Decrease in ventilation time with a standardized weaning process

Prediction of weaning from mechanical ventilation using Convolutional Neural Networks

Weaning from mechanical ventilation covers the process of liberating the patient from mechanical support and removing the associated endotracheal tube. The management of weaning from mechanical ventilation comprises a significant proportion of the care of critically ill intubated patients in Intensive Care Units (ICUs). Both prolonged dependence on mechanical ventilation and premature extubation expose patients to an increased risk of complications and increased health care costs. This work aims to develop a decision support model using routinely-recorded patient information to predict extubation readiness. In order to do so, we have deployed Convolutional Neural Networks (CNN) to predict the most appropriate treatment action in the next hour for a given patient state, using historical ICU data extracted from MIMIC-III. The model achieved 86% accuracy and 0.94 area under the receiver operating characteristic curve (AUC-ROC). We also performed feature importance analysis for the CNN model and interpreted these features using the DeepLIFT method. The results of the feature importance assessment show that the CNN model makes predictions using clinically meaningful and appropriate features. Finally, we implemented counterfactual explanations for the CNN model. This can help clinicians understand what feature changes for a particular patient would lead to a desirable outcome, i.e. readiness to extubate.

Protocol-Driven Ventilator Management in Children: Comparison to Nonprotocol Care

The purpose of this study was to compare ventilator weaning time, time to spontaneous breathing, and overall ventilator hours duration with use of a ventilator management protocol (VMP) versus standard nonprotocol-based care in a pediatric intensive care unit. A multidisciplinary task force developed a comprehensive protocol for ventilator management with four specific phases: initial ventilator set up and adjustment, weaning, minimal settings, and spontaneous mode prior to extubation. Medical records of ventilated patients both before and after protocol implementation were reviewed. A total of 187 patients were studied (89 nonprotocol and 98 VMP patients). No differences were seen between groups in PRISM scores, Murray scores, or oxygenation indices, but VMP patients were significantly younger (P= .03). Ventilator weaning times (P= .005) and time to spontaneous breathing modes (P= .006) were significantly decreased in VMP patients compared to nonprotocol patients, but overall ventilator duration was not significantly different. No significant differences were seen in extubation failure, use of corticosteroids, or use of racemic epinephrine between groups. Use of an institution-specific VMP developed by a multidisciplinary team was associated with significantly reduced ventilator weaning time and time to spontaneous breathing. Further studies are needed.

Effectiveness and safety of a protocolized mechanical ventilation and weaning strategy of COPD patients by respiratory therapists

INTRODUCTION

Prior researches have showed that weaning protocols may decrease the duration of mechanical ventilation. The effect of these protocols on chronic obstructive pulmonary disease (COPD) patients is unknown. The purpose of this study was to evaluate the impact of an extensive mechanical ventilation protocol including weaning applied by a respiratory therapist (RT) on the duration of mechanical ventilation and intensive care unit (ICU) stay in COPD patients.

MATERIALS AND METHODS

A novel mechanical ventilation protocol including weaning was developed and initiated for all intubated COPD patients by a respiratory therapist. Outcomes of patients treated using this protocol during a 6-month period were compared to those of patients treated by physicians without a protocol during the preceding 6 months.

RESULTS

A total of 170 patients were enrolled. Extubation success was significantly higher (98% vs. 78%, P=0.014) and median durations of weaning, mechanical ventilation and ICU stay compared with time to event analysis were significantly shorter in the protocol based group (2 vs. 26 hours, log rank P<0.001, 3.1 vs. 5 days, log rank P<0.001 and 6 vs. 12 days, log rank P<0.001, respectively). Patients who were successfully extubated and patients in the protocol based group were more likely to have shorter ventilation duration [HR: 1.87, 95% confidence intervals (CI): 1.13-3.08, P=0.015 and HR: 2.08, 95% CI: 1.40-3.10, P<0.001 respectively].

CONCLUSIONS

In our center, a protocolized mechanical ventilation and weaning strategy improved weaning success and shortened the total duration of mechanical ventilation and ICU stay in COPD patients requiring mechanical ventilation.

A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application

To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased.

Low mechanical ventilation times and reintubation rates associated with a specific weaning protocol in an intensive care unit setting: a retrospective study

OBJECTIVES

A number of complications exist with invasive mechanical ventilation and with the use of and withdrawal from prolonged ventilator support. The use of protocols that enable the systematic identification of patients eligible for an interruption in mechanical ventilation can significantly reduce the number of complications. This study describes the application of a weaning protocol and its results.

METHODS

Patients who required invasive mechanical ventilation for more than 24 hours were included and assessed daily to identify individuals who were ready to begin the weaning process.

RESULTS

We studied 252 patients with a median mechanical ventilation time of 3.7 days (interquartile range of 1 to 23 days), a rapid shallow breathing index value of 48 (median), a maximum inspiratory pressure of 40 cmH(2)0, and a maximum expiratory pressure of 40 cm H(2)0 (median). Of these 252 patients, 32 (12.7%) had to be reintubated, which represented weaning failure. Noninvasive ventilation was used postextubation in 170 (73%) patients, and 15% of these patients were reintubated, which also represented weaning failure. The mortality rate of the 252 patients studied was 8.73% (22), and there was no significant difference in the age, gender, mechanical ventilation time, and maximum inspiratory pressure between the survivors and nonsurvivors.

CONCLUSIONS

The use of a specific weaning protocol resulted in a lower mechanical ventilation time and an acceptable reintubation rate. This protocol can be used as a comparative index in hospitals to improve the weaning system, its monitoring and the informative reporting of patient outcomes and may represent a future tool and source of quality markers for patient care.

Locating of the required key-variables to be employed in a ventilation management decision support system

The aim of the paper is to identify the key physiological variables and ventilator settings involved in ventilation management, and required for an appropriate Clinical Decision Support System (CDSS). Based on the results of a questionnaire designed for the purpose of the research, 70 hours of physiological and ventilation data were recorded. Recorded data were classified by clinicians into three major lung pathologies and were further statistically analyzed for identifying strong relationships between monitored and controlled ventilator parameters. Correlation analysis was evaluated by Intensive Care Unit (ICU) clinicians. Based on the evaluators' majority voting the number and type of participating variables in a CDSS was drastically decreased. The number and type of monitored variables ranged from a single one to six, depending on the patient's lung pathology, and the controlled ventilator setting. Evaluation results were successfully applied to Neural Network models for providing suggestions on Tidal Volume and the Fraction of inspired Oxygen.

Automatic control of pressure support for ventilator weaning in surgical intensive care patients

RATIONALE

Despite its ability to reduce overall ventilation time, protocol-guided weaning from mechanical ventilation is not routinely used in daily clinical practice. Clinical implementation of weaning protocols could be facilitated by integration of knowledge-based, closed-loop controlled protocols into respirators.

OBJECTIVES

To determine whether automated weaning decreases overall ventilation time compared with weaning based on a standardized written protocol in an unselected surgical patient population.

METHODS

In this prospective controlled trial patients ventilated for longer than 9 hours were randomly allocated to receive either weaning with automatic control of pressure support ventilation (automated-weaning group) or weaning based on a standardized written protocol (control group) using the same ventilation mode. The primary end point of the study was overall ventilation time.

MEASUREMENTS AND MAIN RESULTS

Overall ventilation time (median [25th and 75th percentile]) did not significantly differ between the automated-weaning (31 [19-101] h; n = 150) and control groups (39 [20-118] h; n = 150; P = 0.178). Patients who underwent cardiac surgery (n = 132) exhibited significantly shorter overall ventilation times in the automated-weaning (24 [18-57] h) than in the control group (35 [20-93] h; P = 0.035). The automated-weaning group exhibited shorter ventilation times until the first spontaneous breathing trial (1 [0-15] vs. 9 [1-51] h; P = 0.001) and a trend toward fewer tracheostomies (17 vs. 28; P = 0.075).

CONCLUSIONS

Overall ventilation times did not significantly differ between weaning using automatic control of pressure support ventilation and weaning based on a standardized written protocol. Patients after cardiac surgery may benefit from automated weaning. Implementation of additional control variables besides the level of pressure support may further improve automated-weaning systems. Clinical trial registered with www.clinicaltrials.gov (NCT 00445289).

A weaning protocol administered by critical care nurses for the weaning of patients from mechanical ventilation

PURPOSE

The primary objective of this clinical trial of patients on mechanical ventilation was to determine if a weaning protocol implemented solely by nurses could reduce the weaning time relative to usual care (UC).

MATERIALS AND METHODS

This study is a prospective, randomized, controlled trial conducted from January 2007 to January 2009 that compared protocol-based weaning (PBW) with UC. A total of 122 patients who received invasive ventilation in the medical ICU of the Asan Medical Center were examined. Nurses operated the mechanical ventilators according to a predesigned ventilator-weaning protocol for the PBW group (n = 61), and intensive care unit (ICU) physicians managed weaning in the UC group (n = 61).

RESULTS

There were no significant differences in the 2 groups at baseline. The number of patients who successfully discontinued mechanical ventilation was similar in the 2 groups (PBW, 46 patients, 75.4%; UC, 47 patients, 77.0%; P = .832). The weaning time was 47 hours (interquartile range, 24-168 hours) in the UC group and 25 hours (interquartile range, 5.75-134 hours) in the PBW group (P = .010).

CONCLUSIONS

The weaning protocol administered by the nurses was safe and reduced the weaning time from mechanical ventilation in patients who were recovering from respiratory failure.

Field intensive care--weaning and extubation

Injury following ballistic trauma is the most prevalent indication for providing organ system support within an ICU in the field. Following damage control surgery, postoperative ventilatory support may be required, but multiple factors may influence the indications for and duration of invasive mechanical ventilation. Ballistic trauma and surgery may trigger the systemic inflammatory response syndrome (SIRS) and are important causative factors in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, their pathophysiological effect on the respiratory system is unpredictable and variable. Invasive mechanical ventilation is associated with numerous complications and the return to spontaneous ventilation has many physiological benefits. Following trauma, shorter periods of ICU sedation-amnesia and a protocol for early weaning and extubation, may minimize complications and have a beneficial effect on their psychological recovery. In the presence of stable respiratory function, appropriate analgesia and favourable operational and transfer criteria, we believe that the prompt restoration of spontaneous ventilation and early tracheal extubation should be a clinical objective for casualties within the field ICU.

Strategies in the prevention of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) remains a significant problem in the hospital setting, with very high morbidity, mortality, and cost. We performed an evidence-based review of the literature focusing on clinically relevant pharmacological and nonpharmacological interventions to prevent VAP. Owing to the importance of this condition the implementation of preventive measures is paramount in the care of mechanically ventilated patients. There is evidence that these measures decrease the incidence of VAP and improve outcomes in the intensive care unit. A multidisciplinary approach, continued education, and ventilator protocols ensure the implementation of these measures. Future research will continue to investigate cost/benefit relationships, antibiotic resistance, as well as newer technologies to prevent contamination and aspiration in mechanically ventilated patients.

An evaluation of the impact of a tracheostomy weaning protocol on extubation time

BACKGROUND

To avoid the possible complications of prolonged intubation, it is necessary and advisable to attempt weaning from the tracheostomy tube at the earliest opportunity. However, while weaning protocols have proven successful in reducing ventilation time of critical care patients, there is little evidence of their use and impact on tracheostomy tube weaning time.

AIMS

This pilot study sought to determine if the introduction of a new tracheostomy weaning protocol would reduce the time to extubation of the tracheostomy.

METHOD

A quasi-experimental design used two groups of patients. A retrospective control group of patients (n = 20) who had been weaned using standard practice were identified by a search of medical records. A prospective experimental group (n = 20) had care planned using a new tracheostomy weaning protocol. Data relating to time to extubation were collected on both groups who were all patients in an eight-bedded Critical Care Unit of a District General Hospital. The same inclusion and exclusion criteria were applied to both groups.

RESULTS

The results revealed a reduction of 1.35 days from commencement of weaning to extubation in the prospective (experimental) group. This was not statistically significant (P = 0.181)

CONCLUSION

Although the findings from the study were not statistically significant, they can be seen as clinically significant in terms of patient comfort and reduced dependency in care by a reduction of time with a tracheostomy. It is recommended that a larger scale study be carried out to determine if a tracheostomy weaning protocol does make an impact on length of time to extubation in wider care settings.

Protocol-driven ventilator weaning: reviewing the evidence

Though seminal clinical trials have identified efficacious methods of liberating patients from mechanical ventilation (ie, weaning), this knowledge is not applied often by physicians in routine practice. Weaning protocols are a strategies by which research results can be translated effectively and efficiently into clinical practice, but results of clinical trials evaluating weaning protocols have not been uniform, and controversy continues to surround this important area in critical care medicine. This article reviews the rationale for and against the routine use of weaning protocols and highlights informative details of many clinical trials that have evaluated such protocols.

Decisions Made By Critical Care Nurses During Mechanical Ventilation and Weaning in an Australian Intensive Care Unit

Background Responsibilities of critical care nurses for management of mechanical ventilation may differ among countries. Organizational interventions, including weaning protocols, may have a variable impact in settings that differ in nursing autonomy and interdisciplinary collaboration.

Objective To characterize the role of Australian critical care nurses in the management of mechanical ventilation.

Methods A 3-month, prospective cohort study was performed. All clinical decisions related to mechanical ventilation in a 24-bed, combined medical-surgical adult intensive care unit at the Royal Melbourne Hospital, a university-affiliated teaching hospital in Melbourne, Victoria, Australia, were determined.

Results Of 474 patients admitted during the 81-day study period, 319 (67%) received mechanical ventilation. Death occurred in 12.5% (40/319) of patients. Median durations of mechanical ventilation and intensive care stay were 0.9 and 1.9 days, respectively. A total of 3986 ventilation and weaning decisions (defined as any adjustment to ventilator settings, including mode change; rate or pressure support adjustment; and titration of tidal volume, positive end-expiratory pressure, or fraction of inspired oxygen) were made. Of these, 2538 decisions (64%) were made by nurses alone, 693 (17%) by medical staff, and 755 (19%) by nurses and staff in collaboration. Decisions made exclusively by nurses were less common for patients with predominantly respiratory disease or multiple organ dysfunction than for other patients.

Conclusions In this unit, critical care nurses have high levels of responsibility for, and autonomy in, the management of mechanical ventilation and weaning. Revalidation of protocols for ventilation practices in other clinical contexts may be needed.

Weaning from Mechanical Ventilation

Approximately 20% of all mechanically ventilated patients fail their first attempt to wean. Prolonged mechanical ventilation increases morbidity, mortality, and costs. No single weaning parameter predicts patient ability to wean. Weaning studies suggest that daily trials of spontaneous breathing for appropriate patients assured by standing protocol and driven by respiratory care practitioners and/or nurses improve the weaning process and patient outcome.

Issues in weaning from mechanical ventilation: literature review

AIM

The aim of this paper is to raise questions on the effect of skill mix and organizational structure on weaning from mechanical ventilation.

BACKGROUND

Mechanical ventilation is an essential life-saving technology. There are, however, numerous associated complications that influence the morbidity and mortality of patients receiving intensive care. Therefore, it was essential to use the safest and most effective form of ventilation for the shortest possible duration. Because of the potential complications and costs of mechanical ventilation, research to date have focused on accurate weaning readiness assessment, methods and organizational aspects that influence the weaning process.

METHOD

In early 2005, the literature was reviewed from 1986 to 2004 by accessing the following databases: Medline, Proquest, Science Direct, CINAHL, and Blackwell Science. The keywords mechanical ventilation, weaning, protocols, critical care, nursing role, decision-making and weaning readiness were used separately and combinations.

DISCUSSION

Controversy exists in weaning practices about appropriate and efficacious weaning readiness assessment indicators, the best method of weaning and the use of weaning protocols. Arguably, the implementation of weaning protocols may have little effect in an environment that favours collaboration between nursing and medical staff, autonomous nursing decision-making in relation to weaning practices, and high numbers of nurses qualified at postgraduate level.

CONCLUSION

Further research is required that better quantifies critical care nurses' role in weaning practices and the contextual issues that influence both the nursing role and the process of weaning from mechanical ventilation.

Methodological issues in evaluating complex healthcare interventions

AIM

This paper outlines the difficulties in defining and evaluating a complex intervention and a number of currently available models for assisting this process are discussed.

BACKGROUND

Interventions aimed at producing change in the delivery and organization of healthcare services require rigorous evaluation to demonstrate their effectiveness. Evaluation poses difficulties, however, because these interventions are usually very complex.

METHODS

A framework developed by the United Kingdom Medical Research Council to evaluate complex interventions is described. The use of this framework in designing and evaluating a nurse-led intervention in intensive care for weaning patients from mechanical ventilation is discussed. Semi-structured interviews, a questionnaire survey and observational work were undertaken to define the components of the intervention, which was subsequently evaluated in an exploratory trial using a quasi-experimental design.

CONCLUSION

The framework was a useful tool and can be easily applied in developing and evaluating complex nursing interventions. Three key challenges emerge from this experience: (i) relevant research evidence should be used systematically in developing the components of the intervention, (ii) the definition and measurement of complex intervention outcomes needs to be improved and (iii) appropriate research designs must be used when evaluating complex interventions.

Improving Adherence to a Mechanical Ventilation Weaning Protocol for Critically Ill Adults: Outcomes After an Implementation Program

• Background Despite multiple reminders, education sessions, and multidisciplinary team involvement, adherence to an evidence-based mechanical ventilation weaning protocol had been less than 1% in a general systems intensive care unit since implementation.

• Objective To assess the effectiveness of using an implementation program, the Model for Accelerating Improvement, to improve adherence and clinical outcomes after restarting a mechanical ventilation weaning protocol in an adult general systems intensive care unit.

• Methods A prospective comparative design, before and after implementation of the Model for Accelerating Improvement, was used with a consecutive sample of 129 patients and 112 multidisciplinary team members. Clinical outcomes were rate of unsuccessful extubations, rate of ventilator-associated pneumonia, and duration of mechanical ventilation; practice outcomes were staff’s understanding of the mechanical ventilation weaning protocol, perceptions of the practice safety climate, and adherence to the weaning protocol.

• Results After the intervention, the rate of unsuccessful extubations decreased, and staff’s understanding of and adherence to the weaning protocol increased significantly. The rate of ventilator-associated pneumonia, duration of mechanical ventilation, and staff’s perceptions of the practice safety climate did not change significantly.

• Conclusion Implementing the Model for Accelerating Improvement improved understanding of and adherence to protocol-directed weaning and reduced the rate of unsuccessful extubations.

Prospective Evaluation of an Extubation Protocol in a Trauma Intensive Care Unit Population

Little data exists regarding extubation protocols in critically injured trauma patients. The objective of the current study was to prospectively examine the impact of implementing an extubation protocol on the outcomes of ventilated trauma patients in a surgical intensive care unit (STICU). Trauma patients admitted to the STICU over a 15-month period at a Level 1 trauma center were prospectively evaluated. The total period was divided into an education and institution period (April 2002–November 2003) and an evaluation period (December 2003–July 2003). Patient demographics, hospital course, complications, and outcomes from period I were compared with those obtained during period II. From April 8, 2002 through July 5, 2003, 69 patients intubated for greater than 24 hours were included in our analysis. Thirty-three were treated during period I and 36 were treated during period II. Both groups were well matched in terms of age, sex, Injury Severity Score, and chest Abbreviated Injury Score. Ventilation days significantly decreased from a mean of 16.3 to 8.2 days (P = 0.04). ICU length of stay also decreased, nearly meeting significance. A rigorously enforced extubation protocol significantly decreased ventilator days in STICU patients. Continued education of health care providers is key to the success of the protocol.

Protocol-based titration of intravenous terbutaline decreases length of stay in pediatric status asthmaticus

Although frequently used to treat status asthmaticus in children, intravenous (IV) terbutaline has not been shown to decrease hospital length of stay (LOS). We theorized that this lack of demonstrable benefit resulted from variations in dosing and titration, rather than the drug per se, and that intensive care unit (ICU) LOS would be shortened by the administration of terbutaline according to a protocol incorporating a quantitative assessment of severity of illness. We prospectively treated 20 consecutive children with status asthmaticus with IV terbutaline according to a protocol that titrated the dose based on a clinical asthma score, the Modified Pulmonary Index Score (MPIS). Data were compared to a historic cohort of the previous 20 consecutive ICU patients with status asthmaticus who were treated with IV terbutaline prior to initiation of the protocol. Patients who received terbutaline by standardized protocol had significantly shorter ICU LOS (3.5 +/- 1.1 vs. 5.0 +/- 2.0 days, P = 0.01), shorter hospital LOS (5.5 +/- 1.3 vs. 8.3 +/- 2.7 days, P < 0.01), and reduced hospital charges ($19,298 +/- $10,516 vs. $26,528 +/- $12,328, P = 0.04). The method of administration of IV terbutaline significantly influenced ICU length of stay and hospital charges.

The impact of nurse-directed protocolised-weaning from mechanical ventilation on nursing practice: a quasi-experimental study

BACKGROUND

Internationally, nurse-directed protocolised-weaning has been evaluated by measuring its impact on patient outcomes. The impact on nurses' views and perceptions has been largely ignored.

AIM

To determine the change in intensive care nurses' perceptions, satisfaction, knowledge and attitudes following the introduction of nurse-directed weaning. Additionally, views were obtained on how useful protocolised-weaning was to practice.

METHODS

The sample comprised nurses working in general intensive care units in three university-affiliated hospitals. Nurse-directed protocolised-weaning was implemented in one unit (intervention group); two ICUs continued with usual doctor-led practice (control group). Nurses' perceptions, satisfaction, knowledge and attitudes were measured by self-completed questionnaires before (Phase I) and after the implementation of nurse-directed weaning (Phase II) in all units.

RESULTS

Response rates were 79% (n=140) for Phase 1 and 62% (n=132) for Phase II. Regression-based analyses showed that changes from Phase I to Phase II were not significantly different between the intervention and control groups. Sixty-nine nurses responded to both Phase I and II questionnaires. In the intervention group, these nurses scored their mean perceived level of knowledge higher in Phase II (6.39 vs 7.17, p=0.01). In the control group, role perception (4.41 vs 4.22, p=0.01) was lower and, perceived knowledge (6.03 vs 6.63, p=0.04), awareness of weaning plans (6.09 vs 7.06, p=0.01) and satisfaction with communication (5.28 vs 6.19, p=0.01) were higher in Phase II. The intervention group found protocolised weaning useful in their practice (75%): this was scored significantly higher by junior and senior nurses than middle grade nurses (p=0.02).

CONCLUSION

We conclude that nurse-directed protocolised-weaning had no effect on nurses' views and perceptions due to the high level of satisfaction which encouraged nurses' participation in weaning throughout. Control group changes are attributed to a 'reactive effect' from being study participants. Weaning protocols provide a uniform method of weaning practice and are particularly beneficial in providing safe guidance for junior staff.

A randomised controlled trial of weaning from mechanical ventilation in paediatric intensive care (PIC). Methodological and practical issues

INTRODUCTION

Most children admitted to the Paediatric Intensive Care Unit (PICU) require assistance with breathing via a mechanical ventilator. Weaning from mechanical ventilation is the transition from ventilatory support to spontaneous breathing. Traditionally weaning has been with the authority of the medical staff. However, current opinion suggests that weaning could be performed by nurses using a standardised protocol [Schultz TR, Lin RJ, Watzman HM, Durning SM, Hales R, Woodson A, et al. Weaning children from mechanical ventilation: A prospective randomised trial of protocol-directed versus physician-directed weaning. Respir Care 2001;46(8):772-82]. The potential advantages of nurse-led (protocol-directed) weaning include: A reduction in weaning time and PICU stay with cost savings. Reduced complications. Improved quality of care. Appropriate use of resources.

METHODS

A Randomised Controlled Trial was performed to test the null hypothesis: there is no difference between the clinical effectiveness of nurse-led versus medical-led weaning of infants from mechanical ventilation. Data was collected for 7 infants and analysed.

RESULTS

Results indicated no significant differences between the two study groups. Unfortunately due to recruitment problems few inferences can be drawn from the data.

CONCLUSION

The trial was unsuccessful due to Recruitment issues. Physical constraints. Impractical entry criteria. Limited randomisation service. Ethical constraints. Barriers to parental participation. The methods, the difficulties encountered and the implications for future research are addressed.

Protocolized weaning from mechanical ventilation: ICU physicians' views

BACKGROUND

The use of protocols during weaning from mechanical ventilation is uncommon in the UK, despite research pointing to their potential benefits. This may be because the research evidence is considered not to apply in different settings. Intensive care unit consultant physicians are the major decision-makers in weaning in the UK and any attempt to introduce protocolized weaning will require consideration of their views.

AIM

The aim of this paper is to report a study exploring intensive care physicians' views on (i) weaning from mechanical ventilation, (ii) the utility of weaning protocols and (iii) nurses' roles in the weaning process. A specific goal was to identify potential aids and barriers to developing weaning protocols and their introduction into clinical practice.

METHODS

Qualitative interviews were conducted with a purposive sample of 10 consultant physicians in two intensive care units in Northern Ireland and subjected to content analysis.

FINDINGS

The primary themes identified were (i) information required for weaning decisions and clinical judgement, (ii) professional boundaries, (iii) protocol issues and (iv) timing of weaning. Three types of information were deemed to be required for weaning decisions - empirical objective, empirical subjective and abstract - and interviewees considered that it would be challenging to incorporate all into a protocol. They were divided on whether protocols were useful when nursing experience was limited. Some groups of patients were thought more suitable than others for protocolized weaning.

CONCLUSIONS

Although local physicians were supportive in theory, introduction of protocolized weaning is likely to be difficult because of the breadth of information required for successful decision-making. Consultant views in this study were not consistent with American findings that physicians' caution may unnecessarily prolong weaning.

Impact of a nurses' protocol-directed weaning procedure on outcomes in patients undergoing mechanical ventilation for longer than 48 hours: a prospective cohort study with a matched historical control group

INTRODUCTION

The aim of the study was to determine whether the use of a nurses' protocol-directed weaning procedure, based on the French intensive care society (SRLF) consensus recommendations, was associated with reductions in the duration of mechanical ventilation and intensive care unit (ICU) length of stay in patients requiring more than 48 hours of mechanical ventilation.

METHODS

This prospective study was conducted in a university hospital ICU from January 2002 through to February 2003. A total of 104 patients who had been ventilated for more than 48 hours and were weaned from mechanical ventilation using a nurses' protocol-directed procedure (cases) were compared with a 1:1 matched historical control group who underwent conventional physician-directed weaning (between 1999 and 2001). Duration of ventilation and length of ICU stay, rate of unsuccessful extubation and rate of ventilator-associated pneumonia were compared between cases and controls.

RESULTS

The duration of mechanical ventilation (16.6 +/- 13 days versus 22.5 +/- 21 days; P = 0.02) and ICU length of stay (21.6 +/- 14.3 days versus 27.6 +/- 21.7 days; P = 0.02) were lower among patients who underwent the nurses' protocol-directed weaning than among control individuals. Ventilator-associated pneumonia, ventilator discontinuation failure rates and ICU mortality were similar between the two groups.

DISCUSSION

Application of the nurses' protocol-directed weaning procedure described here is safe and promotes significant outcome benefits in patients who require more than 48 hours of mechanical ventilation.

Continuous monitoring of oxygen consumption in patients undergoing weaning from mechanical ventilation

BACKGROUND

The extubation or discontinuation of mechanical ventilatory support (MVS) is only the final step in the weaning process, and an improvement in the efficiency of the weaning process is required for more successful extubation or discontinuation of MVS.

OBJECTIVE

To evaluate whether continuous monitoring of oxygen consumption (VO2) using the metabolic gas monitor is a useful predictor of failure to tolerate a weaning trial of reduced MVS.

METHOD

Twenty adult patients meeting the criteria for weaning, who required MVS > or = 7 days and who were previously deemed to have failed weaning by their attending physicians. A weaning trial was defined as a 30-min period during the strengthening training of our standardized weaning protocol. The average VO2, respiratory rate (RR), tidal volume (TV), minute ventilation (VE) and energy expenditure (EE) were recorded in respiratory muscles for a stable period of 20 min at rest and for the last 5 min of the trial. Subsequently, the oxygen cost of breathing (OCOB), the ratio of respiratory frequency to tidal volume (f/VT), DeltaRR, DeltaTV, DeltaVE, and DeltaEE were calculated.

RESULTS

Two hundred and eight weaning trials, including 145 successful trials and 63 failed trials from 20 patients were evaluated. In nonparametric analysis, a statistical difference in OCOB, DeltaRR, and DeltaEE was found between successful and failed weaning trials, while no statistical differences were found for the other parameters. An OCOB < 30% was the most accurate predictor of outcome of a weaning trial, and an f/VT < 105 was the least accurate. In a multiple logistic analysis, the OCOB revealed the highest odds ratio among all parameters.

CONCLUSIONS

Measuring the OCOB was clinically beneficial in avoiding the induction of an excessive movement load on the respiratory muscles. In patients treated with MVS, continuous monitoring of VO2 is a useful to predict success or failure of trials attempting to reduce MVS.

The neurologic assessment and treatment of the “difficult to extubate” patient

Neurologic issues are involved in the patient who is difficult to wean. Assessing the patient and performing a complete neurologic examination are important when developing a successful weaning strategy. The neurologist contributes to this process by providing expertise in the various neurologic conditions and skill in performing a thorough neurologic examination.

A prospective, controlled trial of a protocol-based strategy to discontinue mechanical ventilation

Weaning protocols can improve outcomes, but their efficacy may vary with patient and staff characteristics. In this prospective, controlled trial, we compared protocol-based weaning to usual, physician-directed weaning in a closed medical intensive care unit (ICU) with high physician staffing levels and structured, system-based rounds. Adult patients requiring mechanical ventilation for more than 24 hours were assigned to usual care (UC) or protocol weaning based on their hospital identification number. Patients assigned to UC (n=145) were managed at their physicians' discretion. Patients assigned to protocol (n=154) underwent daily screening and a spontaneous breathing trial by respiratory and nursing staff without physician intervention. There were no significant baseline differences in patient characteristics between groups. The proportion of patients (protocol vs. UC) who successfully discontinued mechanical ventilation (74.7% vs. 75.2%, p=0.92), duration of mechanical ventilation (median [interquartile range]: 60.4 hours [28.6-167.0 hours] vs. 68.0 hours [27.1-169.3 hours], p=0.61), ICU (25.3% vs. 28.3%) and hospital mortality (36.4% vs. 33.1%), ICU length of stay (115 vs. 146 hours), and rates of reinstituting mechanical ventilation (10.3% vs. 9.0%) was similar. We conclude that protocol-directed weaning may be unnecessary in a closed ICU with generous physician staffing and structured rounds.

Weaning from ventilation in paediatric intensive care: an intervention study

OBJECTIVE

To standardise the paediatric intensive care unit (PICU) team's approach to weaning paediatric patients from mechanical ventilation.

METHOD

The study employed a time series design over 2 years. A total of 220 patients (pre-intervention n=107 and post-intervention n=113) were studied. Independent variables measured in both the pre- and post-intervention groups included total ventilation time (TVT), weaning duration (WD), and length of stay (LOS), as well as quality indicators (weaning failure and reintubation rates).

RESULTS

The pre-intervention analysis demonstrated an existing fluctuation between outcome variables. When outcome indicators were compared between the pre- and post-intervention groups, both TVT and LOS were longer post-intervention (median difference: TVT -15.8 hours, P<0.068; and LOS -23.75 hours, P<0.088). WD was comparable between groups (median difference: WD -1.5 hours, P<0.427). Quality indicators were better post-intervention. Kaplan-Meier survival analysis demonstrated that long-term ventilated patients post-intervention had a reduced probability of remaining ventilated.

CONCLUSION

Weaning children from mechanical ventilation can be performed safely and effectively with the aid of collaborative guidelines. Although times were prolonged, the quality indicators were slightly improved, indicating that quicker was not always better. Long-term ventilated patients, in particular, would appear to benefit from weaning guidelines.

Can protocolised-weaning developed in the United States transfer to the United Kingdom context: a discussion

Weaning patients from mechanical ventilation using standardised protocols has been demonstrated to be safe and effective in reducing mechanical ventilation time, intensive care unit (ICU) stay and costs. Studies supporting this have all been conducted in the United States of America and weaning protocols are not widely used in the United Kingdom. With such a strong scientific evidence-base for protocolised-weaning, it is unclear why the introduction of evidence-based practice in this area is so low in the UK. There may be a number of reasons for this. First, it may be that the evidence is considered not to apply to different settings, particularly between the USA and UK where there are many differences in health care cultures. Second, it is suggested that the strength of evidence is not the only factor to account for when trying to introduce research evidence into practice [Qual. Health Care 7 (1998) 149]. The context or environment into which the research is to be implemented and how the implementation process is facilitated are equally important factors to be considered. Kitson et al. [Qual. Health Care 7 (1998) 149] argue that the interplay between the three factors of evidence, context and facilitation, enable the successful implementation of evidence-based practice. This discussion paper explores the factors that influence the introduction of weaning protocols. The discussion is structured around the three core elements from Kitson et al.'s conceptual framework and it draws upon examples of UK and USA contextual differences from Northern Ireland (NI) and Virginia (VA).

Extubation failure: magnitude of the problem, impact on outcomes, and prevention

Extubation failure, defined as the need for reinstitution of ventilatory support within 24 to 72 hours of planned endotracheal tube removal, occurs in 2 to 25% of extubated patients. The pathophysiologic causes of extubation failure include an imbalance between respiratory muscle capacity and work of breathing, upper airway obstruction, excess respiratory secretions, inadequate cough, encephalopathy, and cardiac dysfunction. Compared with patients who tolerate extubation, those who require reintubation have a higher incidence of hospital mortality, increased length of ICU and hospital stay, prolonged duration of mechanical ventilation, higher hospital costs, and an increased need for tracheostomy. Given the lack of proven treatments for extubation failure, clinicians must be aware of the factors that predict extubation outcome to improve clinical decision making. Risk factors for extubation failure include being a medical, multidisciplinary, or pediatric patient; age greater than 70 years; a longer duration of mechanical ventilation; continuous intravenous sedation; and anemia. Tests designed to assess for upper airway obstruction, secretion volume, and the effectiveness of cough can help to improve prediction of extubation failure. Rapid reinstitution of ventilatory support in patients who fail extubation may improve outcome.

Non-invasive BiPAP--implementation of a new service

Non-invasive ventilation has been shown to be an effective treatment for acute hypercapnic respiratory failure. It is now increasingly used in the treatment of acute hypoxemic respiratory failure. National guidelines published by the British Thoracic Society state that facilities for NIV should be available 24 hours per day in all hospitals likely to admit such patients. If an acute NIV service is not provided, the shortage of Intensive Care beds means that some patients will die because facilities to invasively ventilate are not available. Conversely, results of a survey performed by the indicate that at the time of data collection, only 48% of United Kingdom hospitals provided an acute NIV service. The BiPAP Vision (Respironics Inc.) offers Continuous Positive Airway Pressure (CPAP), Bi-level Spontaneous/Timed and Proportional Assist Ventilation/Timed modes and is ideal for use in a critical care environment. This article presents some of the issues surrounding NIV, the impact of a new service, and the process of implementing NIV within a critical care setting.

Proactive error prevention in the intensive care unit

Care provided in the ICU accounts for nearly 30% of acute care hospital costs and, with the aging of Americans, there is an increased demand for critical care services [1]. Critical illness reduces an individual's physical resilience. Minute-to-minute care decisions and interventions mean life or death during this acute disease phase. Critically ill patients have limited ability to defend themselves from the consequences of health care error. This patient population has the least ability to communicate symptoms to health care providers. The risk of adverse events caused by medications or equipment malfunction is higher because patients in the ICU receive twice as many medications as patients in general care units [2] and often require mechanical support of normal body functions, such as breathing, eating, and eliminating body waste. Consequently, the patient in the ICU has a higher exposure to medical error than patients in other areas of the hospital.

Nurse led weaning from ventilatory and respiratory support

Weaning from mechanical ventilation is challenging and requires expert knowledge and skill. Weaning can be defined as the process of assisting patients to breathe spontaneously without mechanical ventilatory support [Am. J. Crit. Care 7 (1998) 1491. Weaning from mechanical ventilation is not about the method used but more about how that method is employed [Crit. Care Med. 27 (1999) 2331]. A review of the literature revealed that there was no one method of weaning that was superior, furthermore evidence suggests that the use of a protocol was more effective in reducing the duration of weaning [Dimensions Crit. Care Nurs. 2 (1991) 398; Respir. Care Clin. North Am. 2 (1996) 105; AACN Clin. Issues Crit. Care 7 (1996) 550; Crit. Care Med. 25 (1997) 567; Arch. Surg. 133 (1998) 483; Chest 118 (2000) 459]. A retrospective audit of all patients who were ventilated for 7 or more days in one intensive care over a 1-year period, revealed 94 (of 500) patients were ventilated for an average of 16.8 days. There were no weaning guidelines or protocols in place at this time and weaning from mechanical ventilation was inconsistent and uncoordinated. A process mapping exercise revealed there was a delay in initiating the decision to wean of 96 h. Weaning protocols were put in place and nurse led weaning was initiated and supported by the nurse consultant. Monthly statistics were collated and this revealed the average ventilator time had reduced. Protocol led weaning has been effective in reducing the duration of ventilation. Problems still occur in initiating the decision to wean early. An audit of patient notes has revealed many reasons for this. These reasons include, over sedation, the use of morphine and midazolam, particularly in the elderly and those with renal impairment, is delaying weaning. Other reasons include, delay in tracheostomy placement. Staff are not initiating weaning guidelines early this may be due to lack of knowledge, lack of support or failure of the guidelines. Mechanisms are in place to support nurses at the bedside.

Factors influencing the patient during weaning from mechanical ventilation: a national survey

Successful weaning depends on the application of skilled judgement and decision making to nursing and medical interventions. The intensive care nurse is in an unique position for adopting a holistic approach to weaning. Such an approach needs teamwork and consideration of all the factors that could influence the outcome of the weaning phase. The aim of this study was to conduct a survey, to establish the factors taken into consideration and documented during weaning at the intensive care units (ICUs) in Sweden. A questionnaire was developed and sent to all 92 ICUs. The results identified that nutrition, communication, analgesics and sedatives, psychological and metabolic factors, as well as weaning methods and measurable parameters were taken into consideration. Written instructions for weaning were used by only three ICUs and weaning protocols were not common. A holistic approach to the discontinuation of mechanical ventilation is a valuable means of improving the quality of care and merits further research.

Effects of a multifaceted, multidisciplinary, hospital-wide quality improvement program on weaning from mechanical ventilation

OBJECTIVE

To examine the effects of a mechanical ventilation weaning management protocol that was implemented as a hospital-wide, quality improvement program on clinical and economic outcomes.

DESIGN

Prospective, before-and-after intervention study. Data from a preimplementation year are compared with those of the first 2 yrs after protocol implementation.

PATIENTS AND SETTING

Patients older than 18 yrs in diagnosis-related group 475 and group 483, who were admitted to the adult medical, surgical, and cardiac intensive care units (ICU) in a university hospital.

INTERVENTIONS

After the baseline year, a weaning management program was implemented throughout our institution. Primary endpoints were mortality, days on mechanical ventilation, ICU and hospital lengths of stay, hospital costs, and the percentage of patients requiring tracheostomy.

MAIN RESULTS

The number of patients increased from 220 in the baseline year (year 0) to 247 in the first year (year 1), then to 267 in the second year (year 2). The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score increased from 22.2 to 24.4 in year 1 (p =.006) and to 26.2 in year 2 (p <.0005). When year 0 was compared with year 1, mean days on mechanical ventilation decreased from 23.9 to 21.9 days (p =.608), hospital length of stay decreased from 37.5 to 31.6 days (p =.058), ICU length of stay decreased from 30.5 to 25.9 days (p =.133), and total cost per case decreased from $92,933 to $78,624 (p =.061). When year 0 was compared with year 2, mean days on mechanical ventilation decreased from 23.9 days to 17.5 days (p =.004), mean hospital length of stay decreased from 37.5 to 24.7 days, mean ICU length of stay decreased from 30.5 to 20.3 days, total cost per case decreased from $92,933 to $63,687, and percentage of patients requiring tracheotomy decreased from 61% to 41% (all p <.0005). There was also a reduction in the percentage of patients requiring more than one course of mechanical ventilation during the hospitalization from 33% to 26% (p =.039), a total cost savings of $3,440,787 and a decrease in mortality between all 3 yrs from 32% to 28% (p =.062).

CONCLUSIONS

A multifaceted, multidisciplinary weaning management program can change the process of care used for weaning patients from mechanical ventilation throughout an acute care hospital and across multiple services. This change can lead to large reductions in the duration of mechanical ventilation, length of stay, and hospital costs, even at a time when patients are sicker.

Respiratory and Hemodynamic Management After Cardiac Surgery

In this new era of managed care, the emphasis has been on the reduction of intensive-care stay after coronary artery bypass surgery. "Fast-track" or rapid weaning protocols have become increasingly popular due to evidence that shows their cost-effectiveness and safety. With new advances in surgical and anesthetic techniques, the goal is often to have patients extubated within 4 to 6 hours upon arrival in the intensive-care unit. Patients who are not candidates for the fast-track protocol are often those who either have poor respiratory function and a large A-a gradient or those who have hemodynamic instability from poor cardiac function after bypass. These patients need more intensive care and more traditional weaning from mechanical ventilation. Those that are not able to wean from the mechanical ventilator within a few weeks are candidates for tracheostomy in order to avoid complications from prolonged endotracheal intubation and to improve pulmonary toilet. The treatment of perioperative low cardiac output syndrome is another goal after bypass surgery. Poor cardiac function can be managed with a variety of vasopressor and inotropic agents based on what the suspected derangement is from clinical examination and hemodynamic measurements (eg, low preload, low cardiac index, high or low systemic vascular resistance). Another modality that has been shown to have benefit on reducing hospital stay and costs is prophylaxis for atrial fibrillation, which may occur in 40% of patients who undergo bypass surgery and in 60% of those who undergo valve replacement surgery. Beta-blockers and amiodarone have both been found to be effective as prophylaxis against postoperative atrial fibrillation.