Effect of controlled ventilation on diaphragm

Background : Since diaphragm passivity induces oxidative stress that leads to rapid atrophy of diaphragm, we investigated the effect of controlled ventilation on diaphragm thickness during assist-control ventilation (ACV). Methods : Previously, we measured end-expiratory diaphragm thickness (Tdiee) of patients mechanically ventilated for more than 48 hours on days 1, 3, 5 and 7 after the start of ventilation. We retrospectively investigated the proportion of controlled ventilation during the initial 48-hour ACV (CV48%). Patients were classified according to CV48% : Low group, less than 25% ; High group, higher than 25%. Results : Of 56 patients under pressure-control ACV, Tdiee increased more than 10% in 6 patients (11%), unchanged in 8 patients (14%) and decreased more than 10% in 42 patients (75%). During the first week of ventilation, Tdiee decreased in both groups : Low (difference, -7.4% ; 95% confidence interval [CI], -10.1% to -4.6% ; p < 0.001) and High group (difference, -5.2% ; 95% CI, -8.5% to -2.0% ; p = 0.049). Maximum Tdiee variation from baseline did not differ between Low (-15.8% ; interquartile range [IQR], -22.3 to -1.5) and High group (-16.7% ; IQR, -22.6 to -11.1, p = 0.676). Conclusions : During ACV, maximum variation in Tdiee was not associated with proportion of controlled ventilation higher than 25%

Dexmedetomidine and sleep during HFNC

Purpose : High-flow nasal cannula oxygen therapy (HFNC) is a new type of non-invasive respiratory support for acute respiratory failure patients. However, patients receiving HFNC often develop sleep disturbances. We therefore examined whether dexmedetomidine could preserve the sleep characteristics in patients who underwent HFNC. Patients and Methods : This was a pilot, randomized controlled study. We assigned critically ill patients treated with HFNC to receive dexmedetomidine (0.2 to 0.7 μg / kg / h, DEX group) or not (non-DEX group) at night (9:00 p.m. to 6:00 a.m.). Polysomnograms were monitored during the study period. The primary outcomes were total sleep time (TST), sleep efficiency and duration of stage 2 non-rapid eye movement (stage N2) sleep. Results : Of the 28 patients who underwent randomization, 24 were included in the final analysis (12 patients per group). Dexmedetomidine increased the TST (369 min vs. 119 min, p = 0.024) and sleep efficiency (68% vs. 22%, P = 0.024). The duration of stage N2 was increased in the DEX group compared with the non-DEX group, but this finding did not reach statistical significance. The incidences of respiratory depression and hemodynamic instability were similar between the two groups. Conclusions : In critically ill patients who underwent HFNC, dexmedetomidine may optimize the sleep quantity without any adverse events

Acquired laryngomalacia after craniotomy

Background : Laryngomalacia is a congenital abnormality of the larynx that commonly occurs in children and rarely in adults. We report the first case of acquired laryngomalacia mainly due to postoperative seizure and central pontine myelinolysis after scheduled craniotomy. Case presentation : A 69-year-old man was admitted to the hospital for elective craniotomy for craniopharyngioma. After the surgery, he developed refractory seizure and required intubation and mechanical ventilation in the intensive-care unit (ICU). After treatment for the seizure, he was extubated. However, immediately after extubation, he developed stridor and respiratory retraction. We performed fiberoptic laryngoscopy and confirmed that the epiglottis had collapsed into the posterior wall of the pharynx during inspiration, which was suspected to be laryngomalacia. He received invasive mechanical ventilation for two days following re-extubation. After the second extubation, he developed stridor again due to acquired laryngomalacia. Six days later, his respiratory condition had worsened, and he received re-intubation and tracheostomy. After ICU discharge, central pontine myelinolysis was diagnosed by magnetic resonance imaging. Conclusions : Adult-onset laryngomalacia is a rare cause of upper airway obstruction but should be considered as a cause of postoperative extubation failure. We should not delay performing fiberoptic laryngoscopy to evaluate this pathology and provide optimal treatment

Independent ventilation of graft rejection

Background : We herein report the use of independent lung ventilation (ILV) for managing acute allograft rejection after single-lung transplantation (SLT) for end-stage emphysema. Case presentation : A 54-year-old woman was transferred to our hospital with severe hypoxemia and respiratory distress due to unilateral lung disease with diffuse alveolar damage in the right donor lung associated with acute allograft rejection and with hyperinflation of the left native lung due to emphysema. She was unresponsive to immunosuppressive medications and conventional ventilation strategies, so different ventilator settings for each lung were required. A double-lumen endotracheal tube (DLT) was inserted, and ILV was initiated. The right lung was ventilated with high positive end-expiratory pressure (PEEP), intended for lung recruitment, and the left lung was ventilated with lung protective strategies using a low tidal volume and low levels of PEEP to avoid hyperinflation. Two days later, her lung function was dramatically improved, and the DLT was replaced with a single-lumen endotracheal tube. Gas exchange was maintained, and she was successfully weaned from mechanical ventilation on intensive-care unit day 15. Conclusions : ILV appears to be effective and safe for managing acute allograft rejection after SLT for emphysema

extubation failure due to subglottic stenosis

Background : This report describes a case of dynamic inspiratory airway collapse concomitant with subglottic stenosis in a patient who previously underwent tracheostomy that led to repeated post-operative extubation failure. Case presentation : A 43-year-old woman who had undergone tracheostomy 25 years previously was admitted to our intensive-care unit (ICU) after coronary artery bypass graft surgery. On postoperative day (POD) 0, she was extubated, but stridor was observed. We suspected upper airway obstruction and she was therefore reintubated. Before reintubation, urgent laryngotracheoscopy revealed dynamic inspiratory airway collapse and obstruction concomitant with subglottic stenosis. Preoperative computed tomography showed mild subglottic stenosis. Although intravenous corticosteroids were administered to prevent tracheal mucosal edema and a cuff leak test was confirmed to be negative, she developed extubation failure on POD6. On POD12, we performed tracheostomy to reduce mechanical irritation from the endotracheal tube. Mechanical ventilation was withdrawn and she discharged from the ICU. On POD33, her tracheostomy tube was removed and she remained clinically asymptomatic. Conclusions : We should be aware of the history of tracheostomy, especially at high tracheostomy sites, even in the absence of respiratory symptoms as risk factors for dynamic inspiratory airway collapse concomitant with subglottic stenosis contributing to repeated respiratory failure after extubation

致死的低酸素血症をきたした神経芽細胞腫Stage4Sの一乳児症例

Background : Neuroblastoma is the most common extracranial solid tumor of childhood. Although the prognosis of neuroblastoma is relatively good, newborns less than two months of age with stage 4S neuroblastoma may present with aggressive hypoxia and restrictive respiratory impairment due to abdominal compartment syndrome. Case presentation : Two-month-old girl, height of 63 cm and body weight of 10 kg. She was diagnosed as neuroblastoma with Stage 4S. Because she was suffered from refractory hypoxemia and restrictive respiratory impairment due to abdominal compartment syndrome induced by multiple liver metastasis and massive ascites, she was transferred to our ICU. Her trachea was intubated and ventilated with assist/controlled mode, driving pressure 22 cmH2O, positive end-expiratory pressure（PEEP）8 cmH2O, fraction of inspiratory oxygen（FIO2）1.0, but tidal volume was obtained only 3.2 mL/kg and PaO2/FIO2 ratio of 55 mmHg. Therefore, we insert esophageal sensor and monitored esophageal pressure to performed transpulmonary pressure guided PEEP titration. When we changed PEEP from 8 to 15 cmH2O so that the end-expiratory transpulmonary pressure achieving 0 to 5 cmH2O, her oxygenation（PaO2/FIO2 ratio : 55 to 178 mmHg）and respiratory compliance（1.4 to 3.0 mL/cmH2O）were dramatically improved. Her respiratory condition was further stabilized by ascites puncture and radiotherapy, and the patient was extubated successfully on the 25th ICU day. Conclusions : Although pediatric neuroblastoma with stage 4S may induce severe respiratory efficiency, the responsiveness of treatment for neuroblastoma is promising. Multimodal treatments including optimal ventilator management such as transpulmonary pressure -guided PEEP titration contributes to improved patient’s prognosis

トクシマ ダイガク ビョウイン ノウソッチュウ センター ニ ハンソウ サレタ rt-PA ジョウチュウ リョウホウ ノ Drip and Ship ショウレイ ニオケル ケントウ

Recently,“Drip and Ship”treatment conducted in collaboration of a hospital in remote area and an institution capable of emergency stroke treatment under guidance by a stroke specialist has been reported to be effective. “Drip and Ship” treatment refers to initiating intravenous recombinant tissue-type plasminogen activator（rt-PA）infusion at a remote hospital（Drip）and then transporting patients to an institution capable of multimodality management and endovascular treatment of stroke（Ship）. We report here a case analysis and examinations on treatment methods, prognosis, and some other parameters in １６ patients who were transported to the Stroke Care Unit（SCU）of the Tokushima University Hospital while undergoing“Drip and Ship”treatment between June ２０１３ and November ２０１５. Occluded vessels were recanalized by rt-PA administration in ５／１２patients （４２％）. For ６ cases in which recanalization was not achieved with rt-PA, endovascular treatment was performed, and recanalization was obtained in ３ patients（５０％）. There was a marked improvement（８．４points on average）in NIHSS at the time of discharge compared to that before rt-PA administration. A representative case showed a ２６‐point improvement in NIHSS at the time of discharge compared to the pretreatment value. The advantage of“Drip and Ship”treatment is two-fold : It allows for rt-PA treatment of acute ischemic stroke patients at remote-area institutions incapable of multimodality stroke management, and also makes it possible to add endovascular treatment for rt-PA-irresponsive cases in which recanalization of occluded vessels could not be achieved with rt-PA therapy. The results suggest that the“Drip and Ship”treatment is a safe and effective means to eliminate regional disparities in intravenous rt-PA therapy and can make more contributions to the collaborative stroke care in the Tokushima prefecture in the future