Thoracic-paravertebral blocks: comparative anatomical study with different injection techniques and volumes

Regional Analgesia for Cesarean Delivery: A Narrative Review Toward Enhancing Outcomes in Parturients

Introduction

With the current surge on peripheral nerve blocks in post-cesarean pain management and the historical lack of unequivocal evidence supporting its universal use, this review intended to re-examine the extended scope of literature on regional anesthesia and postoperative analgesia in low-transverse cesarean section.

Methods

A literature search was conducted up to April 2023 using PubMed to identify articles relevant to our search words "cesarean section", "neuraxial morphine", "post-cesarean analgesia", as well as the name of each individual nerve block. The literature search was ultimately narrowed to systematic reviews and randomized controlled trials published between 2012 and 2023. We define, describe, and discuss the evidence surrounding each individual regional anesthetic technique in the presence and absence of intrathecal morphine, which is used as the gold standard when appropriate.

Results

In the absence of neuraxial morphine, all regional anesthetic techniques have some level of analgesic benefit in the post-cesarean analgesia. Transversus Abdominis Plane blocks continue to have the most studies in their use. Newer fascia plane blocks including the anterior Quadratus Lumborum, and Erector Spinae Plane blocks provide significant analgesia. In addition, direct comparison among peripheral nerve blocks consistently favors the more proximal, centralized techniques. Conversely, in the presence of neuraxial morphine, no peripheral anesthetic technique has reliably and reproducibly demonstrated an added analgesic benefit regardless of the peripheral nerve block technique or location of local anesthetic injection in the post-cesarean population.

Conclusion

Neuraxial morphine continues to be the gold standard for post-cesarean section analgesia, the benefit of additional single injection regional anesthetic is currently not evidence supported. In cases where neuraxial opioids have not or cannot be given, there is overwhelming evidence that regional anesthetic techniques improve post-cesarean section analgesia and decrease post-operative opioid consumption. Even though there is no consensus on the optimal peripheral nerve block, emerging evidence suggests more centralized abdominal fascia plane block trends towards better analgesia.

Ultrasound-Guided Bilateral Sequential Thoracic Paravertebral Block for Simultaneous Bilateral Uniportal Video-Assisted Thoracoscopic Surgery: Study Protocol for a Randomized Controlled Trial

Purpose

Simultaneous bilateral pulmonary resection via uniportal video-assisted thoracoscopic surgery (UVATS) was safe and feasible for the treatment of bilateral multiple pulmonary nodules. But, it should be noted that considerable postoperative pain at the bilateral surgical site was a crucial issue. The safety and efficacy of bilateral thoracic paravertebral block (TPVB) have been reported for postoperative analgesia. But, whether bilateral sequential TPVB can be safely and effectively used in simultaneous bilateral UVATS remains unknown. Therefore, this study aimed to determine the analgesic efficacy and safety of bilateral sequential TPVB after simultaneous bilateral UVATS.

Study Design and Methods

In this study, 80 participants scheduled for UVATS will be randomly allocated to the bilateral sequential TPVB group (G2) and the control group (G1). The patient of G2 will be performed bilateral TPVB at 2 time-points: before the start of the first side of pulmonary resection and before the start of the contralateral pulmonary resection. G1 will only receive standard analgesia protocol. The primary outcome is the numeric rating scale score during coughing at 24 h postoperatively. The secondary outcomes include the Prince Henry Pain Score scores, sufentanil consumption, postoperative nausea and vomiting, levels of inflammatory factors, and the Quality of Recovery-40 scores at different time points, as well as chronic pain at postoperative day (POD) 90.

Discussion

This is the first prospective trial to determine the safety and effectiveness of ultrasound-guided bilateral sequential TPVB for postoperative analgesia following simultaneous bilateral UVATS. This study also intended to evaluate the effect of this intervention on postoperative quality of recovery and inflammation levels. The final results will provide clinical evidence related to bilateral sequential TPVB, and promote the application of that acting as a more appropriate analgesic method for simultaneous bilateral UVATS.

Thoracic Paravertebral Block Decreased Body Temperature in Thoracoscopic Lobectomy Patients: A Randomized Controlled Trial

Purpose

Thoracic paravertebral block (TPVB) may be highly beneficial for thoracoscopic lobectomy patients, but it may increase the risk of hypothermia. Apart from its anesthetic-reducing effects, this randomized controlled trial aimed to investigate the hypothermic effect of TPVB, and thus optimize its clinical use.

Patients and methods

Adult patients were randomly allocated to two groups: TPVB + general anesthesia (GA) group or GA group. In the TPVB+GA group, the block was performed after GA induction by an experienced but unrelated anesthesiologist. Both the lower esophageal and axillary temperature were recorded at the beginning of surgery (T₀) and every 15 min thereafter (T₁-T₈), and the end of surgery (T_p). The primary outcome was the lower esophageal temperature at T_p. The secondary outcomes included lower esophageal temperature from T₀-T₈ and axillary temperature from T₀-T_p. The total propofol, analgesics, and norepinephrine consumption and the incidence of adverse events were also recorded.

Results

Forty-eight patients were randomly allocated to the TPVB+GA (n=24) and GA (n=24) groups. The core temperature at the end of the surgery was lower in the TPVB+GA group than the GA group (35.90±0.30°C vs 36.35±0.33°C, P<0.001), with a significant difference from 45 min after the surgery began until the end of the surgery (P<0.05). In contrast, the peripheral temperature showed a significant difference at 60 min after the surgery began till the end (P<0.05). TPVB+GA exhibited excellent analgesic and sedative-sparing effects compared to GA alone (P<0.001), though it increased norepinephrine consumption due to hypotension (P<0.001).

Conclusion

Although thorough warming strategies were used, TPVB combined with GA remarkably reduced the body temperature, which is an easily neglected side effect. Further studies on the most effective precautions are needed to optimize the clinical use of TPVB.

Is It Useful and Necessary to Add a T2 Paravertebral Block to the Regional Anesthesia During Proximal Humeral Fracture Surgery in Elderly Patients? A Prospective and Randomized Controlled Trial

Objective

This study was designed to investigate whether it is useful and necessary to add a T2 level thoracic paravertebral block (TPVB) based on brachial-cervical plexus block to avoid incomplete anesthesia in elderly patients undergoing deltopectoral approach proximal humeral fracture (PHF) surgery.

Materials and Methods

This study involved 80 patients scheduled for PHF surgery who were randomized to receive either IC block (combined interscalene brachial plexus with superficial cervical plexus block) or ICTP block (T2 TPVB supplemented with IC block). The primary outcome was the success rate of regional anesthesia. The patient who experienced incomplete block was administered with intravenous remifentanil for rescue, or conversion to general anesthesia (GA) if remifentanil was still ineffective. Secondary outcomes included requirements of rescue anesthesia, sensory block of the surgical region, the incidence of adverse reactions, and block procedure-related complications.

Results

The success rate of regional anesthesia in the ICTP group was higher compared with the IC group (77.5 vs. 52.5%, p = 0.019). Intravenous remifentanil was required in 32.5% of patients in the IC group and 17.5% in the ICTP group, respectively. Conversion to GA was performed in 15% of patients in the IC group and 5% in the ICTP group. Sensory block at the medial proximal upper arm was achieved in 85% of patients in the ICTP group, whereas 10% in the IC group (p &lt; 0.001). There was no difference between the groups with respect to the incidence of intraoperative adverse reactions. No block-related complications occurred in either group.

Conclusion

Adding a T2 TPVB is helpful to decrease, but not absolutely avoid the occurrence of incomplete regional anesthesia during PHF surgery in elderly patients. However, considering the potential risks, it is not an ideal option while a minor dose of remifentanil can provide a satisfactory rescue effect.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT03919422.

Comparison of the analgesic effect of ultrasound-guided paravertebral block and ultrasound-guided retrolaminar block in Uniportal video-assisted Thoracoscopic surgery: a prospective, randomized study

Background

The optimal modality for postoperative analgesia after uniportal video-assisted thoracoscopic surgery (UVATS) for the treatment of lung cancer has not yet been determined. Both ultrasound-guided paravertebral block (PVB) and retrolaminar block (RLB) have been reported to be successful in providing analgesia after UVATS. However, which block technique provides superior analgesia after UVATS is still unclear. This randomized study was designed to compare the postoperative analgesic effects and adverse events associated with ultrasound-guided PVB and RLB after UVATS.

Methods

Sixty patients with lung cancer were randomized to undergo ultrasound-guided PVB (group P) or ultrasound-guided RLB (group R). In group P, 30 mL of 0.5% ropivacaine was injected at the T3 and T5 levels via ultrasound-guided PVB (15 mL at each level on the operative side). In group R, 30 mL of 0.5% ropivacaine was injected at the T3 and T5 levels via ultrasound-guided RLB (15 mL at each level on the operative side). The primary outcome was the numerical rating scale (NRS) score within 48 h after surgery. The secondary outcomes were total postoperative sufentanil consumption, time to first analgesic request and adverse events.

Results

At 3, 6, 12, 24, 36 and 48 h postoperatively, the NRS score at rest in group P was lower than that in group R (p < 0.05). At 3, 6, 12, 24 and 36 h postoperatively, the NRS score while coughing in group P was lower than that in group R (p < 0.05). The total postoperative sufentanil consumption in group P was significantly lower than that in group R (p < 0.001). Additionally, the time to first analgesic request was longer in group R than in group P (p < 0.0001). The incidence of nausea in group R was higher than that in group P (p < 0.05).

Conclusions

In patients with lung cancer undergoing UVATS, ultrasound-guided PVB with 0.5% ropivacaine provides better analgesia and results in less nausea than ultrasound-guided RLB. Compared with ultrasound-guided RLB, ultrasound-guided PVB seems to be a better technique for analgesia in UVATS.

Trial registration

The name of this study is the Effect And Mechanism Of Ultrasound-guided Multimodal Regional Nerve Block On Acute And Chronic Pain After Thoracic Surgery. This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100044060). The date of registration was March 9, 2021.

Distribution of injectate administered through a catheter inserted by three different approaches to ultrasound-guided thoracic paravertebral block: a prospective observational study

Background

Despite the popularity of continuous thoracic paravertebral block (TPVB), there is a paucity of information on catheter tip position and distribution of injectate through the catheter. We observed, in real time, the spread of dye, the catheter tip position and sensory block levels produced with three different (intercostal (IC), transverse process sagittal (TS) and paralaminar (PL)) approaches to ultrasound-guided TPVB in patients undergoing video-assisted thoracoscopic surgery.

Methods

After the induction of general anesthesia, ultrasound-guided TPVB was conducted with a patient in the lateral decubitus position. During surgery, 10 mL of dye was injected through a catheter to observe the catheter tip and the dye distribution under thoracoscopy. Dermatomal sensory block levels were measured postoperatively.

Results

Ten patients for each of three different approaches completed the study. There were a variety of dye spreading patterns. The median (range) number of segmental levels stained with dye was 1.5 (1–4), 3 (1–4) and 3 (1–5) with the IC, TS and PL approaches, respectively. We observed that a catheter tip was present at the same segmental paravertebral space as intended in 50%–90% of patients using these approaches. The median (range) number of dermatomes with sensory blockade at 6 hours after block was 2.5 (1–4), 3 (2–8) and 3 (1–8) with the IC, TS and PL approaches, respectively.

Conclusions

Although a bolus injection through a catheter for ultrasound-guided TPVB produced multiple levels of spread and sensory blockade in more than half the patients, considerable differences existed in the spread regardless of approach.