ISSUE 1: Routine suction or only when clinically indicated? A comment was made in the previous round about the need to regularly suction an intubated patient rather than to only suction when clinically indicated. CURRENT FORMULATION OF RECOMMENDATION: Only suction the patient when clinically indicated.

Posted Comments:
• SUCTION SHOULD BE ROUTINE AS THERE ARE NOT ANY VALID OR RELIABLE MEANS TO ASSESS THE NEED FOR SUCTIONING eg hypoxaemia, added lung sounds
• Suction should be routine, if the patient has acompromised or defintive airway as often there is no indcation that there are ssecretions preset
• I agree that suctioning should only be done when clinically indicated.

Instilling of 0.9% sodium chloride pryor to suctioning beneficial or detremental? In this Delphi study only comments advocating the use of saline have been posted. In a recent post on Medscape Today (http://www.medscape.com/viewarticle/552862) the following statement was made when discussing saline use in neonates: "All of the scientific evidence suggests an absence of positive effect from saline instillation -- it does not improve pulmonary function, and it does not thin secretions or promote their removal. Yet the practice persists despite a high risk for negative sequelae related to it, including lower oxygen saturation and increased potential for lower airway bacterial colonization. In answer to the question "should saline be instilled when suctioning the neonate?" there should be a resounding "No." A procedure that lacks research-based evidence to support it, has no proven benefit, and has a potential for harm should be abandoned" Puchalski M (The study by Schreuder et al (2004) refered to by a panelmember was completed on 8 patients of which 3 did not complete the trial (unsure why). No statistical analysis of results are provided (abstract). link available on website)

Posted Comments:
• THE RESEARCH ON THE USE OF SALINE LAVAGE FOR SUCTIONING IN ADULT PATIENTS HAS ONLY ASSESSED THE EFFECT ON MEASURES OF GAS EXCHANGE eg ARTERIAL OXYGENATION. THERE HAVE NOT BEEN ANYH DEFINITIVE STUDIES TO ASSESS ITS EFFECT ON THE ABILITY TO ENHANCE SECRETION CLEARANCE. THE EVIDENCE TO ABANDON THE CLINICAL USE OF SALINE IS BASED ON STUDIES THAT HAVE NOT EVALUATED APPROPRIATE OUTCOME MEASURES eg sputum volume, airways resistance.
• The studies findign adverse effects for Na Cl are very poor and also claim an adverse effect when there is no clinical adverse effect eg SpO2 still > 96. I think there are occasions where saline instilation is helpful but not as a routine practice. It should be researved for clinincal situations where the artificial airway is partilally obstructed or secreions are so thick they are not weasily removed on suction. The evidence stated pertains to neonates and therefore is not readilly transferable to the adult population
• I think that the evidence all around is poor. The simple fact that there are so many papers which suggest saline instillation is a potential problem, I believe it should be discouraged at least. As I have written, saline probably does not thin secretions, but it probably does stimulate a cough and the bolus of water may act to help propel mucus forward. The lengthy list of side effects however, still seems to suggest use in selected situations. I also wonder if the issue changes with population. Adults seem to tolerate saline better than children - probably for reasons of lung volume vs slaine volume

SUCTION TECHNIQUE : The use of a limited aseptic technique is recommended. In terms of equipment used: a single suction catheter might be used in a specific patient for a 24 hour period provided tap water is suctioned through the catheter to clear after use and stored in a protective sheath. In terms of personnel: hands should be washed both before and after the procedure and a glove might be worn during the procedure.

STRENGTH OF RECOMMENDATION: weak recommendation. While the use of above mentioned limited aseptic technique was found to be both safe (development of VAP) and cost effective in one RCT performed in a pediatric unit, it is not clear whether the same results will be obtained in an adult unit.

QUALITY OF EVIDENCE: Moderate quality evidence. One RCT Scoble et al (2001) reported similar incidence of VAP and cost when comparing a strict aseptic technique (both in terms of equipment and personnel) to a limited aseptic technique (only in terms of personnel). Evidence was downgraded due to indirectness.

Issue 3: Catheter reuse

Posted Comments:

• I don't consider that a catheter should be reused, even if 'cleaned' with sterile fluid. I need to say this to be consistent with other comments I am making If the assumption is to accept the reuse of a single use catheter then at the very least it would be essential that prior to re-insertion the catheter be cleaned with sterile fluid
  
• Perhaps to be clear the algorithm will need to deal with recommendations for open suction systems (which I would advocate needs an aseptic technique) versus using a closed suction system (in which a 'clean' / limited aspectic technique may be satisfactory, as suggested within submitted comments) would be appropriate.
  
• I would not be happy to recommend a limited aseptic technique and have this applied with open suction equipment.
• Agree aseptic technique should be used. Lack of evidecne but not enough studyies done

RECOMMENDATION: If CSS is available in the unit it might be preferred in patients with ARDS. However the efficacy of this system to effectively clear secretions is suspect. MOTIVATION: An additional search of 3 databases using "ARDS and suction" as keywords resulted in one study performed in adult patients comparing the two systems (Pubmed 14 results and Web of science 20 results and CINAHL 10 with majority of studies performed in animals). Lasocki et al (2006) compared a OSS with CSS in combination with a recruitment maneuver in 18 adult patients. There was a significant drop in PaO2 1 minute after suction between the two groups which remained significant up to 10 minutes. Even though the magnitude of this effect was moderate (SMD 0.6 CI -0.07 to 1.27) the CI also includes 0 which means that not all patients benefited from CSS. The inability of the CSS to effectively clear secretions has been further highlighted in this study. The OSS cleared significantly more secretions than the CSS, the magnitude of the effect was large SMD 0.69 (0.02 ; 1.36), but was again not as effective in all patients (large CI).

Posted Comments:
• I think CS should be sued in ARDS patietns with high levels of PEEP, as the risks of alveolatrauma and derecruitment are worse than the risk of some secretions
• I think this is reasonable as secretions are not a major issue in ARDS and oxygenation is
• I think the issue here is one of priority. In the patient with ARDS on moderate PEEP - OSS will contribute to alveolar de-recruitment and worsending oxygenation. CSS prevents these problems, but may not remove secretions effectively. The study by Lasocki showed that CSS could match OSS if negative pressure of the suction device was increased.

In ARDS patients presenting with excessive secretions an OSS might be used. Clinicians must be aware of the risk of de-cruitment associated with this procedure. As there is currently only very low quality evidence available pertaining to the safety and effectiveness of using recruitment procedure during suction in this population no recommendation is made. Quality of evidence is very low. A recruitment procedure VHI (two hyperinflations using the CPAP function of the ventilator to an airway pressure of 45cmH2O for 20 s, with an interval of 1 min in between) resulted in improved oxygenation without any adverse effects in one cross over design study on 8 ARDS patients (Dyer et al 2003). Quality is downgraded to very low due to high risk of bias and imprecision of data (Even though the study was sufficiently powered to detect a change and the RM resulted in significant improvement in oxygenation; the magnitude of the difference as well as the confidence intervals can not be calculated as Dyer et al only reported percentage increase

Posted Comments:
• I am unclear on this one as to what I am now agreeing/disagreeing to - is the recommendation about use of OSS (which I disagree with as a routine)(but on the other hand I do not advocate the mandation of CSS either, although ARDS clients are the one's most likely to potentially benefit), or about the use of RM following suction (whether OSS or CSS)? Both OSS & CSS are potentially associated with derecruitment & desaturation to varying degrees - RM may be advantageous either way, but I agree the current level of evidence is not sufficiently conclusive to make a recommendation on safety or efficacy of RM - personally I await the results of Carol Hodgson's PhD work on this subject
• different recruitment manouvres have been extensively used in this population and should be applied when "de-recruitment"occurs eg. following OS • I think this may be an issue of patient population and individual response. I would suggest that the need for a RM be determined by the therapist, evaluated by the therapist, and based on patient response further RM either used or abandoned.

This study population (Constantin et al 2008) included both intra pulmonary (n=12) and extra pulmonary (n=7) cause for ARDS. As no subgroup analysis was done in this population the recommendation can not differentiate as to the potential greater benefit of this procedure in either group.

Posted Comments:
• I refer you to 2 references: one a very good review paper 1. P. Pelosi, D. D'Onofrio, D. Chiumello, S. Paolo, G. Chiara, V.L. Capelozzi, C.S.V. Barbas, M. Chiaranda, and L. Gattinoni Pulmonary and extrapulmonary acute respiratory distress syndrome are different Eur. Respir. J., Aug 2003; 22: 48s - 56s. The second (cited in the extract from the review below): Gattinoni L, Pelosi P, Suter PM, Pedoto A, Vercesi P, Lissoni A. Acute respiratory distress syndrome caused by pulmonary and extrapulmonary disease: different syndromes?

Am J Respir Crit Care Med 1998; 158: 3–11. This paper by Gattinoni et al. compared lung mechanics and response to recruitment between 12 patients with pulmonary ARDS (ARDSp) and 9 patients with extrapulmonary ARDS (ARDSexp). They concluded that "the estimated recruitment at 15 cm H2O PEEP was -0.031 +/- 0.092 versus 0.293 +/- 0.241 L in ARDSp and ARDSexp, respectively (p < 0.01). The different respiratory mechanics and response to PEEP observed are consistent with a prevalence of consolidation in ARDSp as opposed to prevalent edema and alveolar collapse in ARDSexp." Extract from Peolosi et al's review paper: "The differences in underlying pathology and respiratory mechanics may have clinical consequences. In fact, the potential for recruitment is higher in alveolar collapse and lower in alveolar consolidation. On the other hand the applied pressures for lung recruitment may lead to different transpulmonary pressures according to chest wall elastance. This hypothesis is supported by the finding that in ARDSp [pulmonary ARDS], increasing PEEP mainly induced overstretching, while in ARDSexp PEEP mainly induced recruitment. GATTINONI et al. [1] found that an increase of PEEP leads to opposite effects on elastance. In ARDSp, increasing PEEP caused an increase of the elastance of the total respiratory system due to an increase in lung elastance with no change in chest wall elastance. Conversely, in ARDSexp the application of PEEP caused a reduction of the elastance of the total respiratory system, mainly due to a reduction in lung elastance and chest wall elastance. Moreover, although an increased PEEP led to an elevation of end-expiratory lung volume in both ARDSp and ARDSexp, it resulted in alveolar recruitment primarily in ARDSexp. In neuro-injured patients with "pure" VAP and severe respiratory insufficiency, the current authors found no beneficial effects on respiratory mechanics, alveolar recruitment, or gas exchange with PEEP or recruitment manoeuvres... really, in the study by Gattinoni et al. [1] the majority of the patients had ARDSp due to VAP, poorly responding to PEEP and recruitment manoeuvres".

I think there is adequate evidecne to support recruitment manuovers in ARDS, The evidence seems to suggest early in ARDS is the key to RM success. If success if based on oxygenation. I agree that an RM has little effect on secretion removal.

The mean time from diagnosis of ARDS to the application of the RM in this study was 27 +- 17 hours. The median time was 24 (range 12-72). REFORMULATION: In the early stages of ARDS (preferable within the first 24 hours of diagnosis) an electronic sigh RM (eSigh) can be performed on a patient ventilated on volume-controlled ventilation to improve oxygenation and volume. The eSigh RM is described as increasing PEEP 10 cm H2 O above the LIP (lower inflection point of the pressure-volume curve) for 15 minutes, limiting the maximum peak airway pressure to 50 cm H2 O. In case of severe arterial hypotension (systolic arterial pressure of less than 70 mm Hg) or severe hypoxemia (SpO2 of less than 80%), the RM should be terminated.

Posted Comments:
• I don't belive on balance in the literature that this procedure can currently be recommended particularly as a phsiotherapy intervention