Regional anaesthesia for major orthopaedic trauma surgery in patients with conservatively managed pneumothoraces

Summary

The anaesthetic management of multiple traumatic injuries poses numerous challenges. In this report, we present the cases of two patients with polytrauma including pneumothoraces and multiple rib fractures. The first patient, a 39‐year‐old man, presented with multiple left upper limb fractures, multiple bilateral rib fractures, bilateral pneumothoraces and fractures of multiple facial and cranial bones. The second patient, a 39‐year‐old woman, presented with right‐sided radial and ulnar fractures, a right‐sided pelvic fracture, and multiple right‐sided rib fractures with an associated pneumothorax. We used ultrasound‐guided superficial cervical plexus, interscalene and supraclavicular blocks in the first case and a combined spinal and epidural after ultrasound‐guided fascia iliaca and supraclavicular blocks in the second case. In both cases, the use of multiple regional techniques allowed us to avoid the risks of general anaesthesia in patients with conservatively managed pneumothoraces.

Introduction

Chest wall trauma is a common reason for presentation to trauma centres; the majority of cases (83.5%) are as a result of blunt trauma [1]. Blunt chest trauma may be associated with other extra‐thoracic orthopaedic injuries in up to 69.5% of cases [2]. The presence of a pneumothorax (especially if conservatively managed) may complicate anaesthetic management for subsequent surgery, as positive pressure ventilation may cause the pneumothorax to expand or tension. In our two cases, regional anaesthesia was used to avoid positive pressure ventilation in patients with conservatively managed pneumothoraces undergoing major orthopaedic surgery.

The first case was a 39‐year‐old man who was admitted to hospital after a fall from a tree. His injuries included multiple rib fractures (the right first and second anteriorly, and the left first, fourth, fifth, sixth and ninth anterolaterally). He also had bilateral pneumothoraces (larger on the right than the left), a small pneumomediastinum, and subcutaneous emphysema extending from the base of skull to the chest wall bilaterally (Fig. 1). The right‐sided pneumothorax was managed with an intercostal drain, and the left was managed conservatively. Other injuries included fractures of the left clavicle, both the radial neck and distal part of the left radius, and the proximal left ulna. He had also sustained multiple small skull and facial fractures with associated pneumocephalus which were conservatively managed.

Figure 1.

Panels (a) to (d) relate to case 1, and panels (e) and (f) relate to case 2. (a) axial computed tomography images depicting right pneumothorax (arrow); (b) sagittal computed tomography images depicting right pneumothorax (arrow); (c) sagittal computed tomography images depicting left pneumothorax (arrow); (d) immediate preoperative chest radiograph showing bilateral expanded lungs; (e) axial computed tomography images depicting right pneumothorax (arrow); (f) immediate preoperative chest radiograph showing bilateral expanded lungs.

Surgical fixation of the upper limb fractures was planned on the fourth day of the patient's hospital admission, after a period of observation, to ensure stability. Because of the pneumothoraces and the pneumomediastinum, a regional anaesthetic technique was planned. After explaining the procedure and obtaining consent, the patient was transferred to the theatre, where standard monitoring was applied. Dexamethasone 8 mg, paracetamol 1 g and diclofenac 75 mg were administered intravenously.

After appropriate positioning, an in‐plane ultrasound‐guided left interscalene brachial plexus block, a superficial cervical plexus block, and a supraclavicular brachial plexus block were performed using a linear ultrasound probe and a 22G 5 cm Sonoplex needle (Pajunk, Alpharetta, USA). Fifty millilitres of local anaesthetic solution was infiltrated in total (20 ml of bupivacaine 0.5%, 20 ml of lidocaine 2% with adrenaline 1:200,000, 50 μg of dexmedetomidine, and 10 ml of normal saline). Twenty millilitres were used to perform each of the interscalene and supraclavicular blocks, and the remaining 10 ml was used for the superficial cervical plexus block. An additional 5 ml of lidocaine 1% with adrenaline was injected subcutaneously superiorly and inferiorly along the axillary crease to block the intercostobrachial nerve.

After confirming the efficacy of regional anaesthesia by assessing temperature sensation using alcohol swabs and motor movements, oxygen was administered via nasal cannula and intravenous dexmedetomidine was administered (0.5 μg.kg⁻¹ over 10 min, followed by an infusion of 0.5 μg.kg⁻¹.h⁻¹). This provided conscious sedation and analgesia; intravenous fentanyl was administered in 50 μg boluses as required to manage pain from the rib fractures. Throughout the operation, the patient maintained a patent airway and remained in verbal contact. The clavicular plating was performed with the patient in the supine position and the ulnar fixation in the right lateral position. Adequate padding of pressure points, a head pillow and a forced air‐warming blanket were used. Completion of the open reduction and plate fixation of the clavicle, left ulnar shaft, and left radial fractures required approximately 4 h operative time.

The patient was comfortable throughout the surgery. The respiratory parameters were stable, and there was no clinical suggestion of phrenic nerve block. The patient was comfortable in the post‐operative period, and rib fracture pain was managed with non‐opioid analgesics. A Horner's syndrome was observed (evident by ptosis and miosis) on the ipsilateral side. It persisted post‐operatively until the patient was transferred back to the critical care unit; it had resolved by the next day. The remaining in‐patient stay was uneventful, and the patient was discharged on post‐operative day 6.

The second case was a 39‐year‐old female admitted after a fall from approximately 3 m. Her injuries included right fourth, fifth and sixth lateral rib fractures, a small right‐sided pneumothorax and mild subcutaneous emphysema. She also had a pelvic fracture including a comminuted, displaced fracture of the right ilium, right acetabulum and left side sacral ala, and a large pelvic haematoma. She had a comminuted fracture of the right proximal ulna and radial head and small right frontal and parietal subgaleal haematomas. The pneumothorax was conservatively managed in the intensive care unit. Surgical fixation of the pelvis and forearm fractures was planned.

Because of the untreated pneumothorax, a regional anaesthetic technique was planned. Consent was obtained, the patient was transferred to the theatre, and standard monitoring was applied. A right fascia iliaca block was performed under ultrasound guidance using a linear probe and a 22G 5 cm Sonoplex needle (Pajunk, Alpharetta, USA) with 15 ml of lidocaine 1% with adrenaline, 15 ml of bupivacaine 0.25%, and 30 μg of dexmedetomidine. After reporting analgesia, the patient was placed in the left lateral position for neuraxial anaesthesia. Spinal anaesthesia was administered with 13 mg of hyperbaric bupivacaine 0.5% and 20 μg of fentanyl (total volume 3 ml), and an epidural catheter was placed at the L3‐L4 level. Intravenous dexamethasone 8 mg, paracetamol 600 mg and ketorolac 30 mg were administered. Oxygen was administered via a face mask. After confirming the efficacy of anaesthesia as described in the previous case, intravenous dexmedetomidine infusion was administered (0.5 μg.kg⁻¹ over 10 min, followed by 0.5 μg.kg⁻¹.h⁻¹) for sedation. An epidural infusion of bupivacaine 0.5% with fentanyl 2 μg.ml⁻¹ was started at 6 ml.h⁻¹, 1 h after the spinal anaesthesia. The pelvic plating was completed in 3 h in the left lateral position. The patient was then repositioned supine, and the epidural infusion was switched to bupivacaine 0.1% with fentanyl 2 μg.ml⁻¹, at 6 ml.h⁻¹. This adjustment was made in part to lower the cumulative dose of local anaesthetic in consideration of the subsequent upper limb nerve blocks. An ultrasound‐guided supraclavicular nerve block was administered using 15 ml of bupivacaine 0.5% and 10 ml of lidocaine 2% with adrenaline. Five millilitres of lidocaine 2% with adrenaline was used to perform an intercostobrachial nerve block for tourniquet pain. Radial head fixation and ulna plating were performed in a procedure lasting 2.5 h. The patient was comfortable in the post‐operative period. Her subsequent post‐operative course was uneventful, and the patient was discharged after successful recovery on post‐operative day 4.

Discussion

Patients with blunt chest trauma commonly have associated orthopaedic injuries requiring surgical management. Anaesthetic considerations for these patients include both the underlying lung injury (including pneumothoraces) and the presence of chest wall pain. Positive pressure ventilation may worsen an existing pneumothorax or cause tension.

Conservatively managed pneumothoraces can enlarge. In a study of 569 patients, conservatively managed pneumothoraces in ventilated patients enlarged in 14% of cases, which was associated with longer in‐patient stays [3]. Even if a pneumothorax appears to have resolved on x‐ray, some residual air may persist in the pleural cavity. In addition, the presence of at least one rib fracture on x‐ray represents a significant risk factor for the development of a delayed pneumothorax [4].

In this report, we present two cases where the use of regional anaesthesia allowed us to avoid administering general anaesthesia and avoid the potential of positive pressure ventilation worsening existing pneumothoraces.

The choice of block is clearly important. Brachial plexus block is commonly used in upper limb orthopaedic surgery. Combined interscalene and superficial cervical blocks have been described for clavicle fixation surgery in a case series of 10 patients and a retrospective observational study of 12 patients [5, 6]. In our cases, additional supraclavicular brachial block and intercostobrachial block were administered for the forearm procedures, anticipating the C8‐T1 segment sparing from the interscalene blocks. Axillary plexus block and selective block of the lower trunk could be considered as alternatives. However, patient movement restrictions (due to clavicular injury) and lack of clinician experience precluded this approach. We have more experience in performing the use of two combined regional anaesthesia techniques rather than three or more. The total safe dose of local anaesthesia that can be used must also be calculated.

There was a concern about potential involvement of phrenic nerve blockade in our case. Phrenic nerve block and resulting hemi‐diaphragmatic palsy is a recognised complication of the interscalene block [7], and the clinical significance of this may be greater in the presence of a pneumothorax.

In the second case, which involved pelvic fixation, the use of the fascia iliaca block before neuraxial anaesthesia was used for analgesia while positioning. This has also been shown to shorten the puncture time to spinal anaesthesia [8]. Central neuraxial blocks provided anaesthesia and post‐operative analgesia following the pelvic fracture fixation. In a retrospective observational study, regional anaesthesia alone was used in 30 patients for fixation of pelvic‐acetabular fractures. There was no significant difference in the outcomes as compared to general anaesthesia or general anaesthesia combined with regional anaesthesia [9].

A backup plan for regional anaesthesia is important, as it may be required due to failure of anaesthesia, extended surgical time, patient distress or hemi‐diaphragmatic palsy. General anaesthesia with supraglottic airway and preservation of spontaneous ventilation was our backup plan. If unsuccessful, we planned for positive pressure ventilation with low inflation pressures and avoidance of positive end‐expiratory pressure. The patients were made aware of this including the possibility of deferring some of the procedures. Intra‐operatively, the anaesthetist must be vigilant to the development of an enlarging or tensioning pneumothorax.

Duration of surgery is an important consideration. In our cases the duration of surgeries was 4 and 6 h. Not only must anaesthesia be sufficient in duration, but the patient must remnain comfortable regarding positioning, pressure areas and temperature. The multiple procedures and prolonged duration were a challenge in both cases. We used dexmedetomidine for sedation because of its analgesic properties and minimal respiratory depressant effect. Intravenous dexmedetomidine is also shown to prolong the effect of brachial plexus block and spinal anaesthesia [10]. One patient required four boluses of intravenous fentanyl 50 μg during surgery for additional analgesia (for rib fractures).

Ensuring analgesia for the thoracic injury is another important consideration. In addition to the dexmedetomidine and fentanyl discussed above, we administered non‐steroidal anti‐inflammatory drugs and paracetamol. Placing a thoracic epidural catheter would be a reasonable alternative, but in our cases, we decided that would exceed the safe total local anaesthesia dose.

Subcutaneous emphysema is common in blunt chest wall trauma and may impair ultrasound‐guided regional anaesthesia as the air‐tissue interface acts as barrier to ultrasound visualisation of deeper structures [11]. In our cases, this had sufficiently resolved to allow safe ultrasound use.

Finally, close communication with the surgical team is critical. Completing all required operations in one episode was agreed upon in the pre‐surgery meeting, but opportunities to abandon and postpone some procedures were identified.

Performance of multiple orthopaedic surgeries under regional anaesthesia in a single sitting in patients with traumatic conservatively managed pneumothorax requires meticulous planning. The administration of more than two ultrasound‐guided regional blocks may be undertaken either sequentially or simultaneously, provided the total dose of local anaesthetic administered is below the toxic dose.