Bouchra Lamia

Predicting volume responsiveness by using the end-expiratory occlusion in mechanically ventilated intensive care unit patients

Objective:During mechanical ventilation, inspiration cyclically decreases the left cardiac preload. Thus, an end-expiratory occlusion may prevent the cyclic impediment in left cardiac preload and may act like a fluid challenge. We tested whether this could serve as a functional test for fluid responsiveness in patients with circulatory failure. Design:Prospective study. Setting:Medical intensive care unit. Patients:Thirty-four mechanically ventilated patients with shock in whom volume expansion was planned. Intervention:A 15-second end-expiratory occlusion followed by a 500 mL saline infusion. Measurements:Arterial pressure and pulse contour-derived cardiac index (PiCCOplus) at baseline, during passive leg raising (PLR), during the 5-last seconds of the end-expiratory occlusion, and after volume expansion. Main Results:Volume expansion increased cardiac index by >15% (2.4 ± 1.0 to 3.3 ± 1.2 L/min/m2, p < 0.05) in 23 patients (“responders”). Before volume expansion, the end-expiratory occlusion significantly increased arterial pulse pressure by 15% ± 15% and cardiac index by 12% ± 11% in responders whereas arterial pulse pressure and cardiac index did not change significantly in nonresponders. Fluid responsiveness was predicted by an increase in pulse pressure ≥5% during the end-expiratory occlusion with a sensitivity and a specificity of 87% and 100%, respectively, and by an increase in cardiac index ≥5% during the end-expiratory occlusion with a sensitivity and a specificity of 91% and 100%, respectively. The response of pulse pressure and cardiac index to the end-expiratory occlusion predicted fluid responsiveness with an accuracy that was similar to the response of cardiac index to PLR and that was significantly better than the response of pulse pressure to PLR (receiver operating characteristic curves area 0.957 [95% confidence interval {CI:} 0.825–0.994], 0.972 [95% CI: 0.849–0.995], 0.937 [95% CI: 0.797–0.990], and 0.675 [95% CI: 0.497–0.829], respectively). Conclusions:The hemodynamic response to an end-expiratory occlusion can predict volume responsiveness in mechanically ventilated patients.

Echocardiographic diagnosis of pulmonary artery occlusion pressure elevation during weaning from mechanical ventilation

Objective:Weaning-induced pulmonary edema is a cause of weaning failure in high-risk patients. The diagnosis may require pulmonary artery catheterization to demonstrate increased pulmonary artery occlusion pressure (PAOP) during weaning. Transthoracic echocardiography can estimate left ventricular filling pressures using early (E) and late (A) peak diastolic velocities measured with Doppler transmitral flow, and tissue Doppler imaging of mitral annulus velocities including early (Ea) peak diastolic velocity. We tested the hypothesis that E/A and E/Ea could be used to detect weaning-induced PAOP elevation defined by a PAOP ≥18 mm Hg during a spontaneous breathing trial (SBT). Measurements and Main Results:We included 39 patients who previously failed two consecutive SBTs. A third SBT was performed over a maximum 1-hour period using a T-piece. The PAOP, E/A, and E/Ea were measured before and during this SBT. Receiver operating characteristic curves were constructed to determine the optimal sensitivity and specificity values of E/A and E/Ea obtained at the end of the SBT for predicting a weaning-induced PAOP elevation. Weaning-induced PAOP elevation occurred in 17 patients. A value of E/A >0.95 at the end of the SBT predicted weaning-induced PAOP elevation with a sensitivity of 88% and a specificity of 68%. A value of E/Ea >8.5 at the end of the SBT predicted weaning-induced PAOP elevation with a sensitivity of 94% and a specificity of 73%. The combination of E/A >0.95 and E/Ea >8.5 predicted a weaning-induced PAOP elevation with a sensitivity of 82% and a specificity of 91%. Conclusion:At the end of an SBT, the combination of E/A >0.95 and E/Ea >8.5 measured with transthoracic echocardiography allowed an accurate noninvasive detection of weaning-induced PAOP elevation.

Clinical review: Interpretation of arterial pressure wave in shock states

In critically ill patients monitored with an arterial catheter, the arterial pressure signal provides two types of information that may help the clinician to interpret haemodynamic status better: the mean values of systolic, diastolic, mean and pulse pressures; and the magnitude of the respiratory variation in arterial pressure in patients undergoing mechanical ventilation. In this review we briefly discuss the physiological mechanisms responsible for arterial pressure generation, with special focus on resistance, compliance and pulse wave amplification phenomena. We also emphasize the utility of taking into consideration the overall arterial pressure set (systolic, diastolic, mean and pulse pressures) in order to define haemodynamic status better. Finally, we review recent studies showing that quantification of respiratory variation in pulse and systolic arterial pressures can allow one to identify the mechanically ventilated patients who may benefit from volume resuscitation.

Pulse oximeter as a sensor of fluid responsiveness: do we have our finger on the best solution?

The pulse oximetry plethysmographic signal resembles the peripheral arterial pressure waveform, and the degree of respiratory variation in the pulse oximetry wave is close to the degree of respiratory arterial pulse pressure variation. Thus, it is tempting to speculate that pulse oximetry can be used to assess preload responsiveness in mechanically ventilated patients. In this commentary we briefly review the complex meaning of the pulse oximetry plethysmographic signal and highlight the advantages, limitations and pitfalls of the pulse oximetry method. Future studies including volume challenge must be performed to test whether the pulse oximetry waveform can really serve as a nonivasive tool for the guidance of fluid therapy in patients receiving mechanical ventilation in intensive care units and in operating rooms.

Traduction française et adaptation culturelle du questionnaire SRI. Questionnaire de qualité de vie liée à la santé des patients insuffisants respiratoires chroniques traités par ventilation à domicile

INTRODUCTION We performed the French translation and cross-cultural adaptation of the Severe Respiratory Insufficiency (SRI) questionnaire. Written and validated in German, this questionnaire evaluates health-related quality of life in patients treated with domiciliary ventilation for chronic respiratory failure. METHODS Four bilingual German-French translators and a linguist were recruited to produce translations and back-translations of the questionnaire constituted of 49 items in seven domains. Two successive versions were generated and compared to the original questionnaire. The difficulty of the translation and the naturalness were quantified for each item using a 1-10 scale and their equivalence to their original counterpart was graded from A to C. The translated questionnaire was finally tested in a pilot study, which included 15 representative patients. RESULTS The difficulty of the first translation and the first back-translation was respectively quantified as 2.5 (range 1-5.5) and 1.5 (range 1-6) on the 10-point scale (P=0.0014). The naturalness and the equivalence of 8/49 items were considered as insufficient, which led to the production of a second translation and a second back-translation. The meanings of two items needed clarification during the pilot study. CONCLUSION The French translation of the SRI questionnaire represents a new instrument for clinical research in patients treated with domiciliary ventilation for chronic respiratory failure. Its validity needs to be tested in a multicenter study.

Article originalTraduction française et adaptation culturelle du questionnaire SRI. Questionnaire de qualité de vie liée à la santé des patients insuffisants respiratoires chroniques traités par ventilation à domicileThe French translation and cultural adaptation of the SRI questionnaire. A questionnaire to assess health-related quality of life in patients with chronic respiratory failure and domiciliary ventilation☆

INTRODUCTION We performed the French translation and cross-cultural adaptation of the Severe Respiratory Insufficiency (SRI) questionnaire. Written and validated in German, this questionnaire evaluates health-related quality of life in patients treated with domiciliary ventilation for chronic respiratory failure. METHODS Four bilingual German-French translators and a linguist were recruited to produce translations and back-translations of the questionnaire constituted of 49 items in seven domains. Two successive versions were generated and compared to the original questionnaire. The difficulty of the translation and the naturalness were quantified for each item using a 1-10 scale and their equivalence to their original counterpart was graded from A to C. The translated questionnaire was finally tested in a pilot study, which included 15 representative patients. RESULTS The difficulty of the first translation and the first back-translation was respectively quantified as 2.5 (range 1-5.5) and 1.5 (range 1-6) on the 10-point scale (P=0.0014). The naturalness and the equivalence of 8/49 items were considered as insufficient, which led to the production of a second translation and a second back-translation. The meanings of two items needed clarification during the pilot study. CONCLUSION The French translation of the SRI questionnaire represents a new instrument for clinical research in patients treated with domiciliary ventilation for chronic respiratory failure. Its validity needs to be tested in a multicenter study.

A Randomized Controlled Trial on the Effect of Needle Gauge on the Pain and Anxiety Experienced during Radial Arterial Puncture

Background Arterial punctures for assessment of arterial blood-gases can be a painful procedure. Lidocaine can be used to reduce pain prior to needle insertion but it is not a widely accepted practice. The purpose of this study was to determine whether a large size needle induces more pain compared to a smaller size needle for radial arterial puncture and to assess the anxiety associated with radial arterial punctures. Methods We conducted a prospective, double-blind, randomized, controlled, monocentric study including all outpatients who had a planned assessment of arterial blood gas analysis. Patients were randomized to have the arterial puncture performed with a 23 or a 25 G needle. The main judgement criteria was pain during arterial puncture. Visual analogue scale for pain (VAS-P) and visual analogue scale for anxiety (VAS-A) were used to assess pain and anxiety during radial arterial puncture. Results Two hundred consecutive patients were randomized. The 25 G needle was as painful as the 23 G needle (6.63 mm [0–19 mm] vs. 5.21 mm [0–18.49 mm], respectively, p = 0.527). Time for arterial puncture was longer with the 25 G needle than with the 23 G needle (42 s [35–55 s] vs. 33 s [24.5–35 s], respectively, p = 0.002). There was a correlation between the level of anxiety prior to the arterial puncture and the pain experienced by the patients (p: 0.369, p<0.0001). There was a correlation between the pain experienced by patients and the anxiety experienced in anticipation of another arterial puncture (p: 0.5124, p<0.0001). Conclusions The use of 23 G needle allows quicker arterial sampling and is not associated with increased pain and symptoms. Anxiety was correlated with the pain experienced by patients during arterial punctures. Trial Registration Clinicaltrials.gov: NCT02320916

Respiratory Failure in the Elderly Patient

Respiratory failure frequently complicates the care of elderly patients with or without chronic lung disease. Recent advances in techniques and applications of noninvasive ventilation provide an exceedingly useful means of managing respiratory compromise, and the clinical utilization of noninvasive mechanical ventilation has transformed the prognosis of acute and chronic respiratory failure in this age group. The majority of elderly patients can recover from an acute respiratory failure episode if adequate support is provided, although some may require long-term ventilatory assistance. Such assistance may be provided in the home setting if an adequate support system is available. As the size of the elderly population grows, an increased number of elderly patients with multifactorial respiratory failure will undoubtedly require episodic or sustained ventilatory assistance, and noninvasive ventilation can be provided for various forms of acute and chronic respiratory failure, including advanced chronic obstructive pulmonary disease, other parenchymal lung disease, and chest wall deformities. Health care organizations must incorporate long-term care facilities with ventilatory support capabilities into their health management strategies.

Comparison of oxygen uptake during cycle ergometry with and without functional electrical stimulation in patients with COPD: protocol for a randomised, single-blind, placebo-controlled, cross-over trial

Introduction Chronic obstructive pulmonary disease (COPD) has systemic repercussions that can lead to peripheral muscle dysfunction. Muscle atrophy reduces aerobic capacity, greatly limiting activities of daily living and quality of life. Pulmonary rehabilitation is the gold standard treatment for these patients, however, patients may not be able to reach sufficient training intensities for benefits to occur. Technologies such as functional electrical stimulation (FES) are currently being adapted and tested to enhance exercise training. We hypothesise that FES coupled with cycling (FES-cycling) will improve maximal uptake of oxygen (VO2) and aerobic capacity more than endurance training with placebo stimulation. Methods A randomised, single-blind, placebo-controlled crossover trial will be carried out to evaluate the effects of FES-cycling on VO2 during endurance exercise on a cycle ergometer in patients with COPD. 25 patients with COPD will carry out two 30 min sessions at a constant load; one session with active and one with placebo FES. The primary outcome is oxygen uptake recorded with a metabolic measurement system. Secondary outcomes include ventilation equivalent for oxygen, ventilation equivalent for carbon dioxide, cardiac output, lactate values, perceived dyspnoea and perceived muscle fatigue. Results and conclusions Approval has been granted by our Institutional Review Board (Comité de Protection des Personnes Nord-Ouest 3). The results of the trial will be presented at national and international meetings and published in peer-reviewed journals. Trial registration number NCT02594722.

Place de la trachéotomie au long cours dans l’insuffisance respiratoire chronique sévère à l’ère de la ventilation non invasive

INTRODUCTION At a time when non-invasive ventilation (NIV) is commonly used in acute as well as chronic respiratory failure, it is important to consider the current place, if any, of long-term tracheostomy. BACKGROUND Except in emergency situations where tracheostomy is mandatory to ensure safe access to the airway, long-term ventilation with tracheostomy (LTVT) is generally considered in the case of inability to wean from NIV after an episode of acute respiratory failure requiring endotracheal ventilation or because of the development of bulbar signs (swallowing, phonation) in advanced neuromuscular disease. It is also appropriate when ventilatory dependence on NIV exceeds 20 hours per day. Historical retrospective studies confirmed the feasibility of LTVT, but this has to be seen in perspective with the results obtained 20 years later with NIV. VIEWPOINT AND CONCLUSION Even if the indications for LTVT have diminished considerably since the emergence of NIV, tracheostomy remains mandatory in some situations of respiratory distress and it should be considered as a potential resource, possibly temporary in some cases in the light of recent work on the possibility of decanulation after LTVT.