Impact of Hypoventilation Training on Muscle Oxygenation, Myoelectrical Changes, Systemic [K+], and Repeated-Sprint Ability in Basketball Players.

This study investigated the impact of repeated-sprint (RS) training with voluntary hypoventilation at low lung volume (VHL) on RS ability (RSA) and on performance in a 30-15 intermittent fitness test (30-15IFT). Over 4 weeks, 17 basketball players included eight sessions of straight-line running RS and RS with changes of direction into their usual training, performed either with normal breathing (CTL, n = 8) or with VHL (n = 9). Before and after the training, athletes completed a RSA test (12 × 30-m, 25-s rest) and a 30-15IFT. During the RSA test, the fastest sprint (RSAbest), time-based percentage decrement score (RSASdec), total electromyographic intensity (RMS), and spectrum frequency (MPF) of the biceps femoris and gastrocnemius muscles, and biceps femoris NIRS-derived oxygenation were assessed for every sprint. A capillary blood sample was also taken after the last sprint to analyse metabolic and ionic markers. Cohen's effect sizes (ES) were used to compare group differences. Compared with CTL, VHL did not clearly modify RSAbest, but likely lowered RSASdec (VHL: -24.5% vs. CTL: -5.9%, group difference: -19.8%, ES -0.44). VHL also lowered the maximal deoxygenation induced by sprints ([HHb]max; group difference: -2.9%, ES -0.72) and enhanced the reoxygenation during recovery periods ([HHb]min; group difference: -3.6%, ES -1.00). VHL increased RMS (group difference: 18.2%, ES 1.28) and maintained MPF toward higher frequencies (group difference: 9.8 ± 5.0%, ES 1.40). These changes were concomitant with a lower potassium (K+) concentration (group difference: -17.5%, ES -0.67), and the lowering in [K+] was largely correlated with RSASdec post-training in VHL only (r = 0.66, p < 0.05). However, VHL did not clearly alter PO2, hemoglobin, lactate and bicarbonate concentration and base excess. There was no difference between group velocity gains for the 30-15IFT (CTL: 6.9% vs. VHL: 7.5%, ES 0.07). These results indicate that RS training combined with VHL may improve RSA, which could be relevant to basketball player success. This gain may be attributed to greater muscle reoxygenation, enhanced muscle recruitment strategies, and improved K+ regulation to attenuate the development of muscle fatigue, especially in type-II muscle fibers.

Similar Recovery of Maximal Cycling Performance after Ischemic Preconditioning, Neuromuscular Electrical Stimulation or Active Recovery in Endurance Athletes.

This study investigated the efficacy of ischemic preconditioning (IPC) on the recovery of maximal aerobic performance and physiological responses compared with commonly used techniques. Nine endurance athletes performed two 5-km cycling time trials (TT) interspersed by 45 minutes of recovery that included either IPC, active recovery (AR) or neuromuscular electrical stimulation (NMES) in a randomized crossover design. Performance, blood markers, arterial O2 saturation (SpO2), heart rate (HR), near-infrared spectroscopy-derived muscle oxygenation parameters and perceptual measures were recorded throughout TTs and recovery. Differences were analyzed using repeated-measures ANOVAs and Cohen's effect size (ES). The decrement in chronometric performance from TT1 to TT2 was similar between recovery modalities (IPC: -6.1 sec, AR: -7.9 sec, NMES: -5.4 sec, p = 0.84, ES 0.05). The modalities induced similar increases in blood volume before the start of TT2 (IPC: 13.3%, AR: 14.6%, NMES: 15.0%, p = 0.79, ES 0.06) and similar changes in lactate concentration and pH. There were negligible differences between conditions in bicarbonate concentration, base excess of blood and total concentration of carbon dioxide, and no difference in SpO2, HR and muscle O2 extraction during exercise (all p > 0.05). We interpreted these findings to suggest that IPC is as effective as AR and NMES to enhance muscle blood volume, metabolic by-products clearance and maximal endurance performance. IPC could therefore complement the athlete's toolbox to promote recovery.

New evidence in diagnosis of pulmonary embolism during pregnancy.

Diagnosis of pulmonary embolism (PE) in pregnancy is notoriously difficult and lacking high quality evidence. Three studies (DiPEP, ARTEMIS and CT-PE-Pregnancy) evaluating a systematic approach to PE diagnosis have recently been published. DiPEP is a retrospective case-control study that found a poor utility of clinical decision rules or D-dimer testing for PE diagnosis in pregnancy. ARTEMIS and CT-PE-Pregnancy are well conducted prospective management studies that proposed two algorithms with different clinical decision rules and D-dimer criteria for the diagnosis of PE in pregnancy. They included few events in high risk patients, which makes difficult the assessment of both algorithm's safety in women with a high probability of PE. Considering this new evidence, D-dimer testing might be useful to avoid radiation imaging in pregnant women considered at low risk for PE. In contrast, a negative D-dimer cannot be considered sufficiently safe to rule out PE when clinicians estimate that PE is the most likely diagnosis.

Extracorporeal Therapies for Amniotic Fluid Embolism.

BACKGROUND: Amniotic fluid embolism (AFE) is a catastrophic disease with significant mortality. Because the cardiopulmonary dysfunction associated with AFE is self-limited, the disease could be well suited to the use of extracorporeal therapies. CASE: A woman progressed into cardiac arrest immediately after an elective cesarean delivery. Owing to severe hypoxemia and hypotension, AFE was suspected and peripheral venoarterial extracorporeal membrane oxygenation was quickly initiated. Subsequent evolution was complicated by intrabdominal bleeding, which required massive transfusion and multiple surgeries. The patient recovered well, with a healthy newborn. We have identified 19 similar cases in the literature and present their outcomes as a series. CONCLUSION: Extracorporeal therapies can support severely ill women affected by AFE and could be considered even in the presence of disseminated intravascular coagulation and bleeding.

Development of a Core Outcome Set for research on critically ill obstetric patients: A study protocol.

BACKGROUND: Current data on critical illness during pregnancy are insufficient for evidence-based decision making. Core outcome sets are promoted to improve reporting of outcomes important to decision makers. We aim to develop a Core Outcome Set for research on critically ill obstetric patients (COSCO study). METHODS: We will perform a systematic review of studies on critical illness in pregnancy and focus groups or interviews with women who were critically ill while being pregnant. These data will inform an international Delphi survey where stakeholders will rank proposed outcomes. Selected outcomes will be brought forward to a consensus meeting where core outcomes will be defined. We will then complete a second consensus process to define measures for each core outcome. CONCLUSION: The Core Outcome Set on Critically ill Obstetric patients study aims to develop a set of core outcomes to be part of all studies on critically ill obstetric patients. Implementation of this core outcome set will help improve future research efforts.Trial registration: This study is registered on the COMET-initiative website (COS #916). This systematic review is registered on PROSPERO (CRD #42017071944).

Transfusion practices in traumatic brain injury.

PURPOSE OF REVIEW: The aim of this review is to summarize the recent studies looking at the effects of anemia and red blood cell transfusion in critically-ill patients with traumatic brain injury (TBI), describe the transfusion practice variations observed worldwide, and outline the ongoing trials evaluating restrictive versus liberal transfusion strategies for TBI. RECENT FINDINGS: Anemia is common among critically-ill patients with TBI, it is also thought to exacerbate secondary brain injury, and is associated with an increased risk of poor outcome. Conversely, allogenic red blood cell transfusion carries its own risks and complications, and has been associated with worse outcomes. Globally, there are large reported differences in the hemoglobin threshold used for transfusion after TBI. Observational studies have shown differential results for improvements in cerebral oxygenation and metabolism after red blood cell transfusion in TBI. SUMMARY: Currently, there is insufficient evidence to make strong recommendations regarding which hemoglobin threshold to use as a transfusion trigger in critically-ill patients with TBI. There is also uncertainty whether the restrictive transfusion strategy used in general critical care can be extrapolated to acutely brain injured patients. Ultimately, the consequences of anemia-induced cerebral injury need to be weighed up against the risks and complications associated with red blood cell transfusion.

Sedation and Mobilization During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Failure: An International Survey.

OBJECTIVES: To characterize sedation, analgesia, delirium, and mobilization practices in patients supported with venovenous extracorporeal membrane oxygenation for severe acute respiratory failure. DESIGN: Cross-sectional electronic survey administered January 2016 to March 2016. SETTING: Three-hundred ninety-four extracorporeal membrane oxygenation centers registered with the Extracorporeal Life Support Organization. SUBJECTS: Extracorporeal membrane oxygenation medical directors and program coordinators. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed responses from 209 respondents (53%), mostly from academic centers (63%); 41% respondents provide venovenous extracorporeal membrane oxygenation to adults exclusively. Following venovenous extracorporeal membrane oxygenation initiation, 97% respondents administer sedative/analgesic infusions, and the sedation target was "sedated" or "very sedated" for 59%, "calm and cooperative" for 25%, and "unarousable" for 16%. Use of daily sedation interruption and a sedation/analgesia protocol was reported by 51% and 39%, respectively. Midazolam (48%) and propofol (19%) were reported as the most frequently used sedatives; fentanyl (44%) and morphine (20%) the most frequent opioids. Use of a delirium scale was reported by 55% respondents. Physical therapy was reported by 84% respondents, with 41% initiating it within 72 hours after cannulation. Mobilization goals varied from range of motion exercises (81%) to ambulation (22%). The most frequently perceived barriers to mobilization were hemodynamic instability, hypoxemia, and dependency on venovenous extracorporeal membrane oxygenation support. CONCLUSIONS: The majority of respondents reported targeting moderate to deep sedation following cannulation, with the use of sedative and opioid infusions. There is considerable variability surrounding early physical therapy and mobilization goals for patients with acute respiratory failure supported by venovenous extracorporeal membrane oxygenation.