Weaning Trial Research Articles

Noninvasive ventilation in the intensive care unit of a university hospital: Success and failure related aspects

A commercially available decision support system (DSS) provides guidance for setting inspiratory pressure support (PS) to maintain work of breathing (WOB/min), breathing frequency (f), and tidal volume (VT) in proper clinical ranges (VentAssist™). If these values are outside the proper clinical range patients may suffer fatigue, atrophy, hypoventilation, hyperventilation, volutrauma, or VT deficiency. The purpose of our study was to evaluate the increase of the percentage of breaths in the targeted clinical ranges when the DSS guidance for setting the PS was followed.The study included 43 intubated adults with respiratory failure in an academic medical intensive care unit. Each of the patients had received ventilatory support for > 24 h with no weaning trials attempted. Clinicians switched the ventilator to PS then proceeded to utilize the guidance recommended by the DSS for setting PS for 21 patients (intervention group); while the clinicians caring for the remaining 23 patients did not have access to the DSS (control group).The use of a DSS to set PS level increased the percentage of breaths in the targeted clinical range [28% to 48%, p value < 0.0001]. An unexpected result was that while following the DSS 18 of the 21 patients were rapidly weaned to minimal ventilator settings within 46 ± 38 min; however, when the DSS was not available weaning to minimal ventilator settings lasted 21 ± 12 h [p value < 0.0001].The DSS is successful at assisting clinicians on how to set PS specific to a patient's individual demands (VT and f) while accounting for their breathing effort (WOB/min). The DSS appears to promote rapid weaning of PS to minimal ventilator settings when appropriate.

Mechanical power in acute respiratory distress syndrome: A possible modeling of mortality prediction

A commercially available decision support system (DSS) provides guidance for setting inspiratory pressure support (PS) to maintain work of breathing (WOB/min), breathing frequency (f), and tidal volume (VT) in proper clinical ranges (VentAssist™). If these values are outside the proper clinical range patients may suffer fatigue, atrophy, hypoventilation, hyperventilation, volutrauma, or VT deficiency. The purpose of our study was to evaluate the increase of the percentage of breaths in the targeted clinical ranges when the DSS guidance for setting the PS was followed.The study included 43 intubated adults with respiratory failure in an academic medical intensive care unit. Each of the patients had received ventilatory support for > 24 h with no weaning trials attempted. Clinicians switched the ventilator to PS then proceeded to utilize the guidance recommended by the DSS for setting PS for 21 patients (intervention group); while the clinicians caring for the remaining 23 patients did not have access to the DSS (control group).The use of a DSS to set PS level increased the percentage of breaths in the targeted clinical range [28% to 48%, p value < 0.0001]. An unexpected result was that while following the DSS 18 of the 21 patients were rapidly weaned to minimal ventilator settings within 46 ± 38 min; however, when the DSS was not available weaning to minimal ventilator settings lasted 21 ± 12 h [p value < 0.0001].The DSS is successful at assisting clinicians on how to set PS specific to a patient's individual demands (VT and f) while accounting for their breathing effort (WOB/min). The DSS appears to promote rapid weaning of PS to minimal ventilator settings when appropriate.

Vagal withdrawal and psychological distress during ventilator weaning and the related outcomes

ObjectiveThis study investigated the associations between changes in autonomic nervous system (ANS) function, psychological status during the mechanical ventilation (MV) weaning process, and weaning outcomes. MethodsIn this prospective study, we recruited 67 patients receiving MV for >24h at a medical center in northern Taiwan. Patients' ANS function, represented by heart rate variability (HRV), the rapid shallow breathing index (RSBI), anxiety, fear, and dyspnea, was repeatedly measured 10min before and 30min after undergoing a weaning trial. Forty-nine patients capable of sustaining a 2-h weaning trial were successfully weaned. ResultsCompared with the failed group, the success group showed significantly smaller decreases in high-frequency HRV (HRV-HF) and smaller increases in RSBI (per 10 breaths/min/L), fear, dyspnea, and anxiety in response to the weaning trial (odds ratio [OR]=2.19, 0.81, 0.69, 0.66, and 0.77, respectively; p<0.05). Multivariate analyses revealed that low-frequency HRV before weaning (OR=2.32; 95% confidence interval [CI]=1.13–4.78, p=0.02), changes in HRV-HF (OR=3.33; 95% CI=1.18–9.44, p=0.02), and psychological fear during the weaning process (OR=0.50; 95% CI=0.27–0.92, p=0.03) were three independent factors associated with 2-h T-piece weaning success. ConclusionsANS responses and psychological distress during weaning were associated with T-piece weaning outcomes and may reflect the need for future studies to utilize these factors to guide weaning processes and examine their impact on outcomes.

Decision support system facilitates rapid decreases in pressure support and appropriate inspiratory muscle workloads in adults with respiratory failure

PurposeA commercially available decision support system (DSS) provides guidance for setting inspiratory pressure support (PS) to maintain work of breathing (WOB/min), breathing frequency (f), and tidal volume (VT) in proper clinical ranges (VentAssist™). If these values are outside the proper clinical range patients may suffer fatigue, atrophy, hypoventilation, hyperventilation, volutrauma, or VT deficiency. The purpose of our study was to evaluate the increase of the percentage of breaths in the targeted clinical ranges when the DSS guidance for setting the PS was followed. Materials and methodsThe study included 43 intubated adults with respiratory failure in an academic medical intensive care unit. Each of the patients had received ventilatory support for >24h with no weaning trials attempted. Clinicians switched the ventilator to PS then proceeded to utilize the guidance recommended by the DSS for setting PS for 21 patients (intervention group); while the clinicians caring for the remaining 23 patients did not have access to the DSS (control group). ResultsThe use of a DSS to set PS level increased the percentage of breaths in the targeted clinical range [28% to 48%, p value<0.0001]. An unexpected result was that while following the DSS 18 of the 21 patients were rapidly weaned to minimal ventilator settings within 46±38min; however, when the DSS was not available weaning to minimal ventilator settings lasted 21±12h [p value<0.0001]. ConclusionsThe DSS is successful at assisting clinicians on how to set PS specific to a patient's individual demands (VT and f) while accounting for their breathing effort (WOB/min). The DSS appears to promote rapid weaning of PS to minimal ventilator settings when appropriate.

Use of automatic tube compensation (ATC) for weaning from mechanical ventilation in acute respiratory failure

Aim of studyTo evaluate the automatic tube compensation (ATC) as a method of weaning from mechanical ventilation in acute respiratory failure in comparison to pressure support volume (PSV). Patients and methods60 patients with, acute respiratory failure were enrolled in this study. Patients who met the criteria of weaning had one hour of a spontaneous breathing trial (SBT) either with ATC (n=35) or with PSV (n=25). Patients who passed the weaning trial were extubated and put on oxygen, while others who didn’t pass were put back on mechanical ventilation. ResultsThe SBT in the 60 enrolled patients weaning was successful in 35 patients (58.3%). 20 of the 35 patients (57.1%) who underwent ATC had successful weaning, and 15 out of the 25 patients (60%) who underwent PSV had also successful weaning. The difference had no statistical significance (p=0.7). Sensitivity of 80.36% with a positive predictive value (PPV) of 90.14% and a specificity of 79.63% with a negative predictive value (NPV) of 81.25% were shown in ATC, while PSV showed a sensitivity of 76.35% with a PPV of 88.63% and a specificity of 80.36% with a NPV of 71.4%. ATC was superior to PSV regarding PaO2/FIO2 ratio, oxygen saturation, oxygen tension, dynamic compliance and airway resistance. ConclusionATC is a useful mode of weaning in patients mechanically ventilated due to acute respiratory failure.

Patient and Family Engagement in Designing and Implementing a Weaning Trial: A Novel Research Paradigm in Critical Care

The call for meaningful patient and family engagement in research has recently gained considerable momentum. This article defines patient and family engagement broadly and specifically in clinical research. Using a multicenter, North American weaning trial as an exemplar, we describe our early experiences as clinical researchers with patient and family engagement. The role of our Patient and Family Advisory Committee in trial design and implementation is illustrated. Through our experiences, we share our insights regarding the perceived opportunities and also highlight some challenges associated with engaging patients and family engagement in critical care research. Although "engagement science" is in its infancy, engaging patients and families in research holds promise as a novel research paradigm that will not only provide new insights into the questions, methods, and outcomes used in ICU research, but it will also make investments in research more accountable and ensure a strong "patient- and family-centered focus" of our research.

Predictive Associations of Music, Anxiety, and Sedative Exposure on Mechanical Ventilation Weaning Trials.

Weaning from mechanical ventilation requires increased respiratory effort, which can heighten anxiety and later prolong the need for mechanical ventilation. To examine the predictive associations of music intervention, anxiety, sedative exposure, and patients' characteristics on time to initiation and duration of weaning trials of patients receiving mechanical ventilation. A descriptive, correlational design was used for a secondary analysis of data from a randomized trial. Music listening was defined as self-initiated, patient-directed music via headphones. Anxiety was measured daily with a visual analog scale. Sedative exposure was operationalized as a daily sedation intensity score and a sedative dose frequency. Analyses consisted of descriptive statistics, graphing, survival analysis, Cox proportional hazards regression, and linear regression. Of 307 patients, 52% were women and 86% were white. Mean age was 59.3 (SD, 14.4) years, mean Acute Physiology and Chronic Health Evaluation III score was 62.9 (SD, 21.6), mean duration of ventilatory support was 8 (range, 1-52) days, and mean stay in the intensive care unit was 18 (range, 2-71) days. Music listening, anxiety levels, and sedative exposure did not influence time to initial weaning trial or duration of trials. Clinical factors of illness severity, days of weaning trials, and tracheostomy placement influenced weaning patterns in this sample. Prospective studies of music intervention and other psychophysiological factors during weaning from mechanical ventilation are needed to better understand factors that promote successful weaning.

Prevention of Allograft Rejection by Use of Regulatory T Cells With an MHC-Specific Chimeric Antigen Receptor.

CD4+ CD25high FOXP3+ regulatory T cells (Tregs) are involved in graft-specific tolerance after solid organ transplantation. However, adoptive transfer of polyspecific Tregs alone is insufficient to prevent graft rejection even in rodent models, indicating that graft-specific Tregs are required. We developed a highly specific chimeric antigen receptor that recognizes the HLA molecule A*02 (referred to as A2-CAR). Transduction into natural regulatory T cells (nTregs) changes the specificity of the nTregs without alteration of their regulatory phenotype and epigenetic stability. Activation of nTregs via the A2-CAR induced proliferation and enhanced the suppressor function of modified nTregs. Compared with nTregs, A2-CAR Tregs exhibited superior control of strong allospecific immune responses in vitro and in humanized mouse models. A2-CAR Tregs completely prevented rejection of allogeneic target cells and tissues in immune reconstituted humanized mice in the absence of any immunosuppression. Therefore, these modified cells have great potential for incorporation into clinical trials of Treg-supported weaning after allogeneic transplantation.

Assessment of weaning failure in chronic obstructive pulmonary disease patients under mechanical ventilation in Zagazig University Hospitals

BackgroundIt was reported that nearly twenty percent of all initial weaning trials in mechanically ventilated chronic obstructive pulmonary disease patients failed, which may lead to prolonged mechanical ventilation and expose the patient to hazardous complications such as ventilator associated pneumonia, critical illness neuromuscular abnormalities and ICU psychosis rather than the complications of mechanical ventilation itself. MethodsThis study was carried out at the Respiratory Intensive Care Unit of Chest Department, Zagazig University Hospitals from May 2013 to May 2015. It included Mechanically ventilated chronic obstructive pulmonary disease patients due to acute respiratory failure who underwent first weaning trial using two hours of spontaneous breathing trial through T piece. They were 60 patients, 44 males and 16 females with an age range from 41 to 65years and a mean age of 54.23±6.41years. At the end of the first weaning trial, patients were classified into two groups according to weaning outcome: Group I: (successful weaning) as a control group they were (20) patients and Group II: (failed weaning) they were (40) patients. Various risk factors were assessed including electrolyte imbalance, nutritional state, delirium, weaning induced myocardial ischemia and impaired thyroid function beside calculation of APACHE II score to assess illness severity. ResultsThis study reported significant risk factors for weaning failure including: malnutrition (62.5%), electrolyte imbalance (42.5%), myocardial ischemia (37.5%), hypoalbuminemia (32.5%), hypothyroidism (25%), delirium (20%) and overfeeding (17.5%) while in 5% of the studied patients no identified risk factor was observed. In this work, multiple regression analysis isolated two independent risk factors for weaning failure in COPD patients including, TSH level >2.65mIU/ml and impaired nutritional status, with P value=(0.018, 0.048) respectively. Conclusions1-Myocardial ischemia, delirium, hypomagnesemia, hypophosphatemia and VAP could be considered as important risk factors for weaning failure, however high TSH level >2.65mIU/ml and abnormal nutritional state were the most valuable independent predictors for weaning failure. 2-An increase in the degree of severity of illness on ICU admission (guided by APACHE II score), previous mechanical ventilation and longer duration of mechanical ventilation could intensify the risk for weaning failure. 3-RSBI below 85breaths/min/L may increase the rate of weaning success.

L-Carnitine Deficiency Causing Hypoxic Respiratory Failure Due to Recurrent Flash Pulmonary Edema

SESSION TITLE: Student/Resident Case Report Poster - Pulmonary Manifestations of Systemic Disease I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: We present a unique case of recurrent flash pumonary edema associated with L-carnitine deficiency. The purpose of our case is to establish clinical significance of L-carnitine replacement, since its deficiency causes pulmonary edema, especially in chronic hepatitis patients. CASE PRESENTATION: 45-y/o African American female with history of cirrhosis from chronic Hepatitis B on Lamivudine was admitted with one week of productive cough with pleuritic pain, nausea and lethargy. On physical exam there were decreased breath sounds bilaterally. ProBNP was elevated at 5297 ng/L. Chest X-ray (pic 1) and CT chest (pic 2) showed bilateral pulmonary vascular congestion without pleural effusions. 2D Transthoracic ECHO showed LVEF-60% with diastolic dysfunction. Upon admission, patient was intubated for acute hypoxic respiratory failure secondary to pulmonary edema. HIV-PCR, PCP, Urine for Legionella Antigen, and AFB cultures were negative. Patient was started on antibiotics for pneumonia based on BAL cultures that grew ESBL E.coli. Patient's severe sepsis significantly improved, but failed multiple weaning trials. She developed recurrent flash pulmonary edema, as noticed on CXR, at the time of weaning from mechanical ventilation that prompted us to check serum carnitine level. Her carnitine levels were extremely low. Despite multiple aggressive attempts to diurese the patient, her clinical condition continued to deteriorate, due to recurrent flash pulmonary edema, requiring hemodialysis until carnitine was replaced. Following carnitine replacement patient’s clinical condition significantly improved, recurrent pulmonary edema completely resolved and hemodialysis was discontinued. DISCUSSION: Serum carnitine is readily measurable and can easily be substituted, but there are no guidelines yet for adults (1). Carnitine levels in patients with chronic hepatitis are lower than in healthy individuals. There are case reports that suggest secondary carnitine deficiency due to some medications like Valproate, Adefovir and Zidovudine. In our patient, carnitine deficiency could be due to chronic hepatitis or even Lamivudine (2,3). CONCLUSIONS: We can clearly establish from our case that carnitine deficiency must be considered as a reversible cause for recurrent flash pulmonary edema in chronic hepatitis patients. Prompt recognition and replacement of carnitine reverses the clinical symptoms. Reference #1: E. Gilbert. Carnitine deficiency. Pathology, 1985;17(2):161-71. Reference #2: M. Vilaseca, R. Artuch, C. Sierra, et al. Low serum carnitine in HIV-infected children on antiretroviral treatment. European Journal of Clinical Nutrition, 2003;57:1317-1322. Reference #3: L. Jansen, A. Niet, F. Stelma, et al. HBsAg loss in patients treated with peginterferon alfa-2a and adefovir is associated with SLC16A9 gene variation and lower plasma carnitine levels. Journal of Hepatology, 2014;61(4):730-737. DISCLOSURE: The following authors have nothing to disclose: Alexandra Sokolova, Shruti Patel, Jagadish Akella No Product/Research Disclosure Information

Fluid Balance and Diuretic Administration in Intubated Patients Undergoing Weaning Trials in a Medical ICU

Fluid Balance and Diuretic Administration in Intubated Patients Undergoing Weaning Trials in a Medical ICU

Diuretics and Malnutrition-Induced Wernicke’s Encephalopathy in the Critically Ill Patient

SESSION TITLE: Student/Resident Case Report Poster - Critical Care V SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Wernicke Encephalopathy has been traditionally associated with alcohol abuse. Among non alcoholic causes are dialysis, diuretic use, malnutrition, parenteral nutrition, bariatric surgery, cancer and AIDS. Wernicke encephalopathy is a heterogeneous entity not only limited to the described triad of ophthalmoplegia, encephalopathy and ataxia. CASE PRESENTATION: 43-year-old male with history of aspergillosis was admitted with pneumonia. Due to increased work of breathing he required endotraqueal intubation. The patient looked cachectic, HR: 100 bpm, BP:130/70, and on lung auscultation bilateral rales were noted. He failed weaning trials for two weeks requiring tracheostomy placement. He also developed renal failure requiring dialysis and high doses of diuretics. His mental status after weaning sedation remained abnormal and multiple attempts to switch to trach collar were also unsuccessful. On his neurological exam completely off sedation, he could not follow commands or communicate. He also had a fixed look and unable to track with eyes, concerning for ophthalmoplegia. CT Head showed no abnormalities and an EEG resulted negative for seizures. Repeated blood cultures, TSH and cortisol levels were normal. The etiology of his abnormal mental status was unclear but given his poor nutritional status, diuretic use, critically ill state and what seemed to be an unspecific encephalopathy with ophthalmoplegia, thiamine deficiency was entertained. High doses of IV thiamine was started with dramatic improvement. He progressively started following commands and communicating and within 48 hours he was able to be completely weaned to trach collar. DISCUSSION: Wernicke encephalopathy can present with different sign and symptoms that may be overlooked by a physician. In early stages there is gait and trunk incoordination, ocular abnormalities or mental status changes, and infrequently hemodynamic instability hypothermia, behavioral changes and seizures. Late stages present with hyperthermia, spastic paralysis or increase muscle tone, choreic dyskinesia and coma.1 Wernicke can present in non-alcoholic patient in the setting of malnutrition, parenteral nutrition, cancer, AIDS, illness, Inflammatory bowel syndrome, diuretic use, peritoneal dialysis, hemodialysis and bariatric surgery.2 CONCLUSIONS: Diagnosing thiamine deficiency and Wernicke encephalopathy can be challenging in non-alcoholic. Wernicke can be treated with intravenous thiamine and its development can be prevented in at risk patients with proper supplementation. No agreement on dosage has yet been stablished but it is clear that high doses of thiamine are effective in the treatment of Wernicke encephalopathy. 2,3. Reference #1: Sechi GP, et al. Wernicke’s encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol 2007; 6: 442-55 Reference #2: Hutcheon DA. Malnutrition-induced Wernicke’s encephalopathy following a water-only fasting diet. Nutr Clin Pract. 2015;30:92-99. DISCLOSURE: The following authors have nothing to disclose: Konstantinos Sdrimas, Supakanya Wongrakpanich, Jean Bustamante Alvarez No Product/Research Disclosure Information

Can diaphragmatic ultrasonography performed during the T-tube trial predict weaning failure? The role of diaphragmatic rapid shallow breathing index.

BackgroundThe rapid shallow breathing index (RSBI), which is the ratio between respiratory rate (RR) and tidal volume (VT), is one of the most widely used indices to predict weaning outcome. Whereas the diaphragm plays a fundamental role in generating VT, in the case of diaphragmatic dysfunction the inspiratory accessory muscles may contribute. If this occurs during a weaning trial, delayed weaning failure is likely since the accessory muscles are more fatigable than the diaphragm. Hence, we hypothesised that the traditional RSBI could be implemented by substituting VT with the ultrasonographic evaluation of diaphragmatic displacement (DD). We named the new index the diaphragmatic-RSBI (D-RSBI). The aim of this study was to compare the ability of the traditional RSBI and D-RSBI to predict weaning failure in ready-to-wean patients.MethodsWe performed a prospective observational study. During a T-tube spontaneous breathing trial (SBT) we simultaneously evaluated right hemidiaphragm displacement (i.e., DD) by using M-mode ultrasonography as well as the RSBI. Outcome of the weaning attempt, length of mechanical ventilation, length of intensive care unit and hospital stay, and hospital mortality were recorded. Receiver operator characteristic (ROC) curves were used to evaluate the diagnostic accuracy of D-RSBI and RSBI.ResultsWe enrolled 51 patients requiring mechanical ventilation for more than 48 h who were ready to perform a SBT. Most of the patients, 34 (66 %), were successfully weaned from mechanical ventilation. When considering the 17 patients that failed the weaning attempt, 11 (64 %) had to be reconnected to the ventilator during the SBT, three (18 %) had to be re-intubated within 48 h of extubation, and three (18 %) required non-invasive ventilation support within 48 h of extubation. The areas under the ROC curves for D-RSBI and RSBI were 0.89 and 0.72, respectively (P = 0.006).ConclusionsD-RSBI (RR/DD) was more accurate than traditional RSBI (RR/VT) in predicting the weaning outcome.Trial registrationOur clinical trial was retrospectively registered with ClinicalTrials.gov (identifier: NCT02696018). ClinicalTrials.gov processed our record on 25 February 2016.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1479-y) contains supplementary material, which is available to authorized users.

Music intervention during daily weaning trials—A 6 day prospective randomized crossover trial

PurposeTo examine the effect of patient-selected music intervention during daily weaning trials for patients on prolonged mechanical ventilation. MethodsUsing a crossover repeated measures design, patients were randomized to music vs no music on the first intervention day. Provision of music was alternated for 6 days, resulting in 3 music and 3 no music days. During weaning trials on music days, data were obtained for 30min prior to music listening and continued for 60min while patients listened to selected music (total 90min). On no music days, data were collected for 90min. Outcome measures were heart rate (HR), respiratory rate (RR), oxygen saturation (SpO2), blood pressure (BP), dyspnea and anxiety assessed with a visual analog scale (VAS-D, VAS-A) and weaning duration (meanh per day on music and non-music days). ResultsOf 31 patients randomized, 23 completed the 6-day intervention. When comparisons were made between the 3 music and 3 no music days, there were significant decreases in RR and VAS-D and a significant increase in daily weaning duration on music days (p<0.05). A multivariate mixed-effects model analysis that included patients who completed ≥2 days of the intervention (n=28) demonstrated significant decreases in HR, RR, VAS-A, and VAS-D and a significant increase in daily weaning duration on music days (p<0.05). ConclusionsProviding patient selected music during daily weaning trials is a simple, low-cost, potentially beneficial intervention for patients on prolonged mechanical ventilation. Further study is indicated to test ability of this intervention to promote weaning success and benefits earlier in the weaning process.

Failure of Calcineurin Inhibitor (Tacrolimus) Weaning Randomized Trial in Long-Term Stable Kidney Transplant Recipients.

Long-term renal transplant outcome is limited by side effects of immunosuppressive drugs, particularly calcineurin inhibitor (CNI). We assumed that some patients selected for a "low immunological risk of rejection" could be eligible and benefit from a CNI weaning strategy. We designed a prospective, randomized, multicenter, double-blind placebo-controlled clinical study (Eudract: 2010-019574-33) to analyze the benefit-risk ratio of tacrolimus weaning on highly selected patients (≥4 years of transplantation, normal histology, stable graft function, no anti-HLA immunization). The primary endpoint was improvement of renal function. Fifty-two patients were scheduled in each treatment arm, placebo compared to the CNI maintenance arm. Only 10 patients were eligible and randomized. Five patients were assigned to the placebo arm and five were assigned to the tacrolimus maintenance arm. In the tacrolimus maintenance arm, all patients maintained stable graft function and no immunological events occurred. Contrastingly, in the placebo arm, all five patients had to reintroduce a full dose of tacrolimus since three of them presented an acute rejection episode (one humoral, one mixed, and one borderline) and two displayed anti-HLA antibodies without histological lesion (one donor-specific antibodies [DSA] and one non-DSA). Clearly, tacrolimus withdrawal must be avoided even in long-term highly selective stable kidney recipients.

Ultrasound-guided laryngeal air column width difference and the cuff leak volume in predicting the effectiveness of steroid therapy on postextubation stridor in adult. Are they useful?

ObjectiveTo evaluate the effectiveness of steroids therapy on postextubation stridor (PES) depending on the clinical response, the ultrasound guided laryngeal air column width difference (LACWD) and the cuff leak volume (CLV). DesignProspective, observer-blinded study. SettingCarried out in intensive care unit in Tanta university hospital. Patients432 patients of both sexes received mechanical ventilation for more than 24 hours and met defined criteria for a weaning trial. MeasurementsUltrasound guided LACWD and CLV were conducted before extubation. Patients developing postextubation stridor were intravenously given 8 mg of dexamethasone every 8 hours for 3 days. The clinical response, ultrasounds guided LACWD and CLV before and after steroid therapy were analyzed. Primary outcome and secondary outcomes of our study were reported. Results387 patients (89.5%) had no PES and 45 patients (10.5%) had PES. Risk factors for PES were longer duration of intubation, younger age and female gender. Both CLV and LACWD showed significant decrease (P< .05) in patients with PES in comparison with no PES patients. 45 patients with PES received dexamethasone treatment; 18 were completely recovered while 27 patients needed reintubation after 1 h. of these 27 patients; 19 patients had successful extubation while 8 patients had tracheostomy. In patients with PES, CLV and LACWD showed significant increase (P< .05) in comparison with before administration. Level of CLV <200 ml and LACWD <0.9 mm carry high sensitivity with high positive predictive value and high accuracy for presence of PES. ConclusionSteroids therapy improves postextubation stridor. Both LACWD and CLV are non-invasive and simple methods for monitoring of laryngeal edema regression after steroid therapy. We recommend administration of corticosteroids to patients with a lower level of leak volume and LACWD before extubation.

Effects of dexmedetomidine and propofol on patient-ventilator interaction in difficult-to-wean, mechanically ventilated patients: a prospective, open-label, randomised, multicentre study.

BackgroundDexmedetomidine can be used for sedation of mechanically ventilated patients and has minor respiratory effects. The aim of this study was to compare the incidence of patient-ventilator dyssynchronies during sedation with dexmedetomidine or propofol.MethodsWe conducted a multicentre, prospective, open-label, randomised clinical trial, comparing dexmedetomidine with standard propofol sedation at three intensive care units of university hospitals in Italy. Twenty difficult-to-wean patients for whom the first weaning trial had failed and who were on pressure support ventilation were randomised to receive sedation with either dexmedetomidine or propofol at a similar level of sedation (Richmond Agitation-Sedation Scale [RASS] score +1 to −2). The asynchrony index (AI) was calculated using tracings of airflow, airway pressure and electrical activity of the diaphragm sampled at 0, 0.5, 1, 2, 6, 12, 18 and 24 h.ResultsThe mean AI was lower with dexmedetomidine than with propofol from 2 h onwards, although the two groups significantly differed only at 12 h (2.68 % vs 9.10 %, p < 0.05). No further difference was observed at 18 and 24 h.ConclusionsWhen sedation with propofol and dexmedetomidine was compared at similar RASS scores of patients in whom first weaning trial had failed, the AI was lower with dexmedetomidine than with propofol, and this difference was statistically significant at 12 h. These results suggest that sedation with dexmedetomidine may offer some advantages in terms of patient-ventilator synchrony.

Diaphragmatic ultrasound as a predictor of successful extubation from mechanical ventilation: thickness, displacement, or both?

Best predictor of successful extubation after mechanical ventilation is a matter of debate. The aim of this study was to assess whether the degree of diaphragm thickening and/or diaphragm displacement (DD) as measured by means of ultrasound during a weaning trial can predict extubation outcomes. Thirty patients who were planned for weaning after being intubated and mechanically ventilated were prospectively enrolled in the study between January and June 2015. The rapid-shallow breathing index (RSBI) was subsequently calculated, and diaphragmatic ultrasound was then carried out to assess DD and diaphragm thickening during tidal inspiration. The primary outcome was extubation success or failure. Of the 30 patients included in the study, 15 were male. The mean age of patients was 59.17+13.17 years. The median duration of intubation before weaning was 4 days. There was a significant difference between mean inspiratory and expiratory diaphragmatic thickness (TDI) (t=9.66, P<0.001). An receiver operating characteristic curve was constructed for the end inspiratory TDI, end expiratory TDI, delta TDI, DD, and RSBI. The RSBI performed better than all other parameters, with an area under the curve of 0.968. A cut-off value of 73.5 had 87% sensitivity and 100% specificity for predicting extubation success. All other parameters had an area under the curve less than 0.7. (0.559, 0.624, 0.655, and 0.512 for end inspiratory TDI, end expiratory TDI, delta TDI, and diaphragmatic displacement, respectively). Sonographically measured TDI performed better than displacement in predicting value for weaning outcome. In a respiratory ICU, however, the RSBI seems to be a more reliable and accurate tool for the purpose and should be considered in every weaning protocol. Whether TDI can be evaluated using low-frequency ultrasound probes needs to be validated by further studies.

Characterization of Shape Differences Among ICP Pulses Predicts Outcome of External Ventricular Drainage Weaning Trial

External ventricular drains (EVD) are widely used to manage intracranial pressure (ICP) and hydrocephalus for aneurysmal subarachnoid hemorrhage (aSAH) patients. After days of use, a decision is made to remove the EVD or replace it with a shunt, involving EVD weaning and CT imaging to observe ventricular size and clinical status. This practice may lead to prolonged hospital stay, extra radiation exposure, and neurological insult due to ICP elevation. This study aims to apply a validated morphological clustering analysis of ICP pulse (MOCAIP) algorithm to detect signatures from the pulse waveform to differentiate an intact CSF circulatory system from an abnormal one during EVD weaning. We performed a retrospective study with 50 aSAH patients with reported weaning trial admitted to our institution between 03/2013 and 08/2014. By reviewing clinical notes and pre/post-brain imaging results, 32 patients were determined as having passed the weaning trial and 18 patients as having failed the trial. MOCAIP algorithm was applied to ICP signals to form a series of artifact-free dominant pulses. Finally, pulses with similar mean ICP were identified, and amplitude, Euclidean, and geodesic inter-pulse distances were calculated in a 4-h moving window. While the traditional measure of mean ICP failed to differentiate the two groups of patients, the proposed amplitude and morphological inter-pulse measures presented significant differences (p≤0.004). Moreover, receiver operating characteristic (ROC) analyses showed their usability to predict the outcome of the EVD weaning trial (AUC 0.85, p<0.001). Patients with an impaired CSF system showed a larger mean and variability of inter-pulse distances, indicating frequent changes on the morphology of pulses. This technique may provide a method to rapidly determine if patients will need placement of a shunt or can simply have the EVD removed.

Ventilator Weaning and Spontaneous Breathing Trials; an Educational Review.

The term "weaning" is used to describe the gradual process of decreasing ventilator support. It is estimated that 40% of the duration of mechanical ventilation is dedicated to the process of weaning. Spontaneous breathing trial (SBT) assesses the patient's ability to breathe while receiving minimal or no ventilator support. The collective task force in 2001 stated that the process of SBT and weaning should start by assessing whether the underlying cause of respiratory failure has been resolved or not. Weaning predictors are parameters that are intended to help clinicians predict whether weaning attempts will be successful or not. Although the international consensus conference in 2005 did not recommend their routine use for clinical decision making, researchers did not stop working in this area. In the present article, we review some of the recent studies about weaning predictors, criteria, procedure, as well as assessment for extubation a mechanically ventilated patient.