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The Effectiveness of Prone Positioning Laura LangenhopWright State UniversityThe Effectiveness of Prone PositioningSignificance of the ProblemAcute Respiratory Distress Syndrome (ARDS) is associated with 3.6 million hospitalizations and 75,000 deaths each year (Beitler et al., 2014). ARDS is defined as worsening respiratory failure within one week of injury or insult, bilateral opacities on chest radiograph, pulmonary congestion not explained by a cardiac origin, and a PaO2/FiO2 ratio of less than 300 mmHg (American Medical Association [AMA], 2012). The Berlin Definition was formed in 2011 to designate more specific categories of ARDS based on lung compliance, positive end expiratory pressure (PEEP), corrected expired volume per minute, and chest radiographic severity (AMA, 2012). ARDS is divided into three categories. There is mild ARDS defined as a PaO2/FiO2 of less than 300 mmHg, moderate ARDS defined as a PaO2/FiO2 ratio of less than 200 mmHg, and severe ARDS defined as a PaO2/FiO2 of less than 100 mmHg (AMA, 2012). There are many reasons for a patient’s severe hypoxemia leading to ARDS. Causes of ARDS include pneumonia, pulmonary aspiration pneumonitis, pulmonary edema, chronic obstructive pulmonary disease, and acute pulmonary embolism (Bloomfield, Noble, & Webster, 2009). There is a challenge to treating severe hypoxemia in the hospitalized patient. There are many techniques and strategies that provide means to combat the deterioration of the patient. Maneuvers used to treat hypoxemia as well as prevent further deterioration include introduction of high PEEP on the ventilator, inhaled nitric oxide, inverse ratio ventilation, neuromuscular blockade, recruitment maneuvers, intravenous steroids, and prone positioning (Bloomfield et al., 2009). The practice of prone positioning began in the late 1970s on patients with severe hypoxemia and has since proven to increase patient oxygenation (Athota, Miller, Branson, & Tsuei, 2014). The act of prone positioning is turning and placing the patient on his or her chest and abdomen to increase oxygenation status. As the criteria and treatment for ARDS have changed over the past few years since the introduction of the Berlin Definition, the effects of prone positioning have been called into question and researched. The purpose of this paper is to discuss evidence-based research on prone positioning in the ARDS patient with a focus on the benefits, the appropriate time for initiation, and the proper duration of such therapy. Discussion of the ProblemMechanical ventilation is used to aide in oxygenation of the patient with ARDS. Often times, the patient is placed in the supine or recumbent position following mechanical ventilation. Mechanical ventilation can cause continued lung injury on patients in supine or recumbent positions (Bloomfield et al., 2009). There are several issues that arise as patients experiencing prolonged hypoxemia remain in the supine position. Atelectasis becomes greater in the posterior portions of the lung when patients stay in the supine position for an extensive period of time. As a result, the posterior portions of the lung are perfused at the expense of ventilation (Benson & Albert, 2014). Perfusion has shown to be unaffected when the patient is in prone position. Dorsal regions continue to receive the majority of blood flow. However, atelectasis does improve as a patient is moved to the prone position (Benson & Albert, 2014). Reasons for this include compression of the dorsal portion of the lungs by abdominal contents, lungs, and mediastinum during supine positioning. When the patient is in prone positioning, the dorsal portions are better able to receive ventilation without the expense of the ventral regions (Benson & Albert, 2014). The dorsal regions continue to receive the same amount of perfusion with improved ventilation, reducing a ventilation/perfusion mismatch (Tekwani & Murugan, 2014). The partial pressure of oxygen of arterial blood (PaO2) is also improved in patients that are placed into prone position. The under-ventilated areas, such as the dorsal regions, are able to ventilate and inflate. By improving gas exchange, the PaO2 is increased (Gattinoni, Taccone, Carlesso, & Martini, 2013). Carbon dioxide clearance in relation to prone positioning is another area that has been studied. Edema, blebs, cysts, and other structural changes are very common in patients with ARDS that affect carbon dioxide clearance and ventilation (Gattinoni et al., 2013). Patients who were placed in prone position decreased their carbon dioxide levels without the expense to the patients’ minute ventilation, and also increased lung recruitment (Gattinoni et al., 2013).Prone positioning has also shown to bring postural drainage to the anterior portions of the lungs. Larger airways also become straightened (Tekwani & Murugan, 2014). Secretions from the posterior portions of the patient’s lung fields are allowed to migrate to the ventral portions of the lungs by gravity. Secretions that were once in the posterior portions of the lungs can now be cleared from the patient’s system, preventing further complications to patients with ventilator associated infections (Benson & Albert, 2014). Finally, lung injury related to the use of mechanical ventilation occurring in patients with ARDS continues to be an issue. The use of high amounts of PEEP and recruitment maneuvers in order to increase oxygenation can cause damage on the lung tissue. The patient’s lung tissue can become affected after prolonged mechanical pressure and tension, causing inflammation (Gattinoni et al., 2013). Prone positioning can lessen chest wall compliance, therefore improving functional residual capacity (Tekwani & Murugan, 2014). Prone positioning can help in lung recovery, assist in the ability to lessen PEEP and FiO2, and may be of significant benefit to the patients with ARDS (Gattinoni et al., 2013). Concerns in the ElderlyThe concern for hypoxemia does not only affect the younger population, but also the older population. As the average age of the patient continues to increase, the risk for ARDS and severe hypoxemia from common illnesses such as pneumonia and influenza continue to be an issue Gattinoni et al., 2013). The elderly, by nature, are more fragile when a severe illness is upon them. Co-morbidities, such as heart disease, chronic lung diseases, diabetes, coagulopathies, and liver disease also play a role in mortality (Nechba, Kadiri, Zeggwagh, & Mesfioui, 2013). The mortality rate of the elderly with ARDS is between 40 and 70 percent (Nechba, Kadiri, Zeggwagh, & Mesfioui, 2013). By quick correction of hemodynamic instability, the patients’ mortality decreases. The importance of early recognition with any disease is of utmost importance, but it is especially so in the older adult. Also, corrective action with high amounts of PEEP, lower tidal volumes, neuromuscular blockade, and prone positioning play a role in the decreased mortality of the older adult with ARDS (Nechba et al., 2013). For this reason, it will continue to be the responsibility of AG-ACNP to identify older adults with ARDS and use current evidence-based practice and research for treatment. Knowledge of the current literature allows the AG-ACNP to effectively treat the patient. Literature ReviewAn extensive literature review was completed focusing on prone positioning in patients with ARDS. Studies were found using NCBI, EMBASE, and the Cochrane Register of Controlled Trials. The terms acute respiratory distress syndrome, ARDS, prone positioning, and prone were used. Current randomized controlled trials, expert reviews, and a meta-analysis were found and reviewed for this paper. There were no Cochrane or systematic reviews obtained in the search of this topic. A multi-center randomized controlled trial of patients with ARDS was designed to determine if prone positioning improves survival (Taccone et al., 2009). Twenty-three hospitals in Spain and two hospitals in France were involved in this study. Patients were eligible if they were receiving invasive mechanical ventilation, had the diagnosis of ARDS, a PaO2/FIO2 ratio equal to or lower than 200 mm Hg, and a PEEP between five and ten cm H2O (Taccone et al., 2009). At randomization, patients were stratified according to the severity of hypoxemia. Patients with moderate hypoxemia were defined by a PaO2/FIO2 ratio between 100 mm Hg and 200 mm Hg at the start of the trial, while severe hypoxemia was defined by a PaO2/FIO2 ratio lower than 100 mm Hg. Patients were randomly assigned to prone positioning and supine positioning groups. Each patient was set at a tidal volume of 8 mL/kg with a goal airway plateau pressure of less than 30 cm H2O (Taccone et al., 2009). Of the 342 patients in this trial, 98 were women. The age ranges for the population was 16 years of age to 61 years of age. The patients in the prone group were placed prone on average of 18 hours a day for eight days until they resolved their respiratory failure (Taccone et al., 2009). The 28-day mortality was 52 percent for the prone group and 57 percent for the supine group with a p-value of 0.72, showing no statistical significance. The 6-month mortality for the prone position group was 79 percent and the supine group was 91 percent with a p-value of 0.33, showing no statistical significance (Taccone et al., 2009). Patients randomized to the prone group suffered more complications such as increased use of sedation, neuromuscular blockade, hemodynamic instability, and device dislodgement. Limitations to the study include the difficulty to standardize hypoxemia with the use of PEEP in the population (Taccone et al., 2009). Also, the study allowed a 72-hour enrollment period, leading the authors to question whether earlier enrollment into the study would have caused different outcomes. Finally, the study may have been underpowered since a mortality decrease by less than 15 percent cannot be detected in a population as small as the one used (Taccone et al., 2009).An experimental and clinical study was completed to assess whether high levels of PEEP and prone positioning affected lung recruitment (Cornejo et al., 2013). Fifteen male patients and nine female patients between the ages of 18 years and 80 years of age in the intensive care unit were enrolled in the study. Patients met criteria for ARDS, were older than 18 years of age, had been mechanically ventilated for greater than 24 hours, had received a computed tomography (CT) scan of their chest, and were not pregnant (Cornejo et al., 2013). The patients were given a tidal volume of 6 mL/kg of ideal body weight. Patients were selected at random for placement in supine or in prone positions. Fifteen and five cm H2O of PEEP was given to patients for a period of 20 minutes. Before adjusting the PEEP, the patient received a recruitment maneuver at 45 cm H2O (Cornejo et al., 2013). Following this, CT scans were completed during breath holding sessions of 5, 45, and then 15 cm H2O of PEEP with a fixed respiratory rate of ten breaths per minute. The PEEP was fixed at 5 and 15 cm H2O during the CT scan and then repeated in randomly selected patients in supine and prone positions (Cornejo et al., 2013). The results of this study revealed increasing the PEEP from to 15 cm H20 in the supine position increased aeration of lung tissue and increased tidal-hyperinflation, with a p-value of 0.001 and a p-value of ? 0.004 respectively (Cornejo et al., 2013). Aeration of the lung and tidal hyperinflation were further increased when the patient was in prone position with a p-value of ? 0.028. De-recruitment was shown to only decrease when prone positioning and high amounts of PEEP were given. A p-value of ? 0.003 was obtained from this finding (Cornejo et al., 2013). Prone positioning did help with lung recruitment and hyperinflation in this study. Limitations to this study include lack of homogenous lung impairment leading to an underrepresentation of the slice used for the CT scan, the inability to scan the exact anatomical structure in different settings, and the weight of the lungs undergoing recruitment and hyperinflation could not be determined definitively (Cornejo et al., 2013). A prospective randomized controlled trial was completed on 466 patients (318 females and 148 males) across 26 intensive care units in France and one intensive care unit in Spain (Guerin et al., 2013). Patients were between the ages of 16 years and 60 years of age. Patients with the diagnosis of ARDS confirmed between 12 to 24 hours following mechanical ventilation were chosen at random to be placed in supine position for the duration of care or to be placed in prone position for extended periods of time during hospitalization. Patients included in this study were those that met the criteria for severe ARDS, required mechanical ventilation, PaO2/FiO2 ratio of less than 150 mmHg, PEEP of greater than or equal to 5 cm of H20, FiO2 was greater than 60 percent, and tidal volume of 6 mL/kg of predicted body weight (Guerin et al., 2013). All patients were given volume-controlled ventilation with a goal of an end-inspiratory plateau pressure of no more than 30 cm of H20 while maintaining a pH level of 7.20 to 7.45 (Guerin et al., 2013). There were 229 patients randomized to supine position. Prone positioning was not used on the supine group unless as a rescue measure for the patient’s severe hypoxemia. There were 237 patients enrolled into the prone group. Prone positioning occurred within one hour of randomization for a total of 16-hour increments. Prone positioning was stopped if the patient’s PaO2/FiO2 ratio became greater than 150 mmHg, PEEP less than 10 cm H20, and FiO2 of less than 60 percent for four consecutive hours following the last prone positioning (Guerin et al., 2013). Mortality rates at 28 days and 90 days, successful extubations, time to extubation, length of stay, ventilator-free days, pneumothorax, non-invasive ventilation, and tracheostomy were evaluated in this study (Guerin et al., 2013). The main results found that patients who were in the prone group had a significantly lower rate of mortality at 28 days (16% vs. 32.8%) and 90 days (56% vs. 94%) compared to the supine group with p-values at <0.001 (Guerin et al., 2013). The rate of successful extubation in the prone group was much higher compared to the supine group (80.5% vs. 65%) with p-values <0.001. The amount of ventilation-free days was also higher in the prone group as compared to the supine group with p-values <0.001 (Guerin et al., 2013). All other secondary outcome measurements were not statistically significant. Limitations to this study include the catecholamines and fluid balances of the patients were not assessed. The differences in patients using neuromuscular blockade, vasopressor therapy, and the patients’ sepsis related organ function assessment (SOFA) scores were also not compared. After customization of these variables, mortality remained lower in the prone group (Guerin et al., 2013). A meta-analysis using seven trials on patients who received prone positioning reviewed whether using lower tidal volumes affected mortality (Beitler et al., 2014). The seven randomized studies trials involved 2,119 patients, with 1,088 patients prone positioned. The measure for this meta-analysis was risk ratio of death at 60 days for patients who were positioned prone as compared to those positioned supine. Following risk-stratification, a decrease in risk ratio with a value of 0.66 was found in patients who were given a lower tidal volume (<8 mL/kg). A 95% confidence interval of 0.50 to 0.86 was viewed as well as a p-value of 0.002 (Beitler et al., 2014). Patients with higher tidal volumes (>8 mL/kg) had a risk ratio of 1.00, showing no significant decrease in death risk ratio. The p-value was 0.949. However, there was high significance between the two compared groups when p-value of <0.001 (Beitler et al., 2014). The amount of time a patient spent prone was also stratified. Patients who spent >12 hours a day showed a reduction of mortality with a risk ratio of 0.71 and a p-value of 0.004 (Beitler et al., 2014). However, patients who spent <12 hours a day in the prone position did not find a reduction in mortality. Risk ratio of death was 1.05 with a p-value of 0.472 (Beitler et al., 2014). Limitations to this meta-analysis are lack of studies on prone positioning in patients with ARDS, randomized controlled trials were the only studies used for this meta-analysis, and the duration of respiratory failure prior to prone positioning could not be completed because of lack of information given from the randomized controlled trials used in this meta-analysis (Beitler et al., 2014).SummaryThe studies and expert opinions raise the question of prone positioning and its efficacy in used of practice. There remains debate on the timing of prone positioning in a patient classified with an ARDS definition as well as the amount of time the patient should spend in the prone position. Patient selection criteria and initiation also seem to play a role in the outcome of prone positioning. It appears that most randomized controlled trials criteria for prone positioning saw the patient had a PaO2/FiO2 ratio of 150 mmHg to 300 mmHg (Taccone et al., 2009; Guerin et al., 2013; Beitler et al., 2014; Athota et al., 2014). The majority of studies implemented prone positioning within three days of diagnosis with the most recent randomized controlled trial placing the patient in prone position within one hour of randomization (Guerin et al., 2013). Since this randomized controlled study revealed a significant decrease in mortality, more research should be completed on the initiation of prone positioning. As the American-European Consensus Conference (AECC) altered protocol on the goal tidal volume to 6 mL/kg in 2012 for patients, there is a call for more research in the area of prone positioning in patients with ARDS (Athota, Miller, Branson, & Tsuei, 2014). The study by Guerin et al. (2013) was completed following the protocol change. The significance in the decrease of mortality in this randomized controlled trial gives weight to the possibility of prone positioning as having a positive affect on patients. The protocol change of a lower tidal volume in patients with ARDS also has shown significance. Not only has there been evidence to suggest a lower tidal volume helps to prevent lung parenchymal damage, but it also prevents mortality (Beitler et al., 2014). Using a lower tidal volume may also make prone positioning effective. Not until the study by Guerin et al. (2013) was completed was there true significance to prone positioning in ARDS patients. Not only does the amount of tidal volume affect the outcome of prone positioning, but the amount of time spent prone affects the outcome as well. Evidence shows a reduction in mortality when the patient is in prone position for more than 12 hours per day (Beitler et al., 2014). More recent studies have had patients in the prone position for longer periods of time (12 to 18 hours a day) for four to ten days (Taccone et al., 2009; Guerin et al., 2013; Beitler et al., 2014). The most recent randomized controlled trial that showed a significant decrease in mortality had patients in prone position for an average of 17 hours for four days (Guerin et al., 2013). More research should be completed in this area to further demonstrate the time-frame effective in decreasing mortality in patients with ARDS.The Role of the AG-ACNPThe role of the AG-ACNP in the acute care setting is to promptly recognize the diagnosis of ARDS and to focus on the responsibility to treat the patient’s hypoxemia. The AG-ACNP can promote awareness of ARDS and the use for prone positioning. Also, the AG-ACNP can educate nurses, nurse practitioners, and physicians on the latest evidence-based research regarding prone positioning in patients with ARDS. Non-maleficence should also play a role for the AG-ACNP in planning for treatment. Though prone positioning has shown to be of benefit to a patient’s hypoxemia, the AG-ACNP must remain mindful of some contraindications. Contraindications include abdominal or thoracic wounds, hemodynamic instability, fixation of a fracture following trauma, and a patient with a traumatic brain injury (Athota et al., 2014). Benefits of prone positioning should always outweigh the risks prior to initiation. The AG-ACNP can play a significant role with furthering the research and evidence-based practice of prone positioning in the ARDS patients. ConclusionIn ARDS patients with severe hypoxemia, prone positioning can aid in mortality and recovery. The purpose of this paper was to establish the significance of prone positioning in patients with ARDS and the time frame in which it should utilized. Prone positioning has shown to increase aeration of the lung fields, increase ventilation to the dorsal regions, increase carbon dioxide clearance, and decrease lung injury. However, there remains work to be done. The initiation of prone positioning, the amount of time spent in prone position, and further studies on the significance of prone position should be researched. It is by research and evidence-based practice that medicine can manage and treat patients with severe hypoxemia while also aiding in the decrease of mortality. ReferencesAmerican Medical Association. (2012). Acute respiratory distress syndrome: The Berlin definition. Retrieved from , K. P., Miller, D., Branson, R. D., & Tsuei, B. J. (2014). A practical approach to the use of prone therapy in acute respiratory distress syndrome. Respiratory Medicine, 8(4), 453-463. , J. R., Shaefi, S., Montesi, S. B., Devlin, A., Loring, S. H., Talmor, D., & Malhotra, A. (2014). Prone positioning reduces mortality from acute respiratory distress syndrome in the low tidal volume era: A meta-analysis. Intensive Care Medicine, 40(3), 332-341. , A. B., & Albert, R. K. (2014). Prone positioning for acute respiratory distress syndrome. Clinical Chest Medicine, 35, 743-752. , R., Noble, D. W., & Webster, N. R. (2009). Prone position for acute respiratory failure in adults (protocol). Retrieved from The Cochrane Collaboration:Cornejo, R. A., Diaz, J. C., Tobar, E. A., Bruhn, A. R., Ramos, C. A., Gonzalez, R. A., ... Pereira, G. L. (2013, August 15). Effects of prone positioning on lung protection in patients with acute respiratory distress syndrome. American Journal of Respiratory and Critical Care Medicine. , 188(4), 440-448. , L., Taccone, P., Carlesso, E., & Martini, J. J. (2013, December 1). Prone position in acute respiratory distress syndrome. American Journal of Respiratory Critical Care Medicine, 188(11), 1286-1293. , C., Reignier, J., Richard, J. C., Beuret, P., Gacouin, A., Boulain, T., ... Ayzac, L. (2013, May 31). Prone positioning in severe acute respiratory distress syndrome. The New England Journal of Medicine, 368(23), 2159-2168. , R. B., Kadiri, M. E., Zeggwagh, A. A., & Mesfioui, A. (2013, October 30). _Epidemiology of elderly patients hospitalized in intensive care unit for severs medical illness. Science Journal of Public Health, 1(5), 215-221. , P., Pesenti, A., Latini, R., Polli, F., Vagginelli, F., Mietto, C., ... Gattononi, L. (2009, November 11). Prone positioning in patients with moderate and severe acute respiratory distress syndrome. The Journal of the American Medical Association, 302(18), 1977-1984. , S. S., & Murugan, R. (2014). To prone or not to prone in severe ARDS: questions answered, but others remain. Critical Care, 18(305). Retrieved from ................
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