Duration Of Noninvasive Ventilation Research Articles

Outcomes of patients receiving non-invasive ventilation (NIV) in the general intensive care unit: is NIV duration an important factor?

The role of non-invasive ventilation in the intensive care unit (ICU) is generally poorly understood. Published guidelines largely relate to the use of NIV outside the ICU1,2. Whilst much focus has been placed on relating indication for NIV on outcome, little attention has been paid to the duration of NIV and whether or not this might have an impact on outcome.

Nosocomial pneumonia in non-invasive ventilation patients: incidence, characteristics, and outcomes

Nosocomial pneumonia occasionally occurs in non-invasive ventilation (NIV) patients. To report the incidence, characteristics, and outcomes of nosocomial pneumonia in NIV patients. A prospective observational study was performed in a respiratory intensive care unit (ICU). After admission, patients who received NIV for more than 48 h were enrolled. Pneumonia was considered nosocomial when it occurred after at least 48 h of NIV. Between January 2012 and August 2014, we enrolled 520 NIV patients. Nosocomial pneumonia occurred in 16 patients (3.1%). The nosocomial pneumonia rate was 4.5 cases per 1000 NIV-days. The most common pathogen was Acinetobacter baumannii (81%). At the initiation of NIV, there were no differences in age, gender, diagnosis, disease severity, or arterial blood gas findings between patients with and without nosocomial pneumonia. Compared to patients without nosocomial pneumonia, nosocomial pneumonia patients had a longer duration of NIV (8.4 vs 5.0 days, P < 0.01), a longer ICU stay (10.8 vs 7.9 days, P = 0.01), a longer hospital stay (25.9 vs 15.3 days, P = 0.04), a higher intubation rate (63% vs 21%, P < 0.01), and higher hospital mortality (75% vs 25%, P < 0.01). Nosocomial pneumonia was an independent risk factor for intubation (OR: 6.74; 95% CI: 2.24-20.28) and death (7.65; 1.34-43.72). The incidence of nosocomial pneumonia in NIV patients in this population was 3.1%. Nosocomial pneumonia increased the time that NIV was required, length of ICU stay, length of hospital stay, intubation rate, and hospital mortality.

P94. Effects of non-invasive ventilation on sleep and nocturnal ventilation in patients with amyotrophic lateral sclerosis

The majority of patients with amyotrophic lateral sclerosis (ALS) develop chronic ventilatory failure which substantially adds to disease burden and massively affects prognosis. Both quality of life and life expectancy can be influenced by non-invasive ventilation (NIV). Initiation of NIV is indicated in case of sleep-disordered breathing (SDB), daytime hypercapnia, or significant diaphragmatic weakness. Since nocturnal hypercapnia and sleep apnea substantially reduce sleep quality we investigated the effects of NIV on objective measures of both sleep quality and ventilation in patients with ALS. We retrospectively analysed polysomnography (PSG) and oxycapnometry (OC) data obtained from patients with ALS in whom NIV was initiated based on the presence of SDB. PSG and OC were used in all patients for establishing the diagnosis of SDB (t0), for treatment initiation (t1) and for follow-up examination at 3, 9, and 15 months (t2, t3, and t4, respectively). As outcome parameters we chose sleep efficiency (SE), slow wave sleep percentage (N3), REM sleep percentage (REM), apnea hypopnea index (AHI), oxygen desaturation index (ODI), desaturation time (T < 90), respiratory rate (RR) and maximal nocturnal transcutaneous carbon dioxide tension (tc-CO2). Records from 62 patients were analysed. Mean age was 63.2 years, and mean disease duration was 23.1 months. 28 patients were female, and 22 patients reported bulbar onset of ALS symptoms. All patients were started on pressure and volume-controlled bilevel ventilation via a nasal or oronasal interface. Comparison of the above parameters at t0 and t1 showed significant improvement of AHI and ODI, oxygenation, CO2 elimination, and sleep stage duration (N3, REM) in the first night on NIV. Sleep efficiency was neither improved nor reduced by NIV. At t2, t3 and t4 the number of PSG records available became smaller because in many patients, follow-up studies included rather polygraphy than PSG (t2, 33 patients, t3, 15 patients, t4, 11 patients with PSG data). ANOVA for repeated measures revealed stable normoxia and eucapnia under bilevel ventilatory support. Objective measures of sleep quality did not show any significant change over time. Increasing duration of NIV per day was found in all patients in the course of the disease, reflecting disease progression. In patients with ALS, NIV initiation significantly improves objective sleep quality, oxygenation and CO2 elimination in the first night of treatment. Over time, NIV is able to warrant nocturnal normoventilation with only minor changes to ventilator settings. Objective sleep quality does not significantly change in the first 15 months after onset of NIV.

Non-Invasive Ventilation in a Pediatric Intensive Care Unit: An Experience of Tertiary Care Hospital Over 4 Years in Oman

Background: Noninvasive ventilation (NIV) has now become an integral tool in the treatment of both acute and chronic respiratory failure, and at the same time reducing the need for invasive ventilation. Aim: To determinate the efficacy of NIV in pediatrics whom admitted to Pediatric intensive care unit (PICU) with respiratory failure (Short term evaluation). Original Research Article Abdelmogheth et al.; BJMMR, 7(7): 561-566, 2015; Article no.BJMMR.2015.362 562 Subjects and Methods: Based on a retrospective review of electronic medical records (EPR) of patients who underwent NIV in the period between January 2007 and December 2010, demographic and clinical data were collected before and after applying the NIV. The data included heart rate (HR), respiratory rate (RR), oxygen concentration (PO2) and CO2 concentration (PCO2). Results: NIV was used for a total of 61 pediatric patients admitted to PICU during the period of the study. Pneumonia was the commonest indication for the NIV (n=25, 40.9%), and continuous positive airway pressure (CPAP) was used in 52(85.2%) patients. The mean duration of NIV was 8±7.2 days, there was a significant clinical improvement after one hour from application of NIV. The mean improvement in RR was from 48.4±2.2 to 35.0±1.5 (P=0.000), SPO2 was improved from 88.1±1.8 to 96.5±0.7 (P= 0.000), and the PCO2 was improved from 61.4±6.1 to 48.7±3.7 (P=0.002). Five patients were failing to respond to the NIV and shifted to mechanical ventilation. Conclusion: The NIV is a useful tool for treatment of respiratory failure in pediatrics, especially under the age of one year. Pneumonia was the commonest indication for the use of the NIV.

Nasal Bilevel Versus Continuous Positive Airway Pressure in Preterm Infants: A Randomized Controlled Trial

Objective: We designed a study with a primary objective of comparing the effectiveness of nasal continuous positive airway pressure (nCPAP) versus bi-level CPAP (BiPAP) as the primary mode of non-invasive ventilation in preterm newborns. The primary outcome was need for invasive ventilation in the first 120 hours of life. The secondary objective was to compare these two groups regarding duration of non-invasive ventilation, use of surfactant, incidence of pneumothorax, bronchopulmonary dysplasia (BPD), peri and intraventricular haemorrhage (PIVH), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), sepsis, length of hospitalisation and mortality. Methods: Prospective, multicentre clinical trial enrolling 220 neonates born at 27 to 32+6 weeks of gestation randomly assigned at birth for either CPAP or BiPAP. Results: One hundred and nine neonates received NCPAP and 111 BiPAP. Invasive ventilation was needed in 18.3% in the CPAP group and 14.4% in the BiPAP group. This difference was not statistically significant. However, when stratifying the groups regarding gestational age (GA), we found a tendency favouring BiPAP in subgroup of 30 to 32+6 weeks. There was no difference regarding the secondary outcomes, except for an increase in NEC in the CPAP group. Multivariate analysis demonstrated a significant association between absence of premature rupture of membranes and the need of invasive ventilation within the first 120 hours of life, independently on the assigned mode of non invasive ventilation. Conclusion: BiPAP and CPAP are both effective and safe as a primary mode of ventilation in preterms between 27 and 32+6 weeks without important complications. In a subgroup of 30 to 32+6 weeks of gestation a better outcome using BiPAP was observed.

Effect of humidified high flow nasal cannula on severe apnea in preterm infants

Objective To investigate the effect of humidified high flow nasal cannula (HHFNC) on severe apnea in preterm infants. Methods Eighty-two preterm infants who developed apnea more than twice in short time, recurred within 6 hours or needed mask respirator were divided into HHFNC group (n=40) and nasal continuous positive airway pressure (NCPAP) group (n=42). Both groups were given aminophylline intravenously. The total therapeutic effect rate, the number of cases who needed mechanical ventilation during the observation period, the duration of non-invasive ventilation, the duration of oxygen therapy, the oxygen exchange indexes and the complications of two groups were observed. Results There were no significant differences between two groups in the therapeutic effect rate, the number of cases who need invasive ventilation, the duration of non-invasive ventilation time, oxygen exchange indexes and the duration of oxygen usage (P>0.05). The numbers of nose injury of HHFNC group were less than those of the NCPAP group[10.0% (4/40) vs.30.9% (13/42)] (P<0.05). No significant differences were found between two groups in the complication of necrotizing enterocolitis or feeding intolerance, respiratory infection, retinopathy of prematurity, bronchopulmonary dysplasia (P<0.05). Conclusion HHFNC has the same effect as NCPAP in the treatment of severe apnea in preterm infants except for lower prevalence of nose injury. Key words: Humidified high flow nasal cannula; Severe apnea; Continuous positive airway pressure; Preterm infants

Is non-invasive ventilation safe in acute severe asthma?

The effect of non-invasive ventilation (NIV) in acute severe asthma is unclear and there are concerns regarding its safety. We undertook a 5-year case-control review of mortality and morbidity associated with NIV use in acute severe asthma and compared this with asthma requiring invasive mechanical ventilation (IMV) and a control group with less severe asthma without ventilatory support. Eight hundred seventy-three patients had acute severe asthma of whom 30 were treated with NIV, 17 with IMV and 90 served as controls. The mean duration of NIV was 9.5 ± 7.3 h with inspiratory positive airway pressure and expiratory positive airway pressure of 11.9 ± 1.4 and 5.8 ± 1.2 cmH2 O respectively. Mortality was zero in the NIV and control groups, compared with 41% in the IMV group. None of the NIV or control groups required escalation to invasive ventilation. There were no instances of haemodynamic compromise in the NIV or control groups. Length of hospital stay was 121 ± 96 h in the NIV group and similar to the severe IMV group (136 ± 99 h, P > 0.05) and significantly longer than the control group (42 ± 40 h, P < 0.05). NIV can be safely used in acute severe asthma although further work is needed to delineate the precise patient selection process.

The use of non-invasive ventilation in very old patients with hypercapnic acute respiratory failure because of COPD exacerbation.

We prospectively enrolled 207 patients (121 were 75 or older and 86 younger than 75) who were admitted to three Respiratory Monitoring Units. The primary outcomes were intubation and mortality rates; the secondary outcomes were changes in arterial blood gases analysis, non-invasive ventilation (NIV) duration and length of hospital stay. Hospital mortality was similar in the two groups, as were intubation rates. The proportion who died in the very old patient group was 19.8% (24/121) vs. 10.4% (9/86) in the younger group. Intubation rate was 10.7% (13/121) in the very old patient group and 11.6% (10/86) in the younger group. The presence of comorbidities, the severity of illness (SAPS II), the level of consciousness, NIV failure (intubation), absolute value of pH prior to NIV, as well as the changes in pH and paCO2 and PaO2 /FiO2 after 2 h of NIV, were the variables associated with higher mortality. Very old patients had significantly higher NIV duration than younger patients (69.0 ± 47.0 vs. 57.0 ± 27.0 h) (p ≤ 0.03) and hospital stays (11.6 ± 3.8 vs. 8.4 ± 1.4) (p ≤ 0.02). The use of NIV in very old patients was effective in many cases. Endotracheal intubation after NIV failure was not efficacious in either group.

Open-Mouthpiece Ventilation Versus Nasal Mask Ventilation in Subjects With COPD Exacerbation and Mild to Moderate Acidosis: A Randomized Trial

Open mouthpiece ventilation is efficacious in patients with neuromuscular disease. We used this ventilation technique in patients with exacerbations of COPD with mild to moderate acidosis. The study was performed in 2 respiratory monitoring care units. Fifty subjects with exacerbations of COPD, breathing frequency > 25, PaCO2 > 45, and pH between 7.25 and 7.30, as well as Kelly scale ≤ 2 were enrolled. Subjects were randomly assigned to receive noninvasive ventilation (NIV) via nasal mask or mouthpiece ventilation. The primary outcome was improvement in arterial blood gases. Arterial blood gases and breathing frequency were recorded 2 h after the start of the enrollment and then after 12, 24, and 48 h. The duration of NIV, hospital stay, and acceptability of the interface (mouthpiece or nasal mask) using a Likert scale were assessed. No subjects had deterioration of gas exchange. The 2 groups had similar trends in arterial blood gases and breathing frequency. No differences in duration of NIV or hospital stay were noted. However, a significant difference in acceptability was found: subjects preferred mouthpiece ventilation (P < .01). Open mouthpiece ventilation is a useful technique and may prevent further deterioration of gas exchange in COPD patients with mild to moderate acidosis (similar to traditional NIV delivered by a nasal mask). www.chictr.org registration ChiCTR-TRC-12002672.

Efficacy and Safety of Early Dexmedetomidine During Noninvasive Ventilation for Patients With Acute Respiratory Failure: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

Successful application of noninvasive ventilation (NIV) for acute respiratory failure (ARF) requires patient cooperation and comfort. The efficacy and safety of early IV dexmedetomidine when added to protocolized, as-needed IV midazolam and fentanyl remain unclear. Adults with ARF and within 8 h of starting NIV were randomized to receive IV dexmedetomidine (0.2 μg/kg/h titrated every 30 min to 0.7 μg/kg/h to maintain a Sedation-Agitation Scale [SAS] score of 3 to 4) or placebo in a double-blind fashion up to 72 h, until NIV was stopped for ≥ 2 h, or until intubation. Patients with agitation (SAS ≥ 5) or pain (visual analog scale ≥ 5 of 10 cm) 15 min after each dexmedetomidine and placebo increase could receive IV midazolam 0.5 to 1.0 mg or IV fentanyl 25 to 50 μg, respectively, at a minimum interval of every 3 h. The dexmedetomidine (n = 16) and placebo (n = 17) groups were similar at baseline. Use of early dexmedetomidine did not improve NIV tolerance (score, 1 of 4; OR, 1.44; 95% CI, 0.44-4.70; P = .54) nor, vs. placebo, led to a greater median (interquartile range) percent time either tolerating NIV (99% [61%-100%] vs. 67% [40%-100%], P = .56) or remaining at the desired sedation level (SAS score = 3 or 4, 100% [86%-100%] vs. 100% [100%-100%], P = .28], or fewer intubations (P = .79). Although use of dexmedetomidine was associated with a greater duration of NIV vs placebo (37 [16-72] vs. 12 [4-22] h, P = .03), the total ventilation duration (NIV + invasive) was similar (3.3 [2-4] days vs. 3.8 [2-5] days, P = .52). More patients receiving dexmedetomidine had one or more episodes of deep sedation vs placebo (SAS ≤ 2, 25% vs. 0%, P = .04). Use of midazolam (P = .40) and episodes of either severe bradycardia (heart rate ≤ 50 beats/min, P = .18) or hypotension (systolic BP ≤ 90 mm Hg, P = .64) were similar. Initiating dexmedetomidine soon after NIV initiation in patients with ARF neither improves NIV tolerance nor helps to maintain sedation at a desired goal. Randomized, multicenter trials targeting patients with initial intolerance are needed to further elucidate the role for dexmedetomidine in this population.

Risk factors for laboratory-confirmed bloodstream infection in neonates undergoing surgical procedures

BackgroundHealthcare Associated Infections constitute an important problem in Neonatal Units and invasive devices are frequently involved. However, studies on risk factors of newborns who undergo surgical procedures are scarce. ObjectiveTo identify risk factors for laboratory-confirmed bloodstream infection in neonates undergoing surgical procedures. MethodsThis case–control study was conducted from January 2008 to May 2011, in a referral center. Cases were of 21 newborns who underwent surgery and presented the first episode of laboratory-confirmed bloodstream infection. Control was 42 newborns who underwent surgical procedures without notification of laboratory-confirmed bloodstream infection in the study period. Information was obtained from the database of the Hospital Infection Control Committee Notification of infections and related clinical data of patients that routinely collected by trained professionals and follow the recommendations of Agência Nacional de Vigilância Sanitária and analyzed with Statistical Package for Social Sciences. ResultsDuring the study period, 1141 patients were admitted to Neonatal Unit and 582 Healthcare Associated Infections were reported (incidence-density of 25.75 Healthcare Associated Infections/patient-days). In the comparative analysis, a higher proportion of laboratory-confirmed bloodstream infection was observed in preterm infants undergoing surgery (p=0.03) and use of non-invasive ventilation was a protective factor (p=0.048). Statistically significant difference was also observed for mechanical ventilation duration (p=0.004), duration of non-invasive ventilation (p=0.04), and parenteral nutrition duration (p=0.003). In multivariate analysis duration of parenteral nutrition remained significantly associated with laboratory-confirmed bloodstream infection (p=0.041). ConclusionsShortening time on parenteral nutrition whenever possible and preference for non-invasive ventilation in neonates undergoing surgery should be considered in the assistance of these patients, with the goal of reducing Healthcare Associated Infections, especially laboratory-confirmed bloodstream infection.

Predicting Failure of Non-invasive Ventilation in a Mixed Population

Objective: Non-invasive ventilation (NIV) is widely used as part of the treatment of acute respiratory failure but it is not always successful. The purpose of this study is to determine if NIV failure can be predicted on the basis of information available at the initial point of contact with the patient. Methods: This is a retrospective study of patients admitted to a six bed non-specialized ICU at Koge University Hospital (Denmark) in the years 2011-2012. Patients were assigned to one of two groups covering successful NIV treatment and NIV failure. Results: 89 patients were included and the two groups were compared on variables available at the initial point of contact with the patient. Patients in whom NIV treatment failed had higher levels of C-reactive protein (p=0.04). Multivariate analysis showed an odds ratio of 1.13 (95% CI: 1.02-1.25) for NIV failure associated with increased respiratory rate. NIV was less likely to fail in patients with known Chronic Obstructive Pulmonary Disease (p=0.05). The mean duration of NIV before intubation in case of NIV failure was 14.1 hours (SD: 15.0) and was not associated with neither the ICU nor the in-hospital mortality. Conclusion: In the present study NIV failure was associated with higher levels of C-reactive protein and increased respiratory rates carried an odds ratio of 1.13 (95% CI: 1.02-1.25) for NIV failure.

Management of severe respiratory failure following influenza A H1N1 pneumonia

The use of non-invasive ventilation (NIV) in severe hypoxemic respiratory failure (PaO2/FIO2 ‰¤250) due to H1H1 virus pneumonia is controversial. In this prospective study, we aimed to assess the efficacy of NIV in avoiding endotracheal intubation and to identify predictors of success or failure. Nineteen patients with H1N1 viral pneumonia had severe respiratory failure (PaO2/FIO2 ratio ‰¤250). Five patients with PaO2/FIO2 lower than 150 and simplified acute physiology score (SAPS II) lower than 34 underwent NIV and were admitted to the Intensive Care Unit and received NIV as first-line therapy. NIV failed in 2 of the 14 patients but had a good outcome in 12. None of the patients treated with NIV died. The duration of NIV was 5.0±1.9 days and the hospital stay was 11.3±1.2 days. The average PaO2/FIO2 ratio after 1 h of NIV was 239.1+38.7. No patient had multi-organ failure. PaO2/FIO2 ratio after 1 h and SAPS II at admission were independent variables correlated with the success of NIV. In our study, NIV was successful in 12 of the 14 patients (85.7%) and this is one of the highest success rates in the literature. In our opinion, the reason for these results is the strict selection of patients with severe respiratory failure (PaO2/FIO2 ratio ‰¥150) and the strict following of predictors of success for NIV such as SAPS II of 34 or lower and PaO2/FIO2 ratio of 175 or lower after 1 h of NIV. Clinicians should be aware of pulmonary complications of influenza A H1N1 and strictly select the patients to undergo NIV. NIV could have an effective and safe role in reducing the high demand for critical care beds, particularly during the pandemic.

Impact of the humidification device on intubation rate during noninvasive ventilation with ICU ventilators: results of a multicenter randomized controlled trial

The use of heat and moisture exchangers (HME) during noninvasive ventilation (NIV) can increase the work of breathing, decrease alveolar ventilation, and deliver less humidity in comparison with heated humidifiers (HH). We tested the hypothesis that the use of HH during NIV with ICU ventilators for patients with acute respiratory failure would decrease the rate of intubation (primary endpoint) as compared with HME. We conducted a multicenter randomized controlled study in 15 centers. After stratification by center and type of respiratory failure (hypoxemic or hypercapnic), eligible patients were randomized to receive NIV with HH or HME. Of the 247 patients included, 128 patients were allocated to the HME group and 119 to the HH group. Patients were comparable at baseline. The intubation rate was not significantly different: 29.7% in the HME group and 36.9% in the HH group (p = 0.28). PaCO2 did not significantly differ between the two arms, even in the subgroup of hypercapnic patients. No significant difference was observed for NIV duration, ICU and hospital LOS, or ICU mortality (HME 14.1 vs. HH 21.5%, p = 0.18). In this study, the short-term physiological benefits of HH in comparison with HME during NIV with ICU ventilators were not observed, and no difference in intubation rate was found. The physiologic effects may have been obscured by leaks or other important factors in the clinical settings. This study does not support the recent recommendation favoring the use of HH during NIV with ICU ventilators.

High Success and Low Mortality Rates With Early Use of Noninvasive Ventilation in Influenza A H1N1 Pneumonia

Background The use of noninvasive ventilation (NIV) in severe hypoxemic respiratory failure (partial pressure of oxygen in the alveoli [PaO2]/fraction of inspired oxygen [FIO2] ≤250 ) is controversial; but in centers with expertise on NIV, when used as a first-line therapy, NIV can avoid orotracheal intubation in 30% to 50% of cases. At beginning of the pandemic, NIV was not recommended for patients with influenza A H1N1 virus infection complicated by pneumonia, acute lung injury, or acute respiratory distress syndrome because although it could temporarily improve oxygenation, it did not necessarily change the natural disease course. In this regard, several authors have reported high rates of NIV failure in pandemic influenza A H1N1 pneumonia. However, other authors have more recently reported some cases demonstrating the effectiveness of NIV in severe respiratory failure related to H1N1 pneumonia. Aim and Methods In this prospective study, we aimed to assess the efficacy of NIV in avoiding endotracheal intubation and to identify predictors of success or failure. Seventy-five patients affected by influenza A H1N1 pneumonia were admitted to our hospitals: among them, 61 patients presented with acute respiratory failure, and 29 patients had severe respiratory failure; 5 patients with PaO2/FIO2 lower than 150 and SAPS II lower than 34 underwent NIV and were admitted to respiratory intermediate care unit. Results Noninvasive ventilation failed in 3 of the 24 patients but had a good outcome in 21 patients. None of the patients treated with NIV died. The mean ± SD duration of NIV was 5.0 ± 1.9 days, and the mean ± SD hospital stay was 11.2 ± 4.0 days. The mean ± SD PaO2/FIO2 ratio at admission was 184.6 ± 29.2, and the mean ± SD SAPS II was 17.8 ± 2.6; the mean ± SD PaO2/FIO2 ratio after 1 hour of NIV was 239.1 ± 42.3. No patient had multiorgan failure. The PaO2/FIO2 ratio after 1 hour and SAPS II at admission were independent variables correlated with the success of NIV. Conclusions In our study, NIV had a success in 21 (87.5 %) of the 24 patients, and this is one of the higher rates of success described in the literature. In our opinion, the reasons explaining the results could be the selection of the patients to be treated with early severe respiratory failure (PaO2/FIO2 ≥150), and the strict adherence to the predictors of success for NIV such as SAPSII ≤34 and PaO2/FIO2 ≤175 after 1 hour of NIV. Physicians should be aware of pulmonary complications of influenza A H1N1 and strictly select the patients to undergo NIV: it could have an effective and safe role in reducing the high demand for critical care beds, particularly during pandemics.

Use of dexmedetomidine to facilitate non-invasive ventilation

Patients with chronic obstructive pulmonary disease and congestive heart failure exacerbations, as well as pneumonia benefit from the use of non-invasive ventilation (NIV), due to increased patient comfort and a reduced incidence of ventilator-associated pneumonia. However, some patients do not tolerate NIV due to anxiety or agitation, and traditionally physicians have withheld sedation from these patients due to concerns of loss of airway protection and respiratory depression. We report our recent experience with a 91-year-old female who received NIV for acute respiratory distress secondary to pneumonia. The duration of NIV was a total time period of 86 h, using the bilevel positive airway pressure mode via a full face mask. The patient was initially agitated with the NIV, but with the addition of the dexmedetomidine, she tolerated it well. The dexmedetomidine was administered without a loading dose, as a continuous infusion ranging from 0.2 to 0.5 mcg/kg/hr, titrated to a Ramsey score of three. This case illustrates the safe use of dexmedetomidine to facilitate NIV, and improve compliance, which may reduce ICU length of stay.

Efficacy and Predictors of Success of Noninvasive Ventilation for Prevention of Extubation Failure in Critically Ill Children With Heart Disease

The study aimed primarily to evaluate the efficacy of noninvasive ventilation (NIV) and to identify possible predictors for success of NIV therapy in preventing extubation failure in critically ill children with heart disease. The secondary objectives of this study were to assess the efficacy of prophylactic NIV therapy initiated immediately after tracheal extubation and to determine the characteristics, outcomes, and complications associated with NIV therapy in pediatric cardiac patients. A retrospective review examined the medical records of all children between the ages 1 day and 18 years who sustained acute respiratory failure (ARF) that required NIV in the cardiovascular intensive care unit (CVICU) at Lucile Packard Children's Hospital between January 2008 and June 2010. Patients were assigned to a prophylactic group if NIV was started directly after extubation and to a nonprophylactic group if NIV was started after signs and symptoms of ARF developed. Patients were designated as responders if they received NIV and did not require reintubation during their CVICU stay and nonresponders if they failed NIV and reintubation was performed. The data collected included demographic data, preexisting conditions, pre-event characteristics, event characteristics, and outcome data. The outcome data evaluated included success or failure of NIV, duration of NIV, CVICU length of stay (LOS), hospital LOS, and hospital mortality. The two complications of NIV assessed in the study included nasal bridge or forehead skin necrosis and pneumothorax. The 221 eligible events during the study period involved 172 responders (77.8 %) and 49 nonresponders (22.2 %). A total of 201 events experienced by the study cohort received continuous positive airway pressure (CPAP), with 156 responders (78 %), whereas 20 events received bilevel positive airway pressure (BiPAP), with 16 responders (80 %). In the study, 58 events (26.3 %) were assigned to the prophylactic group and 163 events (73.7 %) to the nonprophylactic group. Compared with the nonprophylactic group, the prophylactic group experienced significantly shorter CVICU LOS (median, 49 vs 88 days; p = 0.03) and hospital LOS (median, 60 vs 103 days; p = 0.05). The CVICU LOS and hospital LOS did not differ significantly between the responders (p = 0.56) and nonresponders (p = 0.88). Significant variables identifying a responder included a lower risk-adjusted classification for congenital heart surgery (RACHS-1) score (1-3), a good left ventricular ejection fraction, a normal respiratory rate (RR), normal or appropriate oxygen saturation, prophylactic or therapeutic glucocorticoid therapy within 24 h of NIV initiation, presence of atelectasis, fewer than two organ system dysfunctions, fewer days of intubation before extubation, no clinical or microbiologic evidence of sepsis, and no history of reactive airway disease. As a well-tolerated therapy, NIV can be safely and successfully applied in critically ill children with cardiac disease to prevent extubation failure. The independent predictors of NIV success include lower RACHS-1 classification, presence of atelectasis, steroid therapy received within 24 h after NIV, and normal heart rate and oxygen saturations demonstrated within 24 h after initiation of NIV.

Protocol-directed versus physician-directed weaning from noninvasive ventilation

Noninvasive ventilation (NIV), a technique widely used in intensive care units (ICUs), eliminates the need for many patients in respiratory failure to undergo intubation. However, few articles have described how to wean patients from NIV. Herein, we put forward a protocol to be performed by respiratory therapists to wean patients from NIV. A prospective, randomized, controlled trial was performed in a respiratory ICU of a teaching hospital. Respiratory therapists screened patients daily. In the protocol-directed weaning group, the weaning attempt was initiated according to the protocol. In the physician-directed weaning group, the weaning attempt was initiated according to physicians' orders. At randomization, patients in the two groups had similar clinical characteristics. A total of 73 patients were successfully weaned from NIV (37 in the protocol-directed group and 36 in the physician-directed group). The preponderance of them (64%) was chronic obstructive pulmonary disease patients. Compared with physician-directed weaning, protocol-directed weaning reduced the duration of NIV (4.4 ± 2.5 days vs. 2.6 ± 1.5 days, respectively, p < 0.001) and the duration of the ICU stay (8.1 ± 5.5 days vs. 5.8 ± 2.7 days, respectively, p = 0.02). In the protocol-directed group, the successful weaning rate was 57%, 27%, 13%, 0%, and 3% on the 1st, 2nd, 3rd, 4th, and 5th days after randomization, respectively. Protocol-directed weaning reduces the duration of NIV and the duration of the ICU stay. II.

Mixed Acid-Base Disorders, Hydroelectrolyte Imbalance and Lactate Production in Hypercapnic Respiratory Failure: The Role of Noninvasive Ventilation

BackgroundHypercapnic Chronic Obstructive Pulmonary Disease (COPD) exacerbation in patients with comorbidities and multidrug therapy is complicated by mixed acid-base, hydro-electrolyte and lactate disorders. Aim of this study was to determine the relationships of these disorders with the requirement for and duration of noninvasive ventilation (NIV) when treating hypercapnic respiratory failure.MethodsSixty-seven consecutive patients who were hospitalized for hypercapnic COPD exacerbation had their clinical condition, respiratory function, blood chemistry, arterial blood gases, blood lactate and volemic state assessed. Heart and respiratory rates, pH, PaO2 and PaCO2 and blood lactate were checked at the 1st, 2nd, 6th and 24th hours after starting NIV.ResultsNine patients were transferred to the intensive care unit. NIV was performed in 11/17 (64.7%) mixed respiratory acidosis–metabolic alkalosis, 10/36 (27.8%) respiratory acidosis and 3/5 (60%) mixed respiratory-metabolic acidosis patients (p = 0.026), with durations of 45.1±9.8, 36.2±8.9 and 53.3±4.1 hours, respectively (p = 0.016). The duration of ventilation was associated with higher blood lactate (p<0.001), lower pH (p = 0.016), lower serum sodium (p = 0.014) and lower chloride (p = 0.038). Hyponatremia without hypervolemic hypochloremia occurred in 11 respiratory acidosis patients. Hypovolemic hyponatremia with hypochloremia and hypokalemia occurred in 10 mixed respiratory acidosis–metabolic alkalosis patients, and euvolemic hypochloremia occurred in the other 7 patients with this mixed acid-base disorder.ConclusionsMixed acid-base and lactate disorders during hypercapnic COPD exacerbations predict the need for and longer duration of NIV. The combination of mixed acid-base disorders and hydro-electrolyte disturbances should be further investigated.

Non-invasive ventilation in community-acquired pneumonia and severe acute respiratory failure

The use of non-invasive ventilation (NIV) in severe acute respiratory failure (ARF) due to community-acquired pneumonia (CAP) is controversial, and the risk factors for NIV failure in these patients are not well known. We assessed the characteristics and predictors of outcome of patients with CAP and severe ARF treated with NIV. We prospectively assessed 184 consecutive patients; 102 had "de novo" ARF, and 82 previous cardiac or respiratory disease. We defined successful NIV as avoidance of intubation and intensive care unit (ICU) survival at least 24 h in the ward. We assessed predictors of NIV failure and hospital mortality in multivariate analyses. Patients with "de novo" ARF failed NIV more frequently than patients with previous cardiac or respiratory disease (47, 46% versus 21, 26%, p = 0.007). Worsening radiologic infiltrate 24 h after admission, maximum Sepsis-Related Organ Failure Assessment (SOFA) score and, after 1 h of NIV, higher heart rate and lower PaO(2)/FiO(2) and bicarbonate independently predicted NIV failure. Likewise, maximum SOFA, NIV failure and older age independently predicted hospital mortality. Among intubated patients with "de novo" ARF, NIV duration was shorter in hospital survivors than non-survivors (32 ± 24 versus 78 ± 65 h, p = 0.014). In this group, longer duration of NIV before intubation was associated with decreased hospital survival (adjusted odds ratio 0.978, 95% confidence interval 0.962-0.995, p = 0.012). This association was not observed in patients with previous cardiac or respiratory disease. Successful NIV was strongly associated with better survival. If predictors for NIV failure are present, avoiding delayed intubation of patients with "de novo" ARF would potentially minimise mortality.