Effect of aggressive vs conservative screening and confirmatory test on time to extubation among patients at low or intermediate risk: a randomized clinical trial

PURPOSE

This study aimed to determine the best strategy to achieve fast and safe extubation.

METHODS

This multicenter trial randomized patients with primary respiratory failure and low-to-intermediate risk for extubation failure with planned high-flow nasal cannula (HFNC) preventive therapy. It included four groups: (1) conservative screening with ratio of partial pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FiO2) ≥ 150 and positive end-expiratory pressure (PEEP) ≤ 8 cmH2O plus conservative spontaneous breathing trial (SBT) with pressure support 5 cmH2O + PEEP 0 cmH2O); (2) screening with ratio of partial pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FiO2) ≥ 150 and PEEP ≤ 8 plus aggressive SBT with pressure support 8 + PEEP 5; (3) aggressive screening with PaO2/FiO2 > 180 and PEEP 10 maintained until the SBT with pressure support 8 + PEEP 5; (4) screening with PaO2/FiO2 > 180 and PEEP 10 maintained until the SBT with pressure support 5 + PEEP 0. Primary outcomes were time-to-extubation and simple weaning rate. Secondary outcomes included reintubation within 7 days after extubation.

RESULTS

Randomization to the aggressive-aggressive group was discontinued at the interim analysis for safety reasons. Thus, 884 patients who underwent at least 1 SBT were analyzed (conservative-conservative group, n = 256; conservative-aggressive group, n = 267; aggressive-conservative group, n = 261; aggressive-aggressive, n = 100). Median time to extubation was lower in the groups with aggressive screening (p < 0.001). Simple weaning rates were 45.7%, 76.78% (205 patients), 71.65%, and 91% (p < 0.001), respectively. Reintubation rates did not differ significantly (p = 0.431).

CONCLUSION

Among patients at low or intermediate risk for extubation failure with planned HFNC, combining aggressive screening with preventive PEEP and a conservative SBT reduced the time to extubation without increasing the reintubation rate.

Prognostic factors in oncological patients with solid tumours requiring intensive care unit admission

The aim of the present study was to identify factors predicting in-hospital mortality in patients with cancer admitted to a medical Intensive Care Unit (ICU), and to evaluate their functional status and survival during follow-up at the oncology service in the initial 12 months after hospital discharge. A retrospective observational study was performed on 129 consecutive oncological patients with solid tumours admitted to the medical ICU of the Hospital del Mar (Barcelona, Spain) between January 2016 and June 2018. Demographics, and clinical data in-ICU and in-hospital mortality were recorded. Post-hospital discharge follow-up was also carried out. ICU and hospital mortality rates were 24% (n=31) and 40.3% (n=52), respectively. Sequential Organ Failure Assessment (SOFA) score (HR, 1.20; 95% CI, 1.01-1.42; P=0.037), neutropenia on admission (HR, 8.53; 95% CI, 2.15-33.82; P=0.002), metastatic disease (HR, 3.92; 95% CI, 1.82-8.45; P<0.001), need for invasive mechanical ventilation (HR, 5.78; 95% CI, 1.61-20.73; P=0.007), surgery during hospital admission (HR, 0.23; 95% CI, 0.09-0.61; P=0.003) and ICU stay (>48 h) (HR, 0.11; 95% CI, 0.04-0.29; P<0.001) were the independent risk factors for ICU mortality. Overall, 59.5% of the survivors had good functional status at hospital discharge and 28.7% of patients with cancer admitted to the ICU were alive 1 year after hospital discharge, most of them (85.7%) with good functional status (Eastern Cooperative Oncology Group 0-1). In conclusion, hospital mortality may be associated with SOFA score at ICU admission, the need for invasive mechanical ventilation, neutropenia and metastatic disease. Only 40% of patients with oncological disease admitted to the ICU died during their hospital stay, and >50% of the survivors presented good functional status at hospital discharge. Notably, 1 year after hospital discharge, 28.7% of patients were alive, most of them with a good functional status.

Comparing lung aeration and respiratory effort using two different spontaneous breathing trial: T-piece vs pressure support ventilation

OBJECTIVE

To assess the changes in lung aeration and respiratory effort generated by two different spontaneous breathing trial (SBT): T-piece (T-T) vs pressure support ventilation (PSV).

DESIGN

Prospective, interventionist and randomized study.

SETTING

Intensive Care Unit (ICU) of Hospital del Mar.

PARTICIPANTS

Forty-three ventilated patients for at least 24 h and considered eligible for an SBT were included in the study between October 2017 and March 2020.

INTERVENTIONS

30-min SBT with T-piece (T-T group, 20 patients) or 8-cmH2O PSV and 5-cmH2O positive end expiratory pressure (PSV group, 23 patients).

MAIN VARIABLES OF INTEREST

Demographics, clinical data, physiological variables, lung aeration evaluated with electrical impedance tomography (EIT) and lung ultrasound (LUS), and respiratory effort using diaphragmatic ultrasonography (DU) were collected at different timepoints: basal (BSL), end of SBT (EoSBT) and one hour after extubation (OTE).

RESULTS

There were a loss of aeration measured with EIT and LUS in the different study timepoints, without statistical differences from BSL to OTE, between T-T and PSV [LUS: 3 (1, 5.5) AU vs 2 (1, 3) AU; p = 0.088; EELI: -2516.41 (-5871.88, 1090.46) AU vs -1992.4 (-3458.76, -5.07) AU; p = 0.918]. Percentage of variation between BSL and OTE, was greater when LUS was used compared to EIT (68.1% vs 4.9%, p ≤ 0.001). Diaphragmatic excursion trend to decrease coinciding with a loss of aeration during extubation.

CONCLUSION

T-T and PSV as different SBT strategies in ventilated patients do not show differences in aeration loss, nor estimated respiratory effort or tidal volume measured by EIT, LUS and DU.

European Network for ICU-Related Respiratory Infections (ENIRRIs): a multinational, prospective, cohort study of nosocomial LRTI

PURPOSE

Lower respiratory tract infections (LRTI) are the most frequent infectious complication in patients admitted to the intensive care unit (ICU). We aim to report the clinical characteristics of ICU-admitted patients due to nosocomial LRTI and to describe their microbiology and clinical outcomes.

METHODS

A prospective observational study was conducted in 13 countries over two continents from 9th May 2016 until 16th August 2019. Characteristics and outcomes of ventilator-associated pneumonia (VAP), ventilator-associated tracheobronchitis (VAT), ICU hospital-acquired pneumonia (ICU-HAP), HAP that required invasive ventilation (VHAP), and HAP in patients transferred to the ICU without invasive mechanical ventilation were collected. The clinical diagnosis and treatments were per clinical practice and not per protocol. Descriptive statistics were used to compare the study groups.

RESULTS

1060 patients with LRTI (72.5% male sex, median age 64 [50-74] years) were included in the study; 160 (15.1%) developed VAT, 556 (52.5%) VAP, 98 (9.2%) ICU-HAP, 152 (14.3%) HAP, and 94 (8.9%) VHAP. Patients with VHAP had higher serum procalcitonin (PCT) and Sequential Organ Failure Assessment (SOFA) scores. Patients with VAP or VHAP developed acute kidney injury, acute respiratory distress syndrome, multiple organ failure, or septic shock more often. One thousand eight patients had microbiological samples, and 711 (70.5%) had etiological microbiology identified. The most common microorganisms were Pseudomonas aeruginosa (18.4%) and Klebsiella spp (14.4%). In 382 patients (36%), the causative pathogen shows some antimicrobial resistance pattern. ICU, hospital and 28-day mortality were 30.8%, 37.5% and 27.5%, respectively. Patients with VHAP had the highest ICU, in-hospital and 28-day mortality rates.

CONCLUSION

VHAP patients presented the highest mortality among those admitted to the ICU. Multidrug-resistant pathogens frequently cause nosocomial LRTI in this multinational cohort study.

Classic and genetic cardiovascular risk burden and case-fatality from SARS-CoV-2 virus infection. The CARGENCORS study

Background

The disease presentation of the severe acute respiratory syndrome coronavirus 2 infection (COVID-19) ranges from asymptomatic to fatal. COVID-19 patients with pre-existing coronary artery disease (CAD) risk factors or overt cardiovascular disease more often develop severe COVID-19, which are also related to thrombotic, inflammatory, and to viral infectivity response. We hypothesised that despite some genetic predisposition, especially in COVID-19 severity, the main determinants of fatal complications in COVID-19 patients are related to comorbidity.

Purpose

To determine the role of genetics and cardiovascular comorbidity in mortality from COVID-19.

Methods

We conducted a retrospective cohort study including 3,120 patients with positive COVID-19 test from several hospitals and primary care between February 2020 and June 2021. Among them 1,096 required hospitalization, and 121 died within 3 months after symptom onset. Standard parametric and non-parametric methods, as required, were used to compare patient characteristics by vital status. Individual genotypes for 32 CAD, 14 thrombosis, 19 inflammation, and 11 viral infectivity single nucleotide variants (SNV), as well as, 2 COVID-19 SNVs already published were tested for association with mortality with Cochran-Armitage statistics and p-values corrected for multiple comparisons. The mutually-adjusted odds ratio (OR) and 95% confidence interval (95% CI) of fatal COVID-19 was analysed for SNVs significantly associated to case-fatality, with their adverse alleles count (0, 1 or 2), and for comorbidity factors with logistic regression adjusted for age and sex. The discrimination of the models was also estimated by the area under the curve (AUC).

Results

Fatal and non-fatal cases' characteristics are compared in Table 1. Fatal cases had a more adverse cardiovascular and anthropometric risk profile. After correcting for multiple testing by Benjamini-Hochberg method, we observed the inflammation-related rs6993770 SNV to be significantly associated with COVID-19 fatality (p-value = 0.04). The CAD-related rs9982601 and rs2505083 SNVs, and the thrombosis-related rs7853989 SNV were moderately associated with COVID-19 fatality (p-value ≤0.1). On Figure 1 we show the adjusted OR for rs6993770 (OR: 1.02; 95% CI 1.01–1.03 per risk allele) and that for clinical factors related to COVID-19 case-fatality. The AUC of the model was 0.85 (95% CI 0.81–0.88), which not improved that of a model with clinical risk factors alone (AUC: 0.84; 95% CI 0.81–0.87).

Conclusion

The rs6993770 inflammation (interleukin measurement trait)-related SNV was independently associated to case fatality; however the outcome was mainly driven by age, male sex, diabetes, and glomerular filtration rate.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Carlos III Health Institute and the European Regional Development FundAgency for Management of University and Research GrantsCrue-CSIC-Santander FONDO SUPERA COVID-19

Association between histological diaphragm atrophy and ultrasound diaphragm expiratory thickness in ventilated patients

Background

Diaphragm fiber atrophy has been evidenced after short periods of mechanical ventilation (MV) and related to critical illness-associated diaphragm weakness. Atrophy is described as a decrease in diaphragm fiber cross-sectional area (CSA) in human diaphragm biopsy, but human samples are still difficult to obtain in clinics. In recent years, ultrasound has become a useful tool in intensive care to evaluate diaphragm anatomy. The present study aimed to evaluate the ability of diaphragm expiratory thickness (Tdi) measured by ultrasound to predict diaphragm atrophy, defined by a decrease in diaphragm fiber CSA obtained through diaphragm biopsy (the gold standard technique) in ventilated patients.

Methods

Diaphragm biopsies and diaphragm ultrasound were performed in ventilated donors and in control subjects. Demographic variables, comorbidities, severity on admission, treatment, laboratory test results and evolution variables were evaluated. Immunohistochemical analysis to determine CSA and ultrasound measurements of Tdi at end-expiration were performed, and median values of the control group were used as thresholds to determine agreement between them in further analysis. Sensitivity, specificity, and positive and negative predictive values of an ultrasound Tdi cutoff for detecting histologic atrophy were calculated. Agreement between two ultrasound observers was also assessed.

Results

Thirty-five ventilated organ donors and 5 ventilated controls were included, without differences in basic characteristics. CSA and Tdi were lower in donors than in controls. All donors presented lower CSA, but only 74% lower Tdi regarding control group thresholds. The cut-off value for lower diaphragm expiratory thickness (Tdi < 1.7 mm) presented a sensitivity of 73%, a specificity of 67%, a positive predictive value of 96% and a negative predictive value of 17% for determining the presence of diaphragm atrophy (CSA < 2851 μm²).

Conclusions

Diaphragm atrophy and thickness reduction is associated to MV. While a lower Tdi in diaphragm ultrasound is a good tool for diagnosing atrophy, normal or increased Tdi cannot rule atrophy out showing that both parameters should not be considered as synonymous.

Genetic risk score for risk stratification of patients positive for SARS-CoV-2 virus. The CARGENCORS study

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Carlos III Health Institute and the European Regional Development Fund Government of Catalonia through the Agency for Management of University and Research Grants Crue-CSIC-Santander FONDO SUPERA COVID-19

Background

The disease presentation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from asymptomatic to fatal. COVID-19 patients with pre-existing coronary artery disease (CAD) risk factors or overt cardiovascular disease are at particular risk of severe disease. We hypothesised that a specific genetic risk score (GRS) based on single nucleotide polymorphisms (SNPs) allele count to score COVID-19 severity might include SNPs counts related to CAD incidence and to thrombosis, inflammation, and viral infectivity determinants involved in the severity of SARS-CoV-2. Such GRS could improve the early risk stratification of COVID-19 patients and optimize treatment strategies.

Purpose

To evaluate the capacity of a genetic risk score (GRS) with candidate genes to predict COVID-19 severity.

Methods

We conducted an age- and sex-matched case-control study with 1:2 ratio recruitment involving 2454 patients from Catalan hospitals and primary care. Cases were hospitalized severe (requiring at least oxygen treatment) or fatal COVID-19 patients; and controls were moderate-symptom and asymptomatic patients treated at home. Standard parametric and non-parametric methods, as required, were used to compare patient characteristics by severity. Individual genotypes for 33 CAD, 14 thrombosis, 22 inflammation, 15 viral infectivity SNPs and 2 COVID-19 SNPs already published were tested for association with severity with Cochran-Armitage statistics and p-values corrected for multiple comparisons. GRS was computed as the unweighted count of adverse alleles (0, 1 or 2). The odds ratio of severe COVID-19 was analysed for GRS (and its component SNPs) with logistic regression models adjusted for potential confounding factors. Area under the curve (AUC) improvement and net reclassification index (NRI) for GRS was estimated from a basic model including CAD and COVID-19 severity risk factors. Models’ performance was measured with the Akaike information criterion.

Results

SNPs identifications are not shown to prevent patent conflict. Cases and control characteristics are compared in Table 1. Cases had a more adverse cardiovascular and anthropometric risk profile. After correcting for multiple testing by Benjamini-Hochberg criteria, we observed 13 SNPs to be significantly associated with severity. After excluding the close SNPs in linkage disequilibrium, 7 were retained in the GRS model, which yielded the discrimination and reclassification characteristics described in Table 2.

Conclusion

A GRS with 7 SNPs related to CAD, thrombosis and inflammation significantly improves the severe COVID-19 risk assessment done with age, sex, comorbidity, and anthropometry alone.

SARS-CoV-2 could be spread through hospital medication dispensed to patients: A prospective observational study

ABSTRACT

Our objective was to analyze in vitro the persistence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in the packaging material of the drugs dispensed to hospital wards. Additionally, to evaluate if the protection with a double plastic bag prevents the contamination of the medication dispensed to an intensive care unit (ICU).On the first part, different materials containing different drugs within an ICU were sampled to confirm the lack of contamination by SARS-CoV-2. The confirmation of the virus was performed using real time reverse transcription polymerase chain reaction. As a control group, in the microbiology laboratory we inoculated the virus into the different surfaces containing the same drugs included in the first part. Samples were obtained with a sterile swab at 3, 6, 8, 10, 14, 21, and 30 days after inoculation and analyzed through real time reverse transcription polymerase chain reaction.None of the studied materials containing the drugs within an ICU was contaminated by SARS-CoV-2. In the second part, SARS-CoV-2 was found in all surfaces for up to 30 days.The use of double-bag unit-dose system to deliver medication in a pandemic seems effective to prevent the potential transmission of SARS-CoV-2. A striking SARS-CoV-2 RNA stability of up to 30 days was found in the surfaces containing the drugs.

Evolution of Antimicrobial Consumption During the First Wave of COVID-19 Pandemic

Background: The first wave of COVID-19 pandemic may have significantly impacted antimicrobial consumption in hospitals. The objective of this study was to assess the evolution of antimicrobial consumption during this period. Methods: A retrospective quasi-experimental before–after study was conducted in a Spanish tertiary care hospital. The study compared two periods: pre-pandemic, from January 2018 to February 2020, and during the COVID-19 pandemic from March to June 2020. Antimicrobial consumption was analyzed monthly as defined daily doses (DDD)/100 bed-days and overall hospital and ICU consumption were evaluated. Results: An increase in the hospital consumption was noticed. Although only ceftaroline achieved statistical significance (p = 0.014), a rise was observed in most of the studied antimicrobials. A clear temporal pattern was detected. While an increase in ceftriaxone and azithromycin was observed during March, an increment in the consumption of daptomycin, carbapenems, linezolid, ceftaroline, novel cephalosporin/β-lactamase inhibitors or triazoles during April–May was noticed. In the ICU, these findings were more evident, namely ceftriaxone (p = 0.029), carbapenems (p = 0.002), daptomycin (p = 0.002), azithromycin (p = 0.030), and linezolid (p = 0.011) but followed a similar temporal pattern. Conclusion: An increase in the antimicrobial consumption during the first wave of COVID-19 pandemic was noticed, especially in the ICU. Availability of updated protocols and antimicrobial stewardship programs are essential to optimize these outcomes.

Active humidification in mechanical ventilation is not associated to an increase in respiratory infectious complications in a quasi-experimental pre-post intervention study

OBJECTIVE

There is controversy regarding the influence of humidification systems upon the incidence of respiratory infections associated to invasive mechanical ventilation (IMV). An evaluation was made of the differences in the incidence of pneumonia and tracheobronchitis associated to mechanical ventilation (VAP and VAT, respectively) with passive and active humidification.

DESIGN

A retrospective pre-post quasi-experimental study was carried out.

SETTING

A polyvalent ICU with 14 beds.

PATIENTS

All patients connected to IMV for >48h during 2014 and 2016 were included.

INTERVENTIONS

During 2014, passive humidification with an hygroscopic heat and moisture exchanger (HME) was used, while during 2016 active humidification with a heated humidifier (HH) and an inspiratory heated wire was used. Identical measures for the prevention of VAP were established (Zero Pneumonia Project).

MAIN OUTCOME MEASURES

The incidence of VAP and VAT was estimated for 1000 days of IMV in both groups, and statistically significant differences were assessed using Poisson regression analysis.

RESULTS

A total of 287 patients were included (116 with HME and 171 with HH). The incidence density of VAP per 1000 days of IMV was 5.68 in the HME group and 5.80 in the HH group (p=ns). The incidence density of VAT was 3.41 and 3.26 cases per 1000 days of VMI with HME and HH respectively (p=ns). The duration of IMV was identified as a risk factor for VAP.

CONCLUSIONS

In our population, active humidification in patients ventilated for >48h was not associated to an increase in respiratory infectious complications.

Active humidification in mechanical ventilation is not associated to an increase in respiratory infectious complications in a quasi-experimental pre-post intervention study

OBJECTIVE

There is controversy regarding the influence of humidification systems upon the incidence of respiratory infections associated to invasive mechanical ventilation (IMV). An evaluation was made of the differences in the incidence of pneumonia and tracheobronchitis associated to mechanical ventilation (VAP and VAT, respectively) with passive and active humidification.

DESIGN

A retrospective pre-post quasi-experimental study was carried out.

SETTING

A polyvalent ICU with 14 beds.

PATIENTS

All patients connected to IMV for>48hours during 2014 and 2016 were included.

INTERVENTIONS

During 2014, passive humidification with an hygroscopic heat and moisture exchanger (HME) was used, while during 2016 active humidification with a heated humidifier (HH) and an inspiratory heated wire was used. Identical measures for the prevention of VAP were established (Zero Pneumonia Project).

MAIN OUTCOME MEASURES

The incidence of VAP and VAT was estimated for 1000 days of IMV in both groups, and statistically significant differences were assessed using Poisson regression analysis.

RESULTS

A total of 287 patients were included (116 with HME and 171 with HH). The incidence density of VAP per 1000 days of IMV was 5.68 in the HME group and 5.80 in the HH group (p=ns). The incidence density of VAT was 3.41 and 3.26 cases per 1000 days of VMI with HME and HH respectively (p=ns). The duration of IMV was identified as a risk factor for VAP.

CONCLUSIONS

In our population, active humidification in patients ventilated for>48hours was not associated to an increase in respiratory infectious complications.

Successfully non-surgical management of flail chest as first manifestation of multiple myeloma: A case report

BACKGROUND

Multiple myeloma is a malignant neoplasm of the bone marrow characterized by neoplastic proliferation of monoclonal plasma cells with a high relationship with destructive bone disease. We present a case of a patient diagnosed with multiple myeloma and sternal fracture in association with multiple bilateral rib fractures and thoracic kyphosis, who developed a severe acute respiratory failure, thus complicating the initial presentation of multiple myeloma. We discuss the therapeutic implications of this uncommon presentation.

CASE SUMMARY

A 56-year-old man presented to Hematological Department after he had been experiencing worsening back pain over the last five months, with easy fatigability and progressive weight loss. He had no history of previous trauma. The chemical blood tests were compatible with a diagnosis of multiple myeloma. A radiographic bone survey of all major bones revealed, in addition to multiple bilateral rib fractures, a sternal fracture and compression fracture at T9, T10, T11 and L1 vertebrae. Subcutaneous fat biopsy was positive for amyloid. We started treatment with bortezomib and dexamethasone. After 24 h of treatment, he presented dyspnea secondary to flail chest. He required urgent intubation and ventilatory support being transferred to intensive care unit for further management. The patient remained connected to mechanical ventilation (positive pressure) as treatment which stabilized the thorax. A second cycle of bortezomib plus dexamethasone was started and analgesia was optimized. The condition of the patient improved, as evidenced by callus formation on successive computed tomography scans. The patient was taken off the ventilator one month later, and he was extubated successfully, being able to breathe unaided without paradoxical motion.

CONCLUSION

This case highlights the importance of combination between bortezomib and dexamethasone to induce remission of multiple myeloma and the initiation of positive airway pressure with mechanical ventilation to stabilize chest wall to solve the respiratory failure. This combined approach allowed to obtain a quick and complete resolution of the clinical situation.

Aeration changes induced by high flow nasal cannula are more homogeneous than those generated by non-invasive ventilation in healthy subjects

BACKGROUND

Non-invasive mechanical ventilation (NIV) is a standard respiratory support technique used in intensive care units. High-Flow Nasal Cannula (HFNC) has emerged as an alternative, but further evidence is needed. The lung aeration and diaphragm changes achieved with these two strategies in healthy subjects have not been compared to date.

METHODS

Twenty healthy subjects were recruited. Ten were ventilated with NIV and ten underwent HFNC. Lung impedance and diaphragmatic ultrasound measurements were performed before and after 30 min of respiratory support. The Mar-index was defined as the ratio of the diaphragm excursion-time index to the respiratory rate.

RESULTS

Both groups showed significant decreases in respiratory rate (NIV: 14.4 (4.1) vs 10.4 (1.6), p = 0.009; HFNC: 13.6 (4.3) vs 7.9 (1.5) bpm, p = 0.002) and significant increases in the end-expiratory lung impedance (EELI) (NIV: 66,348(10,761) vs. 73,697 (6858), p = 0.005; HFNC: 66,252 (9793) vs 69,869 (9135), p = 0.012). NIV subjects showed a significant increase in non-dependent silent spaces (4.13 (2.25) vs 5.81 (1.49)%, p = 0.037) while the increase was more homogeneous with HFNC. The variation in EELI tended to be higher in NIV than in HFNC (8137.08 (6152.04) vs 3616.94 (3623.03), p = 0.077). The Mar-index was higher in HFNC group (13.15 vs 5.27 cm-sec²/bpm, p = 0.02).

CONCLUSIONS

NIV and HFNC increased EELI in healthy subjects, suggesting an increase in the functional residual capacity. The EELI increase may be higher in NIV, but HFNC produced a more homogeneous change in lung ventilation. HFNC group has a higher MAR-index that could reflect a different ventilatory system adaptation.

Intensive care unit patients with lower respiratory tract nosocomial infections: the ENIRRIs project

The clinical course of intensive care unit (ICU) patients may be complicated by a large spectrum of lower respiratory tract infections (LRTI), defined by specific epidemiological, clinical and microbiological aspects.

A European network for ICU-related respiratory infections (ENIRRIs), supported by the European Respiratory Society, has been recently established, with the aim at studying all respiratory tract infective episodes except community-acquired ones. A multicentre, observational study is in progress, enrolling more than 1000 patients fulfilling the clinical, biochemical and radiological findings consistent with a LRTI. This article describes the methodology of this study. A specific interest is the clinical impact of non-ICU-acquired nosocomial pneumonia requiring ICU admission, non-ventilator-associated LRTIs occurring in the ICU, and ventilator-associated tracheobronchitis. The clinical meaning of microbiologically negative infectious episodes and specific details on antibiotic administration modalities, dosages and duration are also highlighted. Recently released guidelines address many unresolved questions which might be answered by such large-scale observational investigations. In light of the paucity of data regarding such topics, new interesting information is expected to be obtained from our network research activities, contributing to optimisation of care for critically ill patients in the ICU.

Methodology for the first European network for ICU-related respiratory infections (ENIRRIs) projecthttp://ow.ly/sud930fU1e7

Severe vitamin D deficiency upon admission in critically ill patients is related to acute kidney injury and a poor prognosis

OBJECTIVES

To evaluate the prevalence of vitamin D deficiency in critically ill patients upon admission to an Intensive Care Unit (ICU) and its prognostic implications.

DESIGN

A single-center, prospective observational study was carried out from January to November 2015. Patients were followed-up on until death or hospital discharge.

SETTING

The department of Critical Care Medicine of a university hospital.

PATIENTS

All adults admitted to the ICU during the study period, without known factors capable of altering serum 25(OH)D concentration.

INTERVENTIONS

Determination of serum 25(OH)D levels within the first 24h following admission to the ICU.

MAIN VARIABLES OF INTEREST

Prevalence and mortality at 28 days.

RESULTS

The study included 135 patients, of which 74% presented deficient serum 25(OH)D levels upon admission to the ICU. Non-survivors showed significantly lower levels than survivors (8.14ng/ml [6.17-11.53] vs. 12ng/ml [7.1-20.30]; P=.04], and the serum 25(OH)D levels were independently associated to mortality (OR 2.86; 95% CI 1.05-7.86; P=.04]. The area under the ROC curve was 0.61 (95% CI 0.51-0.75), and the best cut-off point for predicting mortality was 10.9ng/ml. Patients with serum 25(OH)D<10.9ng/ml also showed higher acute kidney injury rates (13 vs. 29%; P=.02).

CONCLUSION

Vitamin D deficiency is highly prevalent upon admission to the ICU. Severe Vitamin D deficiency (25[OH]D<10.9ng/ml) upon admission to the ICU is associated to acute kidney injury and mortality.

High-flow nasal cannula to prevent postextubation respiratory failure in high-risk non-hypercapnic patients: a randomized multicenter trial

Background

Extubation failure is associated with increased morbidity and mortality, but cannot be safely predicted or avoided. High-flow nasal cannula (HFNC) prevents postextubation respiratory failure in low-risk patients.

Objective

To demonstrate that HFNC reduces postextubation respiratory failure in high-risk non-hypercapnic patients compared with conventional oxygen.

Methods

Randomized, controlled multicenter trial in patients who passed a spontaneous breathing trial. We enrolled patients meeting criteria for high-risk of failure to randomly receive HFNC or conventional oxygen for 24 h after extubation. Primary outcome was respiratory failure within 72-h postextubation. Secondary outcomes were reintubation, intensive care unit (ICU) and hospital lengths of stay, and mortality. Statistical analysis included multiple logistic regression models.

Results

The study was stopped due to low recruitment after 155 patients were enrolled (78 received high-flow and 77 received conventional oxygen). Groups were similar at enrollment, and all patients tolerated 24-h HFNC. Postextubation respiratory failure developed in 16 (20%) HFNC patients and in 21 (27%) conventional patients [OR 0.69 (0.31–1.54), p = 0.2]. Reintubation was needed in 9 (11%) HFNC patients and in 12 (16%) conventional patients [OR 0.71 (0.25–1.95), p = 0.5]. No difference was found in ICU or hospital length of stay, or mortality. Logistic regression models suggested HFNC [OR 0.43 (0.18–0.99), p = 0.04] and cancer [OR 2.87 (1.04–7.91), p = 0.04] may be independently associated with postextubation respiratory failure.

Conclusion

Our study is inconclusive as to a potential benefit of HFNC over conventional oxygen to prevent occurrence of respiratory failure in non-hypercapnic patients at high risk for extubation failure.

Registered at Clinicaltrials.gov NCT01820507.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0270-9) contains supplementary material, which is available to authorized users.

The role of high flow oxygen therapy in acute respiratory failure

Acute respiratory failure represents one of the most common causes of intensive care unit admission and oxygen therapy remains the first-line therapy in the management of these patients. In recent years, high-flow oxygen via nasal cannula has been described as a useful alternative to conventional oxygen therapy in patients with acute respiratory failure. High-flow oxygen via nasal cannula rapidly alleviates symptoms of acute respiratory failure and improves oxygenation by several mechanisms, including dead space washout, reduction in oxygen dilution and inspiratory nasopharyngeal resistance, a moderate positive airway pressure effect that may generate alveolar recruitment and an overall greater tolerance and comfort with the interface and the heated and humidified inspired gases. However, the experience in adults is still limited and there are no clinical guidelines to establish recommendations for their use. This article aims to review the existing evidence on the use of high-flow oxygen via nasal cannula in adults with acute respiratory failure and its possible applications, advantages and limitations.

Early postoperative management of lung transplantation

Lung transplantation is a widely accepted therapeutic option for patients with end-stage lung disease. However, despite the significant medical progress achieved since the first human lung transplant was performed in 1963, perioperative and long-term patient outcomes are still jeopardised by a variety of complications. Infection and rejection are among the most feared complications in the early post-transplantation period because they are difficult to treat and can have a long-lasting impact on the quality of life and overall life expectancy. Multidisciplinary management of lung transplant recipients focusing on the prevention or early detection of complications, particularly during the early postoperative phase, may improve the short and long-term outcomes of those patients benefiting from this life-saving intervention. However, in the absence of internationally recognised guidelines, the optimal strategies for managing lung transplant recipients remain unclear. This article presents a practical approach to the management of the early post-transplantation period aiming at standardising clinical care and improving patient outcome.

Early non-invasive ventilation treatment for severe influenza pneumonia

The role of non-invasive ventilation (NIV) in acute respiratory failure caused by viral pneumonia remains controversial. Our objective was to evaluate the use of NIV in a cohort of (H1N1)v pneumonia. Usefulness and success of NIV were assessed in a prospective, observational registry of patients with influenza A (H1N1) virus pneumonia in 148 Spanish intensive care units (ICUs) in 2009-10. Significant variables for NIV success were included in a multivariate analysis. In all, 685 patients with confirmed influenza A (H1N1)v viral pneumonia were admitted to participating ICUs; 489 were ventilated, 177 with NIV. The NIV was successful in 72 patients (40.7%), the rest required intubation. Low Acute Physiology and Chronic Health Evaluation (APACHE) II, low Sequential Organ Failure Assessment (SOFA) and absence of renal failure were associated with NIV success. Success of NIV was independently associated with fewer than two chest X-ray quadrant opacities (OR 3.5) and no vasopressor requirement (OR 8.1). However, among patients with two or more quadrant opacities, a SOFA score ≤7 presented a higher success rate than those with SOFA score >7 (OR 10.7). Patients in whom NIV was successful required shorter ventilation time, shorter ICU stay and hospital stay than NIV failure. In patients in whom NIV failed, the delay in intubation did not increase mortality (26.5% versus 24.2%). Clinicians used NIV in 25.8% of influenza A (H1N1)v viral pneumonia admitted to ICU, and treatment was effective in 40.6% of them. NIV success was associated with shorter hospital stay and mortality similar to non-ventilated patients. NIV failure was associated with a mortality similar to those who were intubated from the start.

Effect of high-flow nasal cannula and body position on end-expiratory lung volume: a cohort study using electrical impedance tomography

BACKGROUND

Electrical impedance tomography measures changes in lung impedance, which are mainly related to changes in lung volume. We used electrical impedance tomography to investigate the effects of high-flow nasal cannula (HFNC) and body position on global and regional end-expiratory lung impedance variation (ΔEELI).

METHODS

Prospective study with 20 healthy adults. Two periods were defined: the first in supine position and the second in prone position. Each period was divided into 3 phases. In the first and the third phases the subjects were breathing ambient air, and in the second HFNC was implemented. Four regions of interest were defined: 2 ventral and 2 dorsal. For each respiratory cycle, global and regional ΔEELI were measured by electrical impedance tomography and were expressed as a function of the tidal variation of the first stable respiratory cycle (units).

RESULTS

HFNC increased global EELI by 1.26 units (95% CI 1.20-1.31, P < .001) in supine position, and by 0.87 units (95% CI 0.82-0.91, P < .001) in prone position. The distribution of ΔEELI was homogeneous in prone position, with no difference between ventral and dorsal lung regions (-0.01 units, 95% CI -0.01 to 0, P = .18), while in supine position a significant difference was found (0.22 units, 95% CI 0.21-0.23, P < .001) with increased EELI in ventral areas.

CONCLUSIONS

HFNC increased global EELI in our population, regardless of body position, suggesting an increase in functional residual capacity. Prone positioning was related to a more homogeneous distribution of ΔEELI, while in supine position ΔEELI was higher in the ventral lung regions.

High-flow nasal therapy in adults with severe acute respiratory infection: a cohort study in patients with 2009 influenza A/H1N1v

PURPOSE

The experience with high-flow nasal cannula (HFNC) oxygen therapy in severe acute respiratory infection (SARI) is limited. The objective was to assess the effectiveness of HFNC oxygen therapy in adult patients with SARI by confirmed 2009 influenza A/H1N1v infection (by real-time reverse transcription polymerase chain reaction testing).

MATERIAL AND METHODS

A single-center post hoc analysis of a cohort of intensive care unit patients admitted with SARI due to 2009 Influenza A/H1N1v was done. High-flow nasal cannula (Optiflow; Fisher & Paykel, Auckland, New Zealand) was indicated in the presence of acute respiratory failure when the patient was unable to maintain a pulse oxymetry more than 92% with more than 9 L/min of oxygen using a standard face mask conventional delivery systems. Nonresponders were defined by their need of subsequent mechanical ventilation.

RESULTS

Twenty-five nonintubated adult patients were admitted for SARI (21 pneumonia). Twenty were unable to maintain pulse oxymetry more than 92% with conventional oxygen administration and required HFNC O(2) therapy, which was successful in 9 (45%). All 8 patients on vasopressors required intubation within 24 hours. After 6 hours of HFNC O(2) therapy, nonresponders presented a lower Pao(2)/fraction of inspired oxygen (median, 135 [interquartile range, 84-210] vs 73 [56-81] mm Hg P < .05) and needed higher oxygen flow rate. No secondary infections were reported in health care workers. No nosocomial pneumonia occurred during HFNC O(2) therapy.

CONCLUSION

High-flow nasal cannula O(2) therapy appears to be an innovative and effective modality for early treatment of adults with SARI.

[Electrical impedance tomography in acute lung injury]

Electrical impedance tomography has been described as a new method of monitoring critically ill patients on mechanical ventilation. It has recently gained special interest because of its applicability for monitoring ventilation and pulmonary perfusion. Its bedside and continuous implementation, and the fact that it is a non-ionizing and non-invasive technique, makes it an extremely attractive measurement tool. Likewise, given its ability to assess the regional characteristics of lung structure, it could be considered an ideal monitoring tool in the heterogeneous lung with acute lung injury. This review explains the physical concept of bioimpedance and its clinical application, and summarizes the scientific evidence published to date with regard to the implementation of electrical impedance tomography as a method for monitoring ventilation and perfusion, mainly in the patient with acute lung injury, and other possible applications of the technique in the critically ill patient. The review also summarizes the limitations of the technique and its potential areas of future development.

Effects of an omega-3 fatty acid-enriched lipid emulsion on eicosanoid synthesis in acute respiratory distress syndrome (ARDS): A prospective, randomized, double-blind, parallel group study

Background

The use of lipid emulsions has been associated with changes in lung function and gas exchange which may be mediated by biologically active metabolites derived from arachidonic acid. The type and quantity of the lipid emulsions used could modulate this response, which is mediated by the eicosanoids. This study investigates the use of omega-3 fatty acid-enriched lipid emulsions in ARDS patients and their effects on eicosanoid values.

Methods

Prospective, randomized, double-blind, parallel group study carried out at the Intensive Medicine Department of Vall d'Hebron University Hospital (Barcelona-Spain). We studied 16 consecutive patients with ARDS and intolerance to enteral nutrition (14 men; age: 58 ± 13 years; APACHE II score 17.8 ± 2.3; Lung Injury Score: 3.1 ± 0.5; baseline PaO₂/FiO₂ ratio: 149 ± 40). Patients were randomized into two groups: Group A (n = 8) received the study emulsion Lipoplus^® 20%, B. Braun Medical (50% MCT, 40% LCT, 10% fish oil (FO)); Group B (n = 8) received the control emulsion Intralipid^® Fresenius Kabi (100% LCT). Lipid emulsions were administered for 12 h at a dose of 0.12 g/kg/h. We measured LTB₄, TXB₂, and 6-keto prostaglandin F_1α values at baseline [immediately before the administration of the lipid emulsions (T-0)], at the end of the administration (T-12) and 24 hours after the beginning of the infusion (T 24) in arterial and mixed venous blood samples.

Results

In group A (FO) LTB₄, TXB₂, 6-keto prostaglandin F_1α levels fell during omega-3 administration (T12). After discontinuation (T24), levels of inflammatory markers (both systemic and pulmonary) behaved erratically. In group B (LCT) all systemic and pulmonary mediators increased during lipid administration and returned to baseline levels after discontinuation, but the differences did not reach statistical significance. There was a clear interaction between the treatment in group A (fish oil) and changes in LTB₄ over time.

Conclusions

Infusion of lipids enriched with omega-3 fatty acids produces significant short- term changes in eicosanoid values, which may be accompanied by an immunomodulatory effect.

Trial registration

ISRCTN63673813.

Effects on hemodynamics and gas exchange of omega-3 fatty acid-enriched lipid emulsion in acute respiratory distress syndrome (ARDS): a prospective, randomized, double-blind, parallel group study

INTRODUCTION

We investigated the effects on hemodynamics and gas exchange of a lipid emulsion enriched with omega-3 fatty acids in patients with ARDS.

METHODS

The design was a prospective, randomized, double-blind, parallel group study in our Intensive Medicine Department of Vall d'Hebron University Hospital (Barcelona-Spain). We studied 16 consecutive patients with ARDS and intolerance to enteral nutrition (14 men and 2 women; mean age: 58 +/- 13 years; APACHE II score: 17.8 +/- 2.3; Lung Injury Score: 3.1 +/- 0.5; baseline PaO2/FiO2 ratio: 149 +/- 40). Patients were randomized into 2 groups: Group A (n = 8) received the study emulsion Lipoplus 20%, B.Braun Medical (50% MCT, 40% LCT, 10% omega-3); Group B (n = 8) received the control emulsion Intralipid Fresenius Kabi (100% LCT). Lipid emulsions were administered during 12 h at a dose of 0.12 g/kg/h. Measurements of the main hemodynamic and gas exchange parameters were made at baseline (immediately before administration of the lipid emulsions), every hour during the lipid infusion, at the end of administration, and six hours after the end of administration lipid infusion.

RESULTS

No statistically significant changes were observed in the different hemodynamic values analyzed. Likewise, the gas exchange parameters did not show statistically significant differences during the study. No adverse effect attributable to the lipid emulsions was seen in the patients analyzed.

CONCLUSION

The lipid emulsion enriched with omega-3 fatty acids was safe and well tolerated in short-term administration to patients with ARDS. It did not cause any significant changes in hemodynamic and gas exchange parameters.

TRIAL REGISTRATION

ISRCTN63673813.

[Cohort study on incidence of ARDS in patients admitted to the ICU and prognostic factors of mortality]

OBJECTIVE

Analyze acute respiratory distress syndrome (ARDS) in patients admitted to an Intensive Care Medicine Service (ICMS) and prognostic factors of mortality in these patients.

DESIGN

Prospective study of all the patients admitted consecutively in the ICMS from January 1998 to February 2003.

SCOPE

ICMS of a third level university site with 32 beds in its General Area and 10 beds in the Traumatology Area.

PATIENTS

Patients who met the ARDS criteria of the European-North American Consensus Conference at any time during admission in ICMS. ENDPOINTS OF INTEREST: Mortality at 28 days.

RESULTS

One hundred and ninety-one patients (3.4 of all the admissions in ICMS) had ARDS criteria. The origin of ARDS was intrapulmonary in 63%. A total of 77% of the patients had multiorgan dysfunction and 26% respiratory superinfection. Median stay in the ICMS was 20 days. Mortality at 28 days was 48% and hospital mortality 58%. Multivariant analysis showed that the variables associated independently with an increase in mortality were the following: APACHE II > 22 (odds ratio [OR] 2.7; 95% CI: 1.3-5.8; p = 0.007), minimum PaO2/FIO2 during evolution of ARDS < 81 mmHg (odds ratio 5.5; 95% CI: 2.6-11.9; p < 0.0001), dysfunction > or = 3 organs (odds ratio 11.8; 95% CI: 2.5-55.4; p = 0.002).

CONCLUSIONS

ARDS is an entity with elevated mortality whose prognosis is associated not only with the seriousness of pulmonary function deterioration but also of systemic function, on which some treatment could modulate its evolution.

[The prognostic value of eicosanoids in the acute respiratory distress syndrome]

BACKGROUND

There is a great number of agents involved in the acute respiratory distress syndrome (ARDS) physiopathology, and some of them may have a prognostic value. The objective of the present study has been to analyse the prognostic value of eicosanoids in this syndrome.

MATERIAL AND METHOD

A prospective study with 21 consecutive ARDS patients admitted to the intensive care unit of a therapy hospital in Barcelona, Spain, was carried out. In the first 48 h of the ARDS diagnosis, at baseline, the plasma levels, (in peripheral arterial and pulmonary arterial samples) of thromboxane B2 (TXB2), prostaglandin F1-alpha) (PGF1-alpha) and leukotriene B4 (LTB4) were analysed by RIA. Simultaneously we measured different pulmonary and systemic hemodynamical variables, as well as the pulmonary gas exchange data. We also studied the venous levels of the same eicosanoids in 17 healthy adults, used as reference.

RESULTS

Plasma levels of eicosanoids in the ARDS patients were higher than reference subjects (p < 0.05). No differences were observed between systemic arterial and pulmonary arterial values. From all the eicosanoids, only LTB4, (in both systemic arterial and pulmonary blood), was correlated with LIS (r = 0.49, p < 0.05; and r = 0.45, p < 0.05, respectively). Patients who did not survive presented a lower systemic-pulmonary arterial gradient of eicosanoids levels than survivors (-1.27 vs -0.10 ng/ml; p < 0.01).

CONCLUSIONS

In our ARDS patients only LTB4 plasma levels correlated with the severity of respiratory failure. Patients who did not survive presented a lower LTB4 gradient than survivors.

Gas exchange and pulmonary haemodynamic responses to fat emulsions in acute respiratory distress syndrome

OBJECTIVE

To investigate the gas exchange and pulmonary haemodynamic responses to two different intravenous fat emulsions in patients with acute respiratory distress syndrome (ARDS).

DESIGN

Prospective, randomized, double-blind, placebo-controlled study.

SETTING

Intensive care unit in a university-affiliated hospital.

PATIENTS

21 patients with ARDS [mean age, 57 +/- 3 (SEM) years; Acute Physiology and Chronic Health Evaluation II, 20 +/- 3; Murray's score, 2.85 +/- 0.12] consecutively admitted.

INTERVENTIONS

Patients were assigned to three groups (n = 7 each): group A (LCT) received long-chain triglycerides (20% LCT), group B (MCT/LCT), medium-chain triglycerides/long-chain triglycerides (20% MCT/LCT: 50/50) and group C placebo (0.9% sodium chloride, NaCl). The infusion was always given at the rate of 2 mg/kg min over a total period of 12 h, with a volume infusion of 500 ml in each group.

MEASUREMENTS

Data were collected before, immediately after and 12 h after infusion ceased. Pulmonary and systemic haemodynamic and gas exchange variables were measured at each time point. Serum triglyceride cholesterol, and non-esterified fatty acids levels were measured.

RESULTS

During LCT infusion, cardiac output, oxygen consumption and oxygen delivery increased (all p < 0.05), whereas pulmonary haemodynamics, arterial oxygen tension, mixed venous partial pressure of oxygen and venous admixture ratio remained essentially unaltered. No changes were observed following MCT/LCT infusion.

CONCLUSIONS

The administration of LCT emulsion given at a slow rate did not alter arterial oxygenation because of the beneficial effect of a high cardiac output, hence offsetting the detrimental effect of increased O2 consumption.

Anticoagulative effect of nitric oxide inhalation in ARDS

Some studies have suggested that nitric oxide (NO) may cause platelet dysfunction. We present an ARDS patient who need this treatment, with a transient alteration of platelet function and a significant prolongation of bleeding time.

Effects of F(I)O2 on leg VO2 during cycle ergometry in sedentary subjects

In a recent study of completely sedentary normal young subjects, leg VO2max was reduced by hypoxia in proportion to mean capillary PO2 as F(I)O2 was reduced from 0.15 to 0.12. However, the increase in VO2max from F(I)O2 = 0.15 to 0.21 was less than expected for the increase in mean capillary PO2. This finding has led us to hypothesize that in sedentary subjects breathing room air, VO2max is not limited by O2 supply but rather by oxidative capacity of mitochondria. The present study sought to obtain further evidence for or against this hypothesis in sedentary subjects by assessing leg VO2max (VO2leg) breathing 100% O2, as well as in normoxia and hypoxia. Data from 18 subjects studied at F(I)O2 = 0.12, 0.15, and 0.21 and from six more studied at 0.12, 0.15, and 1.00 were analyzed. In all 24 we measured VO2leg by arterial and venous blood sampling and thermodilution leg blood flow during maximal cycle ergometry at each F(I)O2. VO2leg was not increased by room air or 100% O2 breathing relative to that observed at F(I)O2 = 0.15, but it was reduced while breathing 12% O2. The data at F(I)O2 = 0.12 and 0.15 conformed to the predictions of O2 supply limitation of maximal VO2 as previously. These results confirm and extend our prior observations that in sedentary, as opposed to trained subjects, muscle VO2max is O2 supply limited only in hypoxia.

Effect of inverse I:E ratio ventilation on pulmonary gas exchange in acute respiratory distress syndrome

BACKGROUND

It is not known whether inverse I:E ratio ventilation (IRV) offers any real benefit over conventional mechanical ventilation with positive end-expiratory pressure (CMV-PEEP) at similar levels of end-expiratory pressure.

METHODS

The effects of volume-controlled and pressure-controlled IRV (VC-IRV and PC-IRV, respectively) on VA/Q inequality were compared with those of CMV-PEEP at a similar level of end-expiratory pressure and with CMV without PEEP (CMV) in eight patients in the early stages of acute respiratory distress syndrome (ARDS). Respiratory blood gases, inert gases, lung mechanics, and hemodynamics were measured 30 min after the onset of each ventilatory mode.

RESULTS

Recruitment of nonventilated, poorly ventilated (or both) but well-perfused alveoli increased the partial pressure of oxygen (PaO2) during CMV-PEEP (+13 mmHg) and IRV-VC (+10 mmHg; P < 0.05) compared with CMV. In contrast, PC-IRV did not affect PaO2 but caused a decrease in PaCO2 (-7 mmHg; P < 0.05). The latter was due to a concomitant decrease in dead space (P < 0.01) and shift to the right of VA/Q distributions. During PC-IRV, the increase in the mean of blood flow distribution (mean Q; P < 0.01) without a change in the dispersion (log SD Q) did not result in an increase in PaO2, probably because it reflected redistribution of blood flow within well-ventilated areas.

CONCLUSIONS

Short-term PC-IRV improved carbon dioxide clearance, but the lung became less efficient as an oxygen exchanger. Furthermore, based on mean airway and plateau pressures, the risk of barotrauma was not reduced with this type of ventilation.

Severe acute pancreatitis: treatment with somatostatin

OBJECTIVE

To investigate the efficacy of somatostatin for the treatment of severe acute pancreatitis.

DESIGN

Prospective, randomized and unblinded study.

SETTING

A general intensive care unit (ICU) in a university hospital.

PATIENTS

50 patients with severe acute pancreatitis.

INTERVENTIONS

All patients received the conventional treatment for this clinical condition. The study group received, in addition, somatostatin over a 10-day period.

MEASUREMENTS AND RESULTS

We evaluated age, gender, etiology of the pancreatitis, severity of the illness, complications, length of hospitalization, and mortality in the ICU. The patients were classified as severe (Acute Physiology and Chronic Health Evaluation II score, Ranson's criteria, and computed tomography Balthazar classification). Biliary lithiasis was the most common etiologic factor (63.6% in the control group, 37.5% in study group; NS). The study group required fewer overall surgical interventions than the control group (45.8 vs 86.4%; p = 0.005). Late surgical procedures related to the evolution of pancreatic necrosis were more common in the controls (63.6 vs 37.5%; p = 0.07). No differences in length of stay in hospital or mortality in the ICU were observed.

CONCLUSION

The only advantage of somatostatin administration in the patients studied was a slight reduction in the need for surgery due to local complications.

Neurological disturbances and hyperdynamic shock in a patient with esophagocoloplasty

A 39-year-old man, with no history of alcohol intake, who had had an esophago-ileo-colo-gastroplasty with ileotransversostomy, developed diplopia, seizures, metabolic acidosis, and cardiac failure and finally refractory hyperdynamic shock. He died 20 h after admission to our intensive care unit from cardiocirculatory collapse. Postmortem results revealed low erythrocyte transketolase activity, which was increased by 22% by in vitro addition of thiamine diphosphate (TDP effect). Cerebral pathology showed the alterations of Wernicke's encephalopathy. We discuss the possible mechanisms of fatal cardiovascular collapse and the unusual presentation of a case without a history of alcoholic intake or clinical malnutrition.

Eicosanoids and fat emulsions in acute respiratory distress syndrome patients

Lipid emulsions have been associated with changes in pulmonary function. Although these changes were related to the physical effects of the infusion-induced lipemia on gas exchange, several animal and human studies suggest that the impairment in pulmonary function observed with lipid infusions was mediated by prostaglandins. Prostaglandins are synthesized enzymatically from essential fatty acids. We studied the effects of two lipid emulsions, with different amounts of essential fatty acids (20% long-chain triacylglycerols [LCT] with 55% of linoleic acid and 7% of alpha linolenic acid in 100 g of emulsion, and a physical mixture of 20% medium-chain triacyglycerols [MCT] and LCT with 26% of linoleic acid and 4% of alpha linolenic acid in 100 g of emulsion), on plasma levels of eicosanoids in patients with acute respiratory distress syndrome (ARDS). Although in patients with ARDS, plasma levels of prostanoids were higher than the reference values, neither lipid emulsion, administered at the rate of 2 mg.kg-1.min-1 induced significant changes in the eicosanoids except for a decrease in systemic-pulmonary arterial 6-keto prostaglandin F1 alpha difference.

Salbutamol reduces pulmonary neutrophil sequestration of platelet-activating factor in humans

To investigate whether salbutamol inhibits platelet-activating factor (PAF)-induced neutrophil sequestration in the lungs, we studied eight nonatopic, nonsmoking, healthy subjects (six men; aged 27.0 +/- 1.5 (SE) yr) with PAF-induced bronchial response. Prior to PAF challenge (24 micrograms), they inhaled either salbutamol (300 micrograms) or placebo in a randomized, double-blind, crossover manner two weeks apart. Respiratory system resistance (Rrs), arterial blood gases, and neutrophil counts were measured 4, 8, 12 and 30 min after PAF. Neutrophil kinetics in the lungs were assessed by tracking autologous 99mTc-erythrocytes and 111in-neutrophils. Compared with salbutamol, arterial blood neutrophil counts fell (p < 0.04) maximally at 4 min after PAF, followed by a mild rebound neutrophilia, whereas Rrs increased (p < 0.01) and Pao2 decreased (p < 0.05) at 4 min only. The intrapulmonary activity of 111in-neutrophils after pretreatment with placebo was higher compared with salbutamol (1.98 +/- 0.15 versus 1.33 +/- 0.23 cps/mCi/pixel) (p < 0.01) although both their initial sequestration (first-pass) and subsequent washout were not significantly different. Inhaled salbutamol blocks pulmonary neutrophil sequestration and lung function abnormalities following PAF challenge in humans.

[Lipid emulsions and pulmonary function]

A review is made of possible adverse effects of lipid emulsions on the respiratory function, based on the use and acceptance thereof as part of the non-protein caloric supply of the total parenteral nutrition of critical patients from the first hypotheses of the role played by the subsequent lipemia, to the most recent which lend great importance to the eicosanoids generated by the fatty acids supplied by the lipid emulsions. It is also verified whether the observed effects are similar both in healthy as well as in damaged lungs. Another variable to keep in mind, is the rate of administration of the lipid emulsions, which, related to the clearance thereof, could have different actions. Finally, and due to the fatty acid pattern of the lipid emulsion being different than that of the chylomicron, it is evaluated whether the actions of these emulsions may vary as a function of the quantity and quality of the fatty acids supplied.