Small dead space heat and moisture exchangers do not impede gas exchange during noninvasive ventilation: a comparison with a heated humidifier

Objective

Adverse respiratory and gasometrical effects have been described in patients with acute respiratory failure (ARF) undergoing noninvasive ventilation (NIV) with standard heat and moisture exchangers (HME). We decided to evaluate respiratory parameters and arterial blood gases (ABG) of patients during NIV with small dead space HME compared with heated humidifier (HH).

Design

Prospective randomized crossover study.

Setting

A 16-bed medical intensive care unit (ICU).

Patients

Fifty patients receiving NIV for ARF.

Measurements

The effects of HME and HH on respiratory rate, minute ventilation, EtCO₂, oxygen saturation, airway occlusion pressure at 0.1 s, ABG, and comfort perception were compared during two randomly determined NIV periods of 30 min. The relative impact of HME and HH on these parameters was successively compared with or without addition of a flex tube (40 and 10 patients, respectively).

Main results

No difference was observed between HME and HH regarding any of the studied parameters, whether or not a flex tube was added.

Conclusion

If one decides to humidify patients’ airways during NIV, one may do so with small dead space HME or HH without altering respiratory parameters.     

Early postoperative prophylactic noninvasive ventilation after major lung resection in COPD patients: a randomized controlled trial

Objectives

To investigate whether prophylactic postoperative NIV prevents respiratory complications following lung resection surgery in COPD patients.

Methods

In seven thoracic surgery departments, 360 COPD patients undergoing lung resection surgery were randomly assigned to two groups: conventional postoperative treatment without (n = 179) or with (n = 181) prophylactic NIV, applied intermittently during 6 h per day for 48 h following surgery. The primary endpoint was the rate of acute respiratory events (ARE) at 30 days postoperatively (ITT analysis). Secondary endpoints were acute respiratory failure (ARF), intubation rate, mortality rate, infectious and non-infectious complications, and duration of ICU and hospital stay.

Measurements and main results

ARE rates did not differ between the prophylactic NIV and control groups (57/181, 31.5 vs. 55/179, 30.7 %, p = 0.93). ARF rate was 18.8 % in the prophylactic NIV group and 24.5 % in controls (p = 0.20). Re-intubation rates were similar in the prophylactic NIV and control group [10/181 (5.5 %) and 13/179 (7.2 %), respectively, p = 0.53]. Mortality rates were 5 and 2.2 % in the control and prophylactic NIV groups, respectively (p = 0.16). Infectious and non-infectious complication rates, and duration of ICU and hospital stays were similar between groups.

Conclusions

Prophylactic postoperative NIV did not reduce the rate of ARE in COPD patients undergoing lung resection surgery and did not influence other postoperative complications rates, mortality rates, and duration of ICU and hospital stay.     

Apnoeic oxygenation via high-flow nasal cannula oxygen combined with non-invasive ventilation preoxygenation for intubation in hypoxaemic patients in the intensive care unit: the single-centre,blinded, randomised controlled OPTINIV trial

Purpose

High-flow nasal cannula oxygen (HFNC) has the potential to provide apnoeic oxygenation. We decided to assess in a proof-of-concept study whether the addition of HFNC to non-invasive ventilation (NIV) could reduce oxygen desaturation during intubation, compared with NIV alone for preoxygenation, in severely hypoxaemic intensive care unit (ICU) patients with respiratory failure.

Methods

We conducted a randomised, controlled, single-centre trial with assessor-blinded outcome assessment in patients admitted to the ICU. Hypoxaemic patients requiring orotracheal intubation for respiratory failure were randomised to receive preoxygenation using HFNC [flow = 60 L/min, fraction of inspired oxygen (FiO₂) = 100 %] combined with NIV (pressure support = 10 cmH₂O, positive end-expiratory pressure = 5 cmH₂O, FiO₂ = 100 %) in the intervention group or NIV alone in the reference group prior to intubation. The primary outcome was the lowest oxygen saturation (SpO₂) during the intubation procedure. Secondary outcomes were intubation-related complications and ICU mortality.

Results

Between July 2015 and February 2016, we randomly assigned 25 and 24 patients to the intervention and reference groups, respectively. In both groups the main reasons for respiratory failure were pneumonia and ARDS. During the intubation procedure, the lowest SpO₂ values were significantly higher in the intervention group than in the reference group [100 (95–100) % vs. 96 (92–99) %, p = 0.029]. After exclusion of two patients from analysis for protocol violation, no (0 %) patients in the intervention group and five (21 %) patients in the reference group had SpO₂ below 80 % (p = 0.050). We recorded no significant difference between the groups in intubation-related complications or ICU mortality.

Conclusions

A novel strategy for preoxygenation in hypoxaemic patients, adding HFNC for apnoeic oxygenation to NIV prior to orotracheal intubation, may be more effective in reducing the severity of oxygen desaturation than the reference method using NIV alone.

     

Noninvasive mechanical ventilation in patients having declined tracheal intubation

Purpose

Noninvasive ventilation (NIV) is a treatment option in patients with acute respiratory failure who are good candidates for intensive care but have declined tracheal intubation. The aim of our study was to report outcomes after NIV in patients with a do-not-intubate (DNI) order.

Methods

Prospective observational cohort study in all patients who received NIV for acute respiratory failure in 54 ICUs in France and Belgium, in 2010/2011.

Results

Goals of care, comfort, and vital status were assessed daily. On day 90, a telephone interview with patients and relatives recorded health-related quality of life (HRQOL), posttraumatic stress disorder-related symptoms, and symptoms of anxiety and depression. Post-ICU burden was compared between DNI patients and patients receiving NIV with no treatment-limitation decisions (TLD). Of 780 NIV patients, 574 received NIV with no TLD, and 134 had DNI orders. Hospital mortality was 44 % in DNI patients and 12 % in the no-TLD group. Mortality in the DNI group was lowest in COPD patients compared to other patients in the DNI group (34 vs. 51 %, P = 0.01). In the DNI group, HRQOL showed no significant decline on day 90 compared to baseline; day-90 data of patients and relatives did not differ from those in the no-TLD group.

Conclusions

Do-not-intubate status was present among one-fifth of ICU patients who received NIV. DNI patients who were alive on day 90 experienced no decrease in HRQOL compared to baseline. The prevalences of anxiety, depression, and PTSD-related symptoms in these patients and their relatives were similar to those seen after NIV was used as part of full-code management (clinicaltrial.govNCT01449331).     

Noninvasive ventilation in chest trauma: systematic review and meta-analysis

Purpose

Single studies of Noninvasive Ventilation (NIV) in the management of acute respiratory failure in chest trauma patients have produced controversial findings. The aim of this study is to critically review the literature to investigate whether NIV reduces mortality, intubation rate, length of stay and complications in patients with chest trauma, compared to standard therapy.

Methods

We performed a systematic review and meta-analysis of randomized controlled trials, prospective and retrospective observational studies, by searching PubMed, EMBASE and bibliographies of articles retrieved. We screened for relevance studies that enrolled adults with chest trauma who developed mild to severe acute respiratory failure and were treated with NIV. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis.

Results

Ten studies (368 patients) met the inclusion criteria and were included for the meta-analysis. Five studies (219 patients) reported mortality and results were quite homogeneous across studies, with a summary relative risk for patients treated with NIV compared with standard care (oxygen therapy and invasive mechanical ventilation) of 0.26 (95 % confidence interval 0.09–0.71, p = 0.003). There was no advantage in mortality of continuous positive airway pressure over noninvasive pressure support ventilation. NIV significantly increased arterial oxygenation and was associated with a significant reduction in intubation rate, in the incidence of overall complications and infections.

Conclusions

These results suggest that NIV could be useful in the management of acute respiratory failure due to chest trauma.     

The ETHICA study (part II): simulation study of determinants and variability of ICU physician decisions in patients aged 80 or over

Purpose

To assess physician decisions about ICU admission for life-sustaining treatments (LSTs).

Methods

Observational simulation study of physician decisions for patients aged ≥80 years. Each patient was allocated at random to four physicians who made decisions based on actual bed availability and existence of an additional bed before and after obtaining information on patient preferences. The simulations involved non-invasive ventilation (NIV), invasive mechanical ventilation (IMV), and renal replacement therapy after a period of IMV (RRT after IMV).

Results

The physician participation rate was 100/217 (46 %); males without religious beliefs predominated, and median ICU experience was 9 years. Among participants, 85.7, 78, and 62 % felt that NIV, IMV, or RRT (after IMV) was warranted, respectively. By logistic regression analysis, factors associated with admission were age <85 years, self-sufficiency, and bed availability for NIV and IMV. Factors associated with IMV were previous ICU stay (OR 0.29, 95 % CI 0.13–0.65, p = 0.01) and cancer (OR 0.23, 95 % CI 0.10–0.52, p = 0.003), and factors associated with RRT (after IMV) were living spouse (OR 2.03, 95 % CI 1.04–3.97, p = 0.038) and respiratory disease (OR 0.42, 95 % CI 0.23–0.76, p = 0.004). Agreement among physicians was low for all LSTs. Knowledge of patient preferences changed physician decisions for 39.9, 56, and 57 % of patients who disagreed with the initial physician decisions for NIV, IMV, and RRT (after IMV) respectively. An additional bed increased admissions for NIV and IMV by 38.6 and 13.6 %, respectively.

Conclusions

Physician decisions for elderly patients had low agreement and varied greatly with bed availability and knowledge of patient preferences.     

The feasibility and safety of extracorporeal carbon dioxide removal to avoid intubation in patients with COPD unresponsive to noninvasive ventilation for acute hypercapnic respiratory failure (ECLAIR study): multicentre case–control study

Introduction

The aim of the study was to evaluate the feasibility and safety of avoiding invasive mechanical ventilation (IMV) by using extracorporeal CO₂ removal (ECCO₂R) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) and acute hypercapnic respiratory failure refractory to noninvasive ventilation (NIV).

Methods

Case–control study. Patients with acute hypercapnic respiratory failure refractory to NIV being treated with a pump-driven veno-venous ECCO₂R system (iLA-Activve^®; Novalung, Heilbronn, Germany) were prospectively observed in five European intensive care units (ICU). Inclusion criteria were respiratory acidosis (pH ≤ 7.35, PaCO₂ > 45 mmHg) with predefined criteria for endotracheal intubation (ClinicalTrials.gov NCT01784367). The historical controls were patients with acute hypercapnic respiratory failure refractory to NIV who were treated with IMV. The matching criteria were main diagnosis, age, SAPS-II score and pH.

Results

Twenty-five cases (48.0 % male, mean age 67.3 years) were matched with 25 controls. Intubation was avoided in 14 patients (56.0 %) in the ECCO₂R group with a mean extracorporeal blood flow of 1.3 L/min. Seven patients were intubated because of progressive hypoxaemia and four owing to ventilatory failure despite ECCO₂R and NIV. Relevant ECCO₂R-associated adverse events were observed in 11 patients (44.0 %), of whom 9 (36.0 %) suffered major bleeding complications. The mean time on IMV, ICU stay and hospital stay in the case and control groups were 8.3 vs. 13.7, 28.9 vs. 24.0 and 36.9 vs. 37.0 days, respectively, and the 90-day mortality rates were 28.0 vs. 28.0 %.

Conclusions

The use of veno-venous ECCO₂R to avoid invasive mechanical ventilation was successful in just over half of the cases. However, relevant ECCO₂R-associated complications occurred in over one-third of cases. Despite the shorter period of IMV in the ECCO₂R group there were no significant differences in length of stay or in 28- and 90-day mortality rates between the two groups. Larger, randomised studies are warranted for further assessment of the effectiveness of ECCO₂R.

     

Early CPAP prevents evolution of acute lung injury in patients with hematologic malignancy

Purpose

Although chemotherapy and transplantation improve outcome of patients with hematological malignancy, complications of these therapies are responsible for a 20–50% mortality rate that increases when respiratory symptoms evolve into acute lung injury (ALI). The aim of this study is to determine the effectiveness of early continuous positive airway pressure (CPAP) delivered in the ward to prevent occurrence of ALI requiring intensive care unit (ICU) admission for mechanical ventilation.

Methods

Patients with hematological malignancy presenting in the hematological ward with early changes in respiratory variables were randomized to receive oxygen (N = 20) or oxygen plus CPAP (N = 20). Primary outcome variables were need of mechanical ventilation requiring ICU admission, and intubation rate among those patients who required ICU admission.

Results

At randomization, arterial-to-inspiratory O₂ ratio in control and CPAP group was 282 ± 41 and 256 ± 52, respectively. Patients who received CPAP had less need of ICU admission for mechanical ventilation (4 versus 16 patients; P = 0.0002). CPAP reduced the relative risk for developing need of ventilatory support to 0.25 (95% confidence interval: 0.10–0.62). Among patients admitted to ICU, intubation rate was lower in the CPAP than in the control group (2 versus 14 patients; P = 0.0001). CPAP reduced the relative risk for intubation to 0.46 (95% confidence interval: 0.27–0.78).

Conclusions

This study suggests that early use of CPAP on the hematological ward in patients with early changes in respiratory variables prevents evolution to acute lung injury requiring mechanical ventilation and ICU admission.     

Implementation of a combo videolaryngoscope for intubation in critically ill patients: a before–after comparative study

Purpose

Airway management in intensive care unit (ICU) patients is challenging. The main objective of this study was to compare the incidence of difficult laryngoscopy and/or difficult intubation between a combo videolaryngoscope and the standard Macintosh laryngoscope in critically ill patients.

Methods

In the context of the implementation of a quality-improvement process for airway management, we performed a prospective interventional monocenter before–after study which evaluated a new combo videolaryngoscope. The primary outcome was the incidence of difficult laryngoscopy (defined by Cormack grade 3–4) and/or difficult intubation (more than two attempts). The secondary outcomes were the severe life-threatening complications related to intubation in ICU and the rate of difficult intubation in cases of predicted difficult intubation evaluated by a specific score (MACOCHA score ≥3).

Results

Two hundred and ten non-selected consecutive intubation procedures were included, 140 in the standard laryngoscope group and 70 in the combo videolaryngoscope group. The incidence of difficult laryngoscopy and/or difficult intubation was 16 % in the laryngoscope group vs. 4 % in the combo videolaryngoscope group (p = 0.01). The severe life-threatening complications related to intubation did not differ between groups (16 vs. 14 %, p = 0.79). Among the 32 patients with a MACOCHA score ≥3, there were significantly more patients with difficult intubation in the standard laryngoscope group in comparison to the combo videolaryngoscope group [12/23 (57 %) vs. 0/9 (0 %), p < 0.01].

Conclusions

The systematic use of a combo videolaryngoscope in ICU was associated with a decreased incidence of difficult laryngoscopy and/or difficult intubation.     

Intermittent noninvasive ventilation after extubation in patients with chronic respiratory disorders: a multicenter randomized controlled trial (VHYPER)

Purpose

Early noninvasive ventilation (NIV) after extubation decreases the risk of respiratory failure and lowers 90-day mortality in patients with hypercapnia. Patients with chronic respiratory disease are at risk of extubation failure. Therefore, it could be useful to determine the role of NIV with a discontinuous approach, not limited to patients with hypercapnia. We assessed the efficacy of early NIV in decreasing respiratory failure after extubation in patients with chronic respiratory disorders.

Methods

A prospective randomized controlled multicenter study was conducted. We enrolled 144 mechanically ventilated patients with chronic respiratory disorders who tolerated a spontaneous breathing trial. Patients were randomly allocated after extubation to receive either NIV (NIV group, n = 72), performed with a discontinuous approach, for the first 48 h, or conventional oxygen treatment (usual care group, n = 72). The primary endpoint was decreased respiratory failure within 48 h after extubation. Analysis was by intention to treat. This trial was registered with ClinicalTrials.gov (NCT01047852).

Results

Respiratory failure after extubation was less frequent in the NIV group: 6 (8.5%) versus 20 (27.8%); p = 0.0016. Six patients (8.5%) in the NIV group versus 13 (18.1%) in the usual care group were reintubated; p = 0.09. Intensive care unit (ICU) mortality and 90-day mortality did not differ significantly between the two groups (p = 0.28 and p = 0.33, respectively). Median postrandomization ICU length of stay was lower in the usual care group: 3 days (IQR 2–6) versus 4 days (IQR 2–7; p = 0.008). Patients with hypercapnia during a spontaneous breathing trial were at risk of developing postextubation respiratory failure [adjusted odds ratio (95% CI) = 4.56 (1.59–14.00); p = 0.006] and being intubated [adjusted odds ratio (95% CI) = 3.60 (1.07–13.31); p = 0.04].

Conclusions

Early NIV performed following a sequential protocol for the first 48 h after extubation decreased the risk of respiratory failure in patients with chronic respiratory disorders. Reintubation and mortality did not differ between NIV and conventional oxygen therapy.

     

Early intermittent noninvasive ventilation for acute chest syndrome in adults with sickle cell disease: a pilot study

Purpose

Alveolar hypoxia and hypoxic vasoconstriction lead to trapping of sickle cells within the pulmonary vasculature. Improving alveolar ventilation and oxygenation may improve the outcome of acute chest syndrome (ACS).

Methods

Prospective randomized single-center open study from November 1998 to February 2002 to test whether noninvasive ventilation (NIV) was more effective than oxygen alone in improving oxygenation on day 3 in adults with ACS and to evaluate the effects on pain, transfusion requirements, and length of stay.

Results

Seventy-one consecutive ACS episodes in 67 patients were randomly allocated to oxygen (n = 36) or NIV (n = 35) for 3 days in a medical step-down unit. Baseline respiratory rate and pain score were higher in the NIV group. NIV promptly lowered the respiratory rate, raised $ {\text{Pa}}_{{\text{O}_{2}}} $ , and decreased alveolar–arterial oxygen gradient $ (({\text{A}} - {\text{a}})_{{{\text{O}}_{ 2} }} ) $ , which remained unchanged with oxygen alone. $ {\text{Pa}}_{{{\text{CO}}_{ 2} }} $ significantly worsened only in the oxygen group. On day 3, the groups did not differ regarding the proportion of episodes with normal $ {\text{Pa}}_{{{\text{O}}_{ 2} }} $ (35% with NIV and 25% with oxygen; P = 0.5) or $ (({\text{A}} - {\text{a}})_{{{\text{O}}_{ 2} }} ) $ . Patient satisfaction and compliance were lower with NIV. No differences were noted in pain relief, transfusions, or length of stay. In the subgroup of patients with severe hypoxemia $ ( {\text{Pa}}_{{{\text{O}}_{ 2} }} \le 6 5\,{\text{mmHg)}} $ , physiological variables also improved faster with NIV, the differences being slightly more pronounced.

Conclusions

Respiratory rate and gas exchange improved faster with NIV. However, NIV failed to significantly reduce the number of patients remaining hypoxemic at day 3, and was associated with greater patient discomfort.     

Predicting non-invasive ventilation failure in children from the SpO2/FiO2 (SF) ratio

Purpose

Our objective was to assess whether SpO₂/FiO₂ (SF) ratio could be a useful NIV outcome predictor in children with acute respiratory failure (ARF) and tried to develop a predictive model of NIV failure.

Methods

Prospective, observational, multicenter study. Episodes of ARF-fulfilling inclusion criteria from 15 January 2010 to 14 January 2011 were treated with NIV according to a pre-established protocol. Clinical variables were collected at baseline and at 1, 2, 6, 12 and 24 h. Failure criterion was the need for endotracheal intubation. Failures were considered as “early” if occurring ≤6 h after NIV initiation, “intermediate” if occurring between 6 and 24 h, and “late” if occurring after 24 h. Variables with a p < 0.1 in univariate analysis corrected by age were included in multivariate analysis. Models were calculated based on multivariate analysis.

Results

During the study period, 390 episodes were included. NIV success rate was 81.3 %. Among ARF causes, failure occurred most frequently in ARDS episodes. The failure predictive model for the whole sample included SF ratio at 1 h, age and PRISM III-24 (area under the curve AUC of 0.755). For early NIV failures, SF ratio at 1 h was the only variable within model (AUC 0.748). The analysis of intermediate NIV failures identified 3 variables independently linked to NIV outcome: PRISM III-24, RR decrease at 6 h, and SF ratio at 6 h (AUC 0.895). No model was identified for late NIV failure.

Conclusions

SF ratio is a reliable predictor of early NIV failure in children.     

Assessment of heart rate,acidosis, consciousness,oxygenation, and respiratory rate to predict noninvasive ventilation failure in hypoxemic patients

Purpose

To develop and validate a scale using variables easily obtained at the bedside for prediction of failure of noninvasive ventilation (NIV) in hypoxemic patients.

Methods

The test cohort comprised 449 patients with hypoxemia who were receiving NIV. This cohort was used to develop a scale that considers heart rate, acidosis, consciousness, oxygenation, and respiratory rate (referred to as the HACOR scale) to predict NIV failure, defined as need for intubation after NIV intervention. The highest possible score was 25 points. To validate the scale, a separate group of 358 hypoxemic patients were enrolled in the validation cohort.

Results

The failure rate of NIV was 47.8 and 39.4% in the test and validation cohorts, respectively. In the test cohort, patients with NIV failure had higher HACOR scores at initiation and after 1, 12, 24, and 48 h of NIV than those with successful NIV. At 1 h of NIV the area under the receiver operating characteristic curve was 0.88, showing good predictive power for NIV failure. Using 5 points as the cutoff value, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for NIV failure were 72.6, 90.2, 87.2, 78.1, and 81.8%, respectively. These results were confirmed in the validation cohort. Moreover, the diagnostic accuracy for NIV failure exceeded 80% in subgroups classified by diagnosis, age, or disease severity and also at 1, 12, 24, and 48 h of NIV. Among patients with NIV failure with a HACOR score of >5 at 1 h of NIV, hospital mortality was lower in those who received intubation at ≤12 h of NIV than in those intubated later [58/88 (66%) vs. 138/175 (79%); p = 0.03).

Conclusions

The HACOR scale variables are easily obtained at the bedside. The scale appears to be an effective way of predicting NIV failure in hypoxemic patients. Early intubation in high-risk patients may reduce hospital mortality.

     

Video laryngoscopy versus direct laryngoscopy for orotracheal intubation in the intensive care unit: a systematic review and meta-analysis

Purpose

Single studies of video laryngoscopy (VL) use for airway management in intensive care unit (ICU) patients have produced controversial findings. The aim of this study was to critically review the literature to investigate whether VL reduces difficult orotracheal intubation (OTI) rate, first-attempt success, and complications related to intubation in ICU patients, compared to standard therapy, defined as direct laryngoscopy (DL).

Methods

We performed a systematic review and meta-analysis of randomized controlled trials, as well as prospective and retrospective observational studies, by searching PubMed, EMBASE, and bibliographies of articles retrieved. We screened for relevant studies that enrolled adults in whom the trachea was intubated in the ICU and compared VL to DL. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis. We generated pooled odd ratios (OR) across studies. The primary outcome measure was difficult OTI. The secondary outcomes were first-attempt success, Cormack 3/4 grades, and complications related to intubation (severe hypoxemia, severe cardiovascular collapse, airway injury, esophageal intubation).

Results

Nine trials with a total of 2,133 participants (1,067 in DL and 1,066 in VL) were included in the current analysis. Compared to DL, VL reduced the risk of difficult OTI [OR 0.29 (95 % confidence interval (CI) 0.20–0.44, p < 0.001)], Cormack 3/4 grades [OR 0.26 (95 % CI 0.17–0.41, p < 0.001)], and esophageal intubation [0.14 (95 % CI 0.02–0.81, p = 0.03)] and increased the first-attempt success [OR 2.07 (95 % CI 1.35–3.16, p < 0.001)]. No statistically significant difference was found for severe hypoxemia, severe cardiovascular collapse or airway injury.

Conclusions

These results suggest that VL could be useful in airway management of ICU patients.     

Avoiding invasive mechanical ventilation by extracorporeal carbon dioxide removal in patients failing noninvasive ventilation

Purpose

To evaluate whether extracorporeal carbon dioxide removal by means of a pumpless extracorporeal lung-assist (PECLA) device could be an effective and safe alternative to invasive mechanical ventilation in patients with chronic pulmonary disease and acute hypercapnic ventilatory failure not responding to noninvasive ventilation (NIV).

Methods

In this multicentre, retrospective study, 21 PECLA patients were compared with respect to survival and procedural outcomes to 21 matched controls with conventional invasive mechanical ventilation. Matching criteria were underlying diagnosis, age, Simplified Acute Physiology Score II and pH at ICU admission.

Results

Of the 21 patients treated with PECLA, 19 (90?%) did not require intubation. Median PaCO₂ levels and pH in arterial blood prior to PECLA were 84.0?mmHg (54.2–131.0) and 7.28 (7.10–7.41), respectively. Within 24?h, median PaCO₂ levels and pH had significantly improved to 52.1 (33.0–70.1; p? p? p?=?0.056). There was no group difference in the 28-day (24?% vs. 19?%, adjusted p?=?0.845) or 6-month mortality (33?% vs. 33?%).

Conclusions

In this study the use of extracorporeal carbon dioxide removal allowed avoiding intubation and invasive mechanical ventilation in the majority of patients with acute on chronic respiratory failure not responding to NIV. Compared to conventional invasive ventilation, short- and long-term survivals were similar.     

Impact of hypoxic hepatitis on mortality in the intensive care unit

Purpose

Hypoxic hepatitis (HH) is a form of hepatic injury following arterial hypoxemia, ischemia, and passive congestion of the liver. We investigated the incidence and the prognostic implications of HH in the medical intensive care unit (ICU).

Methods

A total of 1,066 consecutive ICU admissions at three medical ICUs of a university hospital were included in this prospective cohort study. All patients were screened prospectively for the presence of HH according to established criteria. Independent risk factors of mortality in this cohort of critically ill patients were identified by a multivariate Poisson regression model.

Results

A total of 118 admissions (11%) had HH during their ICU stay. These patients had different baseline characteristics, longer median ICU stay (8 vs. 6?days, p?p?p?p?p?=?0.359).

Conclusions

Hypoxic hepatitis (HH) occurs frequently in the medical ICU. The presence of HH is a strong risk factor for mortality in the ICU in patients requiring vasopressor therapy.     

A randomized trial of intravenous glutamine supplementation in trauma ICU patients

Purpose

To evaluate the effect of the intravenous (i.v.) l-alanyl-l-glutamine dipeptide supplementation during 5 days on clinical outcome in trauma patients admitted to the intensive care unit (ICU).

Methods

This was a prospective, randomized, double-blind, multicenter trial. Glutamine was not given as a component of nutrition but as an extra infusion. The primary outcome variable was the number of new infections within the first 14 days.

Results

We included 142 patients. There were no differences between groups in baseline characteristics. Up to 62 % of the patients in the placebo group and 63 % in the treatment group presented confirmed infections (p = 0.86). ICU length of stay was 14 days in both groups (p = 0.54). Hospital length of stay was 27 days in the placebo group and 29 in the treatment group (p = 0.88). ICU mortality was 4.2 % in both groups (p = 1). Sixty percent of the patients presented low glutamine levels before randomization. At the end of the treatment (6th day), 48 % of the patients maintained low glutamine levels (39 % of treated patients vs. 57 % in the placebo group). Patients with low glutamine levels at day 6 had more number of infections (58.8 vs. 80.9 %; p = 0.032) and longer ICU (9 vs. 20 days; p < 0.01) and hospital length of stay (24 vs. 41 days; p = 0.01).

Conclusions

There was no benefit with i.v. l-alanyl-l-glutamine dipeptide supplementation (0.5 g/kg body weight/day of the dipeptide) during 5 days in trauma patients admitted to the ICU. The i.v. glutamine supplementation was not enough to normalize the plasma glutamine levels in all patients. Low plasma glutamine levels at day 6 were associated with a worse outcome.     

Clinical impact of arterial ammonia levels in ICU patients with different liver diseases

Purpose

Increased arterial ammonia levels are associated with high mortality in patients with acute liver failure (ALF). Data on the prognostic impact of arterial ammonia is lacking in hypoxic hepatitis (HH) and scarce in critically ill patients with cirrhosis.

Methods

The patient cohort comprised 72 patients with HH, 43 patients with ALF, 100 patients with liver cirrhosis and 45 patients without evidence for liver disease. Arterial ammonia concentrations were assessed on a daily basis in all patients and the results were compared among these four patient groups and between 28-day survivors and 28-day non-survivors overall and in each group.

Results

Overall 28-day mortality rates in patients with HH, ALF and cirrhosis and in the control group were 54, 30, 49 and 27 %, respectively. Peak arterial ammonia levels differed significantly between transplant-free 28-day survivors and non-survivors in the HH and ALF groups (p < 0.01 for both). Multivariate regression identified peak arterial ammonia concentrations as an independent predictor of 28-day mortality or liver transplantation in patients with HH and ALF, respectively (p < 0.01). There was no association between mortality and arterial ammonia in patients with liver cirrhosis and in the control group. Admission arterial ammonia levels were independently linked to hepatic encephalopathy grades 3/4 in patients with HH (p < 0.01), ALF (p < 0.05) and cirrhosis (p < 0.05), respectively.

Conclusions

Elevated arterial ammonia levels indicate a poor prognosis in acute liver injury and are associated with advanced HE in HH, ALF and cirrhosis. Arterial ammonia levels provide additional information in the risk assessment of critically ill patients with liver disease.     

Noninvasive ventilation after early extubation in patients recovering from hypoxemic acute respiratory failure: a single-centre feasibility study

Purpose

The use of noninvasive ventilation (NIV) to facilitate discontinuation of mechanical ventilation in patients with acute hypoxemic respiratory failure (hypoxemic ARF) has never been explored. This pilot study aims to assess the feasibility of early extubation followed by immediate NIV, compared conventional weaning, in patients with resolving hypoxemic ARF.

Methods

Twenty consecutive hypoxemic patients were randomly assigned to receive either conventional weaning or NIV. The changes in arterial blood gases and respiratory rate were compared between the two groups at 1, 12, 24 and 48?h. Differences in the rate of extubation failure, ICU and hospital mortality, number of invasive-ventilation-free-days at day 28, septic complications, number of tracheotomies, days and rates of continuous intravenous sedation, and ICU length of stay were also determined.

Results

No patient interrupted the study protocol. Arterial blood gases were similar during invasive mechanical ventilation, 1?h after NIV application following extubation, and after 12, 24 and 48?h. Respiratory rate was higher after 1?h in the NIV group, but no different after 12, 24 and 48?h. The number of invasive-ventilation-free-days at day 28 was 20?±?8 (min?=?0, max?=?25) days in the treatment group and 10?±?9 (min?=?0, max?=?25) days in the control group (p?=?0.014). The rate of extubation failure, ICU and hospital mortality, tracheotomies, septic complications, days and rates of continuous sedation, and ICU length of stay were not significantly different between the two groups.

Conclusions

In a highly experienced centre NIV may be used to facilitate discontinuation of mechanical ventilation in selected patients with resolving hypoxemic ARF.