Comparison of the Glidescope® and Airtraq® optical laryngoscopes in patients undergoing direct microlaryngoscopy

Optical laryngoscopes have been developed to facilitate difficult airway management. The Airtraq^® is a single-use device and the GlideScope^® is reusable. In this study, the Airtraq and the Glidescope were compared in 60 ASA I-III patients with tumours of the upper airway undergoing direct endoscopic microlaryngoscopy. Patients were randomly assigned to the Airtraq or the Glidescope group and the Cormack and Lehane grade was assessed by Macintosh laryngoscopy prior to tracheal intubation. There were no differences in tracheal intubation success rates or duration of intubation attempts between both devices. The Cormack and Lehane grade was improved in 77% and 82% of cases in the Airtraq and Glidescope group, respectively. Blood traces on the device and traumatic pharyngeal lesions were found more frequently in the Airtraq group. The Airtraq and Glidescope laryngoscopes are valuable tools for the management of patients with potentially difficult airways with the Glidescope appearing to be less traumatic.     

Evaluation of the HemoCue® for measuring intra-operative haemoglobin concentrations: a comparison with the Coulter Max-M®

We compared haemoglobin concentration values obtained using a portable haemoglobinometer, the HemoCue, in the operating theatre with the results obtained by the Coulter Max-M in the laboratory. Haemoglobin concentrations were measured on 52 arterial blood samples obtained from 13 patients during aortic surgery, in theatre with the HemoCue and again by the Coulter Max-M. Twenty routine samples from the laboratory were also analysed by both methods. There was no significant difference between results, with a mean of 10.94 gdl⁻¹ and 10.90 gdl⁻¹ for the HemoCue and Coulter, respectively (p = 0.12, t  = −1.99, df  = 70). The limits of agreement of the two methods (mean difference ± 2 SD) were −0.37 and +0.45 gdl⁻¹. The coefficients of repeatability of the 20 samples analysed in duplicate on each device were 0.26 gdl⁻¹ and 0.33 gdl⁻¹, respectively. The coefficients of variance were 0.74% (HemoCue) and 0.93% (Coulter). With adequate training and monitoring, the HemoCue provides comparable haemoglobin results for near-patient testing in theatre.     

Homeostatic Repopulation by CD28−CD8+ T Cells in Alemtuzumab-Depleted Kidney Transplant Recipients Treated With Reduced Immunosuppression

Alemtuzumab (CAMPATH-1H) is a depleting agent introduced recently in transplantation and often used with reduced maintenance immunosuppression. In the current study we investigated the immune response of 13 kidney allograft recipients treated with alemtuzumab followed by weaned immunosuppression with reduced dose of mycophenolate mofetil (MMF) and tacrolimus. Tacrolimus was switched to sirolimus at 6 months and MMF withdrawn at 12 months after transplantation.
We found that after alemtuzumab induction the recovery of CD8⁺ T cells was much faster than that of CD4⁺ T cells. It was complete 6 months posttransplant while CD4⁺ T cells did not fully recover even 15 months posttransplant. Repopulating CD8⁺ T cells were mainly of immunosenescent CD28⁻CD8⁺ phenotype. In a series of in vitro experiments we showed that CD28⁻CD8⁺ T cells might suppress proliferation of CD4⁺ T cells. There were three successfully treated acute rejections during the study (first at +70 day, two others +12 months) that occurred in patients with the lowest level of CD28⁻CD8⁺ T cells.
We hypothesize that expanded CD28⁻CD8⁺ T cells might compete for 'immune space' with CD4⁺ T cells suppressing their proliferation and therefore delaying CD4⁺ T-cells recovery. This delay might be associated with the clinical outcome as CD4⁺ T cells, notably CD4⁺ T effector memory cells, were shown to be associated with rejection.     

Chronic anal fissures treated with botulinum toxin injections: a dose-finding study with Dysport®

Botox^® injection of the anal sphincter muscle cures chronic uncomplicated anal fissures in up to 80% of patients. This study examines the therapeutic efficacy and side effect profile of the British botulinum product Dysport^®. Fifty patients (29 women) were recruited to participate in this randomized dose-finding study, their mean age being 32.9 years. The low dose group A was treated with a total dose of 20 U injected in two sites each lateral to the fissure, the high dose group B was treated with 40 U. Eighty-two percent of patients were pain-free within a week following the injections. The fissure was healed in 78% of treated patients after 3 months. Three patients relapsed within 6 months. The most common adverse side effect was transient incontinence ( n  = 4). Clinical outcome was not significantly different between the two treatment groups. The low dose can therefore be regarded sufficient for the treatment of anal fissure. Therapeutic efficacy was equivalent to published data on Botox treatment. Both Dysport^® and Botox^® can therefore be used to treat chronic uncomplicated anal fissures. Both Dysport^® and Botox^® therapy are well tolerated, can be performed on an out-patient basis and avoid the risk of permanent faecal incontinence which complicates surgical treatment of anal fissures.     

Performance of the Airtraq™ laryngoscope after failed conventional tracheal intubation: a case series

Background: The Airtraq^™, a new disposable indirect laryngoscope, was evaluated in patients with difficult intubation.
Methods: The Airtraq^™ was used in 47 patients with predicted or unpredicted difficult intubation after failed orotracheal intubation performed by two senior anaesthesiologists with the Macintosh laryngoscope.
Results: Tracheal intubation with Airtraq^™ was successful in 36 patients (80%). The Cormack and Lehane score was IIb–III in 35 patients, and IV in 12 patients, with the Macintosh laryngoscope, while Cormack and Lehane score was I–IIa in 40 patients, IIb–III in three and IV in four with Airtraq^™. A gum elastic bougie was used to facilitate tracheal access in one-third (11/36) of the cases. Orotracheal intubation was not possible with Airtraq^™ in nine cases, five of whom had a pharyngeal, laryngeal or basal lingual tumour.
Conclusion: In patients with difficult airway, following failed conventional orotracheal intubation, Airtraq^™ allows securing the airway in 80% of cases mainly by improving glottis view. However, the Airtraq^™ does not guarantee successful intubation in all instances, especially in case of laryngeal and/or pharyngeal obstruction.     

STARR with Contour® Transtar™: prospective multicentre European study

Objective  The stapled transanal rectal resection (STARR) in patients with defecation disorders is limited by the shape and capacity of the circular stapler. A new device has been recently developed, the Contour^® Transtar^™ stapler, in order to improve the safety and effectiveness of the STARR technique. The study has been designed to confirm this declaration.
Method  From January to June 2007 a prospective European multicentre study of consecutive patients with defecation disorder caused by internal rectal prolapse underwent the new STARR technique. The assessment of perioperative morbidity and functional outcome after 6 weeks, 3 and 12 months was documented by different scores.
Results  In all 75 patients, median age 64, the Transtar procedure was performed with 9% intraoperative difficulties, 7% postoperative complications and no mortality. The mean reduction of the ODS score was −15.6 (95%−CI: −17.3 to −13.8, P  < 0.0001), mean reduction of SSS was −12.6 (95%−CI: −14.2 to −11.2; P  < 0.0001). 41% stated improvement of their continence status by CCF score, only 4 patients (5%) had deterioration.
Conclusion  The Transtar procedure is technically demanding, with good functional results similar to the conventional STARR.     

Monotherapy rapamycin allows an increase of CD4+ CD25bright+ FoxP3+ T cells in renal recipients

CD4⁺ CD25^bright+ FoxP3⁺ regulatory T cells (Tregs) may control donor-specific allogeneic responses in kidney transplant recipients. Recent evidence demonstrated that three phenotypical Treg-subsets, naive (CCR7⁺CD45RO⁻), central-memory (CCR7⁺CD45RO⁺) and effector-memory (CCR7⁻CD45RO⁺), are essential for the development and function of antigen-specific suppression in the lymphoid and peripheral tissues. Also, it has been appreciated that Tregs are affected by immunosuppressive agents. In clinical practice, however, the effect of a single drug remains to be determined. Therefore, we analyzed the effect of several immunosuppressive agents on the number, phenotype and function of peripheral Tregs from 46 stable kidney transplant recipients. These patients were converted to monotherapy with tacrolimus ( n  = 15), rapamycin ( n  = 17) or mycophenolate mofetil ( n  = 14). Blood was obtained at inclusion and 6 months thereafter. The number of Tregs increased significantly in patients on monotherapy with rapamycin ( P  < 0.001), which was caused by increased numbers of Tregs with a central-memory and an effector-memory phenotype (both P  < 0.05). At 6 months after conversion, however, the suppressive function of Tregs did not significantly change in co-cultures stimulated with donor-Ag. Therefore, monotherapy with rapamycin allows the signals that are needed to increase the number of functional Tregs with a memory phenotype, thereby enhancing the potential capacity to regulate donor-specific responses in the lymphoid and the peripheral tissues.     

The GlideScope Ranger® video laryngoscope can be useful in airway management of entrapped patients

Background: Airway management of entrapped patients is challenging and alternatives to endotracheal intubation with a Macintosh laryngoscope must be considered. In this study, the GlideScope Ranger^® video laryngoscope has been evaluated as an alternative to standard laryngoscopy.
Methods: Eight anaesthesiologists from a Helicopter Emergency Medical Service intubated the trachea of a Laerdal SimMan^® manikin using the studied laryngoscopes in two scenarios: (A) unrestricted access to the manikin in an ambulance and (B) no access from the head end, simulating an entrapped patient. The time used to secure the airway and the scored level of difficulty were the main variables.
Results: In scenario A, all anaesthesiologists managed to secure the airway using both techniques within the 60-s time limit. In scenario B, all secured the airway when using the video laryngoscope, while 50% succeeded with endotracheal intubation using the Macintosh laryngoscope. The difference in the success rate was statististically significant ( P =0.025). There were no significant differences in the time spent on endotracheal intubation in the two scenarios or between the devices. All stated that the availability of a video laryngsoscope would make drug-facilitated intubation a realistic alternative when access to patients is limited. The lack of visual control when using the Macintosh laryngoscope excludes this technique in real-life settings.
Conclusion: This study suggests that the Glidescope Ranger^® may be merited in situations requiring endotracheal intubation by an experienced intubator in patient entrapment. Further studies are required to clarify whether performance in patients mimics that in a manikin.     

Combining the EndoFlex® tube with fiberoptic bronchoscopy in difficult intubation

We applied a combination technique using the EndoFlex^® tube with fiberoptic bronchoscopy for a 69-year-old man presenting with limited mouth opening and neck movement. Awake nasotracheal intubation was performed under conscious sedation with propofol and fentanyl. After positioning the tip of the EndoFlex^® tube in the oropharynx, the fiberoptic bronchoscope was inserted into the tube until the tip reached the bevel of the tube. Anterior flexion of the distal tip of the EndoFlex^® tube facilitated uncomplicated insertion of the tube into the trachea without impingement on the arytenoids. Fiberoptic visualization confirmed that the distal-tip flexing mechanism of the EndoFlex^® tube corrected the direction of the tube tip anteriorly, allowing entry into the trachea. We present a case where this technique proved valuable for tracheal intubation in a patient with limitations of mouth opening and neck movement.     

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.     

Acute Humoral Rejection of Renal Allografts in CCR5–/– Recipients

Increasing detection of acute humoral rejection (AHR) of renal allografts has generated the need for appropriate animal models to investigate underlying mechanisms. Murine recipients lacking the chemokine receptor CCR5 reject cardiac allografts with marked C3d deposition in the parenchymal capillaries and high serum donor-reactive antibody titers, features consistent with AHR. The rejection of MHC-mismatched renal allografts from A/J (H-2^a) donors by B6.CCR5^–/– (H-2^b) recipients was investigated . A/J renal allografts survived longer than 100 days in wild-type C57BL/6 recipients with normal blood creatinine levels (28 ± 7 μmol/L). All CCR5^–/– recipients rejected renal allografts within 21 days posttransplant (mean 13.3 ± 4 days) with elevated creatinine (90 ± 31 μmol/L). The rejected allografts had neutrophil and macrophage margination and diffuse C3d deposition in peritubular capillaries, interstitial hemorrhage and edema, and glomerular fibrin deposition. Circulating donor-reactive antibody titers were 40-fold higher in B6.CCR5^–/– versus wild-type recipients. Depletion of recipient CD8 T cells did not circumvent rejection of the renal allografts by CCR5-deficient recipients. In contrast, μMT^–/–/CCR5^–/– recipients, incapable of producing antibody, did not reject most renal allografts. Collectively, these results indicate the rapid rejection of renal allografts in CCR5^–/– recipients with many histopathologic features observed during AHR of human renal allografts.     

The effects of a high salt diet on gene expression of Na+/H+ exchanger and growth factors in 5/6-nephrectomized rats

SUMMARY: The effects of a high salt diet on renal destruction and the therapeutic effects of amiloride (Na⁺/H⁺ exchanger inhibitor) and furosemide (Na⁺K⁺/2Cl⁻ exchanger inhibitor) were examined in 5/6-nephrectomized rats fed a high salt diet. A simultaneous analysis of the effects of a high salt intake on the renal expression of Na⁺/H⁺ exchanger-1 (NHE-1), transforming growth factor-β1 (TGF-β1) or platelet-derived growth factor-B (PDGF-B) mRNA was performed in this model. the 5/6-nephrectomized Sprague-Dawley rats were given a diet containing 8 or 1% sodium chloride for 5 weeks. This high salt diet accelerated the elevation of blood pressure and aggravated both glomerulosclerosis and interstitial fibrosis in 5/6-nephrectomized rats. the daily administration of amiloride was found to be protective against the elevation of blood pressure, glomerular hypertrophy and the aggravation of renal histology which were induced by a high salt diet. the expression of TGF-β1 and PDGF-B mRNA was up-regulated by a high salt diet, but the expression of NHE-1 mRNA was not. the overexpression of TGF-β1 and PDGF-B mRNA was reduced by the daily administration of amiloride but not by furosemide. In conclusion, the destructive effects of a high salt diet on the kidneys may be mediated through hypertension, glomerular hypertrophy and the overexpression of the growth factors. Amiloride may thus be more protective for high salt induced renal aggravation than furosemide, although the expression of NHE-1 mRNA did not show any substantial increase due to a high salt diet.     

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.     

Ex Vivo-Expanded Natural CD4+CD25+ Regulatory T Cells Synergize With Host T-Cell Depletion to Promote Long-Term Survival of Allografts

Foxp3⁺CD4⁺CD25⁺ natural regulatory T (nT_reg) cells have been shown in immunodeficient mice to suppress allograft rejection after adoptive cotransfer. We hypothesized that immunotherapy using ex vivo -expanded nT_reg could suppress allograft rejection in wild-type mice. Donor alloantigen (alloAg) specificity of naive splenic nT_reg was enriched in vitro by culturing with anti-CD3/CD28-coated Dynabeads plus bone marrow-derived dendritic cells (BM-DC) in the presence of interleukin (IL)-2 or IL-2 plus transforming growth factor (TGF)-β. On average, 96.2% fresh CD4⁺CD25⁺ nT_reg were intracellular Foxp3⁺. By d+20 in culture, 6.4% nT_reg were Foxp3⁺ following expansion with IL-2 alone, and 14.4% or 19.7% nT_reg were Foxp3⁺ when expanded with IL-2 plus 0.5 or 2.5 ng/mL TGF-β, respectively. In vitro , alloAg-enriched, TGF-β/IL-2-conditioned nT_reg exerted stronger donor alloAg-specific suppression than cells with IL-2 alone in mixed lymphocyte reaction (MLR) assays. In vivo , alloAg-enriched, TGF-β/IL-2-conditioned nT_reg expressed high-level Foxp3 following infusion, effectively overcame acute rejection and induced long-term survival of donor but not third-party heart allografts in peritransplant host T-cell-depleted mice. Long-term surviving allografts were noted to possess Foxp3⁺ graft-infiltrating cells of exogenous and endogenous origins. In conjunction with transient host T-cell depletion, therapeutic use of ex vivo -expanded nT_reg may be a practical means of preventing acute allograft rejection.     

CD4+CD25+FOXP3+ Regulatory T Cells Increase De Novo in Kidney Transplant Patients After Immunodepletion with Campath-1H

Campath-1H (Alemtuzumab) is an effective immunodepletion agent used in renal transplantation. To evaluate its influence on T lymphocytes during repletion, we analyzed peripheral blood from Campath-1H-treated renal allograft recipients for the presence of FOXP3⁺ regulatory T (Treg) cells. Flow cytometry demonstrated that CD4⁺CD25⁺FOXP3⁺ lymphocytes increased significantly within the CD4⁺ T-cell population, skewing Treg/Teff (T effector) ratios for up to several years. In contrast, Treg levels in patients treated with anti-CD25 (Basiliximab) and maintained on CsA demonstrated a sustained decrease. The increase in Tregs in Campath-1H treated patients developed independent of maintenance immunosuppression. Importantly, the increase in Tregs was not fully explained by their homeostatic proliferation, increased thymic output, or Treg sparing, suggesting de novo generation/expansion. Consistent with this, in vitro stimulation of PBMCs with Campath-1H, with or without anti-CD3, activation led to an increase in CD4⁺CD25⁺FOXP3⁺ cells that had suppressive capabilities. Together, these data suggest that Campath-1H promotes an increase in peripheral Tregs and may act as an intrinsic generator of Tregs in vivo .     

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.     

Isoflurane enhances spontaneous Ca2+ oscillations in developing rat hippocampal neurons in vitro

Background: During the nervous system development, spontaneous synchronized Ca²⁺ oscillations are thought to possess integrative properties because their amplitude and frequency can influence the patterning of neuronal connection, neuronal differentiation, axon outgrowth, and long-distance wiring. Accumulating studies have confirmed that some drugs such as volatile anesthetic isoflurane produced histopathologic changes in the central nervous system in juvenile animal models. Because the hippocampus plays an important role in learning and memory, the present work was designed to characterize the Ca²⁺ oscillations regulated by volatile anesthetic isoflurane in primary cultures of developing hippocampal neurons (5-day-cultured).
Methods: Primary cultures of rat hippocampal neurons (5-day-cultured) were loaded with the Ca²⁺ indicator Fluo-4AM (4 μM) and were studied with a confocal laser microscope.
Results: Approximately 22% of 5-day-cultured hippocampal neurons exhibited typical Ca²⁺ oscillations. These oscillations were dose-dependently enhanced by isoflurane (EC50 0.5 MAC, minimum alveolar concentration) and this effect could be reverted by bicuculline (50 μM), a specific γ-aminobutyric acid (GABA_A) receptor antagonist.
Conclusion: Unlike its depressant effect on the Ca²⁺ oscillations in adult neurons in previous researches, isoflurane dose-dependently enhanced calcium oscillations in developing hippocampal neurons by activating GABA_A receptors, a major excitatory receptor in synergy with N -methyl- d -aspartate receptors at the early stages of development. It may be involved in the mechanism of an isoflurane-induced neurotoxic effect in the developing rodent brain.     

Direct inhibition of testicular steroidogenesis and gonadotrophin receptor levels by [(imBzl)-D-His6, Pro9-NEt]GnRH and [D-Trp6, Pro9-NEt]GnRH, potent agonists of GnRH

The effects of [(imBzl)-D-His⁶, Pro⁹-NEt]GnRH and [D-Trp⁶. Pro⁹-NEt]GnRH on testicular function in rats was evaluated. In adult rats the administration of 0.01, 0.1 or 10 μg of either agonist induced rapid increases in serum LH, FSH and testosterone (T) levels which started to decline within several hours. Both agonists caused a decrease in testicular LH and FSH receptor concentrations. The testicular FSH receptor concentration started to decline earlier than the LH receptor concentration but, both reached their lowest levels by day 2 after the administration of the agonists. The recovery of FSH receptor content was slower than that of LH. The extrapituitary effects of the 2 agonists were investigated in immature hypophysectomized animals. Administration of hCG (5 IU daily) to hypophysectomized rats for 5 days caused an increase in serum T levels. Concomitant administration of either of the agonists (10 μg) inhibited the steroidogenic action of hCG. Administration of the agonists alone caused a reduction in testicular LH receptor concentration in hypophysectomized rats. Treatment of the hypophysectomized rats for 0–4 days suggested that the direct antitesticular action of the agonists requires 1 - 2 days to become evident.     

Determination of Skin Blood Flow by 133Xe Washout and by Heat Flux from a Heated tc-Po2 Electrode

¹³³Xe washout measurements were used to determine cutaneous and subcutaneous blood flow beneath a specially designed double-thermostated tc-Po₂ electrode. The skin blood flow was determined using thermal methods based on reduced heat dissipation during blood flow cessation. A total of 20 measurements were performed on two healthy volunteers, using the volar side of the right forearm as the experimental area. Cutaneous as well as subcutaneous blood flow increased with increasing electrode temperature. The cutaneous blood flow increased from 12.3 ± 1.3 ml (100 g)^-1-min^-1 (37C) to 49.1 ± 5.4 ml (100 g)^-1.min^-1 (45C) and the subcutaneous values from 20.9 ± 0.2 ml (100 g)^-1 -min^-1 to 57.3 ± 0.5 ml (100 g)^-1 -min^-1. Preheating of the measuring area or injection of papaverine as blood flow accelerator did not increase the maximum blood flow values. A considerable inter-individual difference between cutaneous and subcutaneous blood flow was observed, but in spite of that a good overall correlation between the ¹³³Xe washout measurements and the two thermal flow measurements was found (r = 0.932 and 0.945, respectively). It is concluded that in some cases, but not always, measurements of tc-Po₂ at electrode temperatures of 45C take place on a maximally perfused skin and that it is possible to determine skin blood flow by means of determinations of the heat dissipated from the tc-Po2 electrode to the underlying skin.