Sonographic assessment of hemi-diaphragmatic palsy post brachial plexus blocks
Background and Aim: Brachial plexus blocks (BPB) are
indispensable in providing surgical anaesthesia and postoperative
analgesia. Although Hemi-diaphragmatic palsy (HDP) after
BPB is clinically insignificant in the majority, it can cause
significant physiological impairment in patients with reduced
pulmonary function. Sonographic assessment of diaphragmatic
function using the ABCDE approach provides accurate and
quantitative information on HDP. This can be performed bedside
before and after administration of the nerve block to quantify
HDP. This was a prospective observational study comparing
ultrasound-guided diaphragmatic thickness in two approaches
of ultrasound-guided BPB. Methodology: Eighty participants
receiving eitherinterscalene/supraclavicular BPB were included
in this observational study. Baseline vitals, NRS score for pain
and ultrasound-guided diaphragm thickness at inspiration and
expiration using the ABCDE approach were noted. After 20
minutes of BPB administration, the diaphragm thickness was
remeasured.Results: Eighty participants completed the study,
forty from either group. Average volume of the total local
anaesthetic drug mixture used was noted to be 30ml.
The diaphragmatic thickness ratio in the supraclavicular group
was found to decrease by 2.34% as compared to 2.39% in the
interscalene group. (p-value 0.256 baseline values,0.292 for post
block values) The thickness fraction was found to decrease by
9.21% in Group A as compared to 9.04% in Group B (P value
0.248 baseline values and 0.292 post-block values). There was
no statistically significant difference between the diaphragm
thickness in both the group’spre- and post-block, irrespective of
the approach used. Conclusion: The ABCDE approach to measure
diaphragm thickness can be used as a simple bedside modality to
quantify the amount of HDP occurring after ultrasound-guided
BPB. It is easy to learn & a non-invasive modality which can be
used to improve patient safety during BPB
Keywords
Hemidiaphragmatic palsy, ABCDE, Brachial plexus block
indispensable in providing surgical anaesthesia and postoperative
analgesia. Although Hemi-diaphragmatic palsy (HDP) after
BPB is clinically insignificant in the majority, it can cause
significant physiological impairment in patients with reduced
pulmonary function. Sonographic assessment of diaphragmatic
function using the ABCDE approach provides accurate and
quantitative information on HDP. This can be performed bedside
before and after administration of the nerve block to quantify
HDP. This was a prospective observational study comparing
ultrasound-guided diaphragmatic thickness in two approaches
of ultrasound-guided BPB. Methodology: Eighty participants
receiving eitherinterscalene/supraclavicular BPB were included
in this observational study. Baseline vitals, NRS score for pain
and ultrasound-guided diaphragm thickness at inspiration and
expiration using the ABCDE approach were noted. After 20
minutes of BPB administration, the diaphragm thickness was
remeasured.Results: Eighty participants completed the study,
forty from either group. Average volume of the total local
anaesthetic drug mixture used was noted to be 30ml.
The diaphragmatic thickness ratio in the supraclavicular group
was found to decrease by 2.34% as compared to 2.39% in the
interscalene group. (p-value 0.256 baseline values,0.292 for post
block values) The thickness fraction was found to decrease by
9.21% in Group A as compared to 9.04% in Group B (P value
0.248 baseline values and 0.292 post-block values). There was
no statistically significant difference between the diaphragm
thickness in both the group’spre- and post-block, irrespective of
the approach used. Conclusion: The ABCDE approach to measure
diaphragm thickness can be used as a simple bedside modality to
quantify the amount of HDP occurring after ultrasound-guided
BPB. It is easy to learn & a non-invasive modality which can be
used to improve patient safety during BPB
Keywords
Hemidiaphragmatic palsy, ABCDE, Brachial plexus block