Programmed intermittent bolus versus continuous infusion for catheter-based erector spinae plane block on quality of recovery in thoracoscopic surgery: a single-centre randomised controlled trial.

BACKGROUND: Regional anaesthesia techniques, including the erector spinae fascial plane (ESP) block, reduce postoperative pain after video-assisted thoracoscopic surgery (VATS). Fascial plane blocks rely on spread of local anaesthetic between muscle layers, and thus, intermittent boluses might increase their clinical effectiveness. We tested the hypothesis that postoperative ESP analgesia with a programmed intermittent bolus (PIB) regimen is better than a continuous infusion (CI) regimen in terms of quality of recovery after VATS. METHODS: We undertook a prospective, double-blinded, randomised, controlled trial involving 60 patients undergoing VATS. All participants received ESP block catheters and were randomly assigned to CI or PIB of local anaesthetic regimen for postoperative analgesia. The primary outcome was Quality of Recovery-15 (QoR-15) score 24 h after surgery. Secondary outcomes included postoperative respiratory function, opioid consumption, verbal rating pain score, time to first mobilisation, nausea, vomiting, and length of hospital stay. RESULTS: Overall QoR-15 scores at 24 h after VATS were similar (PIB 115.5 [interquartile range 107-125] vs CI 110 [93-128]; Δ<6, P=0.29). The only quality of recovery descriptor showing a significant difference was nausea and vomiting, which was favourable in the PIB group (10 [10-10] vs 10 [7-10]; P=0.03). Requirement for rescue antiemetics up to 24 h after surgery was lower in the PIB group (4 [14%] vs 11 [41%]; P=0.04). There were no differences in other secondary outcomes between groups. CONCLUSIONS: Delivering ESP block analgesia after VATS via a PIB regimen resulted in similar QoR-15 at 24 h compared with a CI regimen.

Ultrasound-guided, continuous erector spinae plane (ESP) block in minimally invasive thoracic surgery-comparing programmed intermittent bolus (PIB) vs continuous infusion on quality of recovery and postoperative respiratory function: a double-blinded randomised controlled trial.

BACKGROUND: Minimally invasive thoracic surgery (MITS) has been shown to reduce postoperative pain and contribute to better postoperative quality of life as compared to open thoracic surgery (Bendixen et al., Lancet Oncol 17:836-44, 2016). However, it still causes significant post-operative pain. Regional anaesthesia techniques including fascial plane blocks such as the erector spinae plane block (ESP) have been shown to contribute to post-operative pain control after MITS (Finnerty et al., Br J Anaesth 125:802-10, 2020). Case reports relating to ESP catheters have described improved quality of pain relief using programmed intermittent boluses (PIB) instead of continuous infusion (Bendixen et al., Lancet Oncol 17:836-44, 2016). It is suggested that larger, repeated bolus dose may provide superior pain relief, possibly because of improved spread of the local anaesthetic medications (Ilfeld and Gabriel, Reg Anesth Pain Med 44:285-86, 2019). Evidence for improved spread of local anaesthetic may be found in one study which demonstrated that PIB increased the spread of local anaesthetic medication compared to continuous infusions for continuous paravertebral blocks, which are another type of regional anaesthesia technique for the chest wall (Hida et al., Reg Anesth Pain Med 44:326-32, 2019). Similarly, regarding labour epidural analgesia, the weight of evidence is in favour of PIB providing better pain relief compared with continuous infusion (Onuoha, Anesthesiol Clin 35:1-14, 2017). Since fascial plane blocks, such as ESP, rely on the spread of local anaesthetic medication between muscle layers of the chest wall, intermittent boluses may be particularly useful for this group of blocks. However, until recently, pumps capable of providing automated boluses in addition to patient-controlled boluses were not widely available. To best of our knowledge, there are no randomised controlled trials comparing continuous infusion versus intermittent bolus strategies for erector spinae plane block for MITS in terms of patient centred outcomes such as quality of recovery. METHODS: This trial will be a prospective, double-blinded, randomised controlled superiority trial. A total of 60 eligible patients will be randomly assigned to receive an intermittent bolus regime of local anaesthetic vs a continuous infusion of local anaesthetic. The medication will be delivered via an ultrasound-guided erector spinae plane block catheter which will be inserted by an anaesthesiologist while the patient is under general anaesthetic before their MITS surgery begins. The primary outcome being measured is the Quality of Recovery (QoR-15) score between the two groups 24 h after surgery. Secondary outcomes include respiratory testing of maximal inspiratory volume measured with a calibrated incentive spirometer, area under the curve for Verbal Rating Score for pain at rest and on deep inspiration versus time over 48 h, total opioid consumption over 48 h, QoR-15 score at 48 h and time to first mobilisation. DISCUSSION: Despite surgical advancements in thoracic surgery, severe acute post-operative pain following MITS is still prevalent. This study will provide new knowledge and possible recommendations about the efficacy of programmed intermittent bolus regimen of local anaesthetic vs a continuous infusion of local anaesthetic via an ultrasound-guided erector spinae plane catheter for patients undergoing MITS. TRIAL REGISTRATION: This trial was pre-registered on ClinicalTrials.gov Identifier: NCT05181371 . Registered on 6 January 2022. All item from the World Health Organization Trial Registration Data set have been included.

Can Acute Postoperative Pain Management After Tumour Resection Surgery Modulate Risk of Later Recurrence or Metastasis?

BACKGROUND: Cancer is a leading cause of mortality worldwide, but death is rarely from the primary tumour: Rather it is multi-organ dysfunction from metastatic disease that is responsible for up to 90% of cancer-related deaths. Surgical resection of the primary tumour is indicated in 70% of cases. The perioperative stress response, tissue hypoxia at the site of surgery, and acute pain contribute to immunosuppression and neo-angiogenesis, potentially promoting tumour survival, proliferation, and metastasis. Poorly controlled acute postoperative pain decreases Natural Killer (NK) immune cell activity, which could potentially facilitate circulating tumour cells from evading immune detection. This consequently promotes tumour growth and distal metastasis. METHODS: We conducted a comprehensive literature search for links between acute pain and cancer outcomes using multiple online databases. Relevant articles from January 1st, 2010 to September 1st, 2021 were analysed and appraised on whether postoperative pain control can modulate the risk of recurrence, metastasis, and overall cancer survival. RESULTS: Although experimental and retrospective clinical data suggest a plausible role for regional anaesthesia in cancer outcome modulation, this has not been supported by the single, largest prospective trial to date concerning breast cancer. While there are mixed results on anaesthesiology drug-related interventions, the most plausible data relates to total intravenous anaesthesia with propofol, and to systemic administration of lidocaine. CONCLUSION: The hypothesis that anaesthetic and analgesic technique during cancer surgery could influence risk of subsequent recurrence or metastasis has been prevalent for >15 years. The first, large-scale definitive trial among women with breast cancer found robust equivalent findings between volatile anaesthesia with opioid analgesia and regional anaesthesia. Therefore, while regional anaesthesia during tumour resection does not seem to have any effect on cancer outcomes, it remains plausible that other anaesthetic techniques (e.g. total intravenous anaesthesia and systemic lidocaine infusion) might influence oncologic outcome in other major tumour resection surgery (e.g. colorectal and lung). Therefore, another large trial is needed to definitively answer these specific research questions. Until such evidence is available, perioperative analgesia for cancer surgery of curative intent should be based on patient co-morbidity and non-cancer endpoints, such as optimising analgesia and minimising postoperative complications.

Ultrasound-guided erector spinae plane catheter versus video-assisted paravertebral catheter placement in minimally invasive thoracic surgery: comparing continuous infusion analgesic techniques on early quality of recovery, respiratory function and chronic persistent surgical pain: study protocol for a double-blinded randomised controlled trial.

BACKGROUND: Compared to conventional thoracotomy, minimally invasive thoracic surgery (MITS) can reduce postoperative pain, reduce tissue trauma and contribute to better recovery. However, it still causes significant acute postoperative pain. Truncal regional anaesthesia techniques such as paravertebral and erector spinae blocks have shown to contribute to postoperative analgesia after MITS. Satisfactory placement of an ultrasound-guided thoracic paravertebral catheter can be technically challenging compared to an ultrasound-guided erector spinae catheter. However, in MITS, an opportunity arises for directly visualised placement of a paravertebral catheter by the surgeon under thoracoscopic guidance. Alongside with thoracic epidural, a paravertebral block is considered the "gold standard" of thoracic regional analgesic techniques. To the best of our knowledge, there are no randomised controlled trials comparing surgeon-administered paravertebral catheter and anaesthesiologist-assisted erector spinae catheter for MITS in terms of patient-centred outcomes such as quality of recovery. METHODS: This trial will be a prospective, double-blinded randomised controlled trial. A total of 80 eligible patients will be randomly assigned to receive either an anaesthesiologist-assisted ultrasound-guided erector spinae catheter or a surgeon-assisted video-assisted paravertebral catheter, in a 1:1 ratio following induction of general anaesthesia for minimally assisted thoracic surgery. Both groups will receive the same standardised analgesia protocol for both intra- and postoperative periods. The primary outcome is defined as Quality of Recovery (QoR-15) score between the two groups at 24 h postoperative. Secondary outcomes include assessment of chronic persistent surgical pain (CPSP) at 3 months postoperative using the Brief Pain Inventory (BPI) Short Form and Short Form McGill (SF-15) questionnaires, assessment of postoperative pulmonary function, area under the curve for Verbal Rating Score for pain at rest and on deep inspiration versus time over 48 h, total opioid consumption over 48 h, QoR-15 at 48 h, and postoperative complications and morbidity as measured by the Comprehensive Complication Index. DISCUSSION: Despite surgical advancements in thoracic surgery, severe acute postoperative pain following MITS is still prevailing. This study will provide recommendations about the efficacy of an anaesthesia-administered ultrasound-guided erector spinae catheter or surgeon-administered, video-assisted paravertebral catheter techniques for early quality of recovery following MITS. TRIAL REGISTRATION: ClinicalTrials.gov NCT04729712 . Registered on 28 January 2021. All items from the World Health Organization Trial Registration Data Set have been included.