical practice in elderly vascular surgical patients under desflurane/N₂O anaesthesia, since it occurs at an anaesthetic depth which cannot be reached in these patients because of the lowering arterial blood pressure effects of desflurane, which are similar to those of isoflurane.     

SSAT/AGA/ASGE State of the Art Conference on Cystic Neoplasms of the Pancreas

Cystic tumors of the pancreas are an increasingly recognized clinical entity, and the management of these lesions continues to evolve. The Society for Surgery of the Alimentary Tract, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy recently held a “state-of-the-art” conference to discuss the current recommendations for diagnostic evaluation and clinical management of pancreatic cystic tumors. In this article, a brief review of the conference and important teaching points presented at the conference are highlighted. The articles discussed in this paper were originally presented as part of the SSAT/AGA/ASGE State-of-the-Art Conference on Management of Cystic Lesions of the Pancreas at the SSAT 48th Annual Meeting, May 2007, in Washington, DC, and include Adsay NV, Cystic Neoplasia of the Pancreas: Pathology and Biology; Scheiman JM, Management of Cystic Lesions of the Pancreas: Diagnosis: Radiographic Imaging, EUS and Fluid Analysis; Tseng JF, Management of Serous Cystadenoma of the Pancreas; Fernández-del Castillo C, Mucinous Cystic Neoplasms; and Farnell MB, Surgical Management of Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas.     

History of the ISS/SIC: Antoine Depage,one of the founders of the ISS/SIC

Antoine Depage, born near Brussels in 1862, was one of the founders and first Secretary General of the Société Internationale de Chirurgie (ISS–SIC). After an excellent medical education at the Free Brussels University, he became professor at the same university at the age of 27. Surgically trained by Prof. Thiriar, he became one of the leading Belgian surgeons at the end of the nineteenth century, and he published more than 100 articles in national and international journals. In 1907 he founded a school for nurses in Brussels, to be directed by Edith Cavell. He also vigorously transformed the organization of the public hospitals in the Belgian capital. During World War I Queen Elisabeth appointed him surgeon-in-chief of the Océan-hospital in De Panne, where more than 50,000 soldiers with wounds, fractures, cerebral trauma, nitrous gas intoxication, and infectious diseases, among other problems were treated. The results he and his team obtained were excellent, and mortality was low. Many surgeons, including Alexis Carrel, as well as distinguished political leaders came to visit him in the hospital barracks. After the war he was honored by many political and scientific organizations, including the Société Internationale de Chirurgie. He served our Society not only as Secretary General from 1902 to 1912 but became President of the 4th Congress of the ISS–SIC in New York. Antoine Depage died after a long illness in 1925.     

Differences between systematic reviews/meta-analyses of hyaluronic acid/hyaluronan/hylan in osteoarthritis of the knee

OBJECTIVE: To explore reasons for discrepant results between systematic reviews (SR)/meta-analyses (MA) of the efficacy and safety of hyaluronic acid/hyaluronan/hylan (HA) therapy in the treatment of osteoarthritis (OA) of the knee. METHODS: A decision algorithm was utilised to identify reasons for discordance among six SR. Sources of discordance such as clinical question, trial selection and inclusion, data extraction, assessment of study quality, assessment of the ability to combine trials, and statistical methods for data synthesis were examined. RESULTS: A similar question was asked in all six SR. Different trials were selected for inclusion in the reviews mainly because of differences in the search strategies and selection criteria. Although similar methods for data extraction were utilised, differences were found both in the outcome measures and time-points selected for extraction. Methodological quality was not always formally assessed. Different statistical methods for data synthesis resulted in conflicting estimates of therapeutic effect. CONCLUSIONS: Reasons for the inconsistency of results reported in the six SR were identified. Using the principles of the GRADE approach for estimating the therapeutic effect of HA in the treatment of OA of the knee, there is moderate evidence suggesting that further research is unlikely to change our confidence in the estimate of the effect. In the balance of benefit to harm, the trade-off is probable benefit with respect to pain reduction and physical function improvement with low risk of harm.     

Chondroma/Chondrosarcoma of the spine

Chondromas and chondrosarcomas are cartilage-forming tumors that occur rarely in the spine. These neoplasms exist on opposite ends of the pathologic spectrum, ranging from the benign chondroma to the malignant, high-grade chondrosarcoma. Unlike other sarcomas, a patient's long-term prognosis is influenced by the grade of the tumor. A complete en bloc resection is the ideal method of surgical management. This method holds especially true for chondrosarcomas, and can result in prolonged survival. These tumors are resistant to conventional chemotherapy and radiation therapy. Hypofractionated stereotactic radiation therapy may slow tumor progression, although the long-term effect of this modality is unknown.     

Icariin improves the sexual function of male mice through the PI3K/AKT/eNOS/NO signalling pathway

We aimed to investigate the effect and mechanism of icariin on male sexual function. Forty‐eight Crl:CD1(ICR) male mice were randomly divided into control, low‐, medium‐ and high‐dose icariin group (intragastric administration of 50, 100 and 200 mg/kg/d for 21 days). Mating experiment was then performed at a ratio of 1: 3 (male: female). The mating behaviours of male mice were recorded. The genital indexes and serum testosterone, nitric oxide (NO), hypothalamic dopamine (DA) and 5‐ hydroxy tryptophan (5‐HT) concentrations were measured. The expression of endothelial nitric oxide (eNOS), phosphatidylinositol tallow alcohol 3‐kinase (PI3K) and phosphorylated protein kinase (p‐AKT) in penile tissue was detected by Western blot. All icariin groups exhibited shorter capture latency and ejaculation latency, increased number of capture and ejaculation, higher capture and ejaculation rate, and higher testicular and prostate indexes compared with controls (p < .001). These groups had higher serum testosterone and NO concentrations (p < .001), hypothalamic DA and 5‐HT levels, and eNOS, PI3K and phosphorylated AKT expressions in penile tissue (p < .05). The effect of icariin was dose‐dependently increased. Our study suggests that icariin improves the sexual function of male mice, which might be associated with the hypothalamic–pituitary–gonadal axis and the PI3K/AKT/eNOS/NO signalling pathway.     

Studies of the Metabolism of Citanest C14

Citanest C¹⁴ has been shown to be degraded by liver and kidney slices. In vivo experiments demonstrate that metabolites are excreted in the urine and decarboxylation with excretion of C¹⁴0₂ has been demonstrated in the rat.
Further studies are needed to establish all the pathways for metabolism of Citanest.     

The TEG® vs the ROTEM® thromboelastography/thromboelastometry systems

We have evaluated the TEG^® thromboelastograph and the ROTEM^® thromboelastometer, two point-of-care devices that measure blood coagulation. During a one-week period, seven consultant anaesthetists, one consultant haematologist, one associate specialist anaesthetist and two senior trainee anaesthetists were trained by the manufacturers and set up, calibrated and used both systems, after which their views were obtained and specific technical/support information was sought from the manufacturers using a questionnaire. Although the devices shared common features, they differed in complexity and aspects of ease of use, and in their purchase and running costs.