Salah Boussen

Case scenario – thoracic trauma ☆ ☆☆

Among trauma patients, blunt chest trauma remains a major cause of morbidity and mortality. We report the case of an 85-year old patient under new oral anticoagulant implicated in a multiple-vehicle accident. The patient presented a complex thoracic trauma involving multiple rib fractures, flail chest, hemothorax and lung contusions. All the thoracic lesions were situated at the left side. Despite the absence of neurological lesion and hemodynamic instability, the patient required the admission in our intensive care unit related to the worsening of a respiratory distress. This respiratory distress resulted from the association of the thoracic injuries with related hypoxemia and a high level of pain. The management of this case included the reversal of the anticoagulant therapy, use of non-invasive ventilation, the placement of a paravertebral block and the surgical fixation of the flail chest. We provide a discussion of the risk/benefit balance for all the medical and surgical strategies used in this case as the interest of chest ultrasonography in thoracic trauma situations.

Successful Insular Glioma Removal in a Deaf Signer Patient During an Awake Craniotomy Procedure.

BACKGROUND Resection of tumors located within the insula of the dominant hemisphere represents a technical challenge because of the complex anatomy, including the surrounding vasculature, and the relationship to functional (motor and language) structures. We report here the case of a successful resection of a left insular glioma in a native deaf signer during an awake craniotomy. CASE DESCRIPTION The patient, a congenitally deaf right-handed patient who is a native user of sign language, presented with a seizure 1 week before he was referred to our department. Magnetic resonance imaging revealed a left heterogeneous insular tumor enhanced after intravenous gadolinium infusion. Because of its deep and dominant hemisphere location, an awake craniotomy was decided. The patient was evaluated intraoperatively using object naming, text reading, and sign repetition tasks. An isolated inferior frontal gyrus site evoked repeated object naming errors. A transopercular parietal approach was performed and allowed the successful removal of the tumor under direct electric stimulation and electrocorticography. To our knowledge, this is the first report of successful removal of a left insular tumor without any functional sequelae in a native deaf signer using intraoperative direct cerebral stimulation during an awake craniotomy. CONCLUSIONS The methodology used also provides the first evidence of the actual anatomo-functional organization of language in deaf signers.

Evaluation of Transport Ventilators at Mild Simulated Altitude: A Bench Study in a Hypobaric Chamber

BACKGROUND: Previous studies on ventilators used for air transport showed significant effects of altitude, in particular with regard to accuracy of the tidal volume (VT) and breathing frequency. The aim of the study was to evaluate transport ventilators under hypobaric conditions. METHODS: We conducted a bench study of 6 transport ventilators in a Comex hypobaric chamber to simulate mild altitude (1,500 m [4,920 feet] and 2,500 m [8,200 feet]). The ventilators were connected to a test lung to evaluate their accuracy: (1) to deliver a set VT under normal resistance and compliance conditions at FIO2 = 0.6 and 1, (2) to establish a set PEEP (0, 5, 10, and 15 cm H2O), and (3) to establish a set inspiratory pressure in pressure controlled mode, (4) at a FIO2 setting, and (5) and at a frequency setting. RESULTS: Four ventilators kept an average relative error in VT of < 10% without effect of altitude. The Medumat ventilator was affected by the altitude only at FIO2 = 1. The Osiris 3 ventilator had > 40% error even at 1,500 m. We found no change in frequency as a function of altitude for any ventilators studied. No clinically important differences were found between all altitudes with the PEEP or inspiratory pressure setting. Although FIO2 was affected by altitude, the average error did not exceed 11%, and it is unclear whether this fact is an experimental artifact. CONCLUSIONS: We have shown that most of the new transport ventilators tested require no setting adjustment at moderate altitude and are as safe at altitude as at sea level under normal respiratory conditions. Older technologies still deliver more volume with altitude in volumetric mode.

Using an inertial navigation algorithm and accelerometer to monitor chest compression depth during cardiopulmonary resuscitation

We present an original method using a low cost accelerometer and a Kalman-filter based algorithm to monitor cardiopulmonary resuscitation chest compressions (CC) depth. A three-axis accelerometer connected to a computer was used during CC. A Kalman filter was used to retrieve speed and position from acceleration data. We first tested the algorithm for its accuracy and stability on surrogate data. The device was implemented for CC performed on a manikin. Different accelerometer locations were tested. We used a classical inertial navigation algorithm to reconstruct CPR depth and frequency. The device was found accurate enough to monitor CPR depth and its stability was checked for half an hour without any drift. Average error on displacement was ±0.5mm. We showed that depth measurement was dependent on the device location on the patient or the rescuer. The accuracy and stability of this small low-cost accelerometer coupled to a Kalman-filter based algorithm to reconstruct CC depth and frequency, was found well adapted and could be easily implemented.

Motion analysis of cardiopulmonary resuscitation.

OBJECTIVE Some cardiopulmonary resuscitation (CPR) monitoring devices were released in recent years. Some of them are motion sensors. There are no guidelines were to position future or present sensors during CPR. We evaluate the possible influence of the location of motion sensors by a high-speed camera during a CPR on a manikin. MATERIAL AND METHODS We performed a motion analysis by a high-speed camera during chest compression (CC) on a manikin to quantify chest inhomogeneous displacements and rescuer motion. RESULTS Midline chest was found to have an inhomogeneous depth during CC (19 mm for the upper sternum, 27 mm for the middle of the sternum, and 47 mm for the xiphoid). Rescuer anatomy has a complex motion. CONCLUSION The direct application of the sensor under the hand performing CC seems to be the more accurate solution if the device allows it.

Time rescaling reproduces EEG behavior during transition from propofol anesthesia-induced unconsciousness to consciousness

General anesthesia (GA) is a reversible manipulation of consciousness whose mechanism is mysterious at the level of neural networks leaving space for several competing hypotheses. We recorded electrocorticography (ECoG) signals in patients who underwent intracranial monitoring during awake surgery for the treatment of cerebral tumors in functional areas of the brain. Therefore, we recorded the transition from unconsciousness to consciousness directly on the brain surface. Using frequency resolved interferometry; we studied the intermediate ECoG frequencies (4–40 Hz). In the theoretical study, we used a computational Jansen and Rit neuron model to simulate recovery of consciousness (ROC). During ROC, we found that f increased by a factor equal to 1.62 ± 0.09, and δf varied by the same factor (1.61 ± 0.09) suggesting the existence of a scaling factor. We accelerated the time course of an unconscious EEG trace by an approximate factor 1.6 and we showed that the resulting EEG trace match the conscious state. Using the theoretical model, we successfully reproduced this behavior. We show that the recovery of consciousness corresponds to a transition in the frequency (f, δf) space, which is exactly reproduced by a simple time rescaling. These findings may perhaps be applied to other altered consciousness states.

Value of assessment of multivoxel proton chemical shift imaging to predict long term outcome in patients after out-of-hospital cardiac arrest: A preliminary prospective observational study

BACKGROUND Existing methods to predict recovery after out-of-hospital cardiac arrest (OHCA) lack of accuracy. The aim of this study was to determine whether quantitative proton chemical shift imaging (1H-CSI) during the subacute stage of OHCA can predict neurological outcome of such patients. METHODS This monocentric prospective observational study was conducted in a Intensive Care Unit of a teaching hospital. Forty consecutive patients with OHCA were enrolled between January 1st 2011-December 31st 2013. Multivoxel 1H-CSI values were compared to structural magnetic resonance imaging (MRI) sequences (fluid-attenuated inversion recovery and diffusion-weighted imaging). Ratios of N-acetyl-aspartate (NAA) to creatine (Cr) and choline compounds were analyzed using region of interest in bilateral lenticular cores and thalami. The outcome evaluated was the Cerebral Performance Category (CPC) at 6 months, dichotomized as favorable (CPC 1-2) and unfavorable outcome (CPC 3-5). The performance was compared by area under the receiver operating characteristic (ROCAUC) curves analysis. RESULTS Twenty nine OHCA had an interpretable MRI. Eight patients (28%) had favorable outcome at 6 months. The worst NAA/Cr in lenticular cores was the best 1H-CSI marker, with 80% sensitivity (95% confidence interval (CI), 57-94) and a 100% specificity (95% CI, 63-100) with a positive predictive value of 100%. Prognostic accuracy, as quantified by the ROCAUC, was higher with the worst NAA/Cr in lenticular cores (ROCAUC 0.88; 95% CI, 0.70-0.97) than with the structural MRI sequences. CONCLUSION In this preliminary study we found that multivoxel 1H-CSI in lenticular cores was highly predictive of unfavorable outcome at 6 months.

Data on prognostication models comparison for neurological recovery after cardiac arrest using proton chemical shift imaging (1H-CSI)

We report in this data article the statistical comparison of three models for neurological prognostication 6 months after cardiac arrest: M1 associated SAPS II and coma Glasgow score at MRI, M2 associated SAPS II, coma Glasgow score, and FLAIR-DWI “deep gray nuclei”score, M3 associated SAPS II, coma Glasgow score, FLAIR-DWI “deep gray nuclei”score, and Lenticular cores NAA/Cr ratio. These data are related to “Value of assessment of multivoxel proton chemical shift imaging to predict long term outcome in patients after out-of-hospital cardiac arrest: A preliminary prospective observational study” (Quintard et al., 2018) [1].

Xenon Myocardial Protection in Cardiac Surgery: Effective around the Clock?

Xenon Myocardial Protection in Cardiac Surgery: Effective around the Clock? David Lagier;Salah Boussen;Lionel Velly;Nicolas Bruder; Anesthesiology

Simulation studies for device evaluation--reply.

In Reply: Mr Chatburn begins his letter explaining what should be simulation in medicine. Many of the ventilator bench studies published before are only bench tests, as our study, and not a simulation of a more complex reality. The goal of this study was to test transport ventilators under