Physiologic Effects of the Awake Prone Position Combined With High-Flow Nasal Oxygen on Gas Exchange and Work of Breathing in Patients With Severe COVID-19 Pneumonia: A Randomized Crossover Trial.

To determine the effect of the awake prone position (APP) on gas exchange and the work of breathing in spontaneously breathing patients with COVID-19-associated acute hypoxemic respiratory failure (AHRF) supported by high-flow nasal oxygen. DESIGN: Prospective randomized physiologic crossover multicenter trial. SETTINGS: Four ICUs in Marseille, France. PATIENTS: Seventeen patients with laboratory-confirmed COVID-19 pneumonia and Pao2/Fio2 less than or equal to 300 mm Hg while treated with high-flow nasal cannula oxygen therapy. INTERVENTIONS: Periods of APP and semirecumbent position (SRP) were randomly applied for 2 hours and separated by a 2-hour washout period. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases, end-tidal CO2. and esophageal pressure were recorded prior to and at the end of each period. Inspiratory muscle effort was assessed by measuring the esophageal pressure swing (∆PES) and the simplified esophageal pressure-time product (sPTPES). The other endpoints included physiologic dead space to tidal volume ratio (VD/VT) and the transpulmonary pressure swing. The APP increased the Pao2/Fio2 from 84 Torr (61-137 Torr) to 208 Torr (114-226 Torr) (p = 0.0007) and decreased both the VD/VT and the respiratory rate from 0.54 (0.47-0.57) to 0.49 (0.45-0.53) (p = 0.012) and from 26 breaths/min (21-30 breaths/min) to 21 breaths/min (19-22 breaths/min), respectively (p = 0.002). These variables remained unchanged during the SRP. The ∆PES and sPTPES per breath were unaffected by the position. However, the APP reduced the sPTPES per minute from 225 cm H2O.s.m-1 (176-332 cm H2O.s.m-1) to 174 cm H2O.s.m-1 (161-254 cm H2O.s.m-1) (p = 0.049). CONCLUSIONS: In spontaneously breathing patients with COVID-19-associated AHRF supported by high-flow nasal oxygen, the APP improves oxygenation and reduces the physiologic dead space, respiratory rate, and work of breathing per minute.

A severe case of ipilimumab-induced guillain-barré syndrome revealed by an occlusive enteric neuropathy: a differential diagnosis for ipilimumab-induced colitis.

Ipilimumab is a fully human monoclonal antibody directed against cytotoxic T-lymphocyte antigen-4 recently approved for the treatment of metastatic melanoma and currently under investigation in the adjuvant setting of high-risk stage III melanoma. The blockade of CTLA-4 induces activation of T cells, with an expected increase in the immunological reaction directed to cancer. We report a case of ipilimumab-induced Guillain-Barré syndrome revealed by an occlusive enteric neuropathy. Two weeks after the second dose of ipilimumab, our patient started to complain of abdominal meteorism and nausea. Within a few days, an occlusive syndrome developed. Wall biopsies during colonoscopy revealed a slight edema of the mucosa and a high number of lymphocytic follicles, leading to the diagnosis of ipilimumab-induced immune colitis. A respiratory failure occurred and a neurological deficiency developed rapidly. The diagnosis of polyradiculoneuritis was retained. Despite IV steroids, tacrolimus than plasmatic exchanges, the patient died within a few days because of multivisceral failure. Polyradiculoneuritis is a rare but very severe immune-mediated complication of ipilimumab. Occlusive enteric neuropathy may mimic the digestive symptoms of colitis, which is so frequent under ipilimumab.

Effects of high doses of selenium, as sodium selenite, in septic shock: a placebo-controlled, randomized, double-blind, phase II study.

INTRODUCTION: Sepsis is associated with the generation of oxygen free radicals and (lacking) decreased selenium plasma concentrations. High doses of sodium selenite might reduce inflammation by a direct pro-oxidative effect and may increase antioxidant cell capacities by selenium incorporation into selenoenzymes. We investigated the effects of a continuous administration of high doses of selenium in septic shock patients. METHODS: A prospective, multicentre, placebo-controlled, randomized, double-blind study was performed with an intention-to-treat analysis in severe septic shock patients with documented infection. Patients received, for 10 days, selenium as sodium selenite (4,000 microg on the first day, 1,000 microg/day on the nine following days) or matching placebo using continuous intravenous infusion. The primary endpoint was the time to vasopressor therapy withdrawal. The duration of mechanical ventilation, the mortality rates in the intensive care unit, at hospital discharge, and at 7, 14, 28 and 180 days and 1 year after randomization, and adverse events were recorded. RESULTS: Sixty patients were included (placebo, n = 29; selenium, n = 31). The median time to vasopressor therapy withdrawal was 7 days in both groups (95% confidence interval = 5-8 and 6-9 in the placebo and selenium groups, respectively; log-rank, P = 0.713). The median duration of mechanical ventilation was 14 days and 19 days in the placebo and selenium groups, respectively (P = 0.762). Mortality rates did not significantly differ between groups at any time point. Rates of adverse events were similar in the two groups. CONCLUSION: Continuous infusion of selenium as sodium selenite (4,000 microg on the first day, 1,000 microg/day on the nine following days) had no obvious toxicity but did not improve the clinical outcome in septic shock patients. Trial Registration = NCT00207844.

Mandibular nerve blocks for the removal of dentures during trismus caused by tetanus.

We report a case of trismus caused by tetanus in an 80-yr-old woman who developed severe and painful masseter spasms during which she violently bit the tip of her tongue with her dentures. Bilateral mandibular blocks were performed to remove the dentures. The patient fully recovered. We suggest that mandibular blocks are a useful tool in the management of oral events during trismus in conscious patients.

Technical aspects of an impact acceleration traumatic brain injury rat model with potential suitability for both microdialysis and PtiO2 monitoring.

This report describes technical adaptations of a traumatic brain injury (TBI) model-largely inspired by Marmarou-in order to monitor microdialysis data and PtiO2 (brain tissue oxygen) before, during and after injury. We particularly focalize on our model requirements which allows us to re-create some drastic pathological characteristics experienced by severely head-injured patients: impact on a closed skull, no ventilation immediately after impact, presence of diffuse axonal injuries and secondary brain insults from systemic origin... We notably give priority to minimize anaesthesia duration in order to tend to banish any neuroprotection. Our new model will henceforth allow a better understanding of neurochemical and biochemical alterations resulting from traumatic brain injury, using microdialysis and PtiO2 techniques already monitored in our Intensive Care Unit. Studies on efficiency and therapeutic window of neuroprotective pharmacological molecules are now conceivable to ameliorate severe head-injury treatment.

Consensus meeting on microdialysis in neurointensive care.

BACKGROUND: Microdialysis is used in many European neurointensive care units to monitor brain chemistry in patients suffering subarachnoid hemorrhage (SAH) or traumatic brain injury (TBI). DISCUSSION: We present a consensus agreement achieved at a meeting in Stockholm by a group of experienced users of microdialysis in neurointensive care, defining the use of microdialysis, placement of catheters, unreliable values, chemical markers, and clinical use in SAH and in TBI. CONCLUSIONS: As microdialysis is maturing into a clinically useful technique for early detection of cerebral ischemia and secondary brain damage, there is a need to following such definition regarding when and how to use microdialysis after SAH and TBI.

Right-to-left shunt and risk of decompression illness with cochleovestibular and cerebral symptoms in divers: case control study in 101 consecutive dive accidents.

OBJECTIVE: We investigated the role of right-to-left shunt with standardized transcranial Doppler ultrasonography in a large population of divers referred for symptoms of decompression illness. DESIGN: Case series compared with a control group. SETTING: Military teaching hospital, hyperbaric unit. PATIENTS: Patients were 101 consecutive divers with clinical evidence of decompression illness and a control group of 101 healthy divers. INTERVENTION: Specification of the type of decompression illness involved and detection/evaluation of right-to-left shunt by standardized transcranial Doppler. The degree of right-to-left shunt was defined as major if the number of high-intensity transient signals in the middle cerebral artery was >20. MEASUREMENTS AND MAIN RESULTS: We evaluated the odds ratios by logistic regression analysis with vs. without right-to-left shunt for subjects with cochleovestibular symptoms, cerebral decompression illness, spinal decompression illness, and Caisson sickness. Of the 101 divers presenting with decompression illness, transcranial Doppler detected a right-to-left shunt in 59 (58.4%), whereas control subjects demonstrated a right-to-left shunt in 25 cases (24.8%; odds ratio, 4.3; 95% confidence interval, 2.3-7.8; p=.09). When a right-to-left shunt was detected, the right-to-left shunt was major in 12 of 25 patients in the control group and in 49 of 59 patients in the decompression illness group (odds ratio, 8.7; 95% confidence interval, 4.2-18.0; p<.001). Within the decompression illness group, the proportion of major right-to-left shunt was 24 of 34 (odds ratio, 29.7; 95% confidence interval, 10.0-87.2; p<.0001) in the cochleovestibular subgroup, 13 of 21 (odds ratio, 24.1, 95% confidence interval, 6.8-86.0, p< 0.0001) in the cerebral decompression illness subgroup, ten of 31 (odds ratio, 3.9; 95% confidence interval, 1.5-10.3; p<.01) in the spinal decompression illness subgroup, and two of two (odds ratio, 1.1; 95% confidence interval, 0.2-5.7; p=.9) in the subgroup of divers with Caisson sickness. CONCLUSION: Based on our results, we conclude that major right-to-left shunt was associated with an increased incidence of cochleovestibular and cerebral decompression illness, suggesting paradoxical embolism as a potential mechanism.

Percutaneous tracheostomy: prospective comparison of the translaryngeal technique versus the forceps-dilational technique in 100 critically ill adults.

OBJECTIVE: To compare two different techniques of percutaneous tracheostomy: Griggs' forceps-dilational technique and Fantoni's translaryngeal technique, both performed with the manufacturer's basic kit and with bronchoscopic guidance. DESIGN: A prospective, randomized trial was designed to compare the two tracheostomy techniques. Critically ill patients requiring elective tracheostomy for long-term ventilation were randomized for translaryngeal tracheostomy or forceps-dilational tracheostomy. SETTING: Intensive care unit of a military teaching hospital. PATIENTS: A total of 100 adult patients in the intensive care unit who were mechanically ventilated. PROCEDURES: All tracheostomy procedures were performed at the bedside by using a commercially available set. The procedures were performed by two surgeons, one for bronchoscopic guidance and management of the airway and one for the tracheostomy. MEASUREMENTS AND MAIN RESULTS: The measurements were divided into procedure-related variables (duration, technical difficulties, oxygenation): major and minor complications. The procedure was longer in the translaryngeal technique group (12.9 vs. 6.9 mins, p =.0018). Technical difficulties occurred in 11 patients in the translaryngeal technique group. Uneventful forceps dilational tracheostomy was performed instead. There has been no mortality associated with either technique. Serious complications occurred in one patient in the forceps-dilational technique group (one posterior tracheal wall injury) and in four patients in the translaryngeal technique group (one with a posterior tracheal wall injury and three with severe hypoxia). Significant hypercarbia and acidosis occurred in both the translaryngeal technique group and the forceps-dilational technique group. A significant decrease in Pao2 was observed in the translaryngeal technique group (311 to 261, p =.0069). No bleeding requiring intervention occurred. CONCLUSIONS: Serious complications related to percutaneous tracheostomy occurred in 8.5% and 1.8% of the cases in the translaryngeal technique and the forceps-dilational technique group, respectively (p <.001). Technical difficulties were not rare when using the translaryngeal technique (23%). On the basis of our results, we concluded that the forceps-dilation technique is superior to the translaryngeal technique, with fewer technical difficulties and fewer complications for critically ill patients.