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• Fekhkhar K, Charra B, Benslama A, Motaouakkil S
  Ann Fr Anesth Reanim 2006; Jun 29
  Noninvasive ventilation and acute severe asthma
   
• Battisti A, Roeseler J, Tassaux D, Jolliet P
  Intensive Care Med 2006; Jun 28
  Automatic adjustment of pressure support by a computer-driven knowledge-based system during noninvasive ventilation: a feasibility study

OBJECTIVE: To evaluate the feasibility of using a knowledge-based system design ed to automatically titrate pressure support (PS) to maintain the patient in a "respiratory comfort zone" during noninvasive ventilation (NIV) in patients with acute respiratory failure. DESIGN AND SETTING: Prospective crossover interventional study in an intensive care unit of a university hospital. PATIENTS: Twenty patients. INTERVENTIONS: After initial NIV setting and startup in conventional PS by the chest physiotherapist NIV was continued for 45[Symbol: see text]min with the automated PS activated. MEASUREMENTS AND RESULTS: During automated PS minute-volume was maintained constant while respiratory rate decreased significantly from its pre-NIV value (20[Symbol: see text]+/-[Symbol: see text]3 vs. 25[Symbol: see text]+/-[Symbol: see text]3[Symbol: see text]bpm). There was a trend towards a progressive lowering of dyspnea. In hypercapnic patients PaCO(2) decreased significantly from 61[Symbol: see text]+/-[Symbol: see text]9 to 51[Symbol: see text]+/-[Symbol: see text]2[Symbol: see text]mmHg, and pH increased significantly from 7.31[Symbol: see text]+/-[Symbol: see text]0.05 to 7.35[Symbol: see text]+/-[Symbol: see text]0.03. Automated PS was well tolerated. Two system malfunctions occurred prompting physiotherapist intervention. CONCLUSIONS: The results of this feasibility study suggest that the system can be used during NIV in patients with acute respiratory failure. Further studies should now determine whether it can improve patient-ventilator interaction and reduce caregiver workload.

• Demoule A, Girou E, Richard JC, Taille S, Brochard L
  Intensive Care Med 2006; Jun 24
  Increased use of noninvasive ventilation in French intensive care units

OBJECTIVES: A prospective survey of French intensive care units (ICUs) in 1997 showed moderate and variable use of noninvasive ventilation (NIV). This study examined changes in NIV use in French ICUs after the intervening 5[Symbol: see text]years. SETTINGS: Patients were enrolled in a prospective survey in 70 French ICUs. METHODS: Three-week survey, with prospective inclusion of all patients requiring ventilatory support. MEASUREMENTS AND RESULTS: Overall 1,076 patients received ventilatory support (55% of admissions). First-line NIV was significantly more common than 5[Symbol: see text]years earlier, overall (23% vs. 16%) and especially in patients not intubated before ICU admission (52% vs. 35%). Reasons for respiratory failure were coma (33%), cardiogenic pulmonary edema (8%), acute-on-chronic respiratory failure (17%), and de novo respiratory failure (41%). Significant increases in NIV use were noted for acute-on-chronic respiratory failure (64% vs. 50%) and de novo respiratory failure (22% vs. 14%). Among patients given NIV, 38% subsequently required endotracheal intubation (not significantly different). Independent risk factors for NIV failure were high SAPS II and de novo respiratory failure, whereas factors associated with success were good NIV tolerance and high body mass index. CONCLUSIONS: NIV use has significantly increased in French ICUs during the past 5[Symbol: see text]years, and the success rate has remained unchanged. In patients not previously intubated, NIV is the leading first-line ventilation modality. The proportion of patients successfully treated with NIV increased significantly over the 5-year period (13% vs. 9% of all patients receiving ventilatory support).

• Crummy F, Buchan C, Miller B, Toghill J, Naughton MT
  Respir Med 2006; Jun 13
  The use of noninvasive mechanical ventilation in COPD with severe hypercapnic acidosis

Study Objectives: To compare the effect of noninvasive mechanical ventilation (NIV) in severely acidotic with mildly acidotic patients with acute hypercapnic chronic obstructive lung disease (COPD). Design: Comparison of NIV in consecutively enrolled patients with acute hypercapnic COPD with mild (pH 7.25-7.35) or severe (pH<7.25) acidosis on time to normalise pH and improve PaCO(2), duration of NIV treatment, length of stay in hospital and survival. Results (meadian (IQR)): Twenty-nine patients had 36 episodes of acute hypercapnic respiratory failure: Seventeen with pH<7.25 and 19 with pH 7.25-7.34. Compared with the mildly acidotic group, the severely acidotic group took a similar length of time for pH to normalise and PaCO(2) improve (12 (6-34) vs 12 (4-28)h, respectively, P=0.42), with similar duration of NIV treatment (60 (35-96) vs 68 (36-48)h, respectively, P=0.25) and hospital length of stay (8 (7-18) vs 9 (5-17) days, respectively, P=0.61). Overall survival was 89%, with 95% in the mild and 82% in the severely acidotic groups. Conclusions: Noninvasive ventilation is effective in the treatment of patients with severe acidosis due to acute hypercapnic COPD.

• Lumbierres M, Prats E, Farrero E, Monasterio C, Gracia T, Manresa F, Escarrabill J
  Respir Med 2006; Jun 13
  Noninvasive positive pressure ventilation prevents postoperative pulmonary complications in chronic ventilators users

OBJECTIVE: To evaluate the postoperative pulmonary complications and the long-term impact on pulmonary function of different surgical procedures with general anaesthesia in chronic respiratory failure (CRF) patients who were using noninvasive positive pressure ventilation (NPPV). DESIGN: We retrospectively studied 20 stable patients on NPPV for CRF secondary to: kyphoscoliosis (eight), morbid obesity (six), thoracoplasty (four), neuromuscular diseases (two), who underwent surgical procedures with general anaesthesia, between January 1998 and December 2003. MATERIAL AND METHODS: The variables studied were: type of surgery, hours of orotracheal intubation, hours of stay in the postsurgical reanimation unit (PRU), postoperative pulmonary complications and days of hospital stay. These results were compared with those obtained in patients without respiratory pathology and who were submitted to the same type of surgical interventions during the study period. All patients were tested for: arterial blood gases, forced vital capacity (FVC) and forced expiratory volume in 1s (FVE1). These tests were carried out both prior to surgical intervention and 12 months after this intervention, and the use of medical assistance resources the year prior to and the year after the surgical intervention were also analysed. RESULTS: Sixteen patients were using NPPV at home at the time of the intervention and four patients were adapted to NPPV before surgery. The surgical procedures were: gastroplasty: six; mastectomy: five; septoplasty: three; hip prosthesis: two; cholecystectomy: one; Gasserian ganglion thermocoagulation: one; hysterectomy: one; and endoscopic retrograde cholangiopancreatography (ERCP): one. The mean postoperative intubation time was 3.8+/-3.2h, and only one patient remained intubated for more than 12h. The mean stay in the PRU was 19+/-9h (vs 19+/-6h in the general population, p>0.05). The days of hospital stay for the different pathologies were in the majority of cases greater than in the general population. We did not find significant differences on comparing the arterial blood gases, in pulmonary function or in use of assistance resources between the year previous to and the year following the surgical intervention. CONCLUSIONS: In high-risk patients with chronic respiratory failure as a consequence of a restrictive lung pathology, NPPV can play an important role to confront surgical procedure with general anaesthesia with greater security. To obtain these results, it was fundamental to coordinate between the Pulmonary Services and the Anaesthesia Services as well as to follow up jointly in the PRU.

• Essouri S, Chevret L, Durand P, Haas V, Fauroux B, Devictor D
  Pediatr Crit Care Med 2006; May 31
  Noninvasive positive pressure ventilation: Five years of experience in a pediatric intensive care unit

OBJECTIVES:: To evaluate the feasibility and outcome of noninvasive positive pressure ventilation (NPPV) in daily clinical practice. DESIGN:: Observational retrospective cohort study. SETTING:: Pediatric intensive care unit in a university hospital. PATIENTS:: Patients treated by NPPV, regardless of the indication, during five consecutive years (2000-2004). MEASUREMENTS AND RESULTS:: A total of 114 patients were included, and 83 of the 114 patients (77%) were successfully treated by NPPV without intubation (NPPV success group). The success rate of NPPV was significantly lower (22%) in the patients with acute respiratory distress syndrome (p < .05) than in the other patients. The Pediatric Risk of Mortality II (p = .003) and Pediatric Logistic Organ Dysfunction scores (p = .002) at admission were significantly higher in patients who were unsuccessfully treated with NPPV (NPPV failure group). Baseline values of Pco2, pulse oximetry, and respiratory rate did not differ between the two groups. A significant decrease in Pco2 and respiratory rate within the first 2 hrs of NPPV was observed in the NPPV success group. Multivariate analysis showed that a diagnosis of acute respiratory distress syndrome (odds ratio, 76.8; 95% confidence interval, 4.4-1342; p = .003) and a high Pediatric Logistic Organ Dysfunction score (odds ratio, 1.09; 95% confidence interval, 1.01-1.17; p = .01) were independent predictive factors for NPPV failure. A total of 11 patients (9.6%), all belonging to the NPPV failure group, died during the study. CONCLUSIONS:: This study demonstrates the feasibility and efficacy of NPPV in the daily practice of a pediatric intensive care unit. This ventilatory support could be proposed as a first-line treatment in children with acute respiratory distress, except in those with a diagnosis of acute respiratory distress syndrome.

• El Solh AA, Aquilina A, Pineda L, Dhanvantri V, Grant B, Bouquin P
  Eur Respir J 2006; May 31
  Noninvasive ventilation for prevention of postextubation respiratory failure in obese patients

Current recommendations for management of obese patients post extubation are based on clinical experience and expert opinions. We hypothesized that application of noninvasive ventilation during the first 48 hours after extubation in severely obese patients would reduce postextubation failure and avert the need for reintubation.Following protocol-driven weaning trials, sixty two consecutive severely obese patients (BMI>/=35 kg.m(-2)) were assigned to noninvasive ventilation (NIV) via nasal mask immediately post extubation and compared to 62 historically matched controls who were treated with conventional therapy. The primary end point was the incidence of respiratory failure in the first 48 hours post extubation.Compared to conventional therapy, the institution of NIV resulted in 16% (95% confidence interval 2.9%-29.3%) absolute risk reduction in the rate of respiratory failure. There was a significant difference in the ICU and hospital lengths of stay between the two groups (p<0.001 and p=0.007; respectively). Subgroup analysis of hypercapnic patients showed a reduced hospital mortality in the NIV group compared to the control group (p=0.02).Noninvasive ventilation may be effective in averting respiratory failure in severely obese patients when applied during the first 48 hours post extubation. In selected patients with chronic hypercarbia, early application of NIV may confer a survival benefit.

• Jouvet P, Morneau S, Payen V, Santschi M
  Arch Pediatr 2006; May 9
  Non invasive ventilation in children
  
  
• Agarwal R, Reddy C, Aggarwal AN, Gupta D
  Respir Med 2006; May 4
  Is there a role for noninvasive ventilation in acute respiratory distress syndrome? A meta-analysis

The role of noninvasive ventilation (NIV) in the management of acute respiratory distress syndrome (ARDS) is controversial. The aim of this study was to assess the effect of NIV on the rate of endotracheal intubation and intensive care unit (ICU) mortality in patients with ARDS. We searched the MEDLINE database for relevant studies published from 1980 to September 2005, and included studies if (a) the design was a randomized controlled trial; (b) patients had ARDS irrespective of the underlying etiology; (c) the interventions compared NIV and medical therapy with medical therapy alone; and (d) outcomes included need for endotracheal intubation and/or ICU survival. The addition of NIV to standard care in the setting of ARDS did not reduce the rate of endotracheal intubation (absolute risk reduction (RR) 13.5%, 95% confidence interval (CI) -5.2% to 31.3%), and had no effect on ICU survival (absolute RR 4.8%, 95% CI -12.8% to 22.1%). However, the trial results were significantly heterogeneous. Thus, current evidence suggests that patients with ARDS are unlikely to have any significant benefits on outcome when NIV is added to standard therapy. However, this analysis is limited by the presence of significant heterogeneity; hence large randomized controlled trials are required to settle this issue.

• Nonaka M, Imai T, Shintani T, Kawamata M, Chiba S, Matsumoto H
  J Neurol Sci 2006; Apr 25
  Non-invasive positive pressure ventilation for laryngeal contraction disorder during sleep in multiple system atrophy

We examined the usefulness of non-invasive positive pressure ventilation (NPPV) in the management of nocturnal laryngeal stridor associated with vocal cord dysfunction in five cases of multiple system atrophy (MSA). First, the patients were investigated during sleep induced by a minimal dose of propofol. Laryngoscopy showed paradoxical vocal cord movement resulting in inspiratory stridor. Electromyographic (EMG) study revealed synchronized bursts in the thyroarytenoid muscles and diaphragm in every inspiratory phase whenever the stridor emerged. NPPV was initiated after paradoxical movement was recognized with laryngoscopy. The NPPV mask was equipped with an additional channel for laryngoscopic monitoring. The optimal pressure for treatment was determined according to laryngoscopic and EMG findings. Next, NPPV was applied to natural sleep using the conditions determined in propofol-induced sleep. In all cases, NPPV eliminated nocturnal stridor and oxygen desaturation during natural sleep. Laryngoscopic observation during induced sleep is recommended as a useful procedure to titrate the optimal pressure for NPPV therapy. Since central hypoventilation progresses in the course of MSA, the choice of NPPV rather than continuous positive airway pressure should be encouraged to treat laryngeal contraction disorder associated with MSA.

• Gruis KL, Brown DL, Lisabeth LD, Zebarah VA, Chervin RD, Feldman EL
  J Neurol Sci 2006; Apr 21
  Longitudinal assessment of noninvasive positive pressure ventilation adjustments in ALS patients

The absence of data guiding optimal titration of noninvasive positive pressure ventilation (NIPPV) over time in ALS patients may contribute to the under-prescribing of NIPPV. We conducted a retrospective, single-center, chart review assessment of NIPPV pressure settings used for symptomatic treatment of ALS patients to determine NIPPV adjustments, and to compare survival between those who were tolerant and intolerant to NIPPV. All subjects were started on nocturnal NIPPV at 8 and 3 cm H(2)O inspiratory and expiratory pressure, respectively. Of the 18 tolerant subjects identified, 4 (22%) had no NIPPV pressure changes before death; 8 (44%), 1 change; 4 (22%), 2 changes; 1 (6%), 3 changes; and 1 (6%), 5 changes. Most pressure changes occurred during the first year of NIPPV initiation. The maximum pressure needed for comfort by any patient in this study was 19/5 cm H(2)O, while 4 (22%) found the original 8/3 cm H(2)O settings to be sufficient until death. Subjects in the tolerant group had better survival, when adjusting for age and site of symptom onset (bulbar versus limb), with a hazard ratio of 0.23 [95% confidence interval: 0.10, 0.54]. The current data suggest that ALS patients who are tolerant to NIPPV typically need at least one upward change in pressure settings. Tolerance to relatively low NIPPV inspiratory pressures is associated with improved survival.

• Papakonstantinou DK, Gatzioufas ZI, Tzegas GI, Stergiopoulos PI, Tsokantaridis CG, Chalikias GK, Tziakas DN
  Int J Cardiol 2006; Mar 30
  Unilateral pulmonary oedema due to lung re-expansion following pleurocentesis for spontaneous pneumothorax. The role of non-invasive continuous positive airway pressure ventilation

Re-expansion pulmonary oedema represents a rare complication of treatment of spontaneous pneumothorax with only a few cases documented in the current literature. We present the case of a 47-year-old male who presented a right-sided spontaneous pneumothorax and developed respiratory failure after chest tube drainage. The diagnosis of re-expansion pulmonary oedema was made and he was successfully treated with non-invasive continuous positive airway pressure ventilation. Since pathogenesis of re-expansion unilateral pulmonary oedema differs significantly from that of cardiogenic pulmonary oedema, the role of non-invasive continuous positive airway pressure ventilation is discussed as an additional therapeutic option.

• Samolski D, Anton A, Guell R, Sanz F, Giner J, Casan P
  Respir Med 2006; Jan 27
  Inspired oxygen fraction achieved with a portable ventilator: Determinant factors

INTRODUCTION: Non-invasive positive pressure ventilation (NIPPV) is an effective treatment in respiratory failure. Continuous positive pressure (CPAP) may also be useful in acute hypoxaemic patients. Supplementary oxygen is usually necessary in both systems. However, the inspired oxygen fraction (FiO(2)) delivered by a NIV portable ventilator is unknown. The main objectives of this study were to establish the maximal FiO(2) that could be achieved by these devices and to analyse the FiO(2) determinant factors. METHOD: Ten healthy volunteers were evaluated using a BiPAP ST30 ventilator (Respironics, USA) with a single-limb circuit, expiratory port and nasal mask (Respironics, USA). Oxygen (15L/min) was administered at two connection points (proximal and distal). Each volunteer carried out a NIPPV (inspiratory pressure 20cmH(2)O [1.95kPa]-expiratory pressure 8cmH(2)O [0.78kPa]) and a CPAP (10cmH(2)O [0.981kPa]) session. FiO(2) was analysed by a probe located in the mask. Minute volume (MV) was measured using a pneumotachograph. RESULTS: Maximal FiO(2) was obtained with CPAP and distal oxygen connection point (67.39+/-15.39%). NIPPV achieved higher MV than CPAP. FiO(2) was inversely correlated with MV. CONCLUSIONS: FiO(2) obtained while using a NIPPV portable ventilator depends on the ventilatory assistant mode, the oxygen connection point and the MV reached.

• Nava S, Barbarito N, Piaggi G, De Mattia E, Cirio S
  Respir Med 2006; Feb 18
  Physiological response to intrapulmonary percussive ventilation in stable COPD patients

Intrapulmonary percussive ventilation (IPV) is a ventilatory technique that delivers bursts of high-flow respiratory gas into the lung at high rates, intended for treating acute respiratory failure and for mobilization of secretions. We performed a study, aimed at assessing the physiological response to IPV, on patients' breathing pattern, inspiratory effort, lung mechanics and tolerance to ventilation. Ten COPD patients underwent randomized trials of IPV through a face mask at different pressure/frequency combinations (1.2bar/250cycles/min; 1.8/250; 1.2/350; 1.8/350), separated by return to baseline (SB), using the IMP2 ventilator. In 5 patients we have also compared the physiological changes of IPV with those obtained during pressure support ventilation (PSV). Minute ventilation did not vary among the trials, but tidal volumes (V(T)) were significantly greater during 1.2/250, 1.2/350 and 1.8/350 compared to SB. The pressure time product of the diaphragm per minute (PTPdi/min) estimate of the diaphragm oxygen expenditure was also significantly reduced during 1.2/250 and 1.8/250 (209cmH(2)Oxs/min for SB vs. 143 and 125 for 1.2/250 and 1.8/250, respectively P<0.05), as well as dynamic intrinsic end-expiratory pressure (PEEPi,dyn). Similar reduction in PTPdi/min were obtained also during PSV. Tolerance to ventilation and oxygen saturation were satisfactory and did not change during the different trials. In 5 normal subjects a prolonged apnea trial lasting >2min was also performed, without any significant decrease in SaO(2) or subjective discomfort. In conclusion, IPV was able to guarantee an adequate ventilation, while inducing a significant unloading of the diaphragm during the "low-frequency" trials.

• Piastra M, Antonelli M, Caresta E, Chiaretti A, Polidori G, Conti G
  Respiration 2006; Jan 16
  Noninvasive Ventilation in Childhood Acute Neuromuscular Respiratory Failure: A Pilot Study

Background: Over a 36-month study period, 10 nonconsecutive neuromuscular pediatric patients (6 infants, mean age 10.16 months, and 4 children, mean age 9.3 years) presenting with acute respiratory failure (ARF) were treated by noninvasive positive pressure ventilation (NPPV). All patients required immediate respiratory support and fulfilled our intubation criteria. Objective: The aim of the study was to verify if early NPPV was able to avoid endotracheal intubation and to improve both oxygenation and ventilation within 24 h from admission in this clinical setting. Patients andMethods: A prospective pilot study was carried out on neuromuscular patients admitted to the pediatric intensive care unit (PICU) of the Catholic University of Rome because of ARF and managed exclusively with NPPV for at least 24 h following admission. All patients were treated using a flow-triggered mechanical ventilator through a face mask or using the new helmet interface. Results: Eight patients were successfully ventilated during the observation period and 2 early failures occurred. Among children undergoing face mask NPPV, the PaO(2)/FiO(2) ratio increased from a median value of 75 (range 48-149) to 240 (range 133-385; p < 0.001) and 328 (range 180-371; p < 0.001) at selected time points (3 and 12 h after NPPV introduction, respectively); the alveolar-to-arterial oxygenation difference showed a similar trend, i.e. decreasing from a median value of 589 (range 213-659) to 128 (range 62-527; p < 0.01) and 69 (range 45-207; p < 0.001), respectively. Hypercarbic ARF resolved within 6 h from admission even in the most severe cases. Conclusions: NPPV was a safe and effective first-line therapeutic approach in hypoxemic ARF children/infants with neuromuscular disease. It seems of importance to identify children with neuromuscular disorders who may be able to achieve residual ventilator-free breathing and to perform an NPPV trial avoiding tracheal intubation. Life-threatening respiratory distress and very young age should not preclude NPPV application in the PICU setting. The new helmet interface represents a promising tool for noninvasive ventilation in older children.