HAMILTON-C6。 下一代智能 ICU 呼吸机

BACKGROUND

Adaptive support ventilation (ASV) is a closed loop mode of mechanical ventilation (MV) that provides a target minute ventilation by automatically adapting inspiratory pressure and respiratory rate with the minimum work of breathing on the part of the patient. The aim of this study was to determine the effect of ASV on total MV duration when compared with pressure assist/control ventilation.

METHODS

Adult medical patients intubated and mechanically ventilated for > 24 h in a medical ICU were randomized to either ASV or pressure assist/control ventilation. Sedation and medical treatment were standardized for each group. Primary outcome was the total MV duration. Secondary outcomes were the weaning duration, number of manual settings of the ventilator, and weaning success rates.

RESULTS

Two hundred twenty-nine patients were included. Median MV duration until weaning, weaning duration, and total MV duration were significantly shorter in the ASV group (67 [43-94] h vs 92 [61-165] h, P = .003; 2 [2-2] h vs 2 [2-80] h, P = .001; and 4 [2-6] days vs 4 [3-9] days, P = .016, respectively). Patients in the ASV group required fewer total number of manual settings on the ventilator to reach the desired pH and Paco2 levels (2 [1-2] vs 3 [2-5], P < .001). The number of patients extubated successfully on the first attempt was significantly higher in the ASV group (P = .001). Weaning success and mortality at day 28 were comparable between the two groups.

CONCLUSIONS

In medical patients in the ICU, ASV may shorten the duration of weaning and total MV duration with a fewer number of manual ventilator settings.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01472302; URL: www.clinicaltrials.gov.

PURPOSE

This study aims to compare the effectiveness of weaning with adaptive support ventilation (ASV) incorporating progressively reduced or constant target minute ventilation in the protocol in postoperative care after cardiac surgery.

MATERIAL AND METHODS

A randomized controlled unblinded study of 52 patients after elective coronary artery bypass surgery was carried out to determine whether a protocol incorporating a decremental target minute ventilation (DTMV) results in more rapid weaning of patients ventilated in ASV mode compared to a protocol incorporating a constant target minute ventilation.

RESULTS

Median duration of mechanical ventilation (145 vs 309 minutes; P = .001) and intubation (225 vs 423 minutes; P = .005) were significantly shorter in the DTMV group. There was no difference in adverse effects (42% vs 46%) or mortality (0% vs 0%) between the 2 groups.

CONCLUSIONS

Use of a DTMV protocol for postoperative ventilation of cardiac surgical patients in ASV mode results in a shorter duration of ventilation and intubation without evidence of increased risk of adverse effects.

BACKGROUND

Adaptive support ventilation can speed weaning after coronary artery surgery compared with protocolized weaning using other modes. There are no data to support this mode of weaning after cardiac valvular surgery. Furthermore, control group weaning times have been long, suggesting that the results may reflect control group protocols that delay weaning rather than a real advantage of adaptive support ventilation.

METHODS

Randomized (computer-generated sequence and sealed opaque envelopes), parallel-arm, unblinded trial of adaptive support ventilation versus physician-directed weaning after adult fast-track cardiac valvular surgery. The primary outcome was duration of mechanical ventilation. Patients aged 18 to 80 yr without significant renal, liver, or lung disease or severe impairment of left ventricular function undergoing uncomplicated elective valve surgery were eligible. Care was standardized, except postoperative ventilation. In the adaptive support ventilation group, target minute ventilation and inspired oxygen concentration were adjusted according to blood gases. A spontaneous breathing trial was carried out when the total inspiratory pressure of 15 cm H2O or less with positive end-expiratory pressure of 5 cm H2O. In the control group, the duty physician made all ventilatory decisions.

RESULTS

Median duration of ventilation was statistically significantly shorter (P = 0.013) in the adaptive support ventilation group (205 [141 to 295] min, n = 30) than that in controls (342 [214 to 491] min, n = 31). Manual ventilator changes and alarms were less common in the adaptive support ventilation group, and arterial blood gas estimations were more common.

CONCLUSION

Adaptive support ventilation reduces ventilation time by more than 2 h in patients who have undergone fast-track cardiac valvular surgery while reducing the number of manual ventilator changes and alarms.

BACKGROUND

Closed-loop modes automatically adjust ventilation settings, delivering individualized ventilation over short periods of time. The objective of this randomized controlled trial was to compare safety, efficacy and workload for the health care team between IntelliVent®-ASV and conventional modes over a 48-hour period.

METHODS

ICU patients admitted with an expected duration of mechanical ventilation of more than 48 hours were randomized to IntelliVent®-ASV or conventional ventilation modes. All ventilation parameters were recorded breath-by-breath. The number of manual adjustments assesses workload for the healthcare team. Safety and efficacy were assessed by calculating the time spent within previously defined ranges of non-optimal and optimal ventilation, respectively.

RESULTS

Eighty patients were analyzed. The median values of ventilation parameters over 48 hours were similar in both groups except for PEEP (7[4] cmH2O versus 6[3] cmH2O with IntelliVent®-ASV and conventional ventilation, respectively, P=0.028) and PETCO2 (36±7 mmHg with IntelliVent®-ASV versus 40±8 mmHg with conventional ventilation, P=0.041). Safety was similar between IntelliVent®-ASV and conventional ventilation for all parameters except for PMAX, which was more often non-optimal with IntelliVent®-ASV (P=0.001). Efficacy was comparable between the 2 ventilation strategies, except for SpO2 and VT, which were more often optimal with IntelliVent®-ASV (P=0.005, P=0.016, respectively). IntelliVent®-ASV required less manual adjustments than conventional ventilation (P<0.001) for a higher total number of adjustments (P<0.001). The coefficient of variation over 48 hours was larger with IntelliVent®-ASV in regard of maximum pressure, inspiratory pressure (PINSP), and PEEP as compared to conventional ventilation.

CONCLUSIONS

IntelliVent®-ASV required less manual intervention and delivered more variable PEEP and PINSP, while delivering ventilation safe and effective ventilation in terms of VT, RR, SpO2 and PETCO2.

BACKGROUND

The discontinuation of mechanical ventilation after coronary surgery may prolong and significantly increase the load on intensive care unit personnel. We hypothesized that automated mode using INTELLiVENT-ASV can decrease duration of postoperative mechanical ventilation, reduce workload on medical staff, and provide safe ventilation after off-pump coronary artery bypass grafting (OPCAB). The primary endpoint of our study was to assess the duration of postoperative mechanical ventilation during different modes of weaning from respiratory support (RS) after OPCAB. The secondary endpoint was to assess safety of the automated weaning mode and the number of manual interventions to the ventilator settings during the weaning process in comparison with the protocolized weaning mode.

MATERIALS AND METHODS

Forty adult patients undergoing elective OPCAB were enrolled into a prospective single-center study. Patients were randomized into two groups: automated weaning (n = 20) using INTELLiVENT-ASV mode with quick-wean option; and protocolized weaning (n = 20), using conventional synchronized intermittent mandatory ventilation (SIMV) + pressure support (PS) mode. We assessed the duration of postoperative ventilation, incidence and duration of unacceptable RS, and the load on medical staff. We also performed the retrospective analysis of 102 patients (standard weaning) who were weaned from ventilator with SIMV + PS mode based on physician's experience without prearranged algorithm.

RESULTS AND DISCUSSION

Realization of the automated weaning protocol required change in respiratory settings in 2 patients vs. 7 (5-9) adjustments per patient in the protocolized weaning group. Both incidence and duration of unacceptable RS were reduced significantly by means of the automated weaning approach. The FiO2 during spontaneous breathing trials was significantly lower in the automated weaning group: 30 (30-35) vs. 40 (40-45) % in the protocolized weaning group (p < 0.01). The average time until tracheal extubation did not differ in the automated weaning and the protocolized weaning groups: 193 (115-309) and 197 (158-253) min, respectively, but increased to 290 (210-411) min in the standard weaning group.

CONCLUSION

The automated weaning system after off-pump coronary surgery might provide postoperative ventilation in a more protective way, reduces the workload on medical staff, and does not prolong the duration of weaning from ventilator. The use of automated or protocolized weaning can reduce the duration of postoperative mechanical ventilation in comparison with non-protocolized weaning based on the physician's decision.

BACKGROUND

Driving pressure (ΔP) and mechanical power (MP) are predictors of the risk of ventilation- induced lung injuries (VILI) in mechanically ventilated patients. INTELLiVENT-ASV® is a closed-loop ventilation mode that automatically adjusts respiratory rate and tidal volume, according to the patient's respiratory mechanics.

OBJECTIVES

This prospective observational study investigated ΔP and MP (and also transpulmonary ΔP (ΔPL) and MP (MPL) for a subgroup of patients) delivered by INTELLiVENT-ASV.

METHODS

Adult patients admitted to the ICU were included if they were sedated and met the criteria for a single lung condition (normal lungs, COPD, or ARDS). INTELLiVENT-ASV was used with default target settings. If PEEP was above 16 cmH2O, the recruitment strategy used transpulmonary pressure as a reference, and ΔPL and MPL were computed. Measurements were made once for each patient.

RESULTS

Of the 255 patients included, 98 patients were classified as normal-lungs, 28 as COPD, and 129 as ARDS patients. The median ΔP was 8 (7 - 10), 10 (8 - 12), and 9 (8 - 11) cmH2O for normal-lungs, COPD, and ARDS patients, respectively. The median MP was 9.1 (4.9 - 13.5), 11.8 (8.6 - 16.5), and 8.8 (5.6 - 13.8) J/min for normal-lungs, COPD, and ARDS patients, respectively. For the 19 patients managed with transpulmonary pressure ΔPL was 6 (4 - 7) cmH2O and MPL was 3.6 (3.1 - 4.4) J/min.

CONCLUSIONS

In this short term observation study, INTELLiVENT-ASV selected ΔP and MP considered in safe ranges for lung protection. In a subgroup of ARDS patients, the combination of a recruitment strategy and INTELLiVENT-ASV resulted in an apparently safe ΔPL and MPL.

BACKGROUND

Maintaining endotracheal tube cuff pressure within a narrow range is an important factor in patient care. The goal of this study was to evaluate the IntelliCuff against the manual technique for maintaining cuff pressure during simulated mechanical ventilation with and without movement.

METHODS

The IntelliCuff was compared to the manual technique of a manometer and syringe. Two independent studies were performed during mechanical ventilation: part 1, a 2-h trial incorporating continuous mannikin head movement; and part 2, an 8-h trial using a stationary trachea model. We set cuff pressure to 25 cm H2O, PEEP to 10 cm H2O, and peak inspiratory pressures to 20, 30, and 40 cm H2O. Clinical importance was defined as both statistically significant (P<.05) and clinically significant (pressure change [Δ]>10%).

RESULTS

In part 1, the change in cuff pressure from before to after ventilation was clinically important for the manual technique (P<.001, Δ=-39.6%) but not for the IntelliCuff (P=.02, Δ=3.5%). In part 2, the change in cuff pressure from before to after ventilation was clinically important for the manual technique (P=.004, Δ=-14.39%) but not for the IntelliCuff (P=.20, Δ=5.65%).

CONCLUSIONS

There was a clinically important drop in manually set cuff pressure during simulated mechanical ventilation in a stationary model and an even larger drop with movement, but this was significantly reduced by the IntelliCuff in both scenarios. Additionally, we observed that cuff pressure varied directly with inspiratory airway pressure for both techniques, leading to elevated average cuff pressures.

The scientific basis for inhalation therapy in mechanically-ventilated patients is now firmly established. A variety of new devices that deliver drugs to the lung with high efficiency could be employed for drug delivery during mechanical ventilation. Encapsulation of drugs within liposomes could increase the amount of drug delivered, prolong the effect of a dose, and minimize adverse effects. With improved inhalation devices and surfactant formulations, inhaled surfactant could be employed for several indications in mechanically-ventilated patients. Research is unraveling the causes of some disorders that have been poorly understood, and our improved understanding of the causal mechanisms of various respiratory disorders will provide new applications for inhaled therapies.

Recent technological advances and improved nebulizer designs have overcome many limitations of jet nebulizers. Newer devices employ a vibrating mesh or aperture plate (VM/AP) for the generation of therapeutic aerosols with consistent, increased efficiency, predominant aerosol fine particle fractions, low residuals, and the ability to nebulize even microliter volumes. These enhancements are achieved through several different design features and include improvements that promote patient compliance, such as compact design, portability, shorter treatment durations, and quiet operation. Current VM/AP devices in clinical use are the Omron MicroAir, the Nektar Aeroneb, and the Pari eFlow. However, some devices are only approved for use with specific medications. Development of "smart nebulizers" such as the Respironics I-neb couple VM technologies with coordinated delivery and optimized inhalation patterns to enhance inhaled drug delivery of specialized, expensive formulations. Ongoing development of advanced aerosol technologies should improve clinical outcomes and continue to expand therapeutic options as newer inhaled drugs become available.

Ventilator management of patients with acute respiratory distress syndrome (ARDS) has been characterized by implementation of basic physiology principles by minimizing harmful distending pressures and preventing lung derecruitment. Such strategies have led to significant improvements in outcomes. Positive end expiratory pressure (PEEP) is an important part of a lung protective strategy but there is no standardized method to set PEEP level. With widely varying types of lung injury, body habitus and pulmonary mechanics, the use of esophageal manometry has become important for personalization and optimization of mechanical ventilation in patients with ARDS. Esophageal manometry estimates pleural pressures, and can be used to differentiate the chest wall and lung (transpulmonary) contributions to the total respiratory system mechanics. Elevated pleural pressures may result in negative transpulmonary pressures at end expiration, leading to lung collapse. Measuring the esophageal pressures and adjusting PEEP to make transpulmonary pressures positive can decrease atelectasis, derecruitment of lung, and cyclical opening and closing of airways and alveoli, thus optimizing lung mechanics and oxygenation. Although there is some spatial and positional artifact, esophageal pressures in numerous animal and human studies in healthy, obese and critically ill patients appear to be a good estimate for the "effective" pleural pressure. Multiple studies have illustrated the benefit of using esophageal pressures to titrate PEEP in patients with obesity and with ARDS. Esophageal pressure monitoring provides a window into the unique physiology of a patient and helps improve clinical decision making at the bedside.