Hélène Prodanovic

Diaphragm Dysfunction on Admission to the Intensive Care Unit. Prevalence, Risk Factors, and Prognostic Impact—A Prospective Study

RATIONALE Diaphragmatic insults occurring during intensive care unit (ICU) stays have become the focus of intense research. However, diaphragmatic abnormalities at the initial phase of critical illness remain poorly documented in humans. OBJECTIVES To determine the incidence, risk factors, and prognostic impact of diaphragmatic impairment on ICU admission. METHODS Prospective, 6-month, observational cohort study in two ICUs. Mechanically ventilated patients were studied within 24 hours after intubation (Day 1) and 48 hours later (Day 3). Seventeen anesthetized intubated control anesthesia patients were also studied. The diaphragm was assessed by twitch tracheal pressure in response to bilateral anterior magnetic phrenic nerve stimulation (Ptr,stim). MEASUREMENTS AND MAIN RESULTS Eighty-five consecutive patients aged 62 (54-75) (median [interquartile range]) were evaluated (medical admission, 79%; Simplified Acute Physiology Score II, 54 [44-68]). On Day 1, Ptr,stim was 8.2 (5.9-12.3) cm H2O and 64% of patients had Ptr,stim less than 11 cm H2O. Independent predictors of low Ptr,stim were sepsis (linear regression coefficient, -3.74; standard error, 1.16; P = 0.002) and Simplified Acute Physiology Score II (linear regression coefficient, -0.07; standard error, 1.69; P = 0.03). Compared with nonsurvivors, ICU survivors had higher Ptr,stim (9.7 [6.3-13.8] vs. 7.3 [5.5-9.7] cm H2O; P = 0.004). This was also true for hospital survivors versus nonsurvivors (9.7 [6.3-13.5] vs. 7.8 [5.5-10.1] cm H2O; P = 0.004). Day 1 and Day 3 Ptr,stim were similar. CONCLUSIONS A reduced capacity of the diaphragm to produce inspiratory pressure (diaphragm dysfunction) is frequent on ICU admission. It is associated with sepsis and disease severity, suggesting that it may represent another form of organ failure. It is associated with a poor prognosis. Clinical trial registered with www.clinicaltrials.gov (NCT 00786526).

Invasive pulmonary aspergillosis in patients with decompensated cirrhosis: case series

BackgroundOpportunistic invasive fungal infections are increasingly frequent in intensive care patients. Their clinical spectrum goes beyond the patients with malignancies, and for example invasive pulmonary aspergillosis has recently been described in critically ill patients without such condition. Liver failure has been suspected to be a risk factor for aspergillosis.Case presentationWe describe three cases of adult respiratory distress syndrome with sepsis, shock and multiple organ failure in patients with severe liver failure among whom two had positive Aspergillus antigenemia and one had a positive Aspergillus serology. In all cases bronchoalveolar lavage fluid was positive for Aspergillus fumigatus. Outcome was fatal in all cases despite treatment with voriconazole and agressive symptomatic treatment.ConclusionInvasive aspergillosis should be among rapidly raised hypothesis in cirrhotic patients developing acute respiratory symptoms and alveolar opacities.

Identification of prolonged phrenic nerve conduction time in the ICU: magnetic versus electrical stimulation

PurposeRetrospective study of prospectively collected data to assess the reliability of cervical magnetic stimulation (CMS) to detect prolonged phrenic nerve (PN) conduction time at the bedside. Because PN injuries may cause diaphragm dysfunction, their diagnosis is relevant in intensive care units (ICU). This is achieved by studying latency and amplitude of diaphragm response to PN stimulation. Electrical stimulation (ES) is the gold standard, but it is difficult to perform in the ICU. CMS is an easy noninvasive tool to assess PN integrity, but co-activates muscles that could contaminate surface chest electromyographic recordings.MethodsIn a first set of 56 ICU patients with suspected PN injury, presence and latency of compound motor action potentials elicited by CMS and ES were compared. With ES as the reference method, CMS was evaluated as a test designed to indicate presence or absence of PN injury. In eight additional patients, intramuscular diaphragm recordings were compared with surface diaphragm recordings and with the electromyograms of possible contamination sources.ResultsThe sensitivity of CMS to diagnose abnormal PN conduction was 0.91, and specificity was 0.84, whereas positive and negative predictive values were 0.81 and 0.92, respectively. Passing–Bablok regression analysis suggested no differences between the two measures. The correlation between PN latency in response to CMS and ES was significant. The “diaphragm surface” and “needle” latencies were close, and were significantly different from those of possibly contaminating muscles. One hemidiaphragm showed likely signal contamination.ConclusionCMS provides an easy reliable tool to detect prolonged PN conduction time in the ICU.

Six-Month Outcome of Immunocompromised Patients with Severe Acute Respiratory Distress Syndrome Rescued by Extracorporeal Membrane Oxygenation. An International Multicenter Retrospective Study

OBJECTIVES To report outcomes of immunocompromised patients treated with extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) and to identify their pre-ECMO predictors of 6-month mortality and main ECMO-related complications. METHODS Retrospective multicenter study in 10 international intensive care units (ICUs) with high ECMO-case volumes. Immunocompromised patients, defined as having hematological malignancies, active solid tumor, solid-organ transplant, acquired immunodeficiency syndrome, or long-term or high-dose corticosteroid or immunosuppressant use, and severe ECMO-treated ARDS from 2008 to 2015 were included Measurements and Main Results: We collected demographics, clinical, ECMO-related complications, ICU- and 6-month-outcome data for 203 patients (median APACHE II 28 [25th ;75th percentile, 20;33]; age 51 [38;59] years, PaO2/FiO2 60 [50;82] mmHg before ECMO) who fulfilled our inclusion criteria. Six-month survival was only 30%, with a respective median ECMO duration and ICU stay of 8 [5;14] and 25 [16;50] days. Patients with hematological malignancies had significantly poorer outcomes than others (log-rank P=0.02). Multivariate analyses retained <30 days between immunodeficiency diagnosis and ECMO cannulation as being associated with lower 6-month mortality (odds ratio 0.32 (95% confidence interval 0.16-0.66); P=0.002), and lower platelet count, higher PCO2, age and driving pressure as independent pre-ECMO predictors of 6-month mortality. CONCLUSION Recently diagnosed immunodeficiency is associated with a much better prognosis in ECMO-treated severe ARDS. However, low 6-month survival of our large cohort of immunocompromised patients supports restricting ECMO to patients with realistic oncological/therapeutic prognoses, acceptable functional status and few pre-ECMO mortality-risk factors.Rationale: Because encouraging rates for hospital and long‐term survival of immunocompromised patients in ICUs have been described, these patients are more likely to receive invasive therapies, like extracorporeal membrane oxygenation (ECMO). Objectives: To report outcomes of immunocompromised patients treated with ECMO for severe acute respiratory distress syndrome (ARDS) and to identify their pre‐ECMO predictors of 6‐month mortality and main ECMO‐related complications. Methods: Retrospective multicenter study in 10 international ICUs with high volumes of ECMO cases. Immunocompromised patients, defined as having hematological malignancies, active solid tumor, solid‐organ transplant, acquired immunodeficiency syndrome, or long‐term or high‐dose corticosteroid or immunosuppressant use, and severe ECMO‐treated ARDS, from 2008 to 2015 were included. Measurements and Main Results: We collected demographics, clinical data, ECMO‐related complications, and ICU‐ and 6 month‐outcome data for 203 patients (median Acute Physiology and Chronic Health Evaluation II score, 28 [25th‐75th percentile, 20‐33]; age, 51 [38‐59] yr; PaO2/FiO2, 60 [50‐82] mm Hg before ECMO) who fulfilled our inclusion criteria. Six‐month survival was only 30%, with a respective median ECMO duration and ICU stay of 8 (5‐14) and 25 (16‐50) days. Patients with hematological malignancies had significantly poorer outcomes than others (log‐rank P = 0.02). ECMO‐related major bleeding, cannula infection, and ventilator‐associated pneumonia were frequent (36%, 10%, and 50%, respectively). Multivariate analyses retained fewer than 30 days between immunodeficiency diagnosis and ECMO cannulation as being associated with lower 6‐month mortality (odds ratio, 0.32 [95% confidence interval, 0.16‐0.66]; P = 0.002), and lower platelet count, higher Pco2, age, and driving pressure as independent pre‐ECMO predictors of 6‐month mortality. Conclusions: Recently diagnosed immunodeficiency is associated with a much better prognosis in ECMO‐treated severe ARDS. However, low 6‐month survival of our large cohort of immunocompromised patients supports restricting ECMO to patients with realistic oncological/therapeutic prognoses, acceptable functional status, and few pre‐ECMO mortality‐risk factors.

Exploration du diaphragme en réanimation

The diaphragm is the main agonist of normal inspiration. To ensure an alveolar ventilation adequately balancing the production of carbon dioxyde, the diaphragm must be able to overcome the impedance of the respiratory system and must have an adequate endurance. If this is not the case, hypercapnic respiratory failure can occur. Studying diaphragm function in critically ill patients implies a careful clinical examination of the thoraco-abdominal movements during tidal breathing. Spirometry, inspiratory pressures (static and dynamic – “sniff test”) and blood gases must be measured. Phrenic nerve stimulation quantifies diaphragmatic dysfunction and is helpful to understand its mechanisms. Transcranial magnetic stimulation can ascertain the central origin of such abnormality. A careful description of diaphragm function can be useful in diseases impairing the neuromuscular function of the respiratory system, to investigate the mechanisms of difficult weaning from the ventilator or to assess the respiratory repercussions of ICU acquired polyneuropathies. Modern techniques for phrenic stimulation, both non-invasive and easy to apply, should in the future promote diaphragm studies in the clinical setting, in these indications.

Ultrasonographically diagnosed diaphragmatic dysfunction and weaning failure from mechanical ventilation in critically ill patients.

Clinical data suggest that diaphragmatic dysfunction (DD) is associated with difficult weaning from mechanical ventilation. However, studies focusing specifically on diaphragmatic function in this setting are scarce. OBJECTIVE To predict the outcome of a spontaneous breathing trial (SBT) through the ultrasonographic assessment of diaphragmatic and intercostal muscle function.

Reliability of diaphragmatic ultrasonography to detect diaphragm dysfunction in critically ill patients

The gold standard to diagnose diaphragmatic dysfunction (DD) is the measurement of the intra-thoracic depression is response to a bilateral stimulation of the phrenic nerves (Ptr,stim). This technique is costly, requires expertise and is not widely available at the bedside. On the opposite, ultrasonography is easy to perform but has not been compared.