Rate of reintubation in mechanically ventilated neurosurgical and neurologic patients: evaluation of a systematic approach to weaning and extubation. A prospective, controlled trial of a protocol-based strategy to discontinue mechanical ventilation. A randomized, controlled trial of protocol-directed versus physician-directed weaning from mechanical ventilation. A computer-controlled ventilator weaning system. A clinical trial. Effect on the duration of mechanical ventilation of identifying patients capable of breathing spontaneously. Predictors of successful extubation in neurosurgical patients. Optimization of mechanical ventilation support following cardiac surgery. A randomised, controlled trial of conventional versus automated weaning from mechanical ventilation using SmartCare/PS. Protocol weaning of mechanical ventilation in medical and surgical patients by respiratory care practitioners and nurses: effect on weaning time and incidence of ventilator-associated pneumonia.
To assess whether a systematic approach to weaning and extubation (intervention) is superior to the sole physician's judgment (control) in preventing reintubation secondary to extubation failure in patients with neurologic disorders.
                Randomized controlled trial.
                Intensive care unit of a large teaching hospital.
                Three hundred eighteen intubated patients who had been receiving mechanical ventilation for at least 12 hrs and were able to trigger the ventilator.
                Patients were randomized to the intervention (n = 165) or control group (n = 153).
                Rate of reintubation after extubation failure occurring within 48 hrs (primary end point). Duration of mechanical ventilation, length of intensive care unit stay, mortality, rate of tracheotomy (secondary end points). The perception of the research protocol by the intensive care unit staff was also assessed.
                The rate of reintubation was lower in the intervention (5%) than in the control (12.5%) group (p = 0.047). There was no difference in any of the other outcome variables (secondary end points). Simplified Acute Physiologic Score II (adjusted odds ratio 1.042 per unit; 95% confidence interval 1.006-1.080; p = 0.022) and inclusion in the control group (adjusted odds ratio 2.393; 95% confidence interval 1.000-5.726; p = 0.05) were the only two independent predictive factors for the risk of extubation failure. The protocol was felt by the staff to determine an improvement in patients' clinical outcome, but to increase intensive care unit workload; nurses and physiotherapists considered its impact on their professional role more positively than physicians.
                In patients with neurologic diseases, a systematic approach to weaning and extubation reduces the rate of reintubation secondary to extubation failure without affecting the duration of mechanical ventilation, and is overall positively perceived by intensive care unit professionals. 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. To compare a practice of protocol-directed weaning from mechanical ventilation implemented by nurses and respiratory therapists with traditional physician-directed weaning.
                Randomized, controlled trial.
                Medical and surgical intensive care units in two university-affiliated teaching hospitals.
                Patients requiring mechanical ventilation (n = 357).
                Patients were randomly assigned to receive either protocol-directed (n = 179) or physician-directed (n = 178) weaning from mechanical ventilation.
                The primary outcome measure was the duration of mechanical ventilation from tracheal intubation until discontinuation of mechanical ventilation. Other outcome measures included need for reintubation, length of hospital stay, hospital mortality rate, and hospital costs. The median duration of mechanical ventilation was 35 hrs for the protocol-directed group (first quartile 15 hrs; third quartile 114 hrs) compared with 44 hrs for the physician-directed group (first quartile 21 hrs; third quartile 209 hrs). Kaplan-Meier analysis demonstrated that patients randomized to protocol-directed weaning had significantly shorter durations of mechanical ventilation compared with patients randomized to physician-directed weaning (chi 2 = 3.62, p = .057, log-rank test; chi 2 = 5.12, p = .024, Wilcoxon test). Cox proportional-hazards regression analysis, adjusting for other covariates, showed that the rate of successful weaning was significantly greater for patients receiving protocol-directed weaning compared with patients receiving physician-directed weaning (risk ratio 1.31; 95% confidence interval 1.15 to 1.50; p = .039). The hospital mortality rates for the two treatment groups were similar (protocol-directed 22.3% vs. physician-directed 23.6%; p = .779). Hospital cost savings for patients in the protocol-directed group were $42,960 compared with hospital costs for patients in the physician-directed group.
                Protocol-guided weaning of mechanical ventilation, as performed by nurses and respiratory therapists, is safe and led to extubation more rapidly than physician-directed weaning. The purpose of this study was to determine if a computer-directed weaning system could wean patients with complex medical problems from mechanical ventilation and appropriately respond to signs of respiratory failure more effectively than traditional physician-directed weaning methods. In a prospective, randomized, controlled study, we tested the system in 15 patients who had required prolonged mechanical ventilation and met predetermined weaning tests. Patients were randomly assigned to one of two groups: (1) automatic, computer-directed weaning or (2) physician-controlled weaning. The computer-directed system decreased or increased the synchronized intermittent mandatory ventilation rate and pressure support (PS) based on predetermined limits of patient respiratory rate (RR) and tidal volume (TV). Pulse oximeter oxygen saturation was monitored, and alarms were triggered by an oxygen saturation of < 90 percent. In the physician control group, weaning progressed with SIMV rate and PS reduction, as judged appropriate by the physician. Nine patients were assigned to the computer group; six patients were assigned to the control group. The average patient age was 64.8 +/- 14.9 years for the computer group, 65.2 +/- 22.7 years for the control group. The average time on mechanical ventilation prior to weaning was 13.4 +/- 7.8 days for the computer group and 14.5 +/- 11.1 days for the control group. Seven of the nine computer group patients weaned within 48 h of the study, with an average time to wean of 18.7 +/- 5.9 h. All seven were breathing spontaneously 48 h after weaning. Two of the six control group patients weaned within 48 h of the study, with an average time of 25.6 +/- 5.6 h. Both patients who weaned were placed back on mechanical ventilation within 30 h. The number of arterial blood gas samples drawn during the study was 1.4 +/- 0.7 for the computer group, 7.2 +/- 4.3 for the control group. The number of minutes per hour outside acceptable limits of RR > 30, RR < 8, or TV < 5 ml/kg was 3.2 +/- 2.8 min for the computer group and 6.6 +/- 4.1 min for the control group. The study suggests that use of the computer-directed weaning system results in fewer arterial blood gas samples, shorter weaning times, and less time spent outside acceptable RR and TV parameters. Prompt recognition of the reversal of respiratory failure may permit earlier discontinuation of mechanical ventilation, without harm to the patient.
                We conducted a randomized, controlled trial in 300 adult patients receiving mechanical ventilation in medical and coronary intensive care units. In the intervention group, patients underwent daily screening of respiratory function by physicians, respiratory therapists, and nurses to identify those possibly capable of breathing spontaneously; successful tests were followed by two-hour trials of spontaneous breathing in those who met the criteria. Physicians were notified when their patients successfully completed the trials of spontaneous breathing. The control subjects had daily screening but no other interventions. In both groups, all clinical decisions, including the decision to discontinue mechanical ventilation, were made by the attending physicians.
                Although the 149 patients randomly assigned to the intervention group had more severe disease, they received mechanical ventilation for a median of 4.5 days, as compared with 6 days in the 151 patients in the control group (P=0.003). The median interval between the time a patient met the screening criteria and the discontinuation of mechanical ventilation was one day in the intervention group and three days in the control group (P<0.001). Complications -- removal of the breathing tube by the patient, reintubation, tracheostomy, and mechanical ventilation for more than 21 days -- occurred in 20 percent of the intervention group and 41 percent of the control group (P=0.001). The number of days of intensive care and hospital care was similar in the two groups. Total costs for the intensive care unit were lower in the intervention group (median, $15,740, vs. $20,890 in the controls, P=0.03); hospital costs were lower, though not significantly so (median, $26,229 and $29,048, respectively; P=0.3).
                Daily screening of the respiratory function of adults receiving mechanical ventilation, followed by trials of spontaneous breathing in appropriate patients and notification of their physicians when the trials were successful, can reduce the duration of mechanical ventilation and the cost of intensive care and is associated with fewer complications than usual care. A respiratory therapist-driven weaning protocol incorporating daily screens, spontaneous breathing trials (SBT), and prompts to caregivers has been associated with superior outcomes in mechanically ventilated medical patients. To determine the effectiveness of this approach in neurosurgical (NSY) patients, we conducted a randomized controlled trial involving 100 patients over a 14-mo period. All had daily screens of weaning parameters. If these were passed, a 2-h SBT was performed in the Intervention group. Study physicians communicated positive SBT results, and the decision to extubate was made by the primary NSY team. Patients in the Intervention (n = 49) and Control (n = 51) groups had similar demographic characteristics, illness severity, and neurologic injuries. Among all patients, 87 (45 in the Control and 42 in the Intervention group) passed at least one daily screen. Forty (82%) patients in the Intervention group passed SBT, but a median of 2 d passed before attempted extubation, primarily because of concerns about the patient's sensorium (84%). Of 167 successful SBT, 126 (75%) did not lead to attempted extubation on the same day. The median time of mechanical ventilation was 6 d in both study groups, and there were no differences in outcomes. Overall complications included death (36%), reintubation (16%), and pneumonia (9%). Tracheostomies were created in 29% of patients. Multivariate analysis showed that Glasgow Coma Scale (GCS) score (p < 0.0001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (p < 0.0001) were associated with extubation success. The odds of successful extubation increased by 39% with each GCS score increment. A GCS score > or = 8 at extubation was associated with success in 75% of cases, versus 33% for a GCS score < 8 (p < 0.0001). Implementation of a weaning protocol based on traditional respiratory physiologic parameters had practical limitations in NSY patients, owing to concerns about neurologic impairment. Whether protocols combining respiratory parameters with neurologic measures lead to superior outcomes in this population requires further investigation. Mechanical ventilation (MV) is essential in the management of patients that underwent cardiac surgery and cardiopulmonary bypass. It has been demonstrated that MV dependence is directly related to morbidity incidence and ICU length of stay, with a strong impact on economic cost. Therefore identification of measures that can reduce MV interval, may reduce the incidence of respiratory complications and length of hospitalization. The aim of this study was to identify weaning indexes and adopt a weaning algorithm in order to optimize ventilatory support after cardiac surgery.
                Forty-nine patients with low and medium Higgins risk score, who underwent, between February and November 1999, elective surgery at our Institution, were enrolled in this study. All patients were randomized into 2 groups: Group I (weaning group - 24 patients), extubated with the aid of a weaning protocol, and Group II (control group - 25 patients), extubated with conservative weaning, dependent on the physician's subjective clinical judgment. All patients were successfully weaned from mechanical support.
                Intubation time was significantly lower in Group I than Group II and "Fast Track Recovery" group (p=0.05). ICU length of stay was also significantly lower in Group I (p=0.03). Analysis of weaning indexes did not show cut-off points predictive of successful weaning, except for PaO2/FiO2 ratio, which was higher in Group I (p=0.02).
                These results confirm that the use of a weaning algorithm enables the MV interval and hospital length of stay to be shortened, suggesting that it should be used in the management following cardiac surgery. Preliminary assessment of an automated weaning system (SmartCare/PS) compared to usual management of weaning from mechanical ventilation performed in the absence of formal protocols.
                A randomised, controlled pilot study in one Australian intensive care unit.
                A total of 102 patients were equally divided between SmartCare/PS and Control.
                The automated system titrated pressure support, conducted a spontaneous breathing trial and provided notification of success ("separation potential").
                The median time from the first identified point of suitability for weaning commencement to the state of "separation potential" using SmartCare/PS was 20 h (interquartile range, IQR, 2-40) compared to 8 h (IQR 2-43) with Control (log-rank P = 0.3). The median time to successful extubation was 43 h (IQR 6-169) using SmartCare/PS and 40 (14-87) with Control (log-rank P = 0.6). Unadjusted, the estimated probability of reaching "separation potential" was 21% lower (95% CI, 48% lower to 20% greater) with SmartCare/PS compared to Control. Adjusted for other covariates (age, gender, APACHE II, SOFAmax, neuromuscular blockade, corticosteroids, coma and elevated blood glucose), these estimates were 31% lower (95% CI, 56% lower to 9% greater) with SmartCare/PS. The study groups showed comparable rates of reintubation, non-invasive ventilation post-extubation, tracheostomy, sedation, neuromuscular blockade and use of corticosteroids.
                Substantial reductions in weaning duration previously demonstrated were not confirmed when the SmartCare/PS system was compared to weaning managed by experienced critical care specialty nurses, using a 1:1 nurse-to-patient ratio. The effect of SmartCare/PS may be influenced by the local clinical organisational context.
                28. Mechanical ventilation: weaning. (1) To determine the effect of a single ventilator management protocol (VMP) used in medical and surgical ICUs on the duration of mechanical ventilation. (2) To determine the effect of a VMP on the incidence of ventilator-associated pneumonia (VAP).
                Prospective, randomized, controlled study.
                : University medical center.
                Three hundred eighty-five patients receiving mechanical ventilation between June 1997 and May 1998.
                A respiratory care practitioner- and registered nurse-driven VMP.
                Intervention and control groups were comparable with respect to age, sex, severity of illness and injury, and duration of respiratory failure at the time of randomization. The duration of mechanical ventilation for patients was decreased from a median of 124 h for the control group to 68 h in the VMP group (p = 0.0001). Thirty-one total instances of VAP were noted. Twelve patients in the surgical control group had VAP, compared with 5 in the surgical VMP group (p = 0.061). The impact of the VMP on VAP frequency was less for medical patients. Mortality and ventilator discontinuation failure rates were similar between control and VMP groups.
                A VMP designed for multidisciplinary use was effective in reducing duration of mechanical ventilatory support without any adverse effects on patient outcome. The VMP was also associated with a decrease in incidence of VAP in trauma patients. These results, in conjunction with prior studies, suggest that VMPs are highly effective means of improving care, even in university ICUs.