Automated Alerting and Recommendations for the Management of Patients with Preexisting Hypoxia and Potential Acute Lung Injury

Abstract Background: Acute lung injury (ALI) is associated with high mortality. Low tidal volume (Vt) ventilation has been shown to reduce mortality in ALI patients in the intensive care unit. Anesthesiologists do not routinely provide lung-protective ventilation strategies to patients with ALI in the operating room. The authors hypothesized that an alert, recommending lung-protective ventilation regarding patients with potential ALI, would result in lower Vt administration. Methods: The authors conducted a randomized controlled trial on anesthesia providers caring for patients with potential ALI. Patients with an average or last collected ratio of partial pressure of arterial oxygen to inspired fraction of oxygen less than 300 were randomized to providers being sent an alert with a recommended Vt of 6 cc/kg predicted body weight or conventional care. Primary outcomes were Vt/kg predicted body weight administered to patients. Secondary outcomes included ventilator parameters, length of postoperative ventilation, and death. Results: The primary outcome was a clinically significant reduction in mean Vt from 508–458 cc (P = 0.033), with a reduction in Vt when measured in cc/kg predicted body weight from 8 to 7.2 cc/kg predicted body weight (P = 0.040). There were no statistically significant changes in other outcomes or adverse events associated with either arm. Conclusions: Automated alerts generated for patients at risk of having ALI resulted in a statistically significant reduction in Vt administered when compared with a control group. Further research is required to determine whether a reduction in Vt results in decreased mortality and/or postoperative duration of mechanical ventilation.

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A Description of Intraoperative Ventilator Management in Patients with Acute Lung Injury and the Use of Lung Protective Ventilation Strategies

Anesthesiology ◽

10.1097/aln.0b013e31821a8d63 ◽

2011 ◽

Vol 115 (1) ◽

pp. 75-82 ◽

Cited By ~ 21

Author(s):

James M. Blum ◽

Michael Maile ◽

Pauline K. Park ◽

Michelle Morris ◽

Elizabeth Jewell ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Protective Ventilation ◽

Lung Protective Ventilation ◽

Positive End Expiratory Pressure ◽

Predicted Body Weight ◽

Oxygen Oxygen ◽

Ventilator Management ◽

Pressure Peak ◽

Ventilation Strategies

Background The incidence of acute lung injury (ALI) in hypoxic patients undergoing surgery is currently unknown. Previous studies have identified lung protective ventilation strategies that are beneficial in the treatment of ALI. The authors sought to determine the incidence and examine the use of lung protective ventilation strategies in patients receiving anesthetics with a known history of ALI. Methods The ventilation parameters that were used in all patients were reviewed, with an average preoperative PaO₂/Fio₂ [corrected] ratio of ≤ 300 between January 1, 2005 and July 1, 2009. This dataset was then merged with a dataset of patients screened for ALI. The median tidal volume, positive end-expiratory pressure, peak inspiratory pressures, fraction inhaled oxygen, oxygen saturation, and tidal volumes were compared between groups. Results A total of 1,286 patients met criteria for inclusion; 242 had a diagnosis of ALI preoperatively. Comparison of patients with ALI versus those without ALI found statistically yet clinically insignificant differences between the ventilation strategies between the groups in peak inspiratory pressures and positive end-expiratory pressure but no other category. The tidal volumes in cc/kg predicted body weight were approximately 8.7 in both groups. Peak inspiratory pressures were found to be 27.87 cm H₂O on average in the non-ALI group and 29.2 in the ALI group. Conclusion Similar ventilation strategies are used between patients with ALI and those without ALI. These findings suggest that anesthesiologists are not using lung protective ventilation strategies when ventilating patients with low PaO₂/Fio₂ [corrected] ratios and ALI, and instead are treating hypoxia and ALI with higher concentrations of oxygen and peak pressures.

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A simple classification model for hospital mortality in patients with acute lung injury managed with lung protective ventilation*

Critical Care Medicine ◽

10.1097/ccm.0b013e3182266779 ◽

2011 ◽

Vol 39 (12) ◽

pp. 2645-2651 ◽

Cited By ~ 9

Author(s):

Lisa M. Brown ◽

Carolyn S. Calfee ◽

Michael A. Matthay ◽

Roy G. Brower ◽

B. Taylor Thompson ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Hospital Mortality ◽

Protective Ventilation ◽

Classification Model ◽

Lung Protective Ventilation ◽

Simple Classification

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Colloidal gold particles as a new in vivo marker of early acute lung injury

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00078.2004 ◽

2004 ◽

Vol 287 (4) ◽

pp. L867-L878 ◽

Cited By ~ 53

Author(s):

Kai Heckel ◽

Rainer Kiefmann ◽

Martina Dörger ◽

Mechthild Stoeckelhuber ◽

Alwin E. Goetz

Keyword(s):

Electron Microscopy ◽

Acute Lung Injury ◽

Gas Exchange ◽

Lung Injury ◽

Colloidal Gold ◽

Microvascular Permeability ◽

Arterial Oxygen ◽

Control Group ◽

Gold Particles

Permeability of the endothelial barrier to large molecules plays a pivotal role in the manifestation of early acute lung injury. We present a novel and sensitive technique that brings microanatomical visualization and quantification of microvascular permeability in line. White New Zealand rabbits were anesthetized and ventilated mechanically. Rabbit serum albumin (RSA) was labeled with colloidal gold particles. We quantified macromolecular leakage of gold-labeled RSA and thickening of the gas exchange distance by electron microscopy, taking into account morphology of microvessels. The control group receiving a saline solution represented a normal gas exchange barrier without extravasation of gold-labeled albumin. Infusion of lipopolysaccharide (LPS) resulted in a significant displacement of gold-labeled albumin into pulmonary cells, the lung interstitium, and even the alveolar space. Correspondingly, intravital fluorescence microscopy and digital image analysis indicated thickening of width of alveolar septa. The findings were accompanied by a deterioration of alveolo-arterial oxygen difference, whereas wet/dry ratio and albumin concentration in the bronchoalveolar lavage fluid failed to detect that early stage of pulmonary edema. Inhibition of the nuclear enzyme poly(ADP-ribose) synthetase by 3-aminobenzamide prevented LPS-induced microvascular injury. To summarize: colloidal gold particles visualized by standard electron microscopy are a new and very sensitive in vivo marker of microvascular permeability in early acute lung injury. This technique enabling detailed microanatomical and quantitative pathophysiological characterization of edema formation can form the basis for evaluating novel treatment strategies against acute lung injury.

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