Sir,
We would like to share a case series of four morbidly obese patients with traumatic
rib fractures requiring respiratory support in the intensive care unit (ICU) and they
received erector spinae plane (ESP) block[1] as analgesic adjunct. They were males
with median age (interquartile range, IQR), 56 (42–61) years and median body mass
index, BMI (IQR) 35.2 (33.0–36.9) kg/m2. They had sustained polytrauma [Table 1] secondary
to motor vehicle accidents with multilevel rib fractures and other injuries. They
also had multiple comorbidities, required oxygen therapy with non-invasive ventilatory
(NIV) support, therefore, being closely monitored in ICU. They received multimodal
analgesia regime—intravenous patient-controlled analgesia (PCA) morphine, regular
doses of paracetamol, tramadol plus nonsteroidal anti inflammatory drugs (NSAIDs)
or coxib since hospital admission. Despite the above analgesic regime, they still
experienced severes pain. The median pain scores using numerical rating scale (NRS)
were 6.5/10 (IQR 5.25–7.75) at rest and 9/10 (IQR 7.25–10) during movement. The mean
daily morphine consumption prior to block was 48 mg (±8 mg). ESP block was given on
day 2 of ICU admission because of unsatisfactory pain control, poor cough effort with
difficulty to perform chest physiotherapy and requiring NIV support.
Table 1
Case description
Case
Demographic and comorbidities
Major injuries sustained
Site of ESP block*
Analgesic medication prior to ESP block & the block timing
Respiratory support and the best daily partial pressure of oxygen (P02) level in ICU
Pain score and 24 hours morphine consumption
A
38 years old, male; underlying DM, morbid obesity; ASA III
Multiple ribs fractures (Left 1st-7th, 10th-11th, right 1st rib) with bilateral lung
contusion, left hemothorax (on chest drain), minimal bilateral pneumothorax and left
vertebrae transverse process C7 & T1 fracture
Left
Oral paracetamol 1 g QID, Celebrex 200 mg BD, Cap tramadol 50 mg TDS, PCA morphine;
ESP block was given on D2
D1: HFM 02 and subsequently put on NIV-CPAP, baseline P02 level 84 mmHg on HFM;D2:
NIV-CPAP P02 level 150 mmHg;D3: VM 50%, P02 level 110 mmHg;D4: VM30%, P02 level 105
mmHg;D5: NP02, P02 level 110 mmHg D6: NP02, P02 level 115 mmHg; ESP catheter was removed;D7:
NP02, P02 level 105 mmHg
D1: 7(R)/10(M), 58 mg;D2: 7(R)/10(M) pre-block, 2(R)/4(M) post block, 36 mg; D3: 2(R)/4(M),
32 mg;D4: 2(R)/3(M), 26 mg;D5: 2(R)/3(M), 20 mg;D6: 2(R)/4(M), 22 mg;D7: 2(R)/3(M),
16 mg;
B
62 years old, male; underlying major depression, DM, morbid obesity; ASA III
Left hemothorax with multiple ribs and sternal - anterior left 1st rib, anterior left
6th rib, and posterior left 3rd to 7th ribs (on chest drain); Left distal 3rd clavicle
fracture, sternum body fracture; Grade 1 spleen injury; Right distal 3rd tibia fibula
fracture; Acute kidney injury secondary to rhabdomyolysis
Left
Intravenous paracetamol 1 g QID, intravenous tramadol 50 mg TDS, one day trial of
Dexmedetomidine infusion (max dose 0.6 mcg/kg/hour); patient was initially on PCA
Fentanyl (200 meg usage within 4 hours, not effective) then changed to PCA morphine;
ESP block was given on D2
D1: HFM 02 and subsequently put on NIV-BiPAP, baseline P02 level 80 mmHg on HFM;D2:
NIV-BiPAP, P02 level 164 mmHg; D3: VM40%, P02 level 135 mmHg;D4: VM40%, P02 level
110 mmHg;D5: NP02, P02 level 95 mmHg D6: NP02, P02 level 112 mmHg; ESP catheter was
removed;D7: NP02, P02 level 120 mmHg; PCA morphine was discontinued;D8: NP02
D1: 8(R)/10(M), 48 mg;D2: 8(R)/9(M) pre-block, 2(R)/4(M) post block, 29 mg;D3: 2(R)/4(M),
25 mg;D4: 2(R)/4(M), 26 mg;D5: 2(R)/4(M), 22 mg;D6: 1 (R)/2(M), 8 mg;D7: 1 (R)/2(M),
5 mg;
C
55 years old, male; underlying DM, HPT, IHD; active heavy smoker; ASA III
Right pneumothorax (on chest drain), subcutaneous emphysema. Multiple fractures: comminuted
fractures at right scapula, right posterior 2nd rib, right posterior 3rd rib, lateral
right 7th, 8th, 9th ribs
Right
Oral paracetamol 1 g QID, Celebrex 200 mg BD, Cap tramadol 50 mg TDS, PCA Morphine;
ESP block was performed on D2
D1: HFM 02 and subsequently put on NIV-BiPAP, Fi02 0.6, baseline P02 level 90 mmHg
on HFM;D2: NIV-BiPAP, Fi02 0.5, P02 level 117 mmHg;D3: NIV-BiPAP, Fi02 0.4, P02 level
97 mmHg;D4: VM50%, P02 level 98 mmHg;D5: VM50%, P02 level 99 mmHg; ESP catheter was
removed; PCA morphine was discontinued;D6: NP02, P02 level 107 mmHg
D1: 7(R)/8(M), 38 mg;D2: 6(R)/7(M) pre-block, 2(R)/4(M) post block, 17 mg;D3: 1 (R)/3(M),
16 mg;D4: 1 (R)/3(M), 10 mg;D5: 0(R)/2(M)D6: 0(R)/3(M)
D
58 years old, male; underlying DM, HPT; ASA III
Small right pneumothorax, subcutaneous emphysema and bilateral lung contusion. Multiple
rib fractures with flail segments -anterior and posterior right 1st rib and 2nd ribs,
posterior and lateral segments of right 3rd rib, posterior and lateral segments of
right 8th rib; rib fractures - posterior right 4th, posterior 5th, 7th and 9th rib,
lateral right 6th rib
Right
Oral paracetamol 1 g QID, Celebrex 200 mg BD, Cap tramadol 50 mg TDS, PCA Morphine;
ESP block was performed on D2
D1: HFM 02 and subsequently put on NIV- BiPAP Fi02 0.5, baseline P02 100 mmHg on HFM;D2:
NIV-BiPAP Fi02 0.5, P02 104 mmHg;D3: NIV-BiPAP Fi02 0.4, P02 97 mmHg; D4: VM50%, P02
104 mmHg;D5: NP02, P02 125 mmHg;D6: NP02, P02 98 mmHg; ESP catheter was removed;
D1: 5(R)/8(M), 48 mg;D2: 5(R)/8(M) pre-block, 2(R)/5(M) post block, 34 mg;D3: 1 (R)/3(M),
28 mg;D4: 1 (R)/3(M), 30 mg;D5: 1 (R)/3(M), 22 mg;D6: 1 (R)/4(M), 16 mg;
*ESP block with catheter was placed on the most painful site of injury; DM, diabetes
mellitus; HPT, hypertension; IHD, ischemic heart disease; ASA, American Society of
Anesthesiologists; BD, twice daily; TDS, thrice daily, QID, four times a day; PCA,
patient-controlled analgesia; HFM, high flow mask; NIV, non-invasive ventilator; BiPAP,
bilevel positive airway pressure; CPAP, continuous positive airway pressure; VM, Venturi
mask; NP, nasal prong; D1, Day one ICU admission; D2, Day two ICU admission; D3, Day
three ICU admission; D4, Day four ICU admission; D5, Day five ICU admission; D6, Day
six ICU admission; D7, Day seven ICU admission; D8, Day eight ICU admission; R, worst
pain score at rest; M, worst pain score at slightest movement
The blocks were performed using a 10-5 MHz 38 mm linear probe (Sonosite M-Turbo, Bothell,
Washington, USA) and an 80 mm, 18-gauge Tuohy epidural needle (Perifix® Filter set,
BBraun, Melsungen, Germany) with in-plane needling technique. Patients were placed
either in sitting or lateral position, adjusted according to their comfort level as
they had multiple injuries and skin wound affecting the positioning. The transverse
process of the 3rd or 4th thoracic vertebra was identified. Muscle layers of trapezius,
rhomboids major, and erector spinae were identified, and the fascial plane beneath
the erector spinae muscle was entered with the Tuohy epidural needle inserted from
cranial to caudal direction. The needle placement was confirmed with pumping effect
within the fascial plane following hydrodissection and small boluses of local anaesthetic.
A total bolus of 40 ml of ropivacaine 0.375% was delivered within the fascial plane
and an indwelling Perifix epidural catheter was threaded-in and anchored with 4 cm
tip in the fascial plane with transparent film dressing (3M™ Tegaderm™, Maplewood,
Minnesota, USA) [Figure 1]. ESP block is a fascial plane block which relies on high
volume low concentration local anaesthetic to exert its analgesic efficacy. Luftig
et al.[2] recommended a 40 ml local anaesthetic regime for patient above 70 kg in
unilateral ESP block. All patients experienced significant pain reduction within 30
min after the block [Figure 1]. A continuous infusion of 8 ml/h ropivacaine 0.2% was
run with intermittent bolus of 10 ml ropivacaine 0.2% every 12 h. The intermittent
bolus was delivered manually by a trained staff nurse to avoid patient confusion with
the PCA morphine device plus no available programmed infusion pump. The median pain
scores after ESP block were 2/10 (IQR 2 – 2) at rest and 4/10 (IQR 4.0–4.75) during
movement. The pain score remained mild to moderate over the next few days. As patients
also had other injuries [Table 1], it would be difficult to achieve zero pain score
although other injury sites were not the predominant pain area. Therefore, the mean
daily morphine consumption only reduced gradually after ESP block [Table 1]. The median
length of ICU stays were 6.5 days (IQR 6–7.75). The median duration of NIV support
was 2.5 days (IQR 2–3).
Figure 1
(a) Poor sonoanatomy of the erector spinae plane (ESP) despite optimal adjustment
of the ultrasound settings, probe selection and manipulation. The ESP is located deeper
(>4 cm). The 18G Tuohy needle is vaguely seen in the trajectory pathway. (b) Sonoanatomy
of ESP with catheter in a thin lady (unrelated case), a stark difference of sonoanatomy
between a lean and an obese patient. (c) Patient B is on non-invasive ventilator support.
Inset – The monitors showed drastic reduction of blood pressure after the ESP block
because his pain was alleviated and stress response attenuated
Traumatic rib fractures are very painful. Inadequate pain control would impair breathing,
adequate coughing with clearance of pulmonary secretions and compliance with chest
physiotherapy. Consequently, patient would be at risk of secondary pulmonary complications,
that is, atelectasis, pneumonia, respiratory failure, and the need for respiratory
support. Effective analgesia may help to improve a patient's respiratory mechanics
and to avoid intubation of the trachea for ventilatory support and therefore may dramatically
alter the course of recovery. Multimodal systemic analgesics with intravenous patient-controlled
opioid has been the mainstay of pain management and they are usually sufficient for
healthy individuals with one to two fractured ribs.[3] However, for more than three
to four fractured ribs, studies and experience have reaffirmed that regional techniques
like thoracic epidural, thoracic paravertebral, serratus anterior plane, and intercostal
blocks provide superior analgesia.[3
4] Regional techniques are particularly useful in elderly patients, patients with
multiple rib fractures, and in patients with severe pain or compromised pulmonary
function.[3] However, epidural analgesia and paravertebral block may not be feasible
in the presence of anti-coagulation, multisystem trauma, haemodynamic instability,
or in patients unable to be optimally positioned.[3] ESP block was the most feasible
regional technique in our case series because patients were obese. The quality of
the ESP sonoanatomy was already below average and located deeper (>4 cm) [Figure 1]
despite optimal adjustment of the ultrasound settings (knob), probe selection, and
probe manipulation. The paravertebral space which is anatomically located deeper than
ESP could not be properly visualised during scout scan, therefore we did not attempt
paravertebral blocks. A literature review showed that there are three case reports[5
6
7] and one retrospective cohort study[8] about the use of ESP block for pain relief
in rib fractures.
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Nil.
Conflicts of interest
There are no conflicts of interest.