Intraoperative fluid management guided by oesophageal Doppler
We thank Dr Ashworth for his interest in our paper.
We agree that changes in perfusion are reflected by changes in the oxygen
saturation in the effluent of the circulation. Whether this can be used
for peri-operative fluid optimization is debatable with a recent trial
showing no improvement over standard care (1). Central venous
catheterization is expensive and invasive with well known associated
risks. Our quality improvement trial showed that anaesthetists were less
likely to use CVC when offered a better, less invasive alternative. We
think CVC monitoring should be reserved for patients requiring vasoactive
infusions, and not utilized for routine haemodynamic monitoring.
We thank Dr Wilson for his interest.
There have been numerous randomized controlled trials of Doppler. The aim
of this study was not to replicate such trials, but to explore barriers to
purchase and implementation of the Doppler and whether the benefits
predicted by research could be obtained in the real world. The sites were
deliberately chosen to represent the diversity of NHS providers and are
not all large centres. One site had no previous experience of Doppler use
intra-operatively, and across all sites the baseline usage in eligible
patients was only 12%. In this quality improvement project, the effect of
implementing recommended best practice (2) into routine service was
evaluated by comparing a consecutive cohort following implementation to a
historical cohort. There was no blinding or randomisation. The project
was approved by each Trust's clinical audit process and endorsed by
executive teams. Significant barriers to purchase and implementation were
overcome on all 3 sites as discussed in the report. A highly significant
increase in Doppler usage was achieved to 63% of eligible operations. This
was associated with a reduction in total and postoperative length of stay,
suggesting that the benefits predicted by research can be mirrored in
practice. The median length of stay across all sites was reduced from 12
to 10 days. Complications and in-hospital mortality are presented in Table
5, and fell non-significantly. The study design cannot exclude confounding
by other factors changing over time and potential for bias is discussed in
the paper. This quality improvement design could and should not replace
the type of randomized controlled trials conducted by Dr Wilson and
others. However we believe that our implementation study should aid and
encourage clinicians to translate research evidence into real benefit for
patients. The oesophageal Doppler now has evidence spanning the spectrum
from basic science through clinical trials to our real world quality
improvement project.
We thank Dr Miura and colleagues for their interest.
We implemented into routine practice a recommended intervention with a
strong evidence base (2). Differences in the group matching were
acknowledged in the paper. POSSUM is the best weighted, validated scoring
system for evaluating perioperative risk and has been used in many of the
RCT's of peri-operative fluid therapy. The use of different colloids at
different hospitals reflects variation in fluid prescribing practice
across the UK and increases the generalizability of the results. The
concern raised about colloid pharmacology is not supported by evidence
that differences in colloid molecular structure do not significantly
affect volume expansion or the accuracy of cardiovascular measurements
(3).
We note the commentator's active involvement with the NHS Networks
platform. The NHS Technology Adoption Centre has a specific remit and
funding for the purpose of supporting the adoption of technologies which
could be of significant benefit yet are underutilized. We suggest the
relevant peri-operative NHS Networks should encourage the implementation
of Doppler monitoring in accordance with NTAC's aims and with recent NICE
guidance (4), thus improving outcomes for major surgical patients.
References
1. Jammer I, Ulvik A, Erichsen C, L?demel O, Ostgaard G. Does central
venous oxygen saturation-directed fluid therapy affect postoperative
morbidity after colorectal surgery? A randomized assessor-blinded
controlled trial. Anesthesiology. 2010;113(5):1072-80
2. Powell-Tuck J, Gosling P, Lobo DN, Allison SP, Carlson GL, Gore M,
et al. British Consensus Guidelines on Intravenous Fluid Therapy for Adult
Surgical Patients - GIFTASUP. 2008. Available from: http://journal.ics.ac.uk/pdf/1001013.pdf (Accessed 18 June 2011).
3. Lobo DN, Stanga Z, Aloysius MM, Wicks C, Nunes QM, Ingram KL,
Risch L, Allison SP Effect of volume loading with 1 liter intravenous
infusions of 0.9% saline, 4% succinylated gelatine (Gelofusine) and 6%
hydroxyethyl starch (Voluven) on blood volume and endocrine responses: a
randomized, three-way crossover study in healthy volunteers Crit Care
Med. 2010 Feb;38(2):464-70
Rapid Response:
Intraoperative fluid management guided by oesophageal Doppler
We thank Dr Ashworth for his interest in our paper.
We agree that changes in perfusion are reflected by changes in the oxygen
saturation in the effluent of the circulation. Whether this can be used
for peri-operative fluid optimization is debatable with a recent trial
showing no improvement over standard care (1). Central venous
catheterization is expensive and invasive with well known associated
risks. Our quality improvement trial showed that anaesthetists were less
likely to use CVC when offered a better, less invasive alternative. We
think CVC monitoring should be reserved for patients requiring vasoactive
infusions, and not utilized for routine haemodynamic monitoring.
We thank Dr Wilson for his interest.
There have been numerous randomized controlled trials of Doppler. The aim
of this study was not to replicate such trials, but to explore barriers to
purchase and implementation of the Doppler and whether the benefits
predicted by research could be obtained in the real world. The sites were
deliberately chosen to represent the diversity of NHS providers and are
not all large centres. One site had no previous experience of Doppler use
intra-operatively, and across all sites the baseline usage in eligible
patients was only 12%. In this quality improvement project, the effect of
implementing recommended best practice (2) into routine service was
evaluated by comparing a consecutive cohort following implementation to a
historical cohort. There was no blinding or randomisation. The project
was approved by each Trust's clinical audit process and endorsed by
executive teams. Significant barriers to purchase and implementation were
overcome on all 3 sites as discussed in the report. A highly significant
increase in Doppler usage was achieved to 63% of eligible operations. This
was associated with a reduction in total and postoperative length of stay,
suggesting that the benefits predicted by research can be mirrored in
practice. The median length of stay across all sites was reduced from 12
to 10 days. Complications and in-hospital mortality are presented in Table
5, and fell non-significantly. The study design cannot exclude confounding
by other factors changing over time and potential for bias is discussed in
the paper. This quality improvement design could and should not replace
the type of randomized controlled trials conducted by Dr Wilson and
others. However we believe that our implementation study should aid and
encourage clinicians to translate research evidence into real benefit for
patients. The oesophageal Doppler now has evidence spanning the spectrum
from basic science through clinical trials to our real world quality
improvement project.
We thank Dr Miura and colleagues for their interest.
We implemented into routine practice a recommended intervention with a
strong evidence base (2). Differences in the group matching were
acknowledged in the paper. POSSUM is the best weighted, validated scoring
system for evaluating perioperative risk and has been used in many of the
RCT's of peri-operative fluid therapy. The use of different colloids at
different hospitals reflects variation in fluid prescribing practice
across the UK and increases the generalizability of the results. The
concern raised about colloid pharmacology is not supported by evidence
that differences in colloid molecular structure do not significantly
affect volume expansion or the accuracy of cardiovascular measurements
(3).
We note the commentator's active involvement with the NHS Networks
platform. The NHS Technology Adoption Centre has a specific remit and
funding for the purpose of supporting the adoption of technologies which
could be of significant benefit yet are underutilized. We suggest the
relevant peri-operative NHS Networks should encourage the implementation
of Doppler monitoring in accordance with NTAC's aims and with recent NICE
guidance (4), thus improving outcomes for major surgical patients.
References
1. Jammer I, Ulvik A, Erichsen C, L?demel O, Ostgaard G. Does central
venous oxygen saturation-directed fluid therapy affect postoperative
morbidity after colorectal surgery? A randomized assessor-blinded
controlled trial. Anesthesiology. 2010;113(5):1072-80
2. Powell-Tuck J, Gosling P, Lobo DN, Allison SP, Carlson GL, Gore M,
et al. British Consensus Guidelines on Intravenous Fluid Therapy for Adult
Surgical Patients - GIFTASUP. 2008. Available from:
http://journal.ics.ac.uk/pdf/1001013.pdf (Accessed 18 June 2011).
3. Lobo DN, Stanga Z, Aloysius MM, Wicks C, Nunes QM, Ingram KL,
Risch L, Allison SP Effect of volume loading with 1 liter intravenous
infusions of 0.9% saline, 4% succinylated gelatine (Gelofusine) and 6%
hydroxyethyl starch (Voluven) on blood volume and endocrine responses: a
randomized, three-way crossover study in healthy volunteers Crit Care
Med. 2010 Feb;38(2):464-70
4. MTG3 CardioQ-ODM (oesophageal Doppler monitor): NICE guidance
2011 Available from
http://www.nice.org.uk/nicemedia/live/13312/52624/52624.pdf (Accessed 18
June 2011).
Competing interests: DHC received expenses to travel to a meeting from Deltex Medical, this was after acceptance of publication in March 2011.