Spontaneous minute ventilation is a predictor of extubation failure in extremely-low-birth-weight infants.

OBJECTIVE: To validate the percentage of time spent below a target value of spontaneous expiratory minute ventilation (< 125 ml/min per kg) during a 2-h period of continuous positive airway pressure (CPAP) via an endotracheal tube (ETT) as a predictor of failed extubation in preterm infants. METHODS: Forty-one infants intubated for at least 24 h, with birth weight between 500 and 1000 g, who were clinically stable and at ventilator setting compatible with an extubation attempt, were studied during a 2-h period of ETT CPAP. Dynamic lung compliance and total lung resistance were measured during a period of quiet breathing, while tidal volume (Vt), respiratory rate and the corresponding spontaneous expiratory minute ventilation values were calculated for the complete recording period of 2 h using a customized computer program. The time each patient spent below the target spontaneous expiratory minute ventilation value was reported as a percentage of the total recorded time (% spontaneous expiratory minute ventilation < 125 ml/min per kg). Extubation failure was defined as the need for reintubation within 72 h. RESULTS: Eleven out of 41 babies (26.8%) experienced failure of extubation (failure group) while 30 infants (73.2%) were successfully extubated (success group). There were no significant differences in dynamic lung compliance and lung resistance between the two groups, but the mean values of respiratory rate and spontaneous expiratory minute ventilation were significantly lower in the failure group than in the success group: 43 (37-56) breaths/min and 240 (160-353) ml/min per kg vs. 53 (28-67) breaths/min and 309 (223-434) ml/min per kg, respectively (p = 0.0129 and p = 0.0039). Moreover, the babies in whom extubation failed spent a longer time below the target value of spontaneous expiratory minute ventilation when compared with successfully extubated babies (p < 0.0001). Percentage of time spent with spontaneous expiratory minute ventilation < 125 ml/min per kg had a larger area than transcutaneous (Tc)PCO2, TcPO2 and pulse oxymetry saturation (SpO2) under the receiver operator characteristic curves. CONCLUSION: The measurement of spontaneous expiratory minute ventilation prior to extubation could be useful in identifying those babies who are not ready for spontaneous ventilation.     

Vasopressin, when added to norepinephrine, was not associated with increased predicted mortality after cardiac surgery

BACKGROUND AND AIMS: Arginin vasopressin (AVP) is a potent vasoconstrictor which has been used in vasodilatory shock when therapy with catecholamines and fluids has failed. In this study we evaluated the association of AVP with organ failure and mortality in cardiac surgical patients suffering from vasodilatory shock refractory to norepinephrine (NE) treatment. MATERIAL AND METHODS: Cardiac surgical patients who received AVP in addition to NE (N=33, AVP-group) and 33 control patients (NE group) who were treated with an equal dose of NE compared with AVP patients when AVP infusion started. Data on preoperative risk factors according to EuroSCORE and predicted mortality calculated by logistic EuroSCORE were collected preoperatively. Data on hemodynamics, organ dysfunctions, length of intensive care unit stay and mortality were collected. RESULTS: EuroSCORE did not differ between the groups, AVP:10.4 +/- 3.9 vs. NE 8.9 +/- 4.0. Observed 30 day mortality was lower than predicted in both groups, AVP: 7 (21.7%) vs. predicted mortality 25.9% and NE: 2 (6.1%) vs. 16.0%, respectively. There were more renal complications (36.4% vs. 9.1%, p = 0.008) and infections (30.3% vs. 3.0%, p = 0.003) in patients receiving AVP. Cardiovascular complications did not differ between the groups. CONCLUSIONS: In this prospectively observed cohort of cardiac surgical patients, AVP did not increase mortality predicted by Euroscore. Anyhow renal and infection complications were common.     

Evaluation of recombinant antigen-based assays for diagnosis of bullous autoimmune diseases

The diagnosis of autoimmune bullous diseases is based on clinical observation and on the presence of autoantibodies directed to molecules involved in the adhesion systems of the skin. Immunofluorescence assays are the currently accepted method for detection of autoantibodies; such assays depend greatly on the skill of operators and are difficult to standardize. Recombinant desmoglein-1 (Dsg1), Dsg3, and BP180 peptides, the main autoantigens in pemphigus or bullous pemphigoid, have been used to develop new quantitative enzyme immunoassays (EIA) for the detection of specific antibodies. The present study was undertaken to evaluate the sensitivity and specificity of these immunoassays and to determine the correlation between the results and the clinical aspects of diseases. Serum samples from patients with pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, or mucous membrane pemphigoid, from healthy individuals, and from patients with unrelated autoimmune conditions were tested. Anti-desmoglein reactivity was detected in all the patients with pemphigus and in none of the controls. Patients with the more benign form of cutaneous disease had anti-Dsg1 antibodies, while patients with deeper cutaneous lesions or with mucosal involvement had anti-Dsg3 reactivity also, or exclusively. The BP180-based assay was positive for 66.6% of patients with bullous pemphigoid and for none of the patients with mucous membrane pemphigoid, and no reactivity was detected in the control sera. In conclusion, the anti-Dsg1 and anti-Dsg3 assays are useful in the diagnosis of pemphigus and provide information on the clinical phenotype of the disease. However, the sensitivity of EIA for detection of autoantibodies in bullous pemphigoid should be improved by the use of additional antigens or epitopes.     

Effect on growth of two different dexamethasone courses for preterm infants at risk of chronic lung disease. A randomized trial.

A randomized study was designed to evaluate the effects of two different dexamethasone courses on the growth of preterm infants. The first phase included 30 preterm infants at high risk for chronic lung disease (CLD). 15 babies (moderately early dexamethasone group) were treated with dexamethasone for 14 days, from the 10th day of life, and received a total dose of 4.75 mg/kg; 15 babies were assigned to the control group. The second phase included 30 preterm infants at high risk for CLD. 15 babies (early dexamethasone group) were treated with dexamethasone for 7 days, from the 4th day of life, and received a total dose of 2.38 mg/kg; 15 babies were assigned to the control group. All the main clinical baseline characteristics were similar between the groups both in the first and in the second phase. Infants given the two dexamethasone courses showed significantly reduced weight gain during the period of treatment when compared to the respective control group, but they had a weight catch-up soon after the end of treatment. At 30 days of life the weight and length gain of each treated group were similar to those of control infants, but the moderately early dexamethasone group showed a significantly poorer head growth. No differences between the groups were observed at discharge. Dexamethasone treatment induces a slower weight gain which is time-limited to the period of treatment and is followed by a body weight catch-up. However, the poorer head growth detected at 30 days of life in the infants who received a higher dose of dexamethasone could indicate important adverse effects, possibly dose-related, on postnatal brain growth and development.     

Changes in Distribution of Three Isoforms of Nitric Oxide Synthase in Ulcerative Colitis

Background: Nitric oxide (NO) has an important role both in normal physiology and pathological events of the colon. Our aim was to study possible changes of the three nitric oxide synthases in ulcerative colitis (UC). Methods: Tissue samples from normal colon and least and moderately affected regions of ulcerative colitis colon were obtained at surgery and immunostained for NOS-1, NOS-2, NOS-3, and GAP-43, a marker of nerve fibers. Quantitative analysis of NOS-1 immunoreactivity was performed on the circular muscle layer. Results: NOS-1-immunoreactive fibers in the muscularis mucosae disappeared in least affected and moderately affected UC colon. Quantitative analysis of NOS-1-immunoreactive nerve fibers in the circular muscle showed no differences between normal and diseased colon. NOS-2 immunoreactivity appeared apically in the epithelial cells. In normal colon some specimens showed immunoreactivity in lower parts of crypts. NOS-2 immunoreactivity increased according to the severity of UC. NOS-3 immunoreactivity was exclusively localized in the vascular endothelium. The difference in NOS-3 staining intensity between the lamina propria and submucosa observed in normal tissue disappeared in moderately affected UC colon. The number of NOS-3-immunoreactive vascular profiles increased in the lamina propria of UC colon. Conclusions: All three NOS isoforms show specific changes in UC colon.     

The dynamics of cardiac defense: From attention to action

The attentional and motivational significance of cardiac defense is examined in two studies. In Study 1, cardiac defense was evoked by an intense acoustic stimulus in the context of either a visual search or a memory search task using letters as stimuli. Results showed a potentiation of the long latency acceleration of cardiac defense in the visual search task. In Study 2, participants performed the same visual search task using pleasant, neutral, and unpleasant pictures as stimuli. Results showed a further potentiation of the long latency acceleration of cardiac defense when the visual search task was performed with unpleasant, compared to pleasant or neutral pictures. These results indicate that cardiac defense has both attentional and motivational contributions, where the attentional significance is related to increased sensory processing, whereas the motivational significance is associated with preparation for active defense.