Pierre Etienne Leblanc

Effect of Rbc Transfusion on Sublingual Microcirculation in Hemorrhagic Shock Patients: A Pilot Study

Objectives: The effects of RBC transfusion on microvascular perfusion are not well documented. We investigated the effect of RBC transfusion on sublingual microcirculation in hemorrhagic shock patients. Design: Prospective, preliminary observational study. Settings: A 28-bed, surgical ICU in a university hospital. Patients: Fifteen hemorrhagic shock patients requiring RBC transfusion. Intervention: Transfusion of one unit of RBCs. Measurements and Main Results: The sublingual microcirculation was assessed with a Sidestream Dark Field imaging device before and after RBC transfusion. After transfusion of one unit of RBC, hemoglobin concentration increased from 8.5 g/dL (7.6–9.5 g/dL) to 9.6 g/dL (9.1–10.3 g/dL) g/dL (p = 0.02) but no effect on macrocirculatory parameters (arterial pressure, cardiac index, heart rate, and pulse pressure variations) was observed. Transfusion of RBC significantly increased microcirculatory flow index (from 2.3 [1.6–2.5] to 2.7 [2.6–2.9]; p < 0.003), the proportion of perfused vessels (from 79% [57–88%] to 92% [88–97%]; p < 0.004), and the functional capillary density (from 21 [19–22] to 24 [22–26] mm/mm2; p = 0.003). Transfusion of RBC significantly decreased the flow heterogeneity index (from 0.51 [0.34–0.62] to 0.16 [0.04–0.29]; p < 0.001). No correlations were observed between other macrovascular parameters and microvascular changes after transfusion. The change in microvascular perfusion after transfusion correlated negatively with baseline microvascular perfusion. Conclusions: RBC transfusion improves sublingual microcirculation independently of macrocirculation and the hemoglobin level in hemorrhagic shock patients. The change in microvascular perfusion after transfusion correlated negatively with baseline microvascular perfusion. Evaluation of microcirculation perfusion is critical for optimization of microvascular perfusion and to define which patients can benefit from RBC transfusion during cardiovascular resuscitation.

Mid-regional pro-adrenomedullin (MR-proADM), a marker of positive fluid balance in critically ill patients: results of the ENVOL study

BackgroundThe optimal control of blood volume without fluid overload is a main challenge in the daily care of intensive care unit (ICU) patients. Accordingly this study focused on the identification of biomarkers to help characterize fluid overload status.MethodsSixty-seven patients were studied from ICU admission to day 7 (D7). Blood and urine samples were taken daily and sodium and water balance strictly calculated resulting in a total cumulative assessment of ∆Na+ and ∆H2O. Furthermore, plasmatic biomarkers (cortisol, epinephrine, norepinephrine, renin, angiotensin II, aldosterone, pro-endothelin, copeptine, atrial natriuretic peptide, erythropoietin, mid-regional pro-adrenomedullin (MR-proADM)) and Sequential Organ Failure Assessment (SOFA) scores were measured at D2, D5 and D7. Blood volumes were measured with 51Cr fixed on red blood cells at D2 and D7.ResultsThe ∆Na+ or ∆H2O were increased in all patients but never related to blood volumes at D2 nor D7. Total blood volumes were at normal values with constantly low red blood cell volumes and normal or decreased plasmatic volume. Weight, plasmatic proteins, and hemoglobin were weakly related to ∆Na+ or ∆H2O. Amongst all tested biomarkers, only MR-proADM was related to sodium and fluid overload. This biomarker was also a predictor of SOFA scores.ConclusionsPlasmatic concentration in MR-proADM seems to be a good surrogate for evaluation of ∆Na+ or ∆H2O and predicts sodium and extracellular fluid overload.Trial registrationClinicalTrials.gov: NCT01858675 in May 13, 2013.

Monitorage intracérébral d'un patient ayant un vasospasme

Delayed neurological deficit occurs among 30% of patients after aneurysmal subarachnoid haemorrhage, mainly related to cerebral vasospasm. The early detection of cerebral ischemia remains problematic. Conventional cerebral monitoring (as intracranial pressure and cerebral perfusion pressure) appears to be insufficient, because cerebral ischemia may occur without elevated intracranial pressure. Global cerebral monitoring as venous jugular oxygen saturation are useful for regional monitoring. Local monitoring as oxygen tissue partial pressure (PtiO2) and microdialysis are sensible for brain ischemia detection, but may also ignore episodes occurring in non-monitored brain area. For the detection of most episodes of brain ischemia, several monitoring system should be use performing a multimodal intracerebral monitoring. Brain microdialysis and oxygen tissue partial pressure are promising monitoring system.

An Alternative Ultrasonographic Approach to Assess Basilar Artery Flow

BACKGROUND: Assessment of basilar artery blood flow is of interest in many neurosurgical situations. With use of ultrasonography, the standard posterior approach is difficult in neurointensive care. OBJECTIVE: To evaluate the accuracy of an alternative submandibular approach for the assessment of blood flow in the basilar artery. METHOD: Fifty adult trauma patients without cervical spine injury were included in a prospective, comparative study. Doppler color-coded sonography of the basilar artery was performed using a 2-MHz pulsed probe. Blood flow velocities and pulsatility indexes obtained from the new submandibular approach and the standard suboccipital approach were compared. RESULTS: There were no significant differences in systolic, mean, and end-diastolic velocities between both approaches. Strong relationships were found between suboccipital and submandibular approaches for systolic, mean, end-diastolic velocities, and pulsatility indexes (r2 = 0.94, 0.95, 0.95, and 0.91, respectively; P < .001 for all). The mean bias between suboccipital and submandibular approaches was 1.1 cm/s for systolic velocity, 0.4 cm/s for mean velocity, −1.2 cm/s for end-diastolic velocity, and 0.0 for pulsatility index. CONCLUSION: This alternative submandibular approach appears to be accurate in measuring blood flow velocity and pulsatility index in the basilar artery. The main advantage of this approach is to facilitate monitoring of brainstem perfusion by avoiding neck flexion. This can be very helpful in intensive care settings.

Réunion de neuroanesthésie–réanimationMonitorage intracérébral d'un patient ayant un vasospasmeIntracerebral monitoring of a patient with vasopasm☆

Delayed neurological deficit occurs among 30% of patients after aneurysmal subarachnoid haemorrhage, mainly related to cerebral vasospasm. The early detection of cerebral ischemia remains problematic. Conventional cerebral monitoring (as intracranial pressure and cerebral perfusion pressure) appears to be insufficient, because cerebral ischemia may occur without elevated intracranial pressure. Global cerebral monitoring as venous jugular oxygen saturation are useful for regional monitoring. Local monitoring as oxygen tissue partial pressure (PtiO2) and microdialysis are sensible for brain ischemia detection, but may also ignore episodes occurring in non-monitored brain area. For the detection of most episodes of brain ischemia, several monitoring system should be use performing a multimodal intracerebral monitoring. Brain microdialysis and oxygen tissue partial pressure are promising monitoring system.

Unusual dialysis catheter position due to partial anomalous pulmonary venous return: Diagnosis and management.

Central venous catheter (CVC) insertion represents a routine procedure in intensive care units (ICUs) and is used for different purposes such as vasopressor drug administration, parenteral nutrition and continuous renal replacement therapy (CRRT). Although it is a relatively safe procedure, many events may occur during catheter insertion and use. One of these events is catheter misplacement, when the catheter is inserted in a structure different from the intended vein and/or when the catheter tip resides in an inadequate anatomical site. Ultrasound (US)-guided insertion of the catheter, preferably into the right internal jugular vein, and post-cannulation chest radiography are recommended to achieve higher success rates, to limit adverse events and to ensure that catheter placement is correct [1,2]. However, these precautions do not prevent catheter misplacement into unusual anatomical sites such as the controlateral subclavian or jugular veins or the persistent left superior vena cava [3,4]. When catheter misplacement occurs, clinicians are accustomed to removing the catheter and inserting a new one at another site. In the context of difficult venous accesses and partial anomalous pulmonary venous return (PAPVR), the safe use of a dialysis catheter has not been described.

Sudden Loss of Consciousness during a Flight

despite 3 of them having received hyperbaric oxygen therapy. Only 2 patients completely recovered, included 1 treated by hyperbaric oxygen therapy at 48 h, good prognosis being probably related more to the limited extent of the cerebral lesions than to late hyperbaric oxygen therapy [2] . Despite its rarity, medical teams involved in the management of strokes should be aware of this aetiology, in order to rapidly consider this diagnosis in a patient with sudden onset of a neurological deficit or coma during a flight. Indeed, the initial CT abnorBronchogenic cysts can very rarely be responsible for air embolism in a context of significantly increased atmospheric pressure. To our knowledge, only 7 similar cases have been reported in the Medline literature [1] . This cause of stroke can be quickly diagnosed in a suggestive context and if brain imaging (including CT scanner) is properly interpreted. We herewith describe a patient who suddenly became comatose during a flight, due to diffuse cerebral ischaemia caused by air embolism from a pulmonary bronchogenic cyst and review the previous literature.