Variations in the measurement of weaning parameters: a survey of respiratory therapists

Comparison of the Recent ExPreS Score, WEANSNOW Score, and the Parsimonious HACOR Score as the Best Predictor of Weaning: An Externally Validated Prospective Observational Study

Background

Since weaning failure is multifactorial, comprehensive weaning scores encompassing not only the respiratory component but also nonrespiratory aspects are quintessential for successful weaning prediction.

Materials and methods

This was a single-center prospective observational study on 128 intensive care unit (ICU) patients undergoing spontaneous breathing trials (SBT). The extubation prediction score (ExPreS), heart rate, acidosis, consciousness, oxygenation, respiratory rate (HACOR), and weaning parameters, endotracheal tube size, arterial blood gas analysis, nutrition, secretions, neuromuscular affecting agents, obstructive airway problems and wakefulness (WEANSNOW) scores were compared for their diagnostic accuracy for successful weaning prediction.

Results

Out of 128 patients, 49 (38.3%) patients had weaning failure, and 79 (61.7%) had weaning success. The patients in the weaning failure group had significantly higher APACHE II scores, WEANSNOW scores, HACOR scores, MV days, and significantly lower ExPreS scores as compared to the successful weaning group. Multivariable regression analysis showed that ExPreS score p = 0.015, adjusted OR 0.960, 95% CI (0.929-0.992) and HACOR score p < 0.001, adjusted OR 1.357, 95% CI (1.176-1.567) were independent predictors of weaning failure. The HACOR score had an AUC of 0.830, cut-off ≥5, p < 0.001, sensitivity 76%, specificity 68%, diagnostic accuracy 70% to predict weaning failure. The ExPreS score had an AUC of 0.735, cut-off ≥69, p < 0.001, sensitivity of 70.9%, specificity of 69.4%, and diagnostic accuracy of 70.3% to predict weaning success. Both the HACOR and ExPreS scores were good models for predicting weaning outcomes (model quality 0.76 and 0.64 respectively).

Conclusion

The parsimonious HACOR score is comparable to the ExPreS score for the prediction of weaning outcomes in critically ill patients.

How to cite this article

Nayak G, Chaudhuri S, Ravindranath S, Todur P. Comparison of the Recent ExPreS Score, WEANSNOW Score, and the Parsimonious HACOR Score as the Best Predictor of Weaning: An Externally Validated Prospective Observational Study. Indian J Crit Care Med 2024;28(3):273-279.

Predictors of extubation failure and prolonged mechanical ventilation among patients with intracerebral hemorrhage after surgery

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) is a condition associated with high mortality and morbidity. Survivors may require prolonged intubation with mechanical ventilation (MV). The aim of this study was to analyze the predictors of extubation failure and prolonged MV in patients who undergo surgical evacuation.

METHODS

This retrospective study was conducted on adult patients with ICH who underwent MV for at least 48 h and survived > 14 days after surgery. The demographics, clinical characteristics, laboratory tests, and Glasgow Coma Scale score were analyzed.

RESULTS

A total of 134 patients with ICH were included in the study. The average age of the patients was 60.34 ± 15.59 years, and 79.9% (n = 107) were extubated after satisfying the weaning parameters. Extubation failure occurred in 11.2% (n = 12) and prolonged MV in 48.5% (n = 65) patients. Multivariable regression analysis revealed that a white blood cell count > 10,000/mm3 at the time of extubation was an independent predictor of reintubation. Meanwhile, age and initial Glasgow Coma Scale scores were predictors of prolonged MV.

CONCLUSIONS

This study provided the first comprehensive characterization and analysis of the predictors of extubation failure and prolonged MV in patients with ICH after surgery. Knowledge of potential predictors is essential to improve the strategies for early initiation of adequate treatment and prognosis assessment in the early stages of the disease.

Does Arterial Blood Gas (ABG) Provide a Safety Net for Extubation in Surgical Patients?

Background Extubation has always been a critical aspect of anaesthesia. Guidelines and recommendations are in place for achieving successful extubation, but the risk of failure always persists. Through this study, we assess whether arterial blood gas (ABG) values taken intraoperatively help predict extubation success in the operation theatre. Materials and methods This was a prospective observational study for one year of extubated patients whose blood gas values were not within the normal range. The patients of age 18 years and above undergoing high-risk elective and emergency surgeries where at least one intraoperative arterial blood sample was taken for blood gas analysis were included. Apart from parameters of ABG demographic data, urgency and duration of surgery, blood loss, urine output, use of intraoperative fluid(s), and blood product(s) were also observed.  Results Of 578 patients enrolled, 116 patients were extubated based on the predefined extubation criteria. Of these, 24 patients were reintubated within 24 hours. ABG parameters such as partial pressure of arterial oxygen (PaO₂) and serum HCO_3- levels were significantly lower in the reintubated patients compared to non-reintubated patients (p-values of 0.045 and 0.003, respectively). Conclusion This study showed that the PaO₂ <100 mm Hg or ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) of less than 200 and an HCO_3- value of less than 18 are plausible ABG parameters to decide extubation in post-surgery patients in OT. PaCO₂, base deficit, and lactate were less reliable parameters for planning extubation.

Predictors of Prolonged Mechanical Ventilation Among Patients with Aneurysmal Subarachnoid Hemorrhage After Microsurgical Clipping

Introduction

Aneurysmal subarachnoid hemorrhage (aSAH) is a fatal event with high mortality and morbidity rates. Survivors may require prolonged intubation with mechanical ventilation (MV). However, the risk factors for prolonged intubation in these patients remain unclear. The aim of this study was to determine the predictors of prolonged MV in aSAH patients who underwent surgical clipping.

Methods

In total, 108 adult patients with a primary diagnosis of aSAH who were on MV > 48 h and survived > 14 days after surgery were included. Clinicodemographic and radiological characteristics, laboratory tests on admission, and initial Glasgow Coma Scale (GCS) and its components were analyzed.

Results

The average age of the patients included in the analysis was 59.1 ± 12.5 years. Overall, 32 patients (29.6%) had prolonged MV. The group with prolonged MV showed a higher prevalence of diabetes mellitus and hypertension, lower initial GCS and its components, higher World Federation of Neurosurgeons (WFNS) and Hunt and Hess grades, and higher initial white cell counts. The independent factors associated with prolonged MV were a history of diabetes mellitus (odds ratio [OR] 5.799, 95% confidence interval [CI] 1.109–30.334; P = 0.037) and Hunt and Hess grade 3–5 (OR 7.217, 95% CI 1.090–47.770; P = 0.040).

Conclusion

A history of diabetes mellitus and Hunt and Hess grade 3–5 independently predict prolonged MV after microsurgical clipping in patients with aSAH. Thus, knowledge of potential predictors for prolonged MV is essential to improve the early initiation of adequate treatment in the early stages of treatment and provide useful information for communication between caregivers and families.

The rapid shallow breathing index as a predictor of successful mechanical ventilation weaning: clinical utility when calculated from ventilator data

OBJECTIVE:

The use of the rapid shallow breathing index (RSBI) is recommended in ICUs, where it is used as a predictor of mechanical ventilation (MV) weaning success. The aim of this study was to compare the performance of the RSBI calculated by the traditional method (described in 1991) with that of the RSBI calculated directly from MV parameters.

METHODS:

This was a prospective observational study involving patients who had been on MV for more than 24 h and were candidates for weaning. The RSBI was obtained by the same examiner using the two different methods (employing a spirometer and the parameters from the ventilator display) at random. In comparing the values obtained with the two methods, we used the Mann-Whitney test, Pearson's linear correlation test, and Bland-Altman plots. The performance of the methods was compared by evaluation of the areas under the ROC curves.

RESULTS:

Of the 109 selected patients (60 males; mean age, 62 ± 20 years), 65 were successfully weaned, and 36 died. There were statistically significant differences between the two methods for respiratory rate, tidal volume, and RSBI (p < 0.001 for all). However, when the two methods were compared, the concordance and the intra-observer variation coefficient were 0.94 (0.92-0.96) and 11.16%, respectively. The area under the ROC curve was similar for both methods (0.81 ± 0.04 vs. 0.82 ± 0.04; p = 0.935), which is relevant in the context of this study.

CONCLUSIONS:

The satisfactory performance of the RSBI as a predictor of weaning success, regardless of the method employed, demonstrates the utility of the method using the mechanical ventilator.

Rapid shallow breathing index

Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed.

Effect of Tracheostomy on Weaning Parameters in Difficult-to-Wean Mechanically Ventilated Patients: A Prospective Observational Study

Background and Objective

Weaning parameters are commonly measured through an endotracheal tube in mechanically ventilated patients recovering from acute respiratory failure, however this practice has rarely been evaluated in tracheostomized patients. This study aimed to investigate changes in weaning parameters measured before and after tracheostomy, and to explore whether the data measured after tracheostomy were associated with weaning outcomes in difficult-to-wean patients.

Methods

In a two-year study period, we enrolled orotracheally intubated patients who were prepared for tracheostomy due to difficult weaning. Weaning parameters were measured before and after the conversion to tracheostomy and compared, and the post-tracheostomy data were tested for associations with weaning outcomes.

Results

A total of 86 patients were included. After tracheostomy, maximum inspiratory pressure (mean difference (Δ) = 4.4, 95% CI, 2.7 to 6.1, P<0.001), maximum expiratory pressure (Δ = 5.4, 95% CI, 2.9 to 8.0, P<0.001) and tidal volume (Δ = 33.7, 95% CI, 9.0 to 58.5, P<0.008) significantly increased, and rapid shallow breathing index (Δ = -14.6, 95% CI, -25.4 to -3.7, P<0.009) and airway resistance (Δ = -4.9, 95% CI, -5.8 to -4.0, P<0.001) significantly decreased. The patients who were successfully weaned within 90 days of the initiation of mechanical ventilation had greater increments in maximum inspiratory pressure (5.9 vs. 2.4, P = 0.04) and maximum expiratory pressure (8.0 vs. 2.0, P = 0.02) after tracheostomy than those who were unsuccessfully weaned.

Conclusions

In conclusion, the conversion from endotracheal tube to tracheostomy significantly improved the measured values of weaning parameters in difficult-to-wean patients who subsequently weaned successfully from the mechanical ventilator. The change was significant only for airway resistance in patients who failed weaning.

Trial Registration

ClinicalTrials.gov NCT01312142

Ventilatory weaning practices in intensive care units in the city of Cali

Objective

Early weaning from mechanical ventilation is one of the primary goals in managing critically ill patients. There are various techniques and measurement parameters for such weaning. The objective of this study was to describe the practices of ventilatory weaning in adult intensive care units in the city of Cali.

Methods

A survey of 32 questions (some multiple choice) evaluating weaning practices was distributed to physiotherapists and respiratory therapists working in intensive care units, to be answered anonymously.

Results

The most common strategy for the parameter set was the combination of continuous positive airway pressure with pressure support (78%), with a large variability in pressure levels, the most common range being 6 to 8cmH₂O. The most common weaning parameters were as follows: tidal volume (92.6%), respiratory rate (93.3%) and oxygen saturation (90.4%). The most common waiting time for registration of the parameters was >15 minutes (40%). The measurements were preferably obtained from the ventilator display.

Conclusion

The methods and measurement parameters of ventilatory weaning vary greatly. The most commonly used method was continuous positive airway pressure with more pressure support and the most commonly used weaning parameters were the measured tidal volume and respiratory rate.

The use of a weaning and extubation protocol to facilitate effective weaning and extubation from mechanical ventilation in patients suffering from traumatic injuries: a non-randomized experimental trial comparing a prospective to retrospective cohort

PURPOSE

Many patients who have suffered traumatic injuries require mechanical ventilation (MV). Weaning is the transition from ventilatory support to spontaneous breathing. The purpose of this study was to determine whether the use of a nurse and a physiotherapist-driven protocol to wean and extubate patients from MV resulted in decreased MV days and intensive care unit (ICU) length of stay (LOS).

METHODS

A prospective cohort of 28 patients (Phase I), weaned according to the protocol developed for the Union Hospital Trauma Unit, was matched retrospectively with a historical cohort of 28 patients (Phase II), weaned according to physician preference. Pairs in the two groups were matched for gender, age, type, and severity of injury.

RESULTS

For mean MV days, the groups did not differ statistically significantly (p 0.3; 14.4 days vs. 16.3 days), although the reduction in MV is clinically significant in view of the complications of additional MV days. The difference of 0.2 days for ICU LOS was not statistically significant (p = 0.9; 20.8 days vs. 21.0 days) demonstrating that the reduction in MV days may not result in the reduction of ICU LOS. The rate of re-intubation was similar between the groups (Phase I = 3/28 vs. Phase II = 4/24).

CONCLUSION

The use of a weaning and extubation protocol led by nursing staff and physiotherapists resulted in a clinically significant reduction in MV time, reducing risk of ventilator-associated complications. The role of physiotherapists and nursing staff in weaning and extubation from MV could be greatly expanded in South African ICUs.

Predictive parameters for weaning from mechanical ventilation

The use of predictive parameters for weaning from mechanical ventilation is a rather polemic topic, and the results of studies on this topic are divergent. Regardless of the use of these predictive parameters, the spontaneous breathing trial (SBT) is recommended. The objective of the present study was to review the utility of predictive parameters for weaning in adults. To that end, we searched the Medline, LILACS, and PubMed databases in order to review articles published between 1991 and 2009, in English or in Portuguese, using the following search terms: weaning/desmame, extubation/extubação, and weaning indexes/indices de desmame. The use of clinical impression is an inexact means of predicting weaning outcomes. The most widely used weaning parameter is the RR/tidal volume (V T) ratio, although this parameter presents heterogeneous results in terms of accuracy. Other relevant parameters are MIP, airway occlusion pressure (P0.1), the P0.1/MIP ratio, RR, V T, minute volume, and the index based on compliance, RR, oxygenation, and MIP. An index created in Brazil, the integrative weaning index, has shown high accuracy. Although recommended, the SBT is inaccurate, approximately 15% of extubation failures going unidentified in SBTs. The main limitations of the weaning indexes are related to their use in specific populations, the cut-off points selected, and variations in the types of measurement. Since the SBT and the clinical impression are not 100% accurate, the weaning parameters can be useful, especially in situations in which the decision as to weaning is difficult.

The factors which influence nurses when weaning patients from mechanical ventilation: findings from a qualitative study

The aim of the study was to describe the factors that influence critical care nurses when deciding to wean patients from mechanical ventilation. The study adopted a qualitative methodology, using semi-structured interviews and a vignette. An invited sample of critical care nurses (n=24) from one Irish intensive care unit was employed. Each nurse was interviewed once and a vignette was used to structure the interview questioning. The findings were analysed using thematic content analysis. Six major themes influencing nurses' decision to wean emerged, as follows: physiological influences; clinical reassessment and decision making; the nurse's experience, confidence and education; the patient's medical history and current ventilation; the intensive care working environment; and use of protocols. The findings highlight the complex nature of weaning patients from mechanical ventilation and the major role of the nurse in this process.

Clinical Prediction of Weaning and Extubation in Australian and New Zealand Intensive Care Units

Our objective was to describe, in Australian and New Zealand adult intensive care units, the relative frequency in which various clinical criteria were used to predict weaning and extubation, and the weaning methods employed.

Participant intensivists at 55 intensive care units completed a self-administered questionnaire, using visual analogue scales (0=not at all predictive, 10=perfectly predictive, not used=null score) to record the perceived utility of 30 potential predictors.

Survey response rate was 71% (164/230). Those variables thought most predictive of weaning readiness were respiratory rate (median score 8.0, interquartile range 7.0 to 8.6) effective cough (7.3, 5.9 to 8.2) and pressure support setting (7.2, 6.0 to 8.0). The most highly rated predictors of extubation success were effective cough (8.0, 7.0 to 9.0), respiratory rate (8.0, 7.0 to 8.5) and Glasgow Coma Score (7.9, 6.1 to 8.3). Variables perceived least predictive of weaning and extubation success were P0.1, Acute Physiological and Chronic Health Evaluation score II, mean arterial pressure, electrolytes and maximum inspiratory pressure (individual median scores <5). Most popular clinical criteria were those perceived to have high predictive accuracy, both for weaning (respiratory rate 96%, pressure support setting 94% and Glasgow coma score 91%) and extubation readiness (respiratory rate 98%, effective cough 94% and Glasgow Coma Score 92%). Weaning mostly employed pressure support ventilation (55%), with less use of synchronised intermittent mandatory ventilation (32%) and spontaneous breathing trials (13%).

Classic ventilatory performance predictors including respiratory rate and effective cough were reported to be of greater clinical utility than other more recently proposed measures.

Fentanyl Transdermal Therapy System (TTS-Patch) for Post-Traumatic Blunt Chest Injury

Proper post-extubation pain control in traumatic blunt chest injury represents a challenge to provide adequate analgesia for proper lung inflation and to prevent re-intubation. In this case, the average opioid (Remifentanil) infusion drip in a traumatic blunt chest injury patient in the 48 hours prior to extubation was calculated and converted to the equivalent analgesic one of the Fentanyl Transdermal Therapeutic System (Fentanyl TTS Patch). The analgesic gap before the onset of action for the applied fentanyl patch was covered by frequent injections of tramadol. Evaluation of the Fentanyl TTS effect through the post-extubation period was carried out by measuring the analgesic effect on a visual analogue scale, the alertness status by simple sedation score, while the respiratory performance was followed by the negative inspiratory force. The outcome in this case showed that Fentanyl Patch is a reliable, favorable, safe and non-invasive method that produces a good analgesic effect and positive impaction on the post-extubation course of respiratory performance with a satisfactory outcome and no side effects.

Evaluation of maximal inspiratory pressure, tracheal airway occlusion pressure, and its ratio in the weaning outcome

PURPOSE

The objective of this study is to evaluate the predictive performance of maximal inspiratory pressure (Pimax), airway occlusion pressure (P 0.1), and its ratio (P 0.1/Pimax) in the weaning outcome.

MATERIALS AND METHODS

Seventy patients on mechanical ventilation for more than 24 hours, who fulfilled weaning criteria, were prospectively evaluated. Pimax less than -25 cm H(2)O, P 0.1 less than 4.2 cm H(2)O, and P 0.1/Pimax less than 0.14 were evaluated in all patients before spontaneous breathing trials. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index.

RESULTS

Pimax presented the area under the ROC curves smaller than those for P 0.1 and P 0.1/Pimax (0.52 x 0.76 and 0.52 x 0.78; P = .004 and P = .0006, respectively), being the criteria of worst performance. P 0.1/Pimax presented excellent predictive performance in weaned patients, with sensitivity of 98.08, but with the area under the ROC curves only slightly larger than those for P 0.1 (0.78 x 0.76, respectively; P = .69).

CONCLUSION

In our study, P 0.1 and P 0.1/Pimax ratio were moderately accurate, whereas Pimax was less accurate in predicting the weaning outcome.

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.

Assessing data quality in manual entry of ventilator settings

OBJECTIVE

To evaluate the data quality of ventilator settings recorded by respiratory therapists using a computer charting application and assess the impact of incorrect data on computerized ventilator management protocols. DESIGN An analysis of 29,054 charting events gathered over 12 months from 678 ventilated patients (1,736 ventilator days) in four intensive care units at a tertiary care hospital.

MEASUREMENTS

Ten ventilator settings were examined, including fraction of inspired oxygen (Fio (2)), positive end-expiratory pressure (PEEP), tidal volume, respiratory rate, peak inspiratory flow, and pressure support. Respiratory therapists entered values for each setting approximately every two hours using a computer charting application. Manually entered values were compared with data acquired automatically from ventilators using an implementation of the ISO/IEEE 11073 Medical Information Bus (MIB). Data quality was assessed by measuring the percentage of time that the two sources matched. Charting delay, defined as the interval between data observation and data entry, also was measured.

RESULTS

The percentage of time that settings matched ranged from 99.0% (PEEP) to 75.9% (low tidal volume alarm setting). The average charting delay for each charting event was 6.1 minutes, including an average of 1.8 minutes spent entering data in the charting application. In 559 (3.9%) of 14,263 suggestions generated by computerized ventilator management protocols, one or more manually charted setting values did not match the MIB data.

CONCLUSION

Even at institutions where manual charting of ventilator settings is performed well, automatic data collection can eliminate delays, improve charting efficiency, and reduce errors caused by incorrect data.

Intrapulmonary percussive ventilation in tracheostomized patients: a randomized controlled trial

OBJECTIVE

To investigate whether the addition of intrapulmonary percussive ventilation to the usual chest physiotherapy improves gas exchange and lung mechanics in tracheostomized patients.

DESIGN AND SETTING

Randomized multicenter trial in two weaning centers in northern Italy.

PATIENTS AND PARTICIPANTS

46 tracheostomized patients (age 70 +/- 7 years, 28 men, arterial blood pH 7.436 +/- 0.06, PaO(2)/FIO(2) 238 +/- 46) weaned from mechanical ventilation.

INTERVENTIONS

Patients were assigned to two treatment groups performing chest physiotherapy (control), or percussive ventilation (IMP2 Breas, Sweden) 10 min twice/day in addition to chest physiotherapy (intervention).

MEASUREMENTS AND RESULTS

Arterial blood gases, PaO(2)/FIO(2) ratio, and maximal expiratory pressure were assessed every 5th day for 15 day. Treatment complications that showed up in 1 month of follow-up were recorded. At 15 days the intervention group had a significantly better PaO(2)/FIO(2) ratio and higher maximal expiratory pressure; after follow-up this group also had a lower incidence of pneumonia.

CONCLUSIONS

The addition of percussive ventilation to the usual chest physiotherapy regimen in tracheostomized patients improves gas exchange and expiratory muscle performance and reduces the incidence of pneumonia.

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.

Implementing effective ventilator practice at the bedside

PURPOSE OF REVIEW

New data on the efficacy of low tidal volume ventilation for acute lung injury, noninvasive ventilation for chronic obstructive pulmonary disease exacerbation, weaning from mechanical ventilation, and prevention of ventilator-associated pneumonia provide, for perhaps the first time in respiratory care, compelling evidence for clinicians to change practice. However, experience from every other field in medicine suggests that there will be significant barriers to changing clinical practice at the bedside. Studies on implementation of effective practice in medicine shows that a multifaceted, team-oriented approach incorporating reminders, efficient use of non-physician personnel, protocols, and education is required to change clinical practice. Limited data on current practice of mechanical ventilation suggest that it deviates from recommended practice. Unfortunately, there are no studies exploring community-based implementation of mechanical ventilation guidelines and only a few studies to inform clinicians as to why ventilator practice may be difficult to change. As the evidence base grows for effective critical care practice, so does the responsibility to translate practices that improve outcome from research journals to patients' bedsides. Strategies for doing this are presented in the review.

Practice Variation in Respiratory Therapy Documentation During Mechanical Ventilation

STUDY OBJECTIVES

Implementation of new ventilatory strategies such as lung-protective ventilation for ARDS will require a multidisciplinary approach with considerable physician and respiratory therapy (RT) interaction. One of the key factors in this communication is complete and accurate RT documentation of ventilator settings. Few studies have explored the quality and variability of this documentation.

DESIGN

Population-based cross-sectional study.

SETTING

Seventeen adult hospitals in King County, WA.

PARTICIPANTS/INTERVENTIONS

We compared the blank RT ICU flow sheet for each institution to the 1992 American Association for Respiratory Care (AARC) clinical practice guidelines (CPGs) for patient-ventilator system checks. We interviewed RT managers at each hospital about their practices. Finally, we reviewed selected charts of patients with acute lung injury (ALI) or ARDS from each hospital to evaluate the documentation.

MEASUREMENTS/RESULTS

We found substantial variability in RT documentation practices and in their extent of compliance with the AARC CPGs. Only 15 of 52 items recommended by the AARC CPGs were included on blank RT flow sheets of every hospital in our study, and only 26 of 52 items were found on charts of ALI/ARDS patients at most hospitals (ie, > or =10 of 17 hospitals). Only 10 of 17 RT department managers reported using the AARC CPGs as a basis for their documentation policies. Items necessary for the implementation of lung-protective ventilation for ALI/ARDS patients were recorded inconsistently and were not included in the AARC CPGs. Plateau pressure was found on all reviewed charts of ALI/ARDS patients at only 10 of 17 hospitals.

CONCLUSIONS

Considerable variability exists in RT documentation practices. We suggest that new guidelines be developed for documenting the care of patients receiving mechanical ventilation, in light of recent data on ventilator weaning and the management of ALI/ARDS, and that their effect on practice and outcomes be evaluated.