Does nonviolent communication education improve empathy in French medical students?

OBJECTIVES: To evaluate the impact of nonviolent communication (NVC) training on five aspects of medical students' empathy skills using implicit and explicit measures. METHODS: 312 third-year French medical students were randomly allocated to an intervention group (n = 123) or a control group (n = 189). The intervention group received 2.5 days of NVC training. For each group, empathy-related skills were measured implicitly using three cognitive tests (Visuo-Spatial Perspective Taking, Privileged Knowledge, Empathy for Pain evaluation) and explicitly using two self-rating questionnaires (Jefferson Scale of Physician Empathy, Empathy Quotient). Both groups completed tests and questionnaires before (pre-test) and three months after training (post-test). Responses were collected via online software, and data were analyzed using paired linear mixed models and Bayes Factors. RESULTS: We found a significant increase in the Jefferson  Scale of Physician Empathy (JSPE) score between pre- and post-tests in the intervention group compared to the control group (linear mixed models: 0.95 points [0.17, 1.73], t(158) = 2.39, p < 0.05), and an expected gender effect whereby females had higher JSPE scores (1.57 points [0.72, 2.42], t(262) = -3.62, p < 0.001). There was no interaction between these two factors. CONCLUSIONS: Our results show that brief training in nonviolent communication improves subjective empathy three months after training. These results are promising for the long-term effectiveness of NVC training on medical students' empathy and call for the introduction of NVC training in medical school. Further studies should investigate whether longer training will produce larger and longer-lasting benefits.

[Discrepancies in medical textbooks and their impact on medical school students]. / Discordances entre les référentiels des collèges d'enseignants en médecine et leur impact sur les étudiants en médecine.

BACKGROUND: Textbooks endorsed by national medical specialty societies and colleges are used as official references for faculty and national examinations. Oncology is transdisciplinary, practiced and taught by oncologists but also by other specialists. We aimed at identifying discrepancies between chapters on cancers in different official specialty textbooks and evaluating their impact on students. MATERIAL AND METHODS: Volunteer 6th-year medical students of the Sorbonne University faculty were paired and asked to list the discrepancies between all official specialty textbooks addressing a given cancer and then individually asked to evaluate the impact of discrepancies on their learning experience. RESULTS: In March 2018, the 17 cancers listed in the French medical school education program were addressed in 14 official specialty textbooks (2 to 4 textbooks/cancer). Out of a class of 390 students, 78 volunteered and were paired; each cancer was analyzed by 3 pairs of students (1 or 2 cancers/pair); 154 discrepancies were reported (range: 4-18 per cancer). Discrepancies induced doubt and anxiety in students; 85% considered that harmonization should be achieved for all topics of the national medical school program. CONCLUSIONS: Discrepancies between official textbook are frequent, generate anxiety in students and impact learning experience.

Low Back Pain Among Medical Students: A Burden and an Impact to Consider!

STUDY DESIGN: Prospective study. OBJECTIVE: Determine risk factors and consider impact of low back pain for medical students. SUMMARY OF BACKGROUND DATA: Low back pain (LBP) is one of the most prevalent complaints among students. The vulnerability of medical students due to stress and numerous hours of studying and training makes them at risk of LBP. METHODS: We submitted an online self-administered modified version of the Standardized Nordic Questionnaire to 1800 medical students from 2nd to 6th year from December 2017 to March 2018. RESULTS: A total of 1243/1800 (68.9%) students responded to our survey. Mean age was 23.3 ±â€Š2.9 years ranging from 18 to 44 years. 835 (72.1%) students reported suffering from LBP. In multivariate analysis with logistic regression analysis model, the third year of medical studies (odds ratio [OR]: 0.558, 95% confidence interval [CI] 0.387-0.805; P = 0.002) was identified as an independent prognostic factor of LBP. Moreover, exercising weekly (OR: 1.835, 95% CI 0.933-2.5; P = 0.01) and walking at least 30 minutes a day (OR: 1.458, 95% CI 1.129-1.876; P = 0.01) significantly improve LBP. LBP generate higher monthly consumption of an analgesic (OR: 32.8, 95% CI 4.271-252.2; P < 0.001). Finally, LBP had a severe repercussion on student work (OR: 18.89, 95% CI 10.122-35.253; P < 0.0001), on the quality of sleep (OR: 12.162, 95% CI 6.917-21.386; P < 0.0001) and on their personal life (OR: 12.343, 95% CI 5.681-26.8; P < 0.0001). CONCLUSION: Medical students reported high prevalence of LBP with severe consequences. Our educational perspective is to identify the risk factors of LBP, fight them, to improve the medical student' work, and welfare. LEVEL OF EVIDENCE: 3.

Miming neurological syndromes improves medical student's long-term retention and delayed recall of neurology.

Basic examination and diagnostic skills in neurology are important for every graduating medical student. However, a majority of medical students consider neurology as complex and difficult to master. We evaluate the impact a learner-friendly, innovative simulation-based training programme has on long-term retention and delayed recall of neurological semiology amongst third-year medical students from the University Pierre et Marie Curie in Paris, France. The 2013 class received standard teaching in neurological semiology. The 2015 class who received the same standard teaching in neurological semiology were also invited to voluntarily participate in The Move, a mime-based role-play training programme of neurological semiology. During the Move, students were trained to simulate a patient with a neurological syndrome or the physician examining the patient. Students were evaluated with an assessment thirty months after their neurological rotation, including 15 questions to evaluate long-term retention of neurological semiology, and 10 to test background knowledge in general semiology. The semiology test was performed by 366/377 students from the 2013 class (standard education group) and by 272/391 students from the 2015 class, among which 186 participated in The Move (The Move group) and 86 did not (standard education group). The mean neurological semiology score was higher in the 2015 class compared to the 2013 class (p = 0.007) and remained so after adjustment for the general semiology performance (p = 0.003). The adjusted mean neurological semiology score was 1.21/15 points higher [95% CI 0.66, 1.75] in The Move group compared to the standard education group, corresponding to a 14% better ranking. The Move programme improves medical student's long-term retention and delayed recall of neurological semiology. This learner-friendly interactive teaching may in turn enhance clinical proficiency of future physicians in neurological semiology.

How can video-based sessions improve e-learning of respiratory physiology? / ¿Cómo pueden mejorar las sesiones en vídeo la educación a distancia sobre la fisiología respiratoria?

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Google Glass for Residents Dealing With Pediatric Cardiopulmonary Arrest: A Randomized, Controlled, Simulation-Based Study.

OBJECTIVES: To determine whether real-time video communication between the first responder and a remote intensivist via Google Glass improves the management of a simulated in-hospital pediatric cardiopulmonary arrest before the arrival of the ICU team. DESIGN: Randomized controlled study. SETTING: Children's hospital at a tertiary care academic medical center. SUBJECTS: Forty-two first-year pediatric residents. INTERVENTIONS: Pediatric residents were evaluated during two consecutive simulated pediatric cardiopulmonary arrests with a high-fidelity manikin. During the second evaluation, the residents in the Google Glass group were allowed to seek help from a remote intensivist at any time by activating real-time video communication. The residents in the control group were asked to provide usual care. MEASUREMENTS AND MAIN RESULTS: The main outcome measures were the proportion of time for which the manikin received no ventilation (no-blow fraction) or no compression (no-flow fraction). In the first evaluation, overall no-blow and no-flow fractions were 74% and 95%, respectively. During the second evaluation, no-blow and no-flow fractions were similar between the two groups. Insufflations were more effective (p = 0.04), and the technique (p = 0.02) and rate (p < 0.001) of chest compression were more appropriate in the Google Glass group than in the control group. CONCLUSIONS: Real-time video communication between the first responder and a remote intensivist through Google Glass did not decrease no-blow and no-flow fractions during the first 5 minutes of a simulated pediatric cardiopulmonary arrest but improved the quality of the insufflations and chest compressions provided.

An innovative pedagogic course combining video and simulation to teach medical students about pediatric cardiopulmonary arrest: a prospective controlled study.

UNLABELLED: Compliance by residents in pediatrics to pediatric resuscitation guidelines is low. In many French faculties, a 1-h traditional lecture is still used to educate medical students about pediatric cardiopulmonary arrest (CPA). We developed an innovative pedagogic course combining a 23-min video and 3-h simulation exercises to improve knowledge and skills of medical students. A prospective controlled study was conducted. Medical student knowledge was tested before, just after, and 6-12 months after the innovative course and compared to that of a cohort who attended the traditional lecture. A high-fidelity mannequin simulator simulating cardiopulmonary arrest was used to assess and compare the skills of the study and control groups. Costs of the courses were evaluated; 809 of 860 (94 %) medical students were assessed for knowledge. Six to 12 months after the courses, the median score was significantly higher for the innovative group than that for the traditional lecture group (p < 0.001). In terms of skills, student in the innovative group scored higher on the performance score than the control group (p < 0.01). The innovative course was 24 times more expensive. CONCLUSION: Combination of video and simulation allows better retention of knowledge than a traditional lecture and leads to better compliance to resuscitation guidelines. WHAT IS KNOWN: • Compliance by residents to pediatric resuscitation guidelines is low. • We developed an innovative pedagogic course combining an educational video and simulation. What is new: • Knowledge retention after the innovative course was better than after a traditional lecture. • Sixty-six students tested on their skills demonstrated better compliance to resuscitation guidelines.

Effect of Acetazolamide vs Placebo on Duration of Invasive Mechanical Ventilation Among Patients With Chronic Obstructive Pulmonary Disease: A Randomized Clinical Trial.

IMPORTANCE: Acetazolamide has been used for decades as a respiratory stimulant for patients with chronic obstructive pulmonary disease (COPD) and metabolic alkalosis, but no large randomized placebo-controlled trial is available to confirm this approach. OBJECTIVE: To determine whether acetazolamide reduces mechanical ventilation duration in critically ill patients with COPD and metabolic alkalosis. DESIGN, SETTING, AND PARTICIPANTS: The DIABOLO study, a randomized, double-blind, multicenter trial, was conducted from October 2011 through July 2014 in 15 intensive care units (ICUs) in France. A total of 382 patients with COPD who were expected to receive mechanical ventilation for more 24 hours were randomized to the acetazolamide or placebo group and 380 were included in an intention-to treat analysis. INTERVENTIONS: Acetazolamide (500-1000 mg, twice daily) vs placebo administered intravenously in cases of pure or mixed metabolic alkalosis, initiated within 48 hours of ICU admission and continued during the ICU stay for a maximum of 28 days. MAIN OUTCOMES AND MEASURES: The primary outcome was the duration of invasive mechanical ventilation via endotracheal intubation or tracheotomy. Secondary outcomes included changes in arterial blood gas and respiratory parameters, weaning duration, adverse events, use of noninvasive ventilation after extubation, successful weaning, the duration of ICU stay, and in-ICU mortality. RESULTS: Among 382 randomized patients, 380 (mean age, 69 years; 272 men [71.6%]; 379 [99.7%] with endotracheal intubation) completed the study. For the acetazolamide group (n = 187), compared with the placebo group (n = 193), no significant between-group differences were found for median duration of mechanical ventilation (-16.0 hours; 95% CI, -36.5 to 4.0 hours; P = .17), duration of weaning off mechanical ventilation (-0.9 hours; 95% CI, -4.3 to 1.3 hours; P = .36), daily changes of minute-ventilation (-0.0 L/min; 95% CI, -0.2 to 0.2 L/min; P = .72), or partial carbon-dioxide pressure in arterial blood (-0.3 mm Hg; 95% CI, -0.8 to 0.2 mm Hg; P = .25), although daily changes of serum bicarbonate (between-group difference, -0.8 mEq/L; 95% CI, -1.2 to -0.5 mEq/L; P < .001) and number of days with metabolic alkalosis (between-group difference, -1; 95% CI, -2 to -1 days; P < .001) decreased significantly more in the acetazolamide group. Other secondary outcomes also did not differ significantly between groups. CONCLUSIONS AND RELEVANCE: Among patients with COPD receiving invasive mechanical ventilation, the use of acetazolamide, compared with placebo, did not result in a statistically significant reduction in the duration of invasive mechanical ventilation. However, the magnitude of the difference was clinically important, and it is possible that the study was underpowered to establish statistical significance. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01627639.

Weaker compressions after night shift? The WeCAN manikin study.

To assess whether the quality of chest compressions (CC) differs before and after a night shift. We carried out a cluster randomized study in three Emergency Departments and three ICUs in Paris, France. Physicians were assessed on a control day and immediately following after a night shift. The primary endpoint was the proportion of CC with a depth greater than 50 mm. We analyzed 67 participants. The proportion of CC with a depth greater than 50 mm was similar on a control day and after a night shift [52% in both groups, mean difference of 0 (95% confidence interval: -17 to 17)]. Other indicators of CC quality were unchanged after a night shift, except for the mean depth of CC (51 vs. 48 mm, P=0.01). We report in our sample that the quality of CC after a night shift is not inferior to a control day.

Will students pass a competitive exam that they failed in their dreams?

We tested whether dreams can anticipate a stressful exam and how failure/success in dreams affect next-day performance. We collected information on students' dreams during the night preceding the medical school entrance exam. Demographic, academic, sleep and dream characteristics were compared to the students' grades on the exam. Of the 719 respondents to the questionnaire (of 2324 total students), 60.4% dreamt of the exam during the night preceding it. Problems with the exam appeared in 78% of dreams and primarily involved being late and forgetting answers. Reporting a dream about the exam on the pre-exam night was associated with better performance on the exam (p=.01). The frequency of dreams concerning the exam during the first term predicted proportionally higher performance on the exam (R=0.1, p=.01). These results suggest that the negative anticipation of a stressful event in dreams is common and that this episodic simulation provides a cognitive gain.

Video-based feedback of oral clinical presentations reduces the anxiety of ICU medical students: a multicentre, prospective, randomized study.

BACKGROUND: Oral presentations of clinical cases by medical students during medical rounds in hospital wards are a source of anxiety and little is known about how this anxiety can be alleviated. The objective of this study was to investigate whether video-based feedback of public oral presentations can reduce anxiety in 4th year medical students. METHODS: Multicentre randomized study conducted in six intensive care units (ICU) and emergency departments (ED) in France over a 9-month period in 2012. One hundred and forty two 4th year medical students were randomized to two groups: intervention and control. Students in the intervention group were recorded while making an oral presentation of a patient during morning ward rounds, followed by video-based feedback. Students in the control group conducted presented classical oral presentations without being filmed and with no formal feedback. Anxiety levels during a public oral presentation were assessed using the Spielberger State Anxiety Inventory (STAI-S). The primary outcome was the difference in STAI-S scores between groups at the beginning and at the end of a 3-month ICU or ED internship. RESULTS: Seventy four students were randomized to the 'video-based feedback' group and 68 were randomized to the control group. In both groups, STAI-S scores were significantly lower after 3 months of internship. However, the reduction in STAI-S scores was significantly greater in the "video-based feedback" group than in controls (-9.2 ± 9.3 vs. -4.6 ± 8.2, p = 0.024. Compared to the control group, significantly fewer students with high-level anxiety were observed in the "video-based feedback" group after 3 months of internship (68 vs. 28%, p <0.001). CONCLUSIONS: Compared to "usual practice", video-assisted oral feedback reduced anxiety and significantly decreased the proportion of students experiencing severe anxiety.

Induced hypothermia in severe bacterial meningitis: a randomized clinical trial.

IMPORTANCE: Despite advances in care, mortality and morbidity remain high in adults with acute bacterial meningitis, particularly when due to Streptococcus pneumoniae. Induced hypothermia is beneficial in other conditions with global cerebral hypoxia. OBJECTIVE: To test the hypothesis that induced hypothermia improves outcome in patients with severe bacterial meningitis. DESIGN, SETTING, AND PATIENTS: An open-label, multicenter, randomized clinical trial in 49 intensive care units in France, February 2009-November 2011. In total, 130 patients were assessed for eligibility and 98 comatose adults (Glasgow Coma Scale [GCS] score of ≤8 for <12 hours) with community-acquired bacterial meningitis were randomized. INTERVENTIONS: Hypothermia group received a loading dose of 4°C cold saline and were cooled to 32°C to 34°C for 48 hours. The rewarming phase was passive. Controls received standard care. MAIN OUTCOMES AND MEASURES: Primary outcome measure was the Glasgow Outcome Scale score at 3 months (a score of 5 [favorable outcome] vs a score of 1-4 [unfavorable outcome]). All patients received appropriate antimicrobial therapy and vital support. Analyses were performed on an intention-to-treat basis. The data and safety monitoring board (DSMB) reviewed severe adverse events and mortality rate every 50 enrolled patients. RESULTS: After inclusion of 98 comatose patients, the trial was stopped early at the request of the DSMB because of concerns over excess mortality in the hypothermia group (25 of 49 patients [51%]) vs the control group (15 of 49 patients [31%]; relative risk [RR], 1.99; 95% CI, 1.05-3.77; P = .04). Pneumococcal meningitis was diagnosed in 77% of patients. Mean (SD) temperatures achieved 24 hours after randomization were 33.3°C (0.9°C) and 37.0°C (0.9°C) in the hypothermia and control group, respectively. At 3 months, 86% in the hypothermia group compared with 74% of controls had an unfavorable outcome (RR, 2.17; 95% CI, 0.78-6.01; P = .13). After adjustment for age, score on GCS at inclusion, and the presence of septic shock at inclusion, mortality remained higher, although not significantly, in the hypothermia group (hazard ratio, 1.76; 95% CI, 0.89-3.45; P = .10). Subgroup analysis on patients with pneumococcal meningitis showed similar results. Post hoc analysis showed a low probability to reach statistically significant difference in favor of hypothermia at the end of the 3 planned sequential analyses (probability to conclude in favor of futility, 0.977). CONCLUSIONS AND RELEVANCE: Moderate hypothermia did not improve outcome in patients with severe bacterial meningitis and may even be harmful. Careful evaluation of safety issues in future trials on hypothermia are needed and may have important implications in patients presenting with septic shock or stroke. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00774631.

Ultrasound-based teaching of cardiac anatomy and physiology to undergraduate medical students.

BACKGROUND: Ultrasonography is a non-invasive imaging modality that offers the opportunity to teach living cardiac anatomy and physiology. AIMS: The objectives of this study were to assess the feasibility of integrating an ultrasound-based course into the conventional undergraduate medical teaching programme and to analyse student and teacher feedback. METHODS: An ultrasound-based teaching course was implemented and proposed to all second-year medical students (n=348) at the end of the academic year, after all the conventional modules at our faculty. After a brief theoretical and practical demonstration, students were allowed to take the probe and use the ultrasound machine. Students and teachers were asked to complete a survey and were given the opportunity to provide open feedback. RESULTS: Two months were required to implement the entire module; 330 (95%) students (divided into 39 groups) and 37 teachers participated in the course. Student feedback was very positive: 98% of students agreed that the course was useful; 85% and 74% considered that their understanding of cardiac anatomy and physiology, respectively, was improved. The majority of the teachers (97%) felt that the students were interested, 81% agreed that the course was appropriate for second-year medical students and 84% were willing to participate to future sessions. CONCLUSIONS: Cardiac anatomy and physiology teaching using ultrasound is feasible for undergraduate medical students and enhances their motivation to improve their knowledge. Student and teacher feedback on the course was very positive.

Diaphragm dysfunction on admission to the intensive care unit. Prevalence, risk factors, and prognostic impact-a prospective study.

RATIONALE: Diaphragmatic insults occurring during intensive care unit (ICU) stays have become the focus of intense research. However, diaphragmatic abnormalities at the initial phase of critical illness remain poorly documented in humans. OBJECTIVES: To determine the incidence, risk factors, and prognostic impact of diaphragmatic impairment on ICU admission. METHODS: Prospective, 6-month, observational cohort study in two ICUs. Mechanically ventilated patients were studied within 24 hours after intubation (Day 1) and 48 hours later (Day 3). Seventeen anesthetized intubated control anesthesia patients were also studied. The diaphragm was assessed by twitch tracheal pressure in response to bilateral anterior magnetic phrenic nerve stimulation (Ptr,stim). MEASUREMENTS AND MAIN RESULTS: Eighty-five consecutive patients aged 62 (54-75) (median [interquartile range]) were evaluated (medical admission, 79%; Simplified Acute Physiology Score II, 54 [44-68]). On Day 1, Ptr,stim was 8.2 (5.9-12.3) cm H2O and 64% of patients had Ptr,stim less than 11 cm H2O. Independent predictors of low Ptr,stim were sepsis (linear regression coefficient, -3.74; standard error, 1.16; P = 0.002) and Simplified Acute Physiology Score II (linear regression coefficient, -0.07; standard error, 1.69; P = 0.03). Compared with nonsurvivors, ICU survivors had higher Ptr,stim (9.7 [6.3-13.8] vs. 7.3 [5.5-9.7] cm H2O; P = 0.004). This was also true for hospital survivors versus nonsurvivors (9.7 [6.3-13.5] vs. 7.8 [5.5-10.1] cm H2O; P = 0.004). Day 1 and Day 3 Ptr,stim were similar. CONCLUSIONS: A reduced capacity of the diaphragm to produce inspiratory pressure (diaphragm dysfunction) is frequent on ICU admission. It is associated with sepsis and disease severity, suggesting that it may represent another form of organ failure. It is associated with a poor prognosis. Clinical trial registered with www.clinicaltrials.gov (NCT 00786526).

Self-perception of knowledge and confidence in performing basic life support among medical students.

AIM: Before implementing new workshops and teaching in our faculty for performing basic life support (BLS), we aimed to determine the level of self-confidence of medical students with regard to the management of cardiac arrest (CA). METHODS: We conducted a preinterventional study. A questionnaire was sent to third-year to sixth-year medical students. We recorded sex, year of training, and personal witnessing of CA. We asked them about their theoretical knowledge on 10 main items of BLS and their self-perception of qualification to conduct a CA situation. We tested the respective influence of sex, year of training, and personal witnessing of CA. RESULTS: In total, 592 (37%) students completed the questionnaire, 42% of them were men. Less than a third of the students (30%) thought of themselves as being sufficiently qualified to conduct BLS. After the third year, the level of study did not influence their theoretical knowledge or their self-perception of qualification. Male sex and the number of CAs witnessed were the only factors positively associated with better self-confidence regarding qualification. CONCLUSION: Self-perception of qualification in BLS is poor in our faculty. In our study, personal witnessing of CA greatly influenced confidence, whereas level of study did not.

Identification of prolonged phrenic nerve conduction time in the ICU: magnetic versus electrical stimulation.

PURPOSE: Retrospective study of prospectively collected data to assess the reliability of cervical magnetic stimulation (CMS) to detect prolonged phrenic nerve (PN) conduction time at the bedside. Because PN injuries may cause diaphragm dysfunction, their diagnosis is relevant in intensive care units (ICU). This is achieved by studying latency and amplitude of diaphragm response to PN stimulation. Electrical stimulation (ES) is the gold standard, but it is difficult to perform in the ICU. CMS is an easy noninvasive tool to assess PN integrity, but co-activates muscles that could contaminate surface chest electromyographic recordings. METHODS: In a first set of 56 ICU patients with suspected PN injury, presence and latency of compound motor action potentials elicited by CMS and ES were compared. With ES as the reference method, CMS was evaluated as a test designed to indicate presence or absence of PN injury. In eight additional patients, intramuscular diaphragm recordings were compared with surface diaphragm recordings and with the electromyograms of possible contamination sources. RESULTS: The sensitivity of CMS to diagnose abnormal PN conduction was 0.91, and specificity was 0.84, whereas positive and negative predictive values were 0.81 and 0.92, respectively. Passing-Bablok regression analysis suggested no differences between the two measures. The correlation between PN latency in response to CMS and ES was significant. The "diaphragm surface" and "needle" latencies were close, and were significantly different from those of possibly contaminating muscles. One hemidiaphragm showed likely signal contamination. CONCLUSION: CMS provides an easy reliable tool to detect prolonged PN conduction time in the ICU.

Intrathoracic phrenic pacing: a 10-year experience in France.

BACKGROUND: Phrenic pacing is an alternative to positive-pressure ventilation in selected patients, mostly in cases of upper spinal cord injury. We evaluated results of phrenic pacing performed by video-assisted thoracic surgery (VATS). METHOD: Between 1997 and 2007, after complete neuromuscular investigations, 20 patients requiring full-time ventilation were selected for phrenic pacing (19 with posttraumatic tetraplegia and 1 with congenital central hypoventilation syndrome). Quadripolar cuff electrodes were fixed around each intrathoracic phrenic nerve via bilateral VATS. They were connected to a subcutaneous radiofrequency receiver coupled to an external radiofrequency transmitter. All patients participated in a reconditioning program beginning 2 weeks after implantation and continued until ventilatory weaning. RESULTS: Phrenic pacing was successful in all cases. No intraoperative complications or perioperative mortality were observed. Intraoperative testing detected stimulation thresholds in 19 patients (range, 0.05-2.9 mA). Ventilatory weaning was obtained in 18 patients. Median diaphragm reconditioning time was 6 weeks (2 weeks-11 months). Reconditioning was still in process in a young woman and was not achieved in an elderly woman with a 4-year history of tetraplegia. All the patients weaned from mechanical ventilation reported improved quality of life. Failure or delay in recovery of effective diaphragm contraction was due to nonreversible amyotrophy. CONCLUSIONS: VATS implantation of 4-pole electrodes around the intrathoracic phrenic nerve is a safe procedure. Ventilatory weaning correlates with the degree of diaphragmatic amyotrophy. Phrenic pacing, performed as soon as neurologic and orthopedic stabilization is achieved, is the most important prognostic factor for successful weaning.

Neurally adjusted ventilatory assist increases respiratory variability and complexity in acute respiratory failure.

BACKGROUND: Neurally adjusted ventilatory assist (NAVA) is a partial ventilatory support mode where positive pressure is provided in relation to diaphragmatic electrical activity (EAdi). Central inspiratory activity is normally not monotonous, but it demonstrates short-term variability and complexity. The authors reasoned that NAVA should produce a more "natural" or variable breathing pattern than other modes. This study compared respiratory variability and complexity during pressure support ventilation (PSV) and NAVA. METHODS: Flow and EAdi were recorded during routine PSV (tidal volume approximately 6-8 ml/kg) and four NAVA levels (1-4 cm H2O/microVEAdi) in 12 intubated patients. Breath-by-breath variability of flow and EAdi-related variables was quantified by the coefficient of variation (CV) and autocorrelation analysis. Complexity of flow and EAdi was described using noise titration, largest Lyapunov exponent, Kolmogorov-Sinai entropy, and three-dimensional phase portraits. RESULTS: Switching from PSV to NAVA increased the CV and decreased the autocorrelation for most flow-related variables in a dose-dependent manner (P < 0.05, partial eta for the CV of mean inspiratory flow 0.642). The changes were less marked for EAdi. A positive noise limit was consistently found for flow and EAdi. Largest Lyapunov exponent and Kolmogorov-Sinai entropy for flow were greater during NAVA than PSV and increased with NAVA level (P < 0.05, partial eta 0.334 and 0.312, respectively). Largest Lyapunov exponent and Kolmogorov-Sinai entropy for EAdi were not influenced by ventilator mode. CONCLUSIONS: Compared with PSV, NAVA increases the breathing pattern variability and complexity of flow, whereas the complexity of EAdi is unchanged. Whether this improves clinical outcomes remains to be determined.