Keywords anesthesia, local - closed fracture reduction - nerve block - radius fractures - pain
measurement
Introduction
Fractures of the distal third of the radius occur very frequently, being the most
prevalent in the upper limbs.[1 ] Studies indicate an estimated 600,000 cases annually,[2 ] with an incidence in children of approximately 1.5 forearm fractures in every 100
emergency room visits.[3 ]
Despite happening in patients of all ages, fractures of the distal third of the radius
have a great distinction regarding the mechanism of trauma, as it may vary according
to age range.[1 ]
[2 ] In young adults, it is usually related to high-energy trauma, and in the elderly
to low-energy trauma.[1 ]
[2 ] It is also important to highlight that studies indicate that the number of cases
in the elderly should increase due to the increasing life expectancy of the population;
and in children due to increased body mass index (BMI), and increasingly early onset
of sports activities and risk.[3 ]
The treatment of distalic fractures of the radius can range from immobilization with
orthosis to surgical treatment with internal fixation.[1 ]
[2 ]
[3 ] In addition, part of the fractures requires a non-surgical reduction early on admission,
either for definitive treatment, or for improvement of bone alignment to preserve
soft tissues and to provide pain relief while awaiting definitive surgical treatment.[1 ]
[2 ] Thus, analgesia planning is necessary to perform these procedures.[4 ]
[5 ]
[6 ]
[7 ]
In the medical literature, several techniques have been described with the purpose
of analgesia to aid in the non-surgical reduction of the radius' distal fractures.[8 ] Among them, some stand out: fracture hematoma block,[6 ] Bier block,[9 ] sedation with venous drugs,[10 ] brachial plexus block,[11 ] and supracondylar block of the radial nerve.[7 ]
It is possible to find several studies in the medical literature in which different
analgesia techniques are described, but there are few that are comparative, and none
was found to compare two techniques which was possible to perform easily outside the
operating room.
The present study aimed to compare the results of analgesia of fracture hematoma block
with that of the supracondylar block (SCB) of the radial nerve in non-surgical treatment
in patients with radius distal fracture.
Materials and Methods
The work followed the determinations of the declaration of Helsinki with the guidelines
for studies with human beings, being submitted and approved by the research ethics
committee (CAAE 37896620.8.0000.5378). All participants agreed to their participation
by signing a free and informed consent form (TCLE) or consent form.
The study consisted of a near-randomized clinical trial, which compared two analgesia
techniques used to aid in the non-surgical reduction of fractures of the distal third
of the radius. The inclusion criteria in the study were: patients diagnosed with fracture
of the distal third of the radius with indication of non-surgical reduction, agreement
in the participation by part of the patient or guardian, patient with cognitive capacity
that would allow the procedure and answering the questionnaire. The exclusion criteria
of the study involved patients with previous neurological injury or due to current
trauma; as well as those who had some contraindication to perform the procedure in
the emergency room, or contraindication to the use of lidocaine.
Forty patients were involved in the study with the diagnosis of fracture of the distal
third of the radius, which were divided into 2 groups, 20 patients allocated in the
radial nerve SCB group, and 20 patients allocated in the fracture focus infiltration
(FFI) group. The randomization of the patients was performed on a first-come, first-served
basis, and the data collected were: age, gender, joint involvement, presence or not
of comminution and associated ulna fracture.
Anesthetic block was performed with a sterile syringe kit and sterile needle, and
lidocaine 2% (Xylestesin 2% without vasoconstrictor, Cristália, SP, Brazil) was injected[12 ]
[13 ] in both groups. No auxiliary imaging methods were used in either group. All procedures
were performed by two of the study researchers and, for radial nerve block, training
was used before the beginning of the study, using anatomical models and ultrasound,
with the objective of better localization, based on anatomical points.
To perform radial nerve SCB, we used the lateral epicondyle as an anatomical parameter,
inserting the needle into the lateral face of the arm at a point approximately 7 to
8 cm proximal to it, near the distal limit of the radial sulcus of the humerus and
the origin of the brachioradial muscle. The correct location was confirmed by paresthesia
along the nerve path ([Fig. 1 ]).
Fig. 1 Radial nerve block technique.
Palpation of the anatomical defect resulting from the fracture and the insertion of
the needle at this point was used for the FFI. The location was confirmed by aspiration
of the hematoma from the fracture focus.
To quantify and classify pain, we used the numerical pain rate scale (NPRS), which
is a variant of the visual analog scale (VAS),[14 ] measured in four moments: before blockade, after block, during reduction, and after
reduction. To calculate the analgesic effect of the techniques, we used the differences
between the NPRS values obtained at each moment: we called NPRS1 the difference between
the values obtained before and after the blockade, NPRS2 the difference between the
values obtained during the reduction and after the blockade, and NPRS3 the difference
between the values obtained before the blockade and after the reduction.
Statistical Analysis
All data were analyzed using the statistical analysis software Jamovi 2.2.2 (Library
R 4.0.2). The hypothesis of nullity of absence of difference was rejected if the p -value was < 0.05. To evaluate the SCB and FFI's groups homogeneity, we used the Chi-squared
and Fisher tests for the nominal variables.
The normal distribution of parametric variable data was evaluated using the Shapiro-Wilk
test, histograms, and mean and median comparisons. Thus, the results of the means
that presented normal distribution were evaluated using the Student t test. On the
other hand, the results considered as nonparametric were evaluated with the Mann-Whitney
test.
Results
The study included 40 patients with the diagnosis of fracture of the distal third
of the radius, who were divided into 2 groups, 20 patients allocated in the FFI group,
and 20 patients allocated in the radial nerve SCB group.
The age of the patients ranged from 8 to 87 years, with an average of 50 years in
the FFI group; and it ranged from 9 to 90 years, with an average of 41 years in the
SCB group ([Fig. 2 ]). The distribution between genders showed a higher female prevalence in both groups,
being 15 (75%) patients in the FFI group and 11 (55%) patients in the SCB group ([Fig. 3 ]).
Fig. 2 Distribution by age group.
Fig. 3 Distribution by gender.
Associated ulna fracture was present in 7 (35%) patients in the FFI group, and in
5 (25%) patients in the SCB group ([Fig. 4 ]); joint involvement occurred in 6 (30%) patients in the FFI group and 7 (35%) in
the SCB group ( [Fig. 5 ]); and in both groups we found 6 patients with fracture comminution ([Fig. 6 ]). The characteristics of the fracture in relation to the presence of ulna involvement,
comminution and joint involvement were homogeneous in the two groups studied, when
evaluated with the Chi-squared and Fisher tests.
Fig. 4 Association with ulna fracture.
Fig. 5 Joint involvement.
Fig. 6 Comminution of the radius fracture.
There were no complications during the execution of both anesthetic block techniques,
neither in the FFI nor in the SCB group.
The NPRS values found before blockade ranged from 2 to 10 in the FFI group, with an
average of 6.9; and from 0 to 10 in the SCB group, with an average of 6.1. There was
no statistical difference between means of NPRS values before the block. Numerical
pain rate scale values after block ranged from 0 to 8 in the FFI group, with an average
of 3.0; and from 0 to 8 in the SCB group, with an average of 2.6 ([Table 1 ]). There was no statistical difference between means of NPRS values after the block
(Table 2).
Table 1
Technique
Preblock
Postblock
Reduction
Postreduction
Average
FFI
6.90
3.00
7.35
2.25
SCB
6.10
2.60
7.60
2.30
Standard deviation
FFI
2.59
2.66
2.46
2.17
SCB
3.31
2.39
3.10
2.90
Minimum
FFI
2
0
2
0
SCB
0
0
0
0
Maximum
FFI
10
8
10
6
SCB
10
8
10
10
The NPRS values found during reduction ranged from 2 to 10 in the FFI group, with
an average of 7.35; and from 0 to 10 in the SCB group, with an average of 7.6. There
was no statistical difference between means of NPRS values during block The NPRS values
after reduction ranged from 0 to 6 in the FFI group, with an average of 2.25; and
from 0 to 10 in the SCB group, with an average of 2.3. There was no statistical difference
between means of NPRS values after block ([Table 2 ])
Table 2
Preblock
Postblock
Reduction
Postreduction
Shapiro-Wilk
0.022
0.007
< 0.001
< 0.001
Mann-Whitney U
0.494
0.710
0.453
0.776
The results obtained from NPRS1 (difference between the values obtained before and
after blockade) ranged from 1 to 10 in the FFI group, with an average of 3.9; and
from -6 to 10 in the SCB group, with an average of 3.5. There was no statistical difference
between the means of NPRS1 values ([Tables 3 ] and [4 ]). The values found in NPRS2 (difference between the values obtained during reduction
and after blockade) ranged from -5 to 10 in the FFI group, with an average of 4.35;
and from -3 to 10 in the SCB group, with an average of 5.0. There was no statistical
difference between the means of NPRS2 values ([Tables 3 ] and [4 ]). Finally, NPRS3 (difference between the values obtained before block and after
reduction) results ranged from 1 to 10 in the FFI group, with an average of 4.65;
and from -3 to 10 in the SCB group, with an average of 3.8. There was no statistical
difference between the means of NPRS3 values ([Tables 3 ] and [4 ]).
Table 3
Block
NPRS2
NPRS2
NPRS3
Average
FFI
3.90
4.35
4.65
SCB
3.50
5.00
3.80
Minimum
FFI
1
-5
1
SCB
-6
-3
-3
Maximum
FFI
10
10
10
SCB
10
10
10
Table 4
95% confidence interval
p
Inferior
Superior
NPRS2
Shapiro-Wilk
0.026
Mann-Whitney
0.880
-1.00
2.00
NPRS2
Shapiro-Wilk
0.269
Student T
0.583
-3.02
1.72
NPRS3
Shapiro-Wilke
0.267
Student T
0.407
-1.20
2.90
Discussion
Fractures of the distal third of the radius are extremely common in emergency orthopedic
care and affect patients of all ages.[1 ]
[2 ] Reducing and immobilizing in the emergency room can reduce costs, wait time, and
length of hospital stay.[15 ]
[16 ]
For the study, two analgesia methods used in non-surgical treatment of fractures of
the distal third of the radius were chosen, which could be reproduced without major
difficulties, without the use of special equipment or requiring monitoring during
the procedure. Thus, they are applicable in the reality of most emergency care units.
In addition, to quantify pain, we used the NPRS, which is a variant of the VAS, because
it is simple to understand and easy to reproduce.[14 ]
In the institution where the study was conducted, the analgesia pattern used is the
FFI, with good acceptance and effective analgesia.[6 ]
[17 ] Radial nerve block was chosen for the possibility of performing the procedure without
creating communication between the fracture and the external environment, and because
it theoretically facilitates local manipulation, not expanding the volume of the manipulation
site.[18 ]
During the anesthetic procedure, a greater ease was observed in the execution of hematoma
block, requiring less time to perform the procedure due to the fracture deformity
being palpable and the presence of blood on aspiration confirming the correct location.
However, we did not use any evaluation measure for this variable. In radial nerve
block, more specific training was required before the beginning of the study, using
anatomical models and ultrasonography, with the aim of better localization, based
on anatomical points. In addition, we believe that greater collaboration of the patient
is necessary, informing the sensation of paresthesia in the nerve path.
The anesthetic chosen was lidocaine at 2% without vasoconstrictor, because it is easily
accessible, it has low price, low latency, and it provides sufficient effect time
to perform the entire procedure.[19 ] The volume of anesthetic in the SCB group was higher (on average, used 3 to 4mL
more), with consequent higher latency for this purpose, since patients needed a few
minutes to report improvement of pain, while in the FFI group, improvement was almost
immediate.
The study was carried out without major complications, and patients had no complications
or sequelae due to the application of anesthetic methods. The main possible complications
were infection at the infiltration site, administration of anesthetic in the vascular
structure, or nerve injury by intraneural application.[20 ] Although possible, they are rare events when following the hygiene and safety protocols,[17 ] and we did not identify the occurrence in any patient involved in our study.
The results obtained in this study were compatible with those previously published
in the literature, both in terms of analgesic effectiveness of the method and in the
rate of complications.[6 ]
[7 ] Nevertheless, even with the aid of ultrasound, Frenkel et al.[5 ] did not obtain complete anesthesia, and Bear et al.[21 ] had 2 cases (7.69%) of paresthesia. These data are reinforced by the methodology
used in this study, in which no complications were reported with the two analgesia
techniques employed.
Three comparisons were made, and hematoma block was better in all, but statistical
analysis was not significant. Although we obtained effective analgesia, radial nerve
block did not produce complete anesthesia for the procedure, and this can be explained
by the fact the radio region is not completely innervated by the radial nerve.[21 ]
Thus, although both methods were effective in reducing patients' pain before reduction,
as evidenced by the statistical evaluation of means of NPRS measured before and after
the block, none promoted complete anesthesia. Thus, the choice of the technique to
be used should be up to the executing professional, always respecting the autonomy
of the patient, opening the possibility of reduction under sedation in the operating
room, if they so wish, after explaining the risks and benefits.
Conclusion
The study showed that both methods have similar analgesic efficacy, with both showing
improvement. Despite a slight superiority of the hematoma fracture block in the comparisons,
no statistical significance was observed in any of them.
