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Withdrawal from mechanical ventilation (or weaning) is one of the most common procedures in intensive care units. Almost 20 years ago, we published one of the seminal papers on weaning in which we showed that the best method for withdrawal from mechanical ventilation in difficult-to-wean patients was a once-daily spontaneous breathing trial with a T-piece. Progress has not stood still, and in the intervening years up to the present several other studies, by our group and others, have shaped weaning into an evidence-based technique. The results of these studies have been applied progressively to routine clinical practice. Currently, withdrawal from mechanical ventilation can be summarized as the evaluation of extubation readiness based on the patient's performance during a spontaneous breathing trial. This trial can be performed with a T-piece, which is the most common approach, or with continuous positive airway pressure or low levels of pressure support. Most patients can be disconnected after passing the first spontaneous breathing trial. In patients who fail the first attempt at withdrawal, the use of a once-daily spontaneous breathing trial or a gradual reduction in pressure support are the preferred weaning methods. However, new applications of standard techniques, such as noninvasive positive pressure ventilation, or new methods of mechanical ventilation, such as automatic tube compensation, automated closed-loop systems, and automated knowledge-based weaning systems, can play a role in the management of the patients with difficult or prolonged weaning., Author(s): Fernando Frutos-Vivar [sup.1] [sup.2] , Andrés Esteban [sup.1] [sup.2] Author Affiliations: (1) grid.411244.6, 0000000096916072, Hospital Universitario de Getafe, , Carretera de Toledo Km.12,500, Getafe, Madrid, Spain (2) grid.413448.e, 0000000093141427, [...]

Purpose Duration of weaning from mechanical ventilation is decreased with the use of written protocols in adults. In children, the use of written protocols has not had such an impact. Methods and measurements We conducted a single-center trial to assess the feasibility of conducting a multicenter randomized clinical trial comparing the duration of weaning from mechanical ventilation in those managed by a computer-driven explicit protocol versus usual care. Mechanically ventilated children aged between 2 and 17 years on pressure support and not receiving inotropes were included. After randomization, children were weaned either by usual care (n = 15) that was characterized by no protocolized decisions by attending physicians, or by a computer-driven protocol (Smartcare/PS[TM], Drager Medical) (n = 15). Weaning duration until first extubation was the primary outcome. For comparison, a Mann-Whitney U test was employed (p < 0.05). Results Patients characteristics at inclusion were similar. The median duration of weaning was 21 h (range 3-142 h) in the SmartCare/PS[TM] group and 90 h (range 4-552 h) in the usual care group, p = 0.007. The rate of reintubation within 48 h after extubation and the rate of noninvasive ventilation after extubation in the SmartCare/PS[TM] and usual care groups were 2/15 versus 1/15 and 2/15 versus 2/15, respectively. Conclusions A pediatric randomized trial on mechanical ventilation with a computerized protocol in North America is feasible. A computer-driven protocol that also manages children younger than 2 years old would help to decrease the number of PICU admissions screened in a multicentre trial on this topic., Author(s): Philippe A. Jouvet [sup.1] , Valérie Payen [sup.1] , France Gauvin [sup.1] , Guillaume Emeriaud [sup.1] , Jacques Lacroix [sup.1] Author Affiliations: (1) grid.411418.9, 0000000121736322, Pediatric ICU, Soins Intensifs [...]

Purpose To compare breathing pattern descriptors and diaphragm electromyographic activity (EAdi)-derived indices obtained from a neurally adjusted ventilatory assist catheter during a spontaneous breathing trial (SBT) in patients successfully and unsuccessfully separated from the ventilator and to assess their performance as a potential marker to discriminate these two categories of patients. Methods Fifty-seven ready-to-wean patients were included in a prospective observational study. During a 30-min SBT (pressure support 7 cmH.sub.2O, zero end expiratory pressure), tidal volume (V.sub.T) and respiratory rate (RR) were obtained from the flow signal at baseline and at 3, 10, 20 and 30 min during the SBT. EAdi-derived indices were simultaneously computed: maximum of the EAdi (EAdi.sub.max), area under the inspiratory curve of EAdi (EAdi.sub.AUC), the difference between EAdi.sub.max and EAdi.sub.min (âEAdi), EAdi.sub.max/V.sub.T, EAdi.sub.AUC/V.sub.T and âEAdi/V.sub.T. Patients, successfully (success group; n = 35) and unsuccessfully (failure group; n = 22) separated from the ventilator were compared. Results At baseline, the breathing pattern was similar in the two groups, whereas EAdi.sub.max and EAdi.sub.AUC were significantly lower in the success group (p < 0.05). In the failure group, RR and RR/V.sub.T increased significantly during the trial, V.sub.T decreased, whereas EAdi.sub.max and EAdi.sub.AUC did not change. At 3 min, the areas under the receiver operating characteristic-curve of RR/V.sub.T and the EAdi-derived indices to predict weaning outcome were 0.83 for the rapid shallow breathing index (RSBI), 0.84 for EAdi.sub.max/V.sub.T, 0.80 for EAdi.sub.AUC/V.sub.T (0.80) and 0.82 for âEAdi/V.sub.T. The coefficient of variation for V.sub.T decreased in the failure group while that for EAdi.sub.max remained unchanged. Conclusions EAdi-derived indices provide reliable and early predictors of weaning outcome. However, the performance of these indices is not better than the RR/V.sub.T., Author(s): Martin Dres [sup.1] , Matthieu Schmidt [sup.1] [sup.2] , Alexis Ferre [sup.1] , Julien Mayaux [sup.1] , Thomas Similowski [sup.1] [sup.2] , Alexandre Demoule [sup.1] [sup.2] [sup.3] Author Affiliations: [...]

Purpose Rapid shallow breathing may occur at any time during spontaneous breathing trials (SBT), questioning the utility of a single determination of the rapid shallow breathing index (RSBI). We hypothesize that change in RSBI during SBT may more accurately predict successful extubation than a single determination. Methods Prospective observational study. Seventy-two subjects were extubated. At 24 h, 63/72 remained extubated (Extubation Success), and 9 were re-intubated (Extubation Failure). Respiratory rate (RR), tidal volume (VT) and RSBI were measured every 30 min during 2-h T-piece SBT. Change in respiratory parameters was assessed as percent change from baseline. Results Initial RSBI was similar in Extubation Success and Extubation Failure groups (77.0 ± 4.8, 77.0 ± 4.8, p = ns). Nevertheless, RSBI tended to remain unchanged or decreased in the Extubation Success group; in contrast RSBI tended to increase in the Extubation Failure group because of either increased RR and/or decreased VT (p < 0.001 for mean percent change RSBI over time), indicating worsening of the respiratory pattern. Quantitatively, only 7/63 subjects of the Extubation Success group demonstrated increased RSBI [greater than or equal to]20% at any time during the SBT. In contrast, in the Extubation Failure group, RSBI increased in all subjects during the SBT, and eight of nine subjects demonstrated an increase greater than 20%. Thus, with a 2-h SBT the optimal threshold was a 20% increase (sensitivity = 89%, specificity = 89%). Similar results were obtained at 30 min (threshold = 5% increase). Percent change of RSBI predicted successful extubation even when initial values were [greater than or equal to]105. Conclusion Percent change of RSBI during an SBT is a better predictor of successful extubation than a single determination of RSBI., Author(s): Leopoldo N. Segal [sup.1] [sup.2] , Erwin Oei [sup.2] , Beno W. Oppenheimer [sup.1] , Roberta M. Goldring [sup.1] , Rami T. Bustami [sup.3] , Salvatore Ruggiero [sup.2] , [...]

Byline: Andreas Perren (1), Guido Domenighetti (2), Simonetta Mauri (2), Franco Genini (2), Nicoletta Vizzardi (1) Keywords: Weaning Clinical outcome Pressure support ventilation Duration of weaning trial Extubation Adults Abstract: Abstract Objective. To investigate the possibility of successful extubation performing a spontaneous breathing trial (SBT) in pressure support ventilation (PSV) with target durations of 30 and 120 min. Design and setting. Prospective and randomized study in two medical-surgical adult intensive care units. Patients and participants. 98 adult patients supported by mechanical ventilation for at least 48 h and considered ready for a weaning trial. Interventions. An SBT conducted in PSV with 7 cm[H.sub.2]O and patients randomly assigned to two groups with target durations of 30- and 120-min. Measurements and results. In the 30-min group 43 patients (93%) tolerated the SBT and were extubated while 4 (9%) needed reintubation within 48 h in the 120-min group 46 patients (88%) successfully completed the trial and were extubated while 2 (4%) were reintubated. ICU mortality in the groups with short and long periods was 6% and 4%, and in-hospital mortality 20% and 17%, respectively. Those successful in the 30- and 120-min groups had similar length of ICU stay (6 and 7 days, respectively) and in-hospital length of stay (20 and 25 days, respectively). Compared to the successfully extubated, the reintubated patients had significantly higher length of ICU stay and mortality (17 vs. 6 days and 33 vs. 3.6%, respectively). Conclusions. An SBT with PSV of 7 cm[H.sub.2]O lasting 30 min is equally effective in recognizing the successfully extubated patients as a 120-min trial. Author Affiliation: (1) Centro Cure Intense, Ospedale Regionale Bellinzona e Valli, 6500 Bellinzona, Switzerland (2) Cure Intense, Ospedale Regionale La Carita, 6600 Locarno, Switzerland Article History: Received Date: 04/01/2002 Accepted Date: 29/04/2002 Article note: Electronic Publication

Byline: B. Schonhofer (1), S. Euteneuer (1), S. Nava (2), S. Suchi (1), D. Kohler (1) Keywords: Difficult weaning from respirator Outcome Survival Mortality Abstract: Abstract Objective. Hospital mortality and survival rates of long-term ventilated patients. Design. Retrospective cohort study. Setting. Specialised national weaning centre. Intervention. Protocol-directed liberation from ventilator. Patients. Four hundred three of 640 patients with prolonged mechanical ventilation (MV) who were admitted to our respiratory intensive care unit (RICU) were studied. MV lasted longer than 2 weeks and patients had failed more than two weaning trials in the referring ICUs. The majority of patients (59.3%) had chronic obstructive pulmonary disease (COPD). Results. After a mean duration of 41 days of MV prior to transfer, 68% of patients were liberated from the ventilator. In total, 98 of 403 patients (24.3%) died during the stay in our hospital, 305 patients (75.7%) were discharged. Compared to the non-survivors, the survivors were characterised by younger age, longer length of stay in our RICU, lower severity of illness scores at admission, fewer cardiac illnesses and a higher rate of weaning success. In 31.5% of the discharged patients non-invasive MV (NIV) was initiated during the stay at our unit. We gathered follow-up data on 293 patients (96.1%). Post-discharge survival rates were 67.6% at 3 months, 49.4% at 1 year and 38.1% at 3 years. Length of survival was significantly dependent on age, weaning success and main diagnosis (i.e., prognosis in COPD is worse compared to thoracic restriction, neuromuscular disease and others) in the multivariate analysis. Conclusions. Difficult-to-wean patients have a high hospital mortality rate and poor long-term prognosis. Age, main diagnosis, severity of illness, weaning success and institution of NIV predict survival. Author Affiliation: (1) Krankenhaus Kloster Grafschaft (KKG), Zentrum fur Pneumologie, Beatmungs- und Schlafmedizin, 57392 Schmallenberg, Germany (2) Respiratory Intensive Care Unit, Fondazione S. Maugeri, Istituto Scientifico di Pavia, Via Ferrata 8, 100 Pavia, Italy (3) Address for correspondence: Division of Pulmonary and Critical Care Medicine, Edward Hines Jr., VA Hospital and Loyola University of Chicago, 5th & Roosevelt Road, Building 1, Room E 438, RTE. 111 N, Chicago, Hines, IL 60141, USA Article History: Received Date: 16/07/2001 Accepted Date: 11/03/2002 Article note: Electronic Publication

Byline: E. W. Ely (1), A. M. Baker (2), G. W. Evans (3), E. F. Haponik (1) Keywords: Key words Ventilator weaning; Respiration; Artificial; Critical care; Outcomes Abstract: Objective: While 'weaning parameters' are commonly used to guide removal of mechanical ventilation devices, little information exists concerning their prognostic value. We evaluated whether passing weaning parameters was associated with survival. Design: A prospectively followed cohort of mechanically ventilated patients. Setting: Medical and coronary adult intensive care units of an 806-bed medical center. Patients: 300 consecutively enrolled mechanically ventilated patients. Measurements and results: 216 patients who passed a daily screen of weaning parameters were more likely to be extubated successfully (87 vs 30 %, p = 0.0001), less likely to require ventilation for > 21 days (3 vs 30 %, p = 0.0001), and had a higher survival to hospital discharge (74 vs 29 %, p = 0.0001) than 84 patients who never passed the screen. The overall accuracy of the daily screen for predicting successful extubation and in-hospital survival was 82 and 73 %, respectively. Multivariate proportional hazards analysis of time until hospital death confirmed the beneficial effect of passing the daily screen (p = 0.01) and of duration of mechanical ventilation (p = 0.001) even after adjustment for differences in severity of illness, age, race, gender, diagnosis, and treatment assignment. While liberation from mechanical ventilation was predictive of survival at any time during the hospital stay (p = 0.001), the prognostic significance of the daily screen for hospital survival was related to how early after intubation it was passed. The difference in survival between patients who had passed and those who had not passed the daily screen was significant for 1.sup.1/.sub.2 weeks post-intubation but progressively decreased over time. The average time to extubation after passing the daily screen increased from 3 days (range 0 to 56), for those passing within 5 days of intubation, to 8 days (0 to 35), for those passing after 10 days of intubation (r = 0.26, p = 0.001). Conclusions: Passing a daily screen of weaning parameters is an independent predictor of successful extubation and survival, but its prognostic value decreases over time. Time spent on mechanical ventilation after passing the daily screen presents an important opportunity to optimize liberation from the ventilator. Author Affiliation: (1) Department of Internal Medicine, Section on Pulmonary/Critical Care Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA, US (2) Lynchburg Pulmonary Associates, Lynchburg, Virginia, USA, US (3) Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA, US Article note: Received: 15 July 1998 Accepted: 9 March 1999

Author(s): Dimitris Georgopoulos [sup.1] Author Affiliations: (1) grid.8127.c, 0000000405763437, Department of Intensive Care Medicine, University Hospital of Heraklion, Medical School, University of Crete, , Heraklion, Crete, Greece Asynchrony between patient [...]