Post-thoracotomy ipsilateral shoulder pain: What should be preferred to optimize it - phrenic nerve infiltration or paracetamol infusion?

Abstract

Background: Post thoracotomy ipsilateral shoulder pain (PTISP) is a distressing and highly prevalent problem after thoracic surgery and has not received much attention despite the incidence as high as 85%. Objectives: To study the effect of phrenic nerve infiltration with Ropivacaine compared to paracetamol infusion on PTISP in thoracotomy patients with epidural analgesia as standard mode of incisional analgesia in both the groups. Study Design: Prospective Randomised and Double Blind Study. Methods: 126 adult patients were divided randomly into 2 groups, “Group A (Phrenic Nerve Infiltration Group) received 10 mL of 0.2% Ropivacaine close to the diaphragm into the periphrenic fat pad” and “Group B (Paracetamol Infusion Group) received 20mg/kg paracetamol infusion” 30 minutes prior to chest closure respectively. A blinded observer assessed the patients PTISP using the VAS score at 1, 4, 8, 12 and 24 hours (h) postoperatively. The time and number of any rescue analgesic medication were recorded. Results: PTISP was relieved significantly in Group A (25.4℅) as compared to Group B (61.9℅), with significantly higher mean duration of analgesia in Group A. The mean time for first rescue analgesia was significantly higher in Group A (11.1 ± 7.47 hours) than in Group B (7.40 ± 5.30 hours). The number of rescue analgesic required was less in Group A 1.6 ± 1.16 as compared to Group B 2.9 ± 1.37 ( P value <0.5). Conclusions: Phrenic Nerve Infiltration significantly reduced the incidence and delayed the onset of PTISP as compared to paracetamol infusion and was not associated with any adverse effects.

Efficacy of Phrenic Nerve Catheter in Ipsilateral Shoulder Pain After Thoracic Surgery

“…Most targeted phrenic nerve blocks are performed by the surgical team by depositing 10 mL of low-concentration local anesthetic in the periphrenic fat pad near the diaphragm [ 1 , 3 , 4 , 7 ] However, this technique does not reliably manage ISP (the incidence of ISP remains ~33% with this technique), is short-lived, and cannot be repeated. One study placed non-stimulating nerve catheters in the supraclavicular area either where the phrenic nerve is noted to pull away from C5 or between the sternocleidomastoid and anterior scalene muscles (when the phrenic nerve is not visualized) and 10-mL boluses of local anesthetic vastly improved pain scores for ISP [ 5 ].…”

“…Severe ipsilateral shoulder pain (ISP) after thoracic surgery occurs in about 40% to 85% of patients despite successful midthoracic epidural placement and extensive sensory blockade of the chest wall [ 1 - 7 ] and is resistant to opioids, ketamine, and nonsteroidal anti-inflammatory agents and acetaminophen [ 4 , 8 - 10 ]. Two popular postulated mechanisms of ISP are referred pain due to pleural irritation from the pericardium, mediastinum, and diaphragm via the phrenic nerve or musculoskeletal pain arising from surgical manipulation (e.g., scapular retraction).…”

“…The incidence and intensity of ISP has been reduced with interscalene, supraclavicular, cervical plexus, stellate ganglion, suprascapular blocks more proximally in the supraclavicular fossa (and not distally at the suprascapular notch), and phrenic nerve blocks [ 2 - 4 , 11 - 15 ]. The common denominator in these blocks is the likelihood of local anesthetic spread to the phrenic nerve.…”

Impact of regional analgesia techniques on the long-term clinical outcomes following thoracic surgery

“…[ 32 ] Phrenic nerve infiltration is an effective technique for management of PTISP as compared to the other systemic analgesics without any side effects. [ 33 ]…”