PREVENTION AND MANAGEMENT OF ATELECTASES IN INTUBATED AND VENTILATED PATIENTS


Review question: Is pulmonary physiotherapy more effective than no intervention in the prevention and or management of lobar atelectasis in intubated and ventilated patients?

Following a systematic review of the literature; critical appraisal of identified studies; the following conclusions were reached:

SEARCH RESULTS

  • Six experimental studies were identified (Crowe et al 2006; Stiller et al 1996; Raoof et al 1999; Krause et al 2000; Suh-Hwa Maa 2005; Ahrens et al 2004).
  • The interventions evaluated include a package of MHI (Crowe et al 2006; Suh-Hwa Maa et al 2005) positioning and suction (Stiller et al 1996 and Krause et al 2000) and kinetic therapy (Raoof et al 1999; Ahrens et al 2004).
  • Five studies investigated the management of patients where atelectasis was already diagnosed (Crowe et al 2006; Stiller et al 1996; Raoof et al 1999; Krause et al 2000; Suh-Hwa Maa 2005).
  • Only one study were identified that evaluated the prevention of atelectasis (Ahrens et al 2004)
  • None of the studies compared the intervention to a non intervention control.

SUMMARY OF EVIDENCE

  • A package of care should include at least MHI; gravity assisted positioning (modified if contra indicated) and suctioning in patients where volume loss is visible on CxR (Stiller et al 1996; Krause et al 2000; Suh-Hwa Maa et al 2005).
  • The addition of manual techniques in the management of atelectasis is not supported at this time (Stiller et al 1996; Raooff et al 1999)
  • Patients should receive a minimum frequency of two treatment sessions daily (Krause et al 2000) with ideal frequency hourly for at least six hours (Stiller et al 1996).
  • If available, kinetic therapy could be instituted for all patients admitted to a unit to prevent atelectasis (Ahrens et al 2004).

Table 1 Summary of experimental studies identified

Studies / Internal validity (Pedro Score) / Sample size / Population / Intervention and comparison / Study structure / Outcome measured
Stiller et al 1996 / 7 / 35 / Patients (intubated and non intubated) in ICU presenting with acute lobar atelectasis as observed on CxR. / MHI; suction compared to MHI; MPD position; vibration and suction compared to MHI; MPD position; suction compared to MHI; MPD position; suction hourly for 6 hours compared to MHI; MPD position; suction once daily / Factoral RCT / Mean percentage resolution compared to first picture
Raoof et al 1999 / 7 / 24 / Respiratory failure & evidence of atelectasis on X-rays / Kinetic therapy compared to two hourly manual turn and percussion / RCT / Extent of Atelectasis vissible on CxR segmental; lobar etc
Krause et al 2000 / 7 / 17 / Intubated patients lobar atelectasis as observed on CxR / PD position; vibration; suction compared to modified PD position; vibration; suction / RCT / Number of treatments needed for complete resolution of atelectasis vissible on CxR
Ahrens et al 2004 / 8 / 234 / Intubated GCS <11; PaO2:FiO2 <250 / Kinetic therapy compared to two hourly turn by nursing / multicenter RCT / Atelectasis vissible on CxR (Yes or No)
Suh-Hwa Maa 2005 / 4 / 23 / >40 intubated > 7 days clinical diagnosis atelectasis / MHI and standard CPT (MPD position;vibration;suction) compared to standard CPT / multicenter RCT / Improvement vissible on CxR (Yes or No)
Crowe et al 2006 / 7 / 20 / Intubated with unilateral or bilat CxR diagnosis of atelectasis / MHI (Breath stacking) and standard CPT (MPD position;vibration;suction) compared to standard CPT (MPDposition;vibration;suction) / RCT / mean radiology score based on predetermined score

SUMMARY OF THE QUALITY OF THE EVIDENCE

All the studies included in this review accepted that some intervention (physiotherapy or positional changes) is indicated for the management of intubated patients in ICU.

A modified postural drainage position (MPD) was used in four RCT’s evaluating specific CPT techniques (Crowe et al 2006; Stiller et al 1996; Krause et al 2000; Suh-Hwa Maa 2005). One RCT reported a more rapid resolution when using a gravity assisted drainage position compared to the standard (Krause et al 2000). The quality of this evidence is downgraded to low quality due to methodological quality and imprecision of data and sample (refer to table 2).

The addition of MHI to a standard protocol of position and suction was specifically investigated in 3 RCT’s (Crowe et al 2006; Stiller et al 1996; Suh-Hwa Maa 2005).Data could not be pooled because different outcomes had been measured.The addition of MHI improved radiological evidence of atelectases in two RCT’s (Stiller et al 1996; Suh-Hwa Maa 2005) and had no effect in one study (Crowe et al 2006). The quality of the evidence (from the two studies) is downgraded to low quality evidence due to poor methodological quality and imprecision of data and sample(refer to table 2).

The frequency of the physiotherapy intervention used in two RCT’s was twice daily (Crowe et al 2006; Krause et al 2000). An increased frequency of hourly intervention for 6 hours compared to a once daily intervention reported a significant improved resolution on CxR (Stiller et al 1996). The quality of this evidence is downgraded to low quality due to methodological quality and imprecision of data and sample (refer to table 2).

One study multicentre RCT reported a significant reduction in the incidence of atelectasis (Ahrens et al 2004). The quality of this evidenceis downgraded to moderate quality for methodological quality(refer to table 2).

Table 2 Factors considered in determining the quality of the evidence

Experimental Studies / Risk of bias / Directness of evidence / Heterogeneity / Precision
Concealed allocation / LTFO
Lost to follow up / ITT / Intervention investigated / Sample investigated / Publication Bias / Data / Sample
Stiller et al 1996 / No / Yes / No / Yes / No (included intubated and non intubated pt) / NA / Insufficient data to calculate size of treatment effect / No
Raoof et al 1999 / Yes / Yes / Yes / Yes / Yes / NA / No OR 8.57(CI0.83-87.83) / No
Krause et al 2000 / No / Yes / Yes / Yes / Yes / NA / Insufficient data to calculate size of treatment effect / No
Ahrens et al 2004 / No / Yes / Yes / Yes / Yes / NA / Yes OR 0.44 (CI 0.23 – 0.85) / Yes
Suh-Hwa Maa 2005 / No / No / No / Yes / No (pt intubated > 7 days / NA / No OR 10.5 (CI 0.83 – 87.83) / No
Crowe et al 2006 / Yes / Yes / Yes / Yes / Yes / NA / Insufficient data to calculate size of treatment effect / No