Successful extubation conventionally necessitates the passing of spontaneous breathing trials (SBTs) and ventilator weaning parameters. We report successful extubation of patients with neuromuscular ...disease (NMD) and weakness who could not pass them.
NMD-specific extubation criteria and a new extubation protocol were developed. Data were collected on 157 consecutive "unweanable" patients, including 83 transferred from other hospitals who refused tracheostomies. They could not pass the SBTs before or after extubation. Once the pulse oxyhemoglobin saturation (Spo(2)) was maintained at > or = 95% in ambient air, patients were extubated to full noninvasive mechanical ventilation (NIV) support and aggressive mechanically assisted coughing (MAC). Rather than oxygen, NIV and MAC were used to maintain or return the Spo(2) to > or = 95%. Extubation success was defined as not requiring reintubation during the hospitalization and was considered as a function of diagnosis, preintubation NIV experience, and vital capacity and assisted cough peak flows (CPF) at extubation.
Before hospitalization 96 (61%) patients had no experience with NIV, 41 (26%) used it < 24 h per day, and 20 (13%) were continuously NIV dependent. The first-attempt protocol extubation success rate was 95% (149 patients). All 98 extubation attempts on patients with assisted CPF > or = 160 L/m were successful. The dependence on continuous NIV and the duration of dependence prior to intubation correlated with extubation success (P < .005). Six of eight patients who initially failed extubation succeeded on subsequent attempts, so only two with no measurable assisted CPF underwent tracheotomy.
Continuous volume-cycled NIV via oral interfaces and masks and MAC with oximetry feedback in ambient air can permit safe extubation of unweanable patients with NMD.
An effective clearing of the airways requires a balance between production and removal of respiratory secretions through the muco-ciliary escalator. In ICU patients, both sides of the balance can be ...impaired. Te amount of respiratory secretions can be increased from infection, aspiration, or swallowing disorders. Te removal of respiratory secretions can be reduced by upper airway dysfunction and/or respiratory muscle weakness. Many pre-existing or ICU-acquired situations, like chronic neuromuscular disease (NMD), ICU-acquired neuromuscular weakness, sepsis, delirium or conscious level decline due to brain damage may compromise optimal glottis functioning or respiratory muscle strength 1 and, hence, promote unbalance between production and removal of respiratory secretions. Important pathophysiological consequences of this unbalance include increased airway resistance and work of breathing, hypoxemia, atelectasis, and superinfection. Any caregiver in the ICU, whether he/she is a physician, physiotherapist, respiratory therapist, or nurse, has been used to facing the need of tracheal intubation and invasive mechanical ventilation (after a failing attempt of noninvasive ventilation or high oxygen fow) or extubation failure due to copious respiratory secretions.
This is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in ...Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in people with bulbar insufficiency; children and infants) and recommends when and how each technique should be applied.
Weaning protocols that include noninvasive ventilation (NIV) decrease re-intubation rates and ICU length of stay. However, impaired airway clearance is associated with NIV failure. Mechanical ...insufflation-exsufflation (MI-E) has been proven to be very effective in patients receiving NIV. We aimed to assess the efficacy of MI-E as part of an extubation protocol.
Patients with mechanical ventilation (MV) for more than 48 hours with specific inclusion criteria, who successfully tolerated a spontaneous breathing trial (SBT), were randomly allocated before extubation, either for (A) a conventional extubation protocol (control group), or (B) the MI-E extubation protocol (study group). During the postextubation period (48 hours), group A patients received standard medical treatment (SMT), including NIV in case of specific indications, whereas group B received the same postextubation approach plus three daily sessions of mechanical in-exsufflation (MI-E). Reintubation rates, ICU length of stay, and NIV failure rates were analyzed.
Seventy-five patients (26 women) with a mean age of 61.8 ± 17.3 years were randomized to a control group (n = 40; mean SAPS II, 47.8 ± 17.7) and to a study group (n = 35; mean SAPS II, 45.0 ± 15.0). MV time before enrollment was 9.4 ± 4.8 and 10.5 ± 4.1 days for the control and the study group, respectively. In the 48 hours after extubation, 20 control patients (50%) and 14 study patients (40%) used NIV. Study group patients had a significant lower reintubation rate than did controls; six patients (17%) versus 19 patients (48%), P < 0.05; respectively, and a significantly lower time under MV; 17.8 ± 6.4 versus 11.7 ± 3.5 days; P < 0.05; respectively. Considering only the subgroup of patients that used NIV, the reintubation rates related to NIV failure were significantly lower in the study group when compared with controls; two patients (6%) versus 13 (33%); P < 0.05, respectively. Mean ICU length of stay after extubation was significantly lower in the study group when compared with controls (3.1 ± 2.5 versus 9.8 ± 6.7 days; P < 0.05). No differences were found in the total ICU length of stay.
Inclusion of MI-E may reduce reintubation rates with consequent reduction in postextubation ICU length of stay. This technique seems to be efficient in improving the efficacy of NIV in this patient population.
Several distinct fluid flow phenomena occur in solid tumors, including intravascular blood flow and interstitial convection. Interstitial fluid pressure is often raised in solid tumors, which can ...limit drug delivery. To probe low-velocity flow in tumors resulting from raised interstitial fluid pressure, we developed a novel MRI technique named convection-MRI, which uses a phase-contrast acquisition with a dual-inversion vascular nulling preparation to separate intra- and extravascular flow. Here, we report the results of experiments in flow phantoms, numerical simulations, and tumor xenograft models to investigate the technical feasibility of convection-MRI. We observed a significant correlation between estimates of effective fluid pressure from convection-MRI with gold-standard, invasive measurements of interstitial fluid pressure in mouse models of human colorectal carcinoma. Our results show how convection-MRI can provide insights into the growth and responsiveness to vascular-targeting therapy in colorectal cancers.
A noninvasive method for measuring low-velocity fluid flow caused by raised fluid pressure can be used to assess changes caused by therapy.
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Respiratory management of patients with end-stage respiratory muscle failure of neuromuscular disease has evolved from no treatment and inevitable respiratory failure to the use of up to continuous ...noninvasive intermittent positive pressure ventilatory support (CNVS) to avert respiratory failure and to permit the extubation of "unweanable" patients without tracheostomy. An international panel experienced in CNVS was charged by the 69th Congress of the Mexican Society of Pulmonologists and Thoracic Surgeons to analyze changing respiratory management trends and to make recommendations.
Neuromuscular disease respiratory consensuses and reviews were identified from PubMed. Individual respiratory interventions were identified; their importance was established by assessing the quality of evidence-based literature for each one and their patterns of use over time. The panel then determined the evidence-based strength for the efficacy of each intervention and made recommendations for achieving prolonged survival by CNVS.
Fifty publications since 1993 were identified. Continuous positive airway pressure, oxygen therapy, bilevel positive airway pressure used at both low and high spans, "air stacking," manually assisted coughing, low pressure (<35 cm H2O) and high pressure (≥40 cm H2O) mechanically assisted coughing, noninvasive positive pressure ventilation part time (<23 hrs per day) and full time (>23 hrs per day; CNVS), extubation and decannulation of ventilator-dependent patients to CNVS, and oximetry feedback for noninvasive positive pressure ventilation and mechanically assisted coughing were identified. All noted interventions are being used with increasing frequency and were unanimously recommended to achieve prolonged survival by CNVS, with the exception of supplemental oxygen and continuous positive airway pressure, which are being used less and were not recommended for this population.
CNVS and extubation of unweanable patients to CNVS are increasingly being used to prolong life while avoiding invasive interfaces.
The aim of the study was to evaluate the efficacy of noninvasive ventilatory assistance/support via mouthpiece to improve performance in 6-min walk tests for individuals with severe restrictive ...ventilatory disorders.
Each subject performed the 6-min walk test breathing spontaneously and again while using mouthpiece noninvasive ventilatory assistance/support at full ventilatory support. Oxyhemoglobin saturation (O2 sat), heart rate, Borg scale, distance walked, and ambulation duration were recorded.
Eighteen patients using nocturnal nasal noninvasive ventilatory assistance/support, median (interquartile range) age of 58.5 (20) yrs, were studied. Their median baseline forced vital capacity and PaCO2 were 940 (385) ml and 54.1 (6) mm Hg, respectively. All used noninvasive ventilatory assistance/support for at least overnight hours for 36 (111) mos. Because of the progression of ventilatory impairment and hypercapnia, daytime mouthpiece noninvasive ventilatory assistance/support was initiated. All the 6-min walk test parameters improved significantly by using noninvasive ventilatory assistance/support. Both initial and final values of O2 saturation significantly increased (92% 6 vs 96% 2, P < 0.001) and (80% 19 vs 85.50% 13, P = 0.001), respectively. The median distance walked increased by 43% with noninvasive ventilatory assistance/support (175 218 m vs 250 113 m, P = 0.017), and the total ambulation time also increased with noninvasive ventilatory assistance/support (5.45 3 mins vs. 6 0 mins, P = 0.008).
The exercise tolerance of patients with severe ventilatory impairment can improve by using noninvasive ventilatory support.
In neuromuscular disorders (NMDs), nocturnal non-invasive ventilation (NIV) via a nasal mask is offered when hypercapnic respiratory failure occurs. With disease progression, nocturnal NIV needs to ...be extended into the daytime. Mouthpiece ventilation (MPV) is an option for daytime NIV. MPV represents a difficult task for home ventilators due to rapidly changing load conditions resulting from intermittent connections and disconnections from MPV circuit. The 252nd ENMC International Expert Workshop, held March 6th to 8th 2020 in Amsterdam, reported general guidelines for management of daytime MPV in NMDs. This report could not present all the detail regarding the technical issues important for clinical success of MPV. Based on the expert workshop discussions and the evidence from existing studies, the current narrative review aims to identify the technical issues of MPV and offers guidance via a decisional algorithm and educational figures providing relevant information that is important for successful implementation of MPV.
•Mouthpiece ventilation (MPV) represents a difficult task for home ventilators due to rapidly changing load conditions.•Circuit leakage is a natural part of MPV.•Volume-cycled ventilation copes better with circuit leakage than pressure-cycled ventilation.•Volume-cycled ventilation is considered as the first line mode to initiate MPV since it allows intermittent lip sealing without leak compensation.•Ventilators equipped with a dedicated MPV mode provide 10 new technological properties which favors the use of MPV at home.
Solid tumours can undergo cycles of hypoxia, followed by reoxygenation, which can have significant implications for the success of anticancer therapies. A need therefore exists to develop methods to ...aid its detection and to further characterise its biological basis. We present here a novel method for decomposing systemic and tumour-specific contributions to fluctuations in tumour deoxyhaemoglobin concentration, based on magnetic resonance imaging measurements.
Fluctuations in deoxyhaemoglobin concentration in two tumour xenograft models of colorectal carcinoma were decomposed into distinct contributions using independent component analysis. These components were then correlated with systemic pulse oximetry measurements to assess the influence of systemic variations in blood oxygenation in tumours, compared with those that arise within the tumour itself (tumour-specific). Immunohistochemical staining was used to assess the physiological basis of each source of fluctuation.
Systemic fluctuations in blood oxygenation were found to contribute to cycling hypoxia in tumours, but tumour-specific fluctuations were also evident. Moreover, the size of the tumours was found to influence the degree of systemic, but not tumour-specific, oscillations. The degree of vessel maturation was related to the amplitude of tumour-specific, but not systemic, oscillations.
Our results provide further insights into the complexity of spontaneous fluctuations in tumour oxygenation and its relationship with tumour pathophysiology. These observations could be used to develop improved drug delivery strategies.
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