In Vitro Evaluation of an Active Heat-and-Moisture Exchanger: The Hygrovent Gold

BACKGROUND: To improve the heat and humidification that can be achieved with aheat-and-moisture exchanger (HME),a hybrid active (ie,adds heat and water) HME,the Hygrovent Gold,was developed. We evaluated in vitro the performance of theHygrovent Gold. METHODS: We tested the Hygrovent Gold (with and without its supplemental heat andmoisture options activated),the Hygrobac,and the Hygrovent S. We measured theabsolute humidity,using a test lung ventilated at minute volumes of 5,10,and15 L/min,in normothermic (expired temperature 34 degrees C) and hypothermic(expired temperature 28 degrees C) conditions. We also measured the HMEs' flowresistance and weight after 24 h and 48 h. RESULTS: In its active mode the Hygrovent Gold provided the highest absolutehumidity,independent of minute volume,in both normothermia and hypothermia. Therespective normothermia and hypothermia absolute humidity values at 10 L/min were36.3 + 1.3 mg/L and 27.1 + 1.0 mg/L with the active Hygrovent Gold,33.9 + 0.5mg/L and 24.2 + 0.8 mg/L with the passive Hygrovent Gold,33.8 + 0.56 mg/L and24.4 + 0.4 mg/L with the Hygrobac,and 33.9 + 0.8 mg/L and 24.6 + 0.6 mg/L withthe Hygrovent S. The efficiency of the tested HMEs did not change over time. At24 h and 48 h the increase in weight and flow resistance was highest in theactive Hygrovent Gold. CONCLUSIONS: The passive Hygrovent Gold provided adequate heat and moisture innormothermia,but the active Hygrovent Gold provided the highest humidity,inboth normothermia and hypothermia

Current Opinions in Open and Endovascular Treatment of Major Arterial Injuries in Pediatric Patient

Pediatric major arterial vascular injuries may belong to the same principal categories as adults, but have been poorly documented, with an estimated overall incidence of <2% of all vascular traumas. Open surgery has been the mainstay of treatment, but no clear guidelines have been developed to recommend the best practice patterns in terms of strategy or repair as well as postoperative pharmacological regimen. Herein, we report three cases and a narrative review of the available literature regarding the main aspects when dealing with pediatric arterial injuries based on the predominant series available from the most recent published literature

Protective Mechanical Ventilation during General Anesthesia for Open Abdominal Surgery Improves Postoperative Pulmonary Function

BACKGROUND:: The impact of intraoperative ventilation on postoperative pulmonary complications is not defined. The authors aimed at determining the effectiveness of protective mechanical ventilation during open abdominal surgery on a modified Clinical Pulmonary Infection Score as primary outcome and postoperative pulmonary function. METHODS:: Prospective randomized, open-label, clinical trial performed in 56 patients scheduled to undergo elective open abdominal surgery lasting more than 2 h. Patients were assigned by envelopes to mechanical ventilation with tidal volume of 9 ml/kg ideal body weight and zero-positive end-expiratory pressure (standard ventilation strategy) or tidal volumes of 7 ml/kg ideal body weight, 10 cm H2O positive end-expiratory pressure, and recruitment maneuvers (protective ventilation strategy). Modified Clinical Pulmonary Infection Score, gas exchange, and pulmonary functional tests were measured preoperatively, as well as at days 1, 3, and 5 after surgery. RESULTS:: Patients ventilated protectively showed better pulmonary functional tests up to day 5, fewer alterations on chest x-ray up to day 3 and higher arterial oxygenation in air at days 1, 3, and 5 (mmHg; mean \ub1 SD): 77.1 \ub1 13.0 versus 64.9 \ub1 11.3 (P = 0.0006), 80.5 \ub1 10.1 versus 69.7 \ub1 9.3 (P = 0.0002), and 82.1 \ub1 10.7 versus 78.5 \ub1 21.7 (P = 0.44) respectively. The modified Clinical Pulmonary Infection Score was lower in the protective ventilation strategy at days 1 and 3. The percentage of patients in hospital at day 28 after surgery was not different between groups (7 vs. 15% respectively, P = 0.42). CONCLUSION:: A protective ventilation strategy during abdominal surgery lasting more than 2 h improved respiratory function and reduced the modified Clinical Pulmonary Infection Score without affecting length of hospital stay

Catastrophic NAD+ Depletion in Activated T Lymphocytes through Nampt Inhibition Reduces Demyelination and Disability in EAE

Nicotinamide phosphoribosyltransferase (Nampt) inhibitors such as FK866 are potent inhibitors of NAD+ synthesis that show promise for the treatment of different forms of cancer. Based on Nampt upregulation in activated T lymphocytes and on preliminary reports of lymphopenia in FK866 treated patients, we have investigated FK866 for its capacity to interfere with T lymphocyte function and survival. Intracellular pyridine nucleotides, ATP, mitochondrial function, viability, proliferation, activation markers and cytokine secretion were assessed in resting and in activated human T lymphocytes. In addition, we used experimental autoimmune encephalomyelitis (EAE) as a model of T-cell mediated autoimmune disease to assess FK866 efficacy in vivo. We show that activated, but not resting, T lymphocytes undergo massive NAD+ depletion upon FK866-mediated Nampt inhibition. As a consequence, impaired proliferation, reduced IFN-γ and TNF-α production, and finally autophagic cell demise result. We demonstrate that upregulation of the NAD+-degrading enzyme poly-(ADP-ribose)-polymerase (PARP) by activated T cells enhances their susceptibility to NAD+ depletion. In addition, we relate defective IFN-γ and TNF-α production in response to FK866 to impaired Sirt6 activity. Finally, we show that FK866 strikingly reduces the neurological damage and the clinical manifestations of EAE. In conclusion, Nampt inhibitors (and possibly Sirt6 inhibitors) could be used to modulate T cell-mediated immune responses and thereby be beneficial in immune-mediated disorders