effects of manual hyperinflation and suctioning in respiratory mechanics
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effects of manual hyperinflation and suctioning in respiratory mechanicsPlease enable it to take advantage of the complete set of features!Get the latest public health information from CDC. Get the latest research from NIH. Find NCBI SARS-CoV-2 literature, sequence, and clinical content:.As a consequence of infection of the lung parenchyma and alveolitis, accumulation of inflammatory exudates and infiltration of airway mucosa can lead to unfavourable respiratory mechanics in ventilator-associated pneumonia. Tracheal suction is often employed by nursing staff in the management of mechanically ventilated patients with ventilator-associated pneumonia but this technique has the potential to increase respiratory resistance. Manual hyperinflation is used by physiotherapists to improve lung volume and mobilise secretions and has been shown to increase lung compliance. The effect of manual hyperinflation on airway resistance has not been studied. This study aims to demonstrate an additional mechanical benefit to the respiratory system when manual hyperinflation and suction techniques are combined, by comparing the application of manual hyperinflation and suction with suction alone on static lung compliance (C(L)) and inspiratory resistance (R(AW)) in mechanically ventilated patients with ventilator-associated pneumonia. Fifteen adult patients with ventilator-associated pneumonia were recruited and acted as their own controls. Manual hyperinflation followed by suction (manual hyperinflation plus suction) and suction alone were applied consecutively, in random order, on two occasions, four hours apart. Respiratory variables, C(L) and R(AW), were measured five times and the averaged value documented. Data were recorded before, immediately after, and 30 minutes after each intervention protocol. C(L) increased by 22 and R(AW) decreased by 21, up to 30 minutes after manual hyperinflation plus suction, but not after suction alone.http://wekeepyoung.com/UserFiles/d9036-user-manual.xml
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This study suggests that manual hyperinflation in conjunction with suction induces beneficial changes in respiratory mechanics in mechanically ventilated patients with ventilator-associated pneumonia. By continuing to browseFind out about Lean Library here Find out about Lean Library here This product could help you Lean Library can solve it Simply select your manager software from the list below and click on download.Simply select your manager software from the list below and click on download.For more information view the SAGE Journals Sharing page. Search Google ScholarSearch Google ScholarSearch Google ScholarSixteen critically ill patients post-septic shock, with acute lung injury, were studied. Heart rate, arterial pressure, and mean pulmonary artery pressure were recorded every minute. Pulmonary artery occlusion pressure, cardiac output, arterial blood gases, and dynamic compliance (C dyn ) were recorded pre- and post-MHI. From this, systemic vascular resistance index (SVRI), cardiac index, oxygen delivery, and partial pressure of oxygen: fraction of inspired oxygen (PaO 2:FiO 2 ) ratio were calculated. In critically ill patients, MHI resulted in an improvement in lung mechanics and an improvement in gas exchange in patients with lung disease due to extrapulmonary events and did not result in impairment of the cardiovascular system. Keywords cardiac output, hemodynamics, physical therapy, acute lung disease, hyperinflation, compliance 1. Jones AY, Hutchinson RC, Oh TE. Chest physiotherapy practice in intensive care units in Australia, the UK and Hong Kong. Aust J Physiother. 1992;38: 210 -215. Google Scholar 4. Stiller K, Geake T. Acute lobar atelectasis: a comparison of two chest physiotherapy regimes. Chest. 1992;98: 1336 -1340. Google Scholar 5. Hodgson C, Denehy L, Ntoumenopolous G. An investigation of the early effects of manual lung hyperinflation in critically ill patients.http://navigator-nsk.ru/userfiles/d915gev-manual.xml The effect of manual lung hyperinflation and postural drainage on pulmonary complications in mechanically ventilated trauma patients. Sustained inflations improve respiratory compliance during high frequency oscillatory ventilation but not during large tidal volume positive-pressure ventilation in rabbits. Crit Care Med. 1994;22: 1269 -1277. Manual hyperinflation: a description of the technique. Clarke RCN, Kelly BE, Convery PN, Free JPH. Ventilatory characteristics in mechanically ventilated patients during manual hyperinflation for chest physiotherapy. Lichtwarck-Aschoff M, Markstrom AM, Hedlund AJ. Oxygenation remains unaffected by increased inspiration-to-expiration ratio but impairs hemodynamics in surfactant-depleted piglets. Mushin WW, Randall-Baker L, Thompson PW. Automatic Ventilation of the Lung. 3rd ed. Oxford, UK: Blackwell Scientific; 1980. Google Scholar 14. Laws AK, Mcintyre RW. Chest physiotherapy: a physiological assessment during intermittent positive pressure ventilation in respiratory failure. Henman MP, Guthrie MM. Am Rev Respir Dis. 1983;27: 147 -151. Google Scholar 17. ARDSnet ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med. 2000;342: 1301 -1308. Dos Santos CC, Slutsky AS. Invited review: mechanisms of ventilator-induced lung injury: a perspective. J Appl Physiol. 2000;89: 1645 -1655. Held H, Boettcher S, Hamann L. Ventilation induced chemokine and cytokine release is associated with the activation of nuclear factor-kB and is blocked by steroids. Am J Respir Crit Care Med. 2000;163: 711 -716. Google Scholar 20. Papadakos PJ, Apostolakos MJ. Murray JF, Matthay MA, Luce JM, Flick MR. An expanded definition of the adult respiratory distress syndrome. Am Rev Respir Dis. 1988;136: 720 -723. Google Scholar 22. Bone RC, Balk RA, Cerra FB. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis.https://ayurvedia.ch/boss-bx-80-manual Chest. 1992;101: 1644 -1655. Clement AJ, Hubsch SK. Chest physiotherapy by the “bag squeezing” method: a guide to technique. Campbell MJ, Julious SA, Altman DG. Estimating sample sizes for binary, ordered categorical, and continuous outcomes in two group comparisons. Br Med J. 1995;311: 1145 -1148. Patman S, Jenkins S, Bostock S. Cardiovascular responses to manual hyperinflation in post-operative coronary artery surgery patients. Knaus WA, Draper EA, Wagner DP. APACHE II: a severity of disease classification system. Br J Anaesth. 1976;47: 761 -766. Google Scholar 29. Reinhart K, Sakka SG, Meier-Hellmann A. Haemodynamic management of a patient with septic shock. Markstrom AM, Lichtwarck-Aschoff M, Hedlund AJ, Nordgren KA, Sjostrand UH. Under open lung conditions inverse ratio ventilation causes intrinsic PEEP and haemodynamic impairment. Uppsala J Med Sci. 1996;101: 257 -271. Gattinoni L, Pelosi P, Suter PM. Acute respiratory distress syndrome caused by pulmonary and extrapulmonary disease: different syndromes. Theissen IL, Meissner A. Hypoxic pulmonary vasoconstriction. Van der Kloot TA, Blanch L, Youngblood M, et al. Recruitment manoeuvres in three experimental models of acute lung injury. Am J Respir Crit Care Med. 2000;161: 1485 -1494. Villagra A, Ochagavia A, Vatua S, et al. Recruitment maneuvers during lung protective ventilation in acute respiratory distress syndrome. Am J Respir Crit Care Med. 2002;165: 165 -170. Domenighetti G, Stricker H, Waldispuehl B. Nebulized prostacyclin (PGI2) in acute respiratory distress syndrome: impact of primary (pulmonary injury) and secondary (extrapulmonary injury) disease on gas exchange response. Lim CM, Kim EK, Lee JS, et al. Comparisons of the response to the prone position between pulmonary and extrapulmonary acute respiratory distress syndrome. Van der Kloot T, Blanch L, Youngblood AM, et al. Recruitment maneuvers in three experimental models of acute lung injury. Glass C, Grap MJ, Corley MC. Powaser MM, Converse AL.http://cristianpack.com/images/case-821-loader-manual.pdf The relative roles of hyperinflation and oxygen in raising arterial oxygen tension after preoxygenation prior to endotracheal suctioning. Am Rev Respir Dis. 1980;121(suppl): 216. Google Scholar 41. Pelosi P, Cadringher P, Bottino N. Sigh in acute respiratory distress syndrome. Am J Respir Crit Care Med. 1999;159: 872 -880. Schwartz SZ, Shoemaker WC, Nolan-Avila LS. Effects of blood volume and discontinuance of ventilation on pulmonary vascular pressures and blood gases in patients with low levels of positive end expiratory pressure. Bryan-Brown CW. Blood flow to organs: parameters for function and survival in critical illness. Rothen HU, Sporre B, Engberg G, Wegenius G, Reber A, Hedenstierna G. Prevention of atelectasis during general anaesthesia. Lancet. 1995;35: 1387 -1391. Google Scholar Find out about Lean Library here By continuing to browse. As such, MH could prevent plugging of the airways. Methods We performed a search in the databases of Medline, Embase, and the Cochrane Library from January 1990 to April 2012. We systematically reviewed the literature on evidence for postulated benefits and risks of MH in critically ill intubated and mechanically ventilated patients. Results The search identified 50 articles, of which 19 were considered relevant. We included 13 interventional studies and six observational studies. The number of studies evaluating physiological effects of MH is limited. Trials differed too much to permit meta-analysis. It is uncertain whether MH was applied similarly in the retrieved studies. Finally, most studies are underpowered to show clinical benefit of MH. Use of MH is associated with short-term improvements in lung compliance, oxygenation, and secretion clearance, without changes in outcomes. MH has been reported to be associated with short-term and probably clinically insignificant side effects, including decreases in cardiac output, alterations of heart rates, and increased central venous pressures. Conclusions Studies have failed to show that MH benefits critically ill intubated and mechanically ventilated patients. MH is infrequently associated with short-term side effects. By applying a larger-than-normal volume at a low inspiratory flow followed by an inspiratory pause and expiration with a high expiratory flow, MH is suggested to mimic a normal cough. Propagation of airway secretions from the smaller toward the larger airways then allows for easy removal of airway secretions with airway suction. It is far from certain whether MH truly benefits critically ill intubated and mechanically ventilated patients. Also, MH could be disadvantageous in patients with respiratory failure. The airway pressures at the end of the MH maneuver are usually much lower than the applied level of positive end-expiratory pressure, which, in combination with airway suctioning, may promote atelectasis. This systematic review aims to collect the evidence for the suggested benefits and risks of MH in critically ill intubated and mechanically ventilated patients. The main research questions were as follows. Does MH benefit critically ill intubated and mechanically ventilated patients with respect to pulmonary compliance, arterial oxygenation, and sputum clearance. Does MH have an effect on the duration of mechanical ventilation, length of stay in the intensive care unit, and incidence of pneumonia. What are reported side effects of MH. The rationale behind manual hyperinflation Retained airway secretions may occlude the airways of intubated and mechanically ventilated patients, and, as such, cause atelectasis. This may impair oxygenation by increased intrapulmonary shunting and increase pulmonary vascular resistance. Frequent removal of sputum from the airways via tracheal suctioning is mandatory in critically ill intubated and mechanically ventilated patients. Under normal conditions, mucociliary transport clears the smaller airways of airway secretions. Secretions that are transported from the smaller airways into the bronchi and trachea then are removed by coughing. In addition, the cough reflex can be minimal or even absent in sedated critically ill patients, or they may lack force to cough efficiently. Furthermore, sputum may not be easily transported from the trachea into the translaryngeal tube or trachea cannula, and thus could remain in the larger airways. Unfortunately, with airway suctioning, only the trachea is cleared of secretions, as suction catheters cannot reach sputum in the bronchi and smaller airways. Description of the MH technique To enhance the clearance of airway secretions, MH was supposed to include the application of a larger than normal volume (up to one and one half the size of tidal volumes delivered by the ventilator) at a low inspiratory flow (achieved by a slow compression of the ventilation bag), an inspiratory pause (to allow complete distribution of the inflated air among all the ventilated parts of the lung), and a high expiratory flow. As such, MH could resemble a forceful cough, with which a forced and rapid exhalation follows a deep and slow inhalation. Materials and methods Search methods for identification of manuscripts about MH Two methods were used to identify relevant manuscripts in the medical literature. First, we performed a search in the databases of Medline, Embase, the Cochrane Library, the Cochrane Database of Systematic Reviews, and the Database of Abstracts on Reviews and Effectiveness (DARE) from January 1990 to April 2012 (Additional file 1 ). Second, reference lists of identified and selected manuscripts were reviewed to identify additional articles. The initial search strategy was designed for maximal retrieval, with no limitation on the type of study design to be identified. We used no restriction on language. Study selection Two authors (FP and JB) independently reviewed the retrieved articles and abstracts, assessed the eligibility of each study, and resolved disagreement by consensus. Articles were selected if they reported original data from a clinical trial or an observational study. We restricted the selection of articles to those that reported on adult critically ill intubated and mechanically ventilated patients. The same authors made the final selection; we restricted the selection to articles that reported on relevant study end points, including pulmonary compliance, arterial oxygenation, sputum clearance, duration of mechanical ventilation, length of stay in the intensive care unit, and incidence of pneumonia, and only if the main objective concerned the evaluation of the MH procedure. Data-collection process We extracted data from the included studies by using a data-extraction sheet. We extracted the following data: characteristics of the studies (design, setting), participants, intervention characteristics (MH technique), comparison intervention, and results of all relevant outcomes. Assessment of methodologic quality of individual studies Two reviewers (FP and JB) assessed the risk of bias of the interventional studies and used the categories randomization, random sequence generation allocation concealment, description of withdrawals and dropouts, the method of and use of intention-to-treat analysis, and standardization of important co-interventions. Synthesis of results The decision to combine studies in a quantitative analysis was made by assessing clinical heterogeneity (examining types of participants, interventions, and outcomes in each study). Results Study selection The search (Figure 1 ) identified 50 articles, of which 19 were considered relevant (Tables 1, 2, and 3 ). Figure 1 Number of articles identified at each stage of the review process for potential inclusion in the systematic review. Risk of bias within studies The risk of bias among included studies is summarized in Table 4. Quality assessment revealed that five studies did not describe concealment of allocation. Only three studies clearly reported standardization of important co-interventions to prevent performance bias. Most studies did not report the use of intention-to-treat analysis. Description of the losses to follow-up was not included in three studies. All studies were open label, because blinding of the ICU clinicians was not feasible for these types of studies. Because of the substantial clinical heterogeneity, we focused on describing individual study results, rather than using a meta-analysis. Physiological end points The results of the physiological end points for the individual studies are summarized in Figures 2 and 3. We separated studies with an active control group (for example, hyperinflation by the ventilator) from studies comparing MH with standard care. Figure 2 Change in PaO Discussion MH is suggested to mimic a cough so that airway secretions are mobilized from the smaller airways toward the larger airways, where they can easily be removed. As such, MH could benefit critically ill intubated and mechanically ventilated patients. We reviewed studies of diverse intensive care unit populations investigating the potential beneficial effects and side effects of MH. Most investigations consistently showed MH to be feasible and safe. MH improved pulmonary compliance, arterial oxygenation, and clearance of airway secretions, albeit not in all investigations. MH inconsistently affected clinical outcome. Side effects of MH seemed relatively infrequent. Apart from the possibility that MH may indeed not benefit critically ill intubated and mechanically ventilated patients, studies simply may have been underpowered to detect any beneficial effect of MH, such as duration of mechanical ventilation, length of stay in the intensive care unit, and prevention of ventilator-associated pneumonia. Studies in this review were heterogeneous in regard to patient populations, MH intervention, and outcome measurements and could not be combined in a meta-analysis. Only a few studies compared MH with standard care. In some studies, MH was compared with another strategy (for example, hyperinflation by the ventilator). Two of the retrieved studies reported the use of position changes in conjunction with MH. Multiple other strategies could have been used in conjunction with MH in other studies, such as postural drainage, vibrations, and manually assisted cough. This, however, was not clearly reported. In addition, most studies included in this review had methodologic flaws, which may have resulted in bias. Better evidence to support the use of MH is required. Therefore, appropriately powered, well-designed, randomized controlled trials evaluating the effect of MH should be conducted. The focus of these studies should be on clinical end points, including, but not restricted to, duration of mechanical ventilation or ventilator-free days, length of stay in the ICU, and incidence of ventilator-associated pneumonia. It is difficult to give clear recommendations on how to perform MH maneuvers. Most reports did not adequately describe how MH actually was performed. Monitoring airway pressures is feasible, but may not have priority. Outside the importance of conducting future studies that comprehensively describe the MH technique used, additional studies could establish how the different components of the technique are of influence on the therapeutic aims of MH. Unfortunately, MH is frequently referred to as a maneuver to recruit lung tissue. We would like to emphasize that MH was originally designed to mimic a forceful cough. The most important principle for MH to be effective may be the high expiratory flow. Consequently, airway pressures at the end of each MH cycle are low, which may very well promote derecruitment. With the performance of MH, the necessity exists to disconnect the patient from the mechanical ventilator. Breaking the ventilatory circuit may lead to airway contamination and eventually to ventilator-associated pneumonia. Breaking the ventilatory circuit may also lead to significant airway pressure decreases and promote lung derecruitment. Finally, the delivery of larger than normal tidal volumes with MH, even for a very short time, may cause overinflation. Although scientific evidence for the existence of these potential side effects is lacking, they may very well limit adoption of MH. Derecruitment and overinflation could be harmful, especially in patients with acute lung injury, or its more severe form, acute respiratory distress syndrome. It is imaginable that derecruitment and overinflation affect the lungs differently among diverse populations of ICU patients. We suggest that MH may better recruit lung tissue in patients with easy-to-recruit lungs (for example, patients after cardiac surgery or patients with indirect lung injury) than in patients with less compliant lungs (for example, patients with direct lung injury). The dissimilar findings of investigations reviewed here are in line with this suggestion Future studies should include patients with different pulmonary conditions and should address overinflation and derecruitment with MH. It may be necessary to add recruitment maneuvers to MH, but as far as we know, this has not been the subject of clinical studies. The retrieved studies reported side effects of MH relatively infrequently, and most of the reported side effects were minor. Because most if not all studies were not specifically designed to detect side effects of MH, absence of reported side effects may not mean that the procedure is necessarily safe. Given the paucity of data, one might simply recommend abandoning MH as a relic of good intentions with little scientific evidence, but with potential harm. However, absence of evidence does not necessarily mean evidence of absence. A pathophysiological rationale exists for MH as a secretion-clearance technique that should be tested in clinical trials. From this review of studies,we conclude that until now, no adequately powered studies tested the hypothesis that MH benefits intubated and mechanically ventilated patients. The same also applies for the potential adverse events of MH. Limitations exist in the way we conducted our review. First, two of the authors are ICU clinicians and frequent users of the MH procedure and may be potentially biased. Second, electronic and hand searches do not completely reflect the extent of research outcomes; for example, studies presented at congresses are more likely to contain negative reports than are studies reported in the literature. Furthermore, many studies not published in English may not be included in the most commonly used searches. Conclusions MH is associated with short-term beneficial effects on lung compliance, oxygenation, and airway clearance in intubated and mechanically ventilated patients. MH is inconsistently associated with clinical benefit. MH only infrequently has been associated with side effects. It should be noted, though, that the majority of published studies were not designed to detect potential adverse events like derecruitment. Appropriately powered and methodologically sound studies of MH are needed before recommendations can be made for routine use of MH. Key messages Aust J Physiother. 1999, 45: 185-193. PubMed J Appl Physiol. 1987, 62: 959-971. PubMed Am J Respir Crit Care Med. 2000, 162: 1898-1904. PubMed Physiotherapy. 1968, 54: 355-359. PubMed Aust J Physiother. 2003, 49: 31-38. PubMed Am J Respir Crit Care Med. 2009, 179: A2306- Respir Care. 2008, 53: 1276-1279. PubMed Respir Care. 2008, 53: 1287-1294. PubMed Anaesth Intensive Care. 2000, 28: 255-261. PubMed Minerva Anestesiol. 2010, 76: 1036-1042. PubMed Med Sci Monit. 2009, 15: CR418-CR422. PubMed Authors' contributions FP and JMB performed the literature search and selected the relevant articles for inclusion independently. FP and JMB reviewed the selected articles. FP and JMB wrote the initial draft of the manuscript. MJS contributed to the interpretation of the results and drafting of the manuscript. MBV and MJS critically revised the manuscript. All authors read and approved the manuscript for publication. Electronic supplementary material A summary of search strategy and search terms for the identification of articles with MH. (DOC 30 KB) Authors’ original submitted files for images Below are the links to the authors’ original submitted files for images. Authors’ original file for figure 1 Authors’ original file for figure 2 Authors’ original file for figure 3 Rights and permissions Reprints and Permissions About this article Cite this article Paulus, F., Binnekade, J.M., Vroom, M.B. et al. Benefits and risks of manual hyperinflation in intubated and mechanically ventilated intensive care unit patients: a systematic review.Download citation Received: 24 November 2011 Revised: 15 July 2012 Accepted: 03 August 2012 Published: 03 August 2012 DOI: Keywords Acute Lung Injury Pulmonary Compliance Airway Secretion Randomized Crossover Trial Inspiratory Pause. Instituto do Coracao, Hospital das Clinicas HCFMUSP. Faculdade de Medicina da Universidade de Sao Paulo. Sao Paulo, Brazil Find this author on Google Scholar Find this author on PubMed Search for this author on this site For correspondence. Sao Paulo, Brazil Find this author on Google Scholar Find this author on PubMed Search for this author on this site Nadja C Carvalho Divisao de Pneumologia. Sao Paulo, Brazil Find this author on Google Scholar Find this author on PubMed Search for this author on this site Marcia S Volpe Instituto do Coracao, Hospital das Clinicas HCFMUSP. Sao Paulo, Brazil. Department of Sciences of Human Movement. Federal University of Sao Paulo. Santos, Brazil Find this author on Google Scholar Find this author on PubMed Search for this author on this site The fact that manual hyperinflation is also applied to recruit alveoli in patients without copious secretions has created confusion in the literature. Its use, indication, and expected outcomes are frequently mistaken. Inconsistencies in the indication and application of manual hyperinflation may have contributed to the association of manual hyperinflation with only short-term improvements in lung compliance, oxygenation, and secretion clearance but not on important clinical outcomes. 1, 12 At the beginning of the 21st century, ventilator hyperinflation was proposed as an alternative to manual hyperinflation. 13 Ventilator hyperinflation is applied with the mechanical ventilator and was designed to mimic manual hyperinflation (ie, the application of a high tidal volume with a low inspiratory flow, an inspiratory pause, and high expiratory flow). Clinical studies have previously compared manual hyperinflation with ventilator hyperinflation and found no significant differences in the amount of secretions recovered, respiratory compliance, or oxygenation. 1, 12, 14 However, ventilator hyperinflation does have potential advantages over manual hyperinflation. Indeed, it plays a well-recognized role in the development and spread of ventilator-associated pneumonia. 20 It is noteworthy that there is evidence showing that airway clearance in mechanically ventilated patients is primarily driven by gravity rather than by the expiratory flow bias. 21 In the current issue of R espiratory C are, Li Bassi et al 22 compared the effects of manual hyperinflation and ventilator hyperinflation on secretion clearance, gas exchange, pulmonary mechanics, and hemodynamics in pigs with severe bilateral pneumonia. They found that neither maneuver significantly modified pulmonary mechanics or hemodynamic parameters, nor did they improve secretion clearance. Most surprising was that, although both maneuvers increased the expiratory flow bias, this increase did not improve mucus clearance. In some pigs, the mucus clearance rate even deteriorated compared to baseline assessment. In light of the evidence that higher expiratory bias flow is associated with better mucus transport, 11, 16, 23, 24 the authors raised a number of hypotheses to explain this unexpected negative result. We will discuss further some of the presented hypotheses and suggest others mainly related to the methods applied. However, despite the methodological concerns raised in this article, it is important to state that their findings may correctly indicate that the use of both maneuvers as secretion clearance techniques should be reappraised. The primary concern is that, despite the animals having pneumonia and being heavily sedated, they seemed not to have retained secretions, making it difficult for any airway clearance maneuver to show benefit, especially maneuvers that have expiratory flow bias as a main mechanism of action, which relies on mucus thickness to function. This issue is raised because the animals were submitted to tracheal suction 1 h before intervention, and because the amount of secretions collected, independent of the maneuver applied or day of the assessment, was too small (ie, 15, 19 a volume 20 times greater than that seen in the paper by Li Bassi et al.