Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery

Boden. BMJ 2018; 360:j5916 doi: https://doi.org/10.1136/bmj.j5916

Clinical Question

• In patients undergoing upper abdominal surgery (UAS), does the addition of a single pre-op physiotherapy session compared to standard care reduce the rate of post-operative pulmonary complications (PPC)?

Background

• PPC is the most common complication following UAS with an incidence of between 10 and 50%
• PPC is strongly associated with increased mortality, morbidity, and healthcare costs

Design

• Multicentre, randomised controlled trial
• Ethics approval in accordance with Helsinki Declaration
• Trial registered with Australian New Zealand Clinical Trials Registry: ACTRN126130006644741
• Consecutive participants
• Randomised using sequentially numbered sealed opaque envelopes
• Computer-generated allocation sequence
• Healthcare professionals and trial assessors in the post-op phase blinded to allocation
• PPC diagnosed using standardised validated tool – Melbourne group score
• Power calculation based on previous studies of absolute risk reduction and institutions own unpublished data in the area
  • Powered at 80%
  • Baseline PPC incidence of 20%, 10% absolute risk reduction
  • Significance set at 0.05
  • 441 patients required, which includes 11% inflation for drop-outs, non-compliance and uncertainty of baseline
• Intention-to-treat analysis
• Authors conducted various exploratory post-hoc analyses

Setting

• 2 hospitals in Australia, 1 in New Zealand
• June 2013 – August 2015

Population

• Inclusion:
  • Over 18 years of age
  • Elective surgery
  • Surgery requiring abdominal incision >5cm in length, that will be above, or extending above, the umbilicus
  • Minimum single overnight hospital stay
• Exclusion:
  • Unable to comprehend verbal instructions in English
  • Unable to participate in single pre-admission session with physiotherapist (PT)
  • Emergency surgery
  • Current hospital admission for a different indication
  • Organ transplant
  • Open abdominal hernia repairs
  • Unable to stand and ambulate for at least 1 minute
• 504 pts listed for UAS; 441 met inclusion criteria and randomised; 222 intervention and 219 control
• Baseline characteristics: intervention vs control (selected)
  • Age: 63.4 vs 67.5 years
  • ASA physical health status 1 or 2: 69% vs 58%
  • Comorbidities – respiratory: 19% vs 26%
  • Current smoker – 21% vs 27%
  • Surgical category – colorectal: 50% vs 47%
  • Surgical category – hepatobiliary/upper GI: 22% vs 28%
  • Surgical category – renal/urology: 28% vs 24%
  • Post-op location – ICU: 43% vs 46%

Intervention

• Standard Care + Extended Physiotherapy Session
  • Seen in multidisciplinary pre-operative outpatient clinic
    • Standard care included assessment by “nurse, anaesthetist, doctor ± stomal therapist”
    • Basic physiotherapy session included assessment and provision of information booklet
      • Booklet instructed:
        • 2x 10 deep breaths
        • Followed by 3x coughs
        • To be performed hourly
    • Extended physiotherapy session immediately followed with a single 30 minute education and breathing exercise coaching session
      • Educated about:
        • Individual risk of PPCs
        • Impact of anaesthesia and surgery on lung volumes and sputum clearance
        • Prevention strategies
      • Training provided for:
        • Breathing exercises as detailed in booklet
      • Also included memory cues for patients to remember hourly exercises in the post-op phase

Control

• Standard Care Only
  • Seen in multidisciplinary pre-operative outpatient clinic
    • Standard care included assessment by “nurse, anaesthetist, doctor ± stomal therapist”
    • Basic physiotherapy session included assessment and provision of information booklet
      • Booklet instructed:
        • 2x 10 deep breaths
        • Followed by 3x coughs
        • To be performed hourly

Management common to both groups

• Post-op physiotherapy care in both groups standardised
• If PPC identified, patient flagged and subsequent physiotherapy delivered at attending physiotherapists discretion
• All others aspects of peri-operative clinical care were left to discretion of medical and nursing teams

Outcome

• Primary outcome: the number of patients diagnosed with PPC was significantly lower in the intervention group
  • Extended Physiotherapy Session: 12%
  • Standard Care: 27%
  • Absolute Risk Reduction (ARR): 15% (95% CI 7 to 22%, p<0.001)
  • Unadjusted hazard ratio (HR): 0.43 (95% CI 0.27 to 0.67).
  • Incidence remains halved (adjusted HR 0.48; 95% CI 0.30-0.75) when adjusted for baseline imbalances in 3 prespecified covariates – age, respiratory comorbidities and surgical procedure
  • NNT 7
  • Fragility Index 14
• Secondary outcome:
  • Incidence of hospital acquired pneumonia halved in intervention group
    • 8% vs 20% (OR 0.45, CI 0.26 – 0.78, p<0.001)
  • No difference in –
    • Mortality
    • Hospital length of stay
    • Readiness for hospital discharge
    • Unplanned readmissions
    • ICU length of stay
    • Hospital readmissions at 6 weeks
    • Ambulation attainment measures
  • No adverse events attributable to intervention

Authors’ Conclusions

• In a general population of patients listed for elective upper abdominal surgery, a 30 minute preoperative physiotherapy session provided within existing hospital multidisciplinary preadmission clinics halves the incidence of PPCs and specifically hospital acquired pneumonia.

Strengths

• Study protocol and analysis plan pre-published
• Comprehensive intervention arm
• Variability in physiotherapy experience reduced by AV education video to standardised delivery of intervention
• High screening and recruitment rate
• High level of masking
• Rate of PPC in study as per study power

Weaknesses

• Inability to attend PT session as an exclusion criteria
• Although described as an international, multi-centre study, the majority of patients were recruited from a single-centre in Australia
  • Significant between site differences, with the NZ site showing no benefit of the intervention, albeit with small numbers
• Baseline difference between groups
  • Age, respiratory co-morbidities and surgical type corrected for in analysis and authors report similar conclusion
• Compliance of patients in intervention arm unmeasured (authors’ justified this as assessment could have Hawthorne effect)
• The primary outcome of the study was based on a surrogate outcome measure, scoring four or more out of eight on the Melbourne Group Score (MGS)
  • A patient-centred outcome, such as hospital length of stay, may have been more valid and relevant
• Pre-op clinic extensively staffed which may not be standard of care in other healthcare settings
• Cost and health economics analysis awaited

The Bottom Line

• Despite the lower rates of PPC (and HAP) in the intervention arm, this did not translate into improved clinical outcomes as measured in this trial
• The introduction of such a comprehensive pre-op physiotherapy programme whilst probably feasible and safe, has significant cost and health economics implications
• I will await further studies before preparing a business plan to take to the hospital funders

External Links

• [article] Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery: pragmatic, double blinded, multicentre randomised controlled trial
• [further reading] Trial protocol
• [further reading] Postoperative Pulmonary Complications by Miscovik and Lumb in BJA 2017

Metadata

Summary author: Adrian Wong
Summary date: 31 January 2018
Peer-review editor: Fraser Magee
Additional editing: Duncan Chambler