Comparison between Two Inspiratory Muscle Training Protocols, Low Loads versus High Loads, in Institutionalized Elderly Women: A Double-Blind Randomized Controlled Trial.

BACKGROUND: Aging results in a decline in the function of the respiratory muscles. Inspiratory muscle training is presented as a possible solution to attenuate the loss of respiratory function in the elderly. The objective of the study was to evaluate and compare the efficacy of 2 protocols with inspiratory muscle training (IMT), low loads and high loads, to improve respiratory strength, functional capacity and dyspnea in institutionalized elderly women, over 65 years. METHODS: The study was a controlled, randomized, double-blind trial and with allocation concealment performed on 26 institutionalized elderly women distributed in 2 groups, the high-intensity group (HIG) and low-intensity group (LIG). Over an 8-week period an IMT protocol was followed 5 days/week, 15 min/day. The HIG trained with a load of 40% of the maximum inspiratory pressure (MIP) and the LIG with 20%. MIP, maximum expiratory pressure (MEP), functional capacity and dyspnea were evaluated. RESULTS: After training, in the HIG MIP, MEP and functional capacity increased 52, 16 and 7%, respectively (p = 0.000, p = 0.001, p = 0.001) and in the LIG 30, 18 and 9%, respectively (p = 0.002, p = 0.014, p = 0.001). The improvement in MIP was significantly higher in the HIG than in the LIG (p = 0.042). CONCLUSION: IMT with low and high loads improves respiratory muscle strength and functional capacity in institutionalized elderly women. In addition, high loads were significantly more effective to improve MIP.

Central deficiency of norepinephrine synthesis and norepinephrinergic neurotransmission contributes to seizure-induced respiratory arrest.

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of mortality in patients with intractable epilepsy. However, the pathogenesis of SUDEP seems to be poorly understood. Our previous findings showed that the incidence of seizure-induced respiratory arrest (S-IRA) was markedly reduced by atomoxetine in a murine SUDEP model. Because the central norepinephrine α-1 receptor (NEα-1R) plays a vital role in regulating respiratory function, we hypothesized that the suppression of S-IRA by atomoxetine was mediated by NE/NEα-1R interactions that can be reversed by NEα-1R antagonism. We examined whether atomoxetine-mediated suppression of S-IRA evoked by either acoustic stimulation or pentylenetetrazole (PTZ) in DBA/1 mice can be reversed by intraperitoneal (IP) and intracerebroventricular (ICV) administration of prazosin, a selective antagonist of NEα-1R. The content and activity of tyrosine hydroxylase (TH), a rate-limiting enzyme for NE synthesis, in the lower brainstem was measured by ELISA. Electroencephalograms (EEG) were obtained from using the PTZ-evoked SUDEP model. In our models, atomoxetine-mediated suppression of S-IRA evoked by either acoustic stimulation or PTZ was significantly reversed by low doses of IP and ICV prazosin. Neither repetitive acoustic stimulation nor S-IRA reduced TH levels in lower brainstem. However, the enzyme activity of TH levels in lower brainstem was significantly increased by mechanical ventilation with DBA/1 mice, which makes the dying DBA/1 mice suffering from S-IRA and SUDEP recover. EEG data showed that although the protective effect of atomoxetine was reversed by prazosin, neither drug suppressed EEG activity. These data suggest that deficient synthesis of NE and norepinephrinergic neurotransmission contributed to S-IRA and that the NEα-1R is a potential therapeutic target for the prevention of SUDEP.

Comorbidities and Readmissions in Survivors of Acute Hypercapnic Respiratory Failure.

Chronic obstructive pulmonary disease (COPD) is defined by chronic airflow obstruction, but is presently considered as a complex, heterogeneous, and multicomponent disease in which comorbidities and extrapulmonary manifestations make important contributions to disease expression. COPD-related hospital readmission. In particular frequent intensive care unit (ICU) readmissions for exacerbations represent a major challenge and place a high burden on patient outcomes and health-related quality of life, as well as on the healthcare system.In this narrative review, we first address major and often undiagnosed comorbidities associated with COPD that could have an impact on hospital readmission after an index ICU admission for acute hypercapnic respiratory failure. Some guidance for treatment is discussed. Second, we present predictors of hospital and ICU readmission and discuss various strategies to reduce such events.There is a strong rationale to detect and treat major comorbidities early after index ICU admission for acute hypercapnic respiratory failure. It still remains unclear, however, if a comprehensive and holistic approach to comorbidities in frail patients surviving hypercapnic respiratory failure can efficiently reduce the readmission rate.

Training, detraining, and retraining: Two 12-week respiratory muscle training regimens in a child with infantile-onset Pompe disease.

BACKGROUND: Respiratory muscle weakness is a primary cause of morbidity and mortality in patients with Pompe disease. We previously described the effects of our 12-week respiratory muscle training (RMT) regimen in 8 adults with late-onset Pompe disease [1] and 2 children with infantile-onset Pompe disease [2]. CASE REPORT: Here we describe repeat enrollment by one of the pediatric participants who completed a second 12-week RMT regimen after 7 months of detraining. We investigated the effects of two 12-week RMT regimens (RMT #1, RMT #2) using a single-participant A-B-A experimental design. Primary outcome measures were maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP). Effect sizes for changes in MIP and MEP were determined using Cohen's d statistic. Exploratory outcomes targeted motor function. RELEVANCE: From pretest to posttest, RMT #2 was associated with a 25% increase in MIP and a 22% increase in MEP, corresponding with very large effect sizes (d= 2.92 and d= 2.65, respectively). Following two 12-week RMT regimens over 16 months, MIP increased by 69% and MEP increased by 97%, corresponding with very large effect sizes (d= 3.57 and d= 5.10, respectively). MIP and MEP were largely stable over 7 months of detraining between regimens. Magnitude of change was greater for RMT #1 relative to RMT #2.

Interhospital ECMO Transport: Regional Focus.

Utilization of extracorporeal membrane oxygenation (ECMO) has increased dramatically over the last decade. Despite this trend, many medical centers have limited, if any, access to this technology or the resources necessary to manage these complex patients. In an effort to improve the current infrastructure of regional ECMO care, ECMO centers of excellence have an obligation to partner with facilities within their communities and regions to increase access to this potentially life-saving technology. While the need for this infrastructure is widely acknowledged in the ECMO community, few reports describe the actual mechanisms by which a successful interfacility transport program can operate. As such, the purpose of this document is to describe the elements of and methods for providing safe and efficient mobile ECMO services from the perspective of an experienced, high-volume tertiary ECMO center of excellence in the Southeastern United States.

Temporary transvenous diaphragm pacing vs. standard of care for weaning from mechanical ventilation: study protocol for a randomized trial.

BACKGROUND: Mechanical ventilation (MV) is a life-saving technology that restores or assists breathing. Like any treatment, MV has side effects. In some patients it can cause diaphragmatic atrophy, injury, and dysfunction (ventilator-induced diaphragmatic dysfunction, VIDD). Accumulating evidence suggests that VIDD makes weaning from MV difficult, which involves increased morbidity and mortality. METHODS AND ANALYSIS: This paper describes the protocol of a randomized, controlled, open-label, multicenter trial that is designed to investigate the safety and effectiveness of a novel therapy, temporary transvenous diaphragm pacing (TTVDP), to improve weaning from MV in up to 88 mechanically ventilated adult patients who have failed at least two spontaneous breathing trials over at least 7 days. Patients will be randomized (1:1) to TTVDP (treatment) or standard of care (control) groups. The primary efficacy endpoint is time to successful extubation with no reintubation within 48 h. Secondary endpoints include maximal inspiratory pressure and ultrasound-measured changes in diaphragm thickness and diaphragm thickening fraction over time. In addition, observational data will be collected and analyzed, including 30-day mortality and time to discharge from the intensive care unit and from the hospital. The hypothesis to be tested postulates that more TTVDP patients than control patients will be successfully weaned from MV within the 30 days following randomization. DISCUSSION: This study is the first large-scale clinical trial of a novel technology (TTVDP) aimed at accelerating difficult weaning from MV. The technology tested provides the first therapy directed specifically at VIDD, an important cause of delayed weaning from MV. Its results will help delineate the place of this therapeutic approach in clinical practice and help design future studies aimed at defining the indications and benefits of TTVDP. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03096639 . Registered on 30 March 2017.

High-flow nasal therapy vs standard oxygen during breaks off noninvasive ventilation for acute respiratory failure: A pilot randomized controlled trial.

PURPOSE: To assess the role of high-flow nasal therapy (HFNT) compared to standard oxygen (SO) as complementary therapy to non-invasive ventilation (NIV). METHODS: Multicenter trial including patients (n = 54) anticipated to receive NIV for ≥24 h due to acute or acute-on-chronic respiratory failure. Subjects were randomized (1:1) to SO or HFNT during breaks off NIV. Primary outcome was total time on and off NIV. Secondary outcomes were comfort and dyspnea, respiratory rate (RR), oxygen saturation (SpO2), tolerance and side effects. RESULTS: Total time per patient on NIV (1315 vs 1441 min) and breaks (1362 vs 1196 min), and mean duration of each break (520 vs 370 min) were similar in the HFNT and SO arms (p > .05). Comfort score was higher on HFNT than on SO (8.3 ±â€¯2.7 vs 6.9 ±â€¯2.3, p = .001). Dyspnea, RR and SpO2 were similar in the two arms, but the increase in RR and dyspnea seen with SO during breaks did not occur with HFNT. CONCLUSION: Compared to SO, HFNT did not reduce time on NIV. However, it was more comfortable and the increase in RR and dyspnea seen with SO did not occur with HFNT. Therefore, HFNT could be a suitable alternative to SO during breaks off NIV.

How New Support Devices Change Critical Care Delivery.

Mechanical support devices are used to support failing cardiac, respiratory, or both systems. Since Gibbon developed the cardiopulmonary bypass in 1953, collaborative efforts by medical centers, bioengineers, industry, and the National Institutes of Health have led to development of mechanical devices to support heart, lung, or both. These devices are used as a temporary or long-term measures for acute collapse of circulatory system and/or respiratory failure. Patients are managed on these support devices as a bridge to recovery, bridge to long term devices, or bridge to transplant. The progress in development of these devices has improved mortality and quality of life in select groups of patients. Care of these patients requires a multidisciplinary team approach, which includes cardiac surgeons, critical care physicians, cardiologists, pulmonologists, nursing staff, and perfusionists. Using a team approach improves outcomes in these patients.

Effects of Nutritional Intervention on the Survival of Patients with Cardiopulmonary Failure Undergoing Extracorporeal Membrane Oxygenation Therapy.

BACKGROUND/AIM: This study aimed to examine the effects of nutritional intervention on the prognosis of patients with cardiopulmonary failure undergoing extracorporeal membrane oxygenation (ECMO) therapy in Taiwan. MATERIALS AND METHODS: An institutional review board-approved retrospective study was conducted on patients receiving ECMO therapy in the intensive care unit of the China Medical University Hospital, Taiwan, from January 2013 to December 2013. The study included 102 patients with cardiopulmonary failure receiving ECMO therapy. RESULTS: The data indicated that higher survival rates were closely related to lower age and APACHE II scores among the patients. In addition, compared to patients who deceased, those who survived had a higher total calorie intake. Most patients could tolerate bolus feeding and polymeric formulas. Furthermore, patients who underwent nutritional therapy with nutritional goals greater than 80% achieved a better outcome and lower mortality than other patients. CONCLUSION: Early nutritional intervention could benefit patients undergoing ECMO, and those who reached the delivery goal of 80% had significantly better outcomes than other patients. Enteral feeding can begin early and was well tolerated by patients receiving ECMO therapy. Following individual nutrition goals is critical for better outcomes, and this analysis might be useful in establishing individualized nutrition goals for oriental population when caring for critically ill patients.

The clinical practice of high-flow nasal cannula oxygen therapy in adults: A Japanese cross-sectional multicenter survey.

BACKGROUND: High-flow nasal cannula oxygen therapy (HFNC) is widely used mainly in the acute care setting, but limited data are available on real-world practice in adults. The objective of this study was to describe HFNC practices in Japanese adults. METHODS: A retrospective cross-sectional multicenter survey of adult patients receiving HFNC from January through March 2015 was conducted in 33 participating hospitals in Japan. RESULTS: We obtained information on 321 patients (median age, 76; 218 men, 103 women; median estimated PaO2/FIO2, 178 mm Hg) from 22 hospitals. Do-not-intubate status was determined in 37.4% of patients. Prior to HFNC, 57.9% of patients received conventional oxygen therapy; 25.9%, noninvasive ventilation; and 15.0%, invasive mechanical ventilation. The common indications for HFNC were acute hypoxemic respiratory failure (ARF) (65.4%), postoperative respiratory support (15.9%), and post-extubation respiratory support (11.2%). The underlying etiology of ARF included interstitial lung disease, pneumonia, and cardiogenic pulmonary edema. HFNC was administered mostly in intensive care units or intermittent care units (60.7%) and general wards (36.1%). Median duration of HFNC was 4 days; median total flow rate, 40 L/min; and median FIO2, 50%. HFNC significantly improved PaO2, PaCO2, SpO2 and respiratory rate from baseline. Two-thirds of patients finally survived to be discharged or transferred. CONCLUSIONS: We documented patient demographics, clinical indications, and settings of HFNC use in the real world. We also demonstrated positive effects of HFNC on respiratory parameters. Further studies are urgently needed regarding the efficacy and safety of HFNC in populations outside of previous clinical trials.

Stimulation of abdominal and upper thoracic muscles with surface electrodes for respiration and cough: Acute studies in adult canines.

OBJECTIVE: To optimize maximal respiratory responses with surface stimulation over abdominal and upper thorax muscles and using a 12-Channel Neuroprosthetic Platform. METHODS: Following instrumentation, six anesthetized adult canines were hyperventilated sufficiently to produce respiratory apnea. Six abdominal tests optimized electrode arrangements and stimulation parameters using bipolar sets of 4.5 cm square electrodes. Tests in the upper thorax optimized electrode locations, and forelimb moment was limited to slight-to-moderate. During combined muscle stimulation tests, the upper thoracic was followed immediately by abdominal stimulation. Finally, a model of glottal closure for cough was conducted with the goal of increased peak expiratory flow. RESULTS: Optimized stimulation of abdominal muscles included three sets of bilateral surface electrodes located 4.5 cm dorsal to the lateral line and from the 8th intercostal space to caudal to the 13th rib, 80 or 100 mA current, and 50 Hz stimulation frequency. The maximal expired volume was 343 ± 23 ml (n=3). Optimized upper thorax stimulation included a single bilateral set of electrodes located over the 2nd interspace, 60 to 80 mA, and 50 Hz. The maximal inspired volume was 304 ± 54 ml (n=4). Sequential stimulation of the two muscles increased the volume to 600 ± 152 ml (n=2), and the glottal closure maneuver increased the flow. CONCLUSIONS: Studies in an adult canine model identified optimal surface stimulation methods for upper thorax and abdominal muscles to induce sufficient volumes for ventilation and cough. Further study with this neuroprosthetic platform is warranted.

Acute effects of glossopharyngeal insufflation in people with cervical spinal cord injury.

OBJECTIVES: To evaluate acute effects of glossopharyngeal insufflation (GI) on lung function, airway pressure (Paw), blood pressure and heart rate (HR) in people with cervical spinal cord injury (CSCI). DESIGN: Case-control design. SETTING: Karolinska Institutet, Stockholm, Sweden. PARTICIPANTS: Ten participants with CSCI suffering from lesions between C4 and C8, and ASIA classification of A or B were recruited. Ten healthy particpants familiar with GI were recruited as a reference group. OUTCOME MEASURES: Spirometry, mean arterial blood pressure (MAP), Paw, and HR were measured in a sitting and a supine position before, during, and after GI. RESULTS: GI in the study group in a sitting position increased total lung capacity (TLC) by 712 ml: P < 0.001, vital capacity (VC) by 587 ml: P < 0.0001, Paw by 13 cm H2O: P < 0.01, and HR by 10 beats/min: P < 0.001. MAP decreased by 25 mmHg, P < 0.0001. Significant differences were observed between groups comparing baseline with GI. The reference group had a higher increase in; TLC (P < 0.01), VC (P < 0.001), Paw (P < 0.001) and HR (P < 0.05) and a higher decrease in MAP (P < 0.001). With GI in a sitting compared to a supine position, TLC, MAP, HR, Paw remained unchanged in the study group, while residual volume decreased in the supine position (P < 0.01). CONCLUSION: There was a difference between the groups in the increase in TLC; VC; Paw, HR and in the decrease in MAP with GI, however MAP, HR and Paw responded in similar way in both groups in a sitting as well as a supine position. If performed correctly, the risks of GI resulting in clinically significant hemodynamic changes is low, although syncope may still occur.

Nasal high flow therapy: a novel treatment rather than a more expensive oxygen device.

Nasal high flow is a promising novel oxygen delivery device, whose mechanisms of action offer some beneficial effects over conventional oxygen systems. The administration of a high flow of heated and humidified gas mixture promotes higher and more stable inspiratory oxygen fraction values, decreases anatomical dead space and generates a positive airway pressure that can reduce the work of breathing and enhance patient comfort and tolerance. Nasal high flow has been used as a prophylactic tool or as a treatment device mostly in patients with acute hypoxaemic respiratory failure, with the majority of studies showing positive results. Recently, its clinical indications have been expanded to post-extubated patients in intensive care or following surgery, for pre- and peri-oxygenation during intubation, during bronchoscopy, in immunocompromised patients and in patients with "do not intubate" status. In the present review, we differentiate studies that suggest an advantage (benefit) from other studies that do not suggest an advantage (no benefit) compared to conventional oxygen devices or noninvasive ventilation, and propose an algorithm in cases of nasal high flow application in patients with acute hypoxaemic respiratory failure of almost any cause.

Specific subcortical structures are activated during seizure-induced death in a model of sudden unexpected death in epilepsy (SUDEP): A manganese-enhanced magnetic resonance imaging study.

Sudden unexpected death in epilepsy (SUDEP) is a major concern for patients with epilepsy. In most witnessed cases of SUDEP generalized seizures and respiratory failure preceded death, and pre-mortem neuroimaging studies in SUDEP patients observed changes in specific subcortical structures. Our study examined the role of subcortical structures in the DBA/1 mouse model of SUDEP using manganese-enhanced magnetic resonance imaging (MEMRI). These mice exhibit acoustically-evoked generalized seizures leading to seizure-induced respiratory arrest (S-IRA) that results in sudden death unless resuscitation is rapidly instituted. MEMRI data in the DBA/1 mouse brain immediately after acoustically-induced S-IRA were compared to data in C57 (control) mice that were exposed to the same acoustic stimulus that did not trigger seizures. The animals were anesthetized and decapitated immediately after seizure in DBA/1 mice and after an equivalent time in control mice. Comparative T1 weighted MEMRI images were evaluated using a 14T MRI scanner and quantified. We observed significant increases in activity in DBA/1 mice as compared to controls at previously-implicated auditory (superior olivary complex) and sensorimotor-limbic [periaqueductal gray (PAG) and amygdala] networks and also in structures in the respiratory network. The activity at certain raphe nuclei was also increased, suggesting activation of serotonergic mechanisms. These data are consistent with previous findings that enhancing the action of serotonin prevents S-IRA in this SUDEP model. Increased activity in the PAG and the respiratory and raphe nuclei suggest that compensatory mechanisms for apnea may have been activated by S-IRA, but they were not sufficient to prevent death. The present findings indicate that changes induced by S-IRA in specific subcortical structures in DBA/1 mice are consistent with human SUDEP findings. Understanding the changes in brain activity during seizure-induced death in animals may lead to improved approaches directed at prevention of human SUDEP.

Intravenous Poison Hemlock Injection Resulting in Prolonged Respiratory Failure and Encephalopathy.

BACKGROUND: Poison hemlock (Conium maculatum) is a common plant with a significant toxicity. Data on this toxicity is sparse as there have been few case reports and never a documented poisoning after intravenous injection. OBJECTIVES: We present a case of intravenous poison hemlock injection encountered in the emergency department. CASE REPORT: We describe a 30-year-old male who presented to the emergency department after a brief cardiac arrest after injecting poison hemlock. The patient had return of spontaneous circulation in the emergency department but had prolonged muscular weakness and encephalopathy later requiring tracheostomy. CONCLUSION: Intravenous injection of poison hemlock alkaloids can result in significant toxicity, including cardiopulmonary arrest, prolonged weakness, and encephalopathy.

Fish Oil Supplementation Enhances Pulmonary Strength and Endurance in Women Undergoing Chemotherapy.

We investigated the effect of fish oil (FO) supplementation, at 4 g/day, on the respiratory performance and blood lipid profile of 32 patients with breast cancer at the beginning of chemotherapy. They were randomized into two groups: control (C) and FO supplemented (S). Both groups underwent three respiratory evaluations and blood harvest (before chemotherapy-Day 0, and 30 and 60 days after supplementation). The S group showed a significant increase in the maximal inspiratory and expiratory pressure (P ≤ 0.05 vs. Day 0) and in the maximum voluntary ventilation (P ≤ 0.05). In the treadmill 6-min-walk test, the S group had a significant increase in the walked distance (P ≤ 0.05). Blood lactate concentration was significantly lower in the S group after 60 days, at rest, when compared to C (P ≤ 0.05). Plasma high-density lipoprotein (HDL) cholesterol concentration remained the same after 60 days of supplementation, while in the C group, it decreased significantly (P ≤ 0.05 Day 0 vs. Day 60). Triacylglycerol (TAG) plasma concentration in the S group was lower when compared to the C group (P ≤ 0.05 Day 60S vs. Day 60). Supplementation with FO caused improvement in the respiratory muscle strength and endurance, ameliorated functional performance, and kept TAG, HDL cholesterol, and lactate plasma concentration at normal levels.

Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series.

BACKGROUND AND PURPOSE: Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments. CASE DESCRIPTION: Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function. OUTCOMES: During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support. DISCUSSION: The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but further study is needed. Diaphragm pacing represents a paradigm shift in the management of respiratory insufficiency for Pompe disease that warrants further controlled examination.

Intramuscular diaphragmatic stimulation for patients with traumatic high cervical injuries and ventilator dependent respiratory failure: A systematic review of safety and effectiveness.

BACKGROUND: Intramuscular diaphragmatic stimulation using an abdominal laparoscopic approach has been proposed as a safer alternative to traditional phrenic nerve stimulation. It has also been suggested that early implementation of diaphragmatic pacing may prevent diaphragm atrophy and lead to earlier ventilator independence. The aim of this study was therefore to systematically review the safety and effectiveness of intramuscular diaphragmatic stimulators in the treatment of patients with traumatic high cervical injuries resulting in long-term ventilator dependence, with particular emphasis on the affect of timing of insertion of such stimulators. METHODS: The Cochrane database and PubMed were searched between January 2000 and June 2015. Reference lists of selected papers were also reviewed. The inclusion criteria used to select from the pool of eligible studies were: (1) reported on adult patients with traumatic high cervical injury, who were ventilator-dependant, (2) patients underwent intramuscular diaphragmatic stimulation, and (3) commented on safety and/or effectiveness. RESULTS: 12 articles were included in the review. Reported safety issues post insertion of intramuscular electrodes included pneumothorax, infection, and interaction with pre-existing cardiac pacemaker. Only one procedural failure was reported. The percentage of patients reported as independent of ventilatory support post procedure ranged between 40% and 72.2%. The mean delay of insertion ranged from 40 days to 9.7 years; of note the study with the average shortest delay in insertion reported the greatest percentage of fully weaned patients. CONCLUSIONS: Although evidence for intramuscular diaphragmatic stimulation in patients with high cervical injuries and ventilator dependent respiratory failure is currently limited, the technique appears to be safe and effective. Earlier implantation of such devices does not appear to be associated with greater surgical risk, and may be more effective. Further high quality studies are warranted to investigate the impact of delay of insertion on ventilator weaning.

Importance of diaphragm thickness in amyotrophic lateral sclerosis patients with diaphragm pacing system implantation.

INTRODUCTION: Severe respiratory failure develops as a result of the involvement of the respiratory muscles in patients with amyotrophic lateral sclerosis (ALS). Implantation of diaphragm pacing system (DPS) has been carried out on ALS patients since 2005 to avoid these situations, but the importance of diaphragm thickness has not yet been established clearly. MATERIAL AND METHOD: We retrospectively evaluated 34 ALS patients who had previously implanted DPS to detect the importance of diaphragm thickness. We investigated the effect of diaphragm thickness, which was measured by preoperative thorax computerized tomography on preoperative respiratory function tests (RFT), arterial blood gas (ABG) analysis, postoperative 3- and 6-month oxygen saturations and mortality. RESULTS: The right diaphragm thickness was calculated as 4.60 (2.95-6.00) mm, while the left diaphragm thickness was 4.10 (2.77-6.00) mm. Six patients died during the follow-up period. We did not detect a significant relationship between ABG parameters, RFT and diaphragm thickness. However, according to our observations, the diaphragm thickness was significantly related to mortality. The right diaphragm was significantly thinner in cases that required preoperative respiratory support and had percutaneous endoscopic gastrostomy. When the cut-off values for the diaphragm thickness were accepted as 3.50 mm, significantly higher mortality among patients below this was observed. CONCLUSION: Diaphragm thickness is an important criterion in cases for which DPS implantation is planned. We consider that avoidance of DPS implantation is more suitable for cases with a diaphragm thickness below 3.50 mm because of mortality.

Respiratory neuromodulation in patients with neurological pathologies: for whom and how?

Implanted phrenic nerve stimulation is a technique restoring spontaneous breathing in patients with respiratory control failure, leading to being dependent on mechanical ventilation. This is the case for quadriplegic patients with a high spinal cord injury level and for patients with congenital central hypoventilation syndrome. The electrophysiological diaphragm explorations permits better patient selection, confirming on the one hand a definite issue with central respiratory command and on the other hand the integrity of diaphragmatic phrenic nerves. Today there are two different phrenic stimulation techniques: the quadripolar intrathoracic stimulation and the bipolar intradiaphragmatic stimulation. Both techniques allow patients to be weaned off their mechanical ventilator, improving dramatically their quality of life. In fact, one of the systems (phrenic intradiaphragmatic stimulation) was granted social security reimbursement in 2009, and now both are reimbursed. In the future, phrenic intradiaphragmatic stimulation may find its place in the intensive care unit, for patients needing it temporarily, for example, after certain surgeries with respiratory complications as well as diaphragmatic atrophies induced by prolonged mechanical ventilation.