|Year : 2018 | Volume
| Issue : 4 | Page : 314-322
Comparison of ultrasound-guided serratus plane block and thoracic paravertebral block for postoperative analgesia after thoracotomy: a randomized controlled trial
Amani A Aly, Shereen E Abd Ellatif
Anesthesia and Intensive Care Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
|Date of Submission||29-Jul-2017|
|Date of Acceptance||07-Mar-2018|
|Date of Web Publication||13-Dec-2018|
Amani A Aly
54, 2nd Region, 2nd District, 5th Settlement, New Cairo, 11835
Source of Support: None, Conflict of Interest: None
Background Post-thoracotomy pain can be severe and difficult to control. Paravertebral block (PVB) has been proven to be effective in controlling post-thoracotomy pain; however, it has its own set of complications. Ultrasound-guided serratus plane block (SPB) is a newly described field block that may provide thoracic wall analgesia.
Objective This prospective randomized controlled study was carried out to compare the analgesic effects of PVB and SPB on post-thoracotomy pain.
Patients and methods The study was done on 60 adult patients aged 18–65 years undergoing thoracotomy for pulmonary resection. The patients were randomly allocated to receive either thoracic PVB or SPB guided by ultrasound before induction of general anesthesia. The primary outcome was the visual analogue scale, which was recorded on arrival to the ICU and then at 1, 2, 4, 8, 12, 18, and 24 h postoperatively both at rest and during coughing. The secondary outcomes were time to perform the block, onset of sensory block, number of blocked dermatomes, block success rate, total postoperative morphine consumption, and any complications related to the regional block.
Results The time to perform the block was significantly shorter in SPB than in PVB (3.76±1.1 vs. 6.14±1.6 min, P<0.05). The onset of complete sensory block was significantly faster with SPB than with PVB (14.3±2.8 vs. 17.6±3.5 min, P<0.05). The visual analogue scale was also comparable between the two blocks at all measuring times except at 12 and 18 h postoperatively, where it was significantly higher with SPB than with PVB during coughing (P<0.05). The total postoperative morphine consumption was significantly lower in the PVB group than in the SPB group (13.2±2.6 vs. 18.4±1.8 mg, P<0.05). There was no significant difference between the two blocks regarding complications.
Conclusion SPB had a shorter time to perform and a faster onset of action than thoracic PVB and provided adequate analgesia in the early postoperative period; however, postoperative morphine consumption was higher in patients who received SPB.
Keywords: analgesia, serratus plane block, thoracic paravertebral block, thoracotomy pain, ultrasonography
|How to cite this article:|
Aly AA, Abd Ellatif SE. Comparison of ultrasound-guided serratus plane block and thoracic paravertebral block for postoperative analgesia after thoracotomy: a randomized controlled trial. Res Opin Anesth Intensive Care 2018;5:314-22
|How to cite this URL:|
Aly AA, Abd Ellatif SE. Comparison of ultrasound-guided serratus plane block and thoracic paravertebral block for postoperative analgesia after thoracotomy: a randomized controlled trial. Res Opin Anesth Intensive Care [serial online] 2018 [cited 2020 Nov 25];5:314-22. Available from: http://www.roaic.eg.net/text.asp?2018/5/4/314/247407
| Introduction|| |
Pain after thoracic surgery is considered one of the most intense acute postoperative pain. The origin of such pain is multifactorial, resulting from a significant amount of trauma and distraction forces involving several muscle and facial layers, ribs, neurovascular bundles, and the pleura ,. Inadequate analgesia after thoracotomy can lead to serious postoperative complications such as pulmonary complications, prolonged immobility, and development of chronic pain syndrome, which can be very difficult to treat. Effective management of acute pain following thoracotomy is mandatory to prevent these complications ,. Many analgesic options were suggested for thoracotomy, and each technique has its own merits and demerits. Those techniques include systemic analgesics, local anesthetic infiltration of the wound, multilevel intercostal nerve block, thoracic epidural block, and thoracic paravertebral block (PVB) . Epidural analgesia is considered as the gold standard for post-thoracotomy pain management; however, thoracic PVB has been proven to provide similar analgesia to epidural block with lower rate of complications .
Serratus plane block (SPB), first described by Blanco et al. , is a new field block that provides analgesia to the chest wall from the second to the ninth thoracic dermatomes. SPB is performed under ultrasound guidance by injecting the local anesthetic in a plane either above or below the serratus anterior muscle, targeting the lateral and anterior cutaneous branches of the intercostal nerves as they pierce the external intercostals and the serratus anterior muscle between the anterior to mid-axillary line .
To the best of our knowledge, SPB has been tested in isolated case studies ,,,, and two randomized controlled trial, one comparing it to thoracic epidural analgesia in post-thoracotomy pain  and the other compared it to PVB for analgesia after mastectomy . Therefore, we conducted this randomized controlled trial to compare the analgesic effect of SPB with that of thoracic PVB after thoracic surgery. We hypothesized that SPB would provide equipotent post-thoracotomy analgesia to that obtained by PVB with less complications.
The primary outcome of the study was the visual analogue scale (VAS) at rest and with coughing at 0, 1, 2, 4, 8, 12, 18 and 24 postoperative hours. The secondary outcome parameters were time to perform the block, onset time of the block, first time to call for analgesia, postoperative morphine consumption, block success rate, and any complications related to the block or the drug used.
| Patients and methods|| |
After obtaining the approval of Zagazig University Hospital Ethical Committee, the study was carried out at the cardiothoracic operating theater over a period of 12 months from February 2016 to January 2017. The study included 60 patients aged between 18 and 65 years with ASA class 1 and 2, undergoing elective thoracotomy for lung resection. A written informed consent was obtained from each patient participating in the study after detailed explanation of the analgesic technique. The patient was then trained to report the level of pain on a VAS from 0 to 10 (where 0 indicates no pain and 10 indicates the most severe pain). Exclusion criteria were mental or psychiatric disorders, chronic pain therapy, BMI more than 35 kg/m2, infection at injection site, forced expiratory volume in 1 s (FEV₁) less than 50% of the reference range, severe spine or chest wall deformity, severe coagulopathy, history of allergy to local anesthetics, and patient refusal to have regional block. The patients were randomly allocated using a computer-generated randomization program to receive either SPB or thoracic PVB and the random number was sealed in an opaque envelop that was just opened before the procedure.
The blocks were performed in the preoperative holding area. For each patient, an intravenous access was established, and lactated Ringer infusion was started slowly. Standard monitors were then attached in the form of five-lead ECG, noninvasive blood pressure, and pulse oximeter. The patients were then sedated using midazolam 0.02 mg/kg, and oxygen was given via a nasal cannula at 4 l/min. Both PVB and SPB were performed before induction of general anesthesia under ultrasound guidance using SonoSite M-Turbo Ultrasound System (FUJIFIM SonoSite, Inc., Bothell, WA, USA). All the blocks were performed by one senior staff anesthesiologist experienced in regional blocks.
The technique of thoracic paravertebral block
The block was performed in the sitting position. Identification and marking of T6 spinous process was done by counting down from C7 (vertebral prominence). After skin sterilization, the ultrasound probe (6–13-MHz high-frequency linear transducer) was put just lateral to the spinous process of T6 in a transverse plane and moved laterally till identification of the transverse process by its typical dark cone shadow. The transducer is moved slightly upward between the fifth and sixth transverse processes. The pleura was then identified with its characteristic bright hyperecoic structure and sliding motion over the lung. The internal intercostal membrane (IIM), which is the lateral continuation of the superior costotransverse ligament, is then identified extending from the transverse process. When the ultrasound visualization of the transverse process, the pleura, and the IIM was adequate in one image, the skin at the proposed injection site was infiltrated with 1 ml 2% lidocaine. A 20-G spinal needle was introduced in plane relative to the ultrasound probe from lateral to medial. When the tip is visualized between the pleura and IIM, 20 ml of 0.5% bupivacaine was injected in divided doses after negative aspiration while observing the anterior displacement of the pleura ,.
The technique of serratus plane block
The block was performed in the supine position. The skin of anterior to lateral chest wall on the operative side was sterilized. The second rib was identified, and then the ribs were counted downwards and laterally till the fifth rib. The ultrasound probe (6–13-MHz high-frequency linear transducer) was placed in a sagittal plane over the fifth rib in the midaxillary line. The latissimus dorsi muscle (superficial and posterior) and the serratus anterior muscle (deep and inferior) were identified in the fifth intercostal space. The skin was infiltrated with 1 ml of 2% lidocaine, and then a 20-G spinal needle was introduced in the plane relative to the ultrasound probe in superoanterior to posteroinferior direction. The needle was inserted superficial to the serratus anterior muscle ([Figure 3]) and 30 ml of 0.25% bupivacaine was injected in divided doses under complete ultrasound observation ,.
|Figure 3 Ultrasound image showing injection superficial to the serratus anterior muscle. LD, latissimus dorsi muscle; SA, serratus anterior muscle.|
Click here to view
For techniques, block onset and extent of anesthesia were assessed by loss of sensation to pinprick over the chest wall using 22-G needle every 5 min after local anesthetic injection. The blocked area was tested from the fifth thoracic dermatome at the anterior axillary line in a cranial and then in a caudal direction compared with the unblocked contralateral dermatome. If the sensory block was not achieved till 30 min after local anesthetic injection, the block was recorded as failure and the patient was excluded from the study. Block assessment was done by an investigator not involved in the block performance or patient’s anesthesia.
After the regional blockade was performed, the patients were transferred to the operating room where monitoring of vital signs was continued. General anesthesia was induced by propofol 2 mg/kg, fentanyl 2 µg/kg, and cisatracurium 0.15 mg/kg. Patients were intubated using left double-lumen endotrachial tube of appropriate size (37–41 Fr) to allow deflation of the lung on the operative size. Anesthesia was maintained with isoflurane 1–2% in oxygen and intermittent doses of 0.05 mg/kg cisatracurium. Incremental doses of fentanyl 1 µg/kg were given if the heart rate or blood pressure increased more than 20% of the baseline. Mechanical ventilation was adjusted to maintain normocapnia (EtCO2 of 35–40 mmHg). Lung resection was performed through a posterolateral thoracotomy in the fifth intercostal space. At the end of lung resection, two chest tubes were placed in the eighth intercostal space ([Figure 2]).
|Figure 2 The posterolateral thoracotomy incision in the fifth intercostal space and the chest tubes in the eighth intercostal space.|
Click here to view
After conclusion of surgery and closure of the thoracotomy incision, anesthesia was discontinued and muscle relaxation was reversed using atropine 0.01 mg/kg and neostigmine 0.05 mg/kg. The patient was extubated awake, and according to the local protocol, he/she was then transferred to the surgical ICU to be observed for 24 h. Postoperative analgesia was provided with 75-mg diclofenac natrium (voltaren) intramuscular every 12 h, and 1-g paracetamol intravenously every 8 h, with the first dose administered just before the end of the procedure. Rescue analgesia was provided by intravenous morphine 0.1 mg/kg if the VAS was more than 3. Data collection in the ICU was done by an observer unaware of the patient’s group.
For each patient, the following data were collected:
- Age, sex, weight, and height.
- Duration and type of surgery.
- Time to perform the block, which was defined as the time needed for adequate ultrasonic visualization, needle introduction, and drug injection (time from placement of ultrasound probe on the patient′s skin to the end of local anesthetic injection) .
- Block onset time is defined as the time between the end of local anesthetic injection till decreased sensation to pinprick in the appropriate dermatomes .
- Complete sensory block was defined as the time between the end of local anesthetic injection till complete sensory loss in the appropriate dermatomes .
- Number of blocked dermatomes.
- VAS at rest and on coughing measured on first arrival at the ICU (0) and then 1, 2, 4, 8, 12, 18 and 24 h after surgery.
- Time to first analgesic request defined as the time from recovery till the VAS was more than 3.
- FEV1 before the block and then at 6, 12, and 24 h postoperatively.
- Block success rate.
- Total morphine consumption over the postoperative 24 h.
- Any complications related to the regional block, bupivacaine, or morphine were recorded such as inadvertent vascular puncture, hematoma formation, intravascular injection, systemic toxicity, pleural puncture, difficult breathing, pneumothorax, and hypotension. Nausea, vomiting, pruritus, and urine retention were also recorded.
- Patient satisfaction with the analgesic technique was assessed the day following surgery using a four-point scale (0=very unsatisfied, 1=unsatisfied, 2=satisfied, 3=very satisfied) .
Based on the two previous studies comparing thoracic PVB with thoracic epidural for post-thoracotomy pain ,, it was estimated that a sample size of 26 patients in each group was needed to detect a significant difference in VAS between the two study groups with 90% power of calculation and α error=5%.
Statistical analysis was done using SPSS, version 20 (SPSS Inc., Chicago, Illinois, USA). Data were expressed as mean±SD or median (interquartile range) for quantitative variable. Categorical variables were expressed as number and percentage and analyzed using χ2 or Fisher’s exact test where appropriate. P value less than 0.05 was considered significant.
| Results|| |
Eighty-six patients were assessed for eligibility to participate in the study. Fourteen patients did not meet the inclusion criteria and 12 patients refused to participate in the study. Therefore, 60 patients were included and randomized equally into the thoracic PVB group or the SPB group. The block failed in two patients in the PVB group who were excluded from the study; on the contrary, it was successful in all patients in the SPB group ([Figure 1]).
Patients’ demographic data, type of surgery, duration of surgery, duration of anesthesia, and intraoperative fentanyl consumption were comparable between the two studied groups, with P value more than 0.05 ([Table 1]).
The characteristics of PVB and SPB are shown in [Table 2]. The time to perform the block was significantly longer in PVB the than in the SPB (6.14±1.6 vs. 3.76±1.1 min, P<0.05). The onset of sensory block and time to complete sensory were also significantly slower with PVB than with SPB (P<0.05). There were no significant statistical differences between the two groups regarding the number of blocked dermatomes or the block success rate (P>0.05).
The results of the present study showed no significant statistical difference in postoperative pain score (VAS) at rest or during coughing at all measuring points except at 12 and 18 h postoperative time where VAS was significantly higher in the SPB group during coughing (P<0.05) ([Table 3]). The time to first analgesic request and VAS at the first rescue analgesia were comparable between the two groups. Postoperative 24 h morphine consumption was significantly lower in the PVB group than in the SPB group (13.2±2.6 vs. 18.4±1.8, P<0.05). The FEV1 showed also no significant difference between the two groups at all measuring points except at 12 and 18 h postoperatively where it was significantly higher with the PVB group (P<0.05). There was no statistical significant difference regarding the incidence of complications recorded between the two groups, the patient’s satisfaction with the analgesic technique, or the hospital length of stay ([Table 4]).
Hypotension (defined as 20% decrease in blood pressure below the basal value) occurred in two patients in PVB group during the intraoperative period and was managed by fluid boluses and ephedrine 5 mg increments. Cases of resistant nausea and vomiting were treated by intravenous ondansetron 4 mg.
| Discussion|| |
The present study compared ultrasound-guided single injection thoracic PVB and SPB for post-thoracotomy pain, and its results showed that SPB had a shorter time to perform and faster onset of sensory block than thoracic PVB block. The time to first analgesic request was comparable between the two groups. The VAS at rest and during coughing was also comparable between both groups except at 12 and 18 h postoperatively where the VAS during coughing was significantly lower in the PVB group. Postoperative 24 h morphine consumption was significantly lower in patients receiving the PVB.
Post-thoracotomy pain is considered the most important single factor that can lead to ineffective ventilation and inadequate clearance of secretion. Adequate postoperative analgesia will lead to early mobilization and rapid regain of pulmonary functions facilitating the patient’s recovery .
Although thoracic PVB has been proved effective in providing post-thoracotomy analgesia, it is not devoid of complications such as neurological damage, pneumothorax, and neuroaxial spread ,,. The SPB, which was described for the first time by Blanco and colleagues ,,, is supposed to provide paresthesia to the hemithorax without autonomic block and with lower risk of local anesthetic toxicity than other regional analgesic techniques used for thoracotomy pain as it involves injecting lower dose of local anesthetic into less vascular plane guided by ultrasonography.
In the present study, the time to perform SPB was significantly shorter than that of PVB (3.76±0.99 vs. 6.14±1.6 min). Carassiti et al.  studied single-injection thoracic PVB guided by both ultrasound and nerve stimulator and reported a median time of 4 min to visualize the space and the needle (the time for drug injection was not counted). The shorter time of performing SPB may be owing to the easy identification of the serratus muscle and the superficial position of the serratus plane especially in the mid-axillary line .
The results of the present study showed that the onset of sensory block was significantly faster with SPB than with PVB (5.26±1.04 vs. 7.82±2.2 min). Moreover, time to complete sensory block was significantly shorter with SPB than PVB (14.3±2.8 vs. 17.6±3.5 min).
Kaya et al.  compared single-injection and multiple-injection thoracic PVB using also bupivacaine 0.5% and reported that the onset of sensory block in the single-injection group was 8.3±1.8 min. Previous studies on thoracic PVB using bupivacaine 0.5% reported that complete sensory block was achieved within 15–25 min ,.
Apart from two case reports, previous studies on SPB did not clearly identify the onset of sensory block. The first case study on SPB for post-thoracotomy pain reported pain relief after 10 min from injecting 6 ml of 1% lidocaine followed by continuous infusion of 0.1% bupivacaine at 7 ml/h . Takimoto et al.  in another case report performed with SPB for persistent pain after mastectomy and reported loss of sensation over the axilla 15 min after injecting 10 ml 1% lidocaine above the serratus muscle.
There was no significant difference in the number of dermatomes blocked by SPB or PVB in the present study (P>0.05). The median number of dermatomes blocked by PVB was 5 (range: 4–6), which is consistent with the results of two previous studies on single-injection thoracic PVB ,. However, some other studies reported different results. The study done by Marhofer et al.  on the spread of local anesthetic after single-injection PVB reported an MRI distribution of local anesthetic over a median of 4 (range: 2–6) dermatomes but a sensory loss over a median of 10 (range: 3–19) dermatomes. Two other studies on single-injection PVB for analgesia after mastectomy reported a median of 8 and 7 blocked dermatomes ,. Marhofer et al.  reported that although ultrasonography allows observation of the spread of local anesthetic, the exact somatic distribution of PVB is still unpredictable. This may be attributed to the spread of local anesthetic to the prevertebral, epidural, or to the contralateral paravertebral spaces in a considerable number of cases ,.
The median number of dermatomes blocked by SPB in the present study was 6 (range: 5–8), which is similar to the results of the first study on SPB done by Blanco et al. . They reported that injecting the local anesthetic superficial to the serratus muscle resulted in sensory loss from T2 to T9 dermatomes in the lateral and posterior chest wall and sensory loss from T2 to a level ranging from T6 to T9 dermatomes in the anterior chest wall. They also reported that the spread of local anesthetic in SPB appeared to be wide and reliable with tendency of more posterior distribution after injection superficial to the serratus muscle as evidenced by MRI. Those results were also consistent with the results of a case report by Okmen et al.  who performed a SPB for a patient to control post-thoracotomy pain that resulted in sensory block from T2 to T10 dermatomes by injecting 20 ml of bupivacaine 0.25%.
The block was successful in 94% of patients in the PVB group and 100% of patients in the SPB group, without statistical significant difference. The reported failure rate of PVB in the previous studies is between 6 and 13% ,,,.
The present study showed no significant difference in VAS between the two studied groups either at rest or during cough at all measuring point in the 24-h postoperative period, except at 12 and 18-h postoperative times, where the VAS was significantly lower in the PVB group than the SPB group only during cough. FEV1 in the present study was comparable between the two groups at all measuring times except at 12 and 18 h postoperatively, as it was significantly higher in the PVB group than in the SPB group, which may be owing to increase in pain in the SPB group at those times. The postoperative morphine consumption was significantly lower in the PVB group than in the SPB group (13.2±2.6 vs. 18.4±1.8 mg with P<0.05).
The higher postoperative morphine consumption in patients who received the SPB may be explained by the possibility of SBP to miss the posterior cutaneous branches of the intercostal nerves. Moreover, SBP does not involve autonomic blockade which plays a role in pain control after thoracotomy. The sympathetic neurons mediate painful stimuli coming from the lungs, the visceral pleura, and neurohumoral mediators ,.
The analgesic efficacy of SPB in post-thoracotomy pain was tested against thoracic epidural analgesia in one randomized controlled study done by Khalil et al. . They used 30-ml 0.25% levobupivacaine superficial to the serratus anterior followed by continuous infusion of 5 ml/h 0.125% levobupivacaine. They reported that the VAS recorded every 2 h for the postoperative 24 h was comparable between the two groups at all times except at 14, 16, and 22 h time periods, where the VAS was higher in the SPB group. However, they reported no significant difference in postoperative morphine consumption between the two groups.
The first time to call for analgesia in our study was 6.5±1.81 h in the PVB group and 6.2±1.66 h in the SPB group, with no statistical significant difference. In accordance with duration of analgesia of thoracic PVB in our study are the results of the study done by Fibla et al.  on thoracic PVB comparing 15 ml bupivacaine 0.5% and 15 ml ropivacaine 0.2%; they reported a peak increase in VAS 6 h postoperatively in both groups. Kulkarni  also studied single-shot thoracic PVB for mastectomy surgery and reported that the duration of analgesia was 360±60 min.
Okmen et al.  in their case study reported that the duration of analgesia obtained by the SPB lasted for 7 h, which is close to our results. Blanco et al.  reported that the duration of SPB was 752±21 min after injecting 0.4 ml/kg levobupivacaine 0.125%. However, this was the duration of paresthesia induced by the block done on healthy volunteers.
Ohgoshi et al.  performed SPB for 20 patient as a postoperative analgesia after mastectomy by injecting 30-ml ropivacaine 0.375–0.5% superficial to the serratus anterior muscle and reported a sensory block of 5–6 dermatomes that lasted for 12 h which may be owing to the high concentration of local anesthetic they used.
Gupta et al.  compared the postoperative analgesic effect of PVB with that of SPB in fifty female patients who underwent radical mastectomy using 20-ml bupivacaine 0.5% for both techniques and reported that PVB had a longer duration of analgesia than SPB (346±57 vs. 245.6±58 min); moreover, the patients who received PVB had lower total morphine consumption.
In the current study, there were no complications related to the block placement or signs suggesting local anesthetic toxicity in either group. There was no significant difference in the complications recorded between the two groups.
The possible limitations of our study included the nonblinded nature of the observer who collected the block characteristics before surgery, which was probably unavoidable. Moreover, we did not use catheter to extend the analgesic effect of the blocks. Other limitation is that the number of patients included in the study may not be enough to detect the actual incidence of complications.
To summarize, although postoperative morphine consumption was higher with SPB, it can be used as a part of multimodal analgesia to control post-thoracotomy pain, as it provided similar analgesic quality to that obtained by PVB in the first 12 h postoperatively. SPB took a shorter time to perform than PVB with a faster onset of sensory block.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Fibla JJ, Molins L, Mier JM, Sierra A, Vidal G. Comparative analysis of analgesic quality in the postoperative of thoracotomy: paravertebral block with bupivacaine 0.5% vs ropivacaine 0.2%. Eur J Cardiothorac Surg 2008; 33:430–434.
Kavanagh BP, Katz J, Sandler AN. Pain control after thoracic surgery. A review of current techniques. Anesthesiology 1994; 81:737–759.
Garner P. Post thoracotomy pain management problems. Anesthesiol Clin 2008; 26:355–357.
Raveglia F, Rizzi A, Di Mauro P, Moro DG, Leporati A, Cioffi U, Baisi A. Epidural versus paravertebral analgesia in thoracotomy patients: a randomized, prospective study. Interact Cardiovasc Thorac Surg 2014; 17:469–474.
Joshi GP, Bonnet F, Shah R, Wilkinson RC, Camu F, Fischer B et al.
A systematic review of randomized trials evaluating regional techniques for post thoracotomy analgesia. Anesth Analg 2008; 107:1026–1040.
Scarci M, Joshi A, Attia R. In patients undergoing thoracic surgery is paravertebral block as effective as epidural analgesia for pain management? Interact Cardiovasc Thorac Surg 2010; 10:92–96.
Blanco R, Parras T, MaDonnel JG, Parts Galino A. Serratus plane block: a novel ultrasound-guided thoracic wall nerve block. Anaesthesia 2013; 68:1107–1113.
Madabushi R, Tewari S, Gautam SK, Agarwal A, Agarwal A. Serratus anterior plane block: a new analgesic technique for post-thoracotomy pain. Pain Physician 2015; 18:412–424.
Ohgoshi Y, Yokozuka M, Terajima K. Serratus-intercostal plane block for brest surgery: case reports. Masui 2015; 64:610–614.
Okmen K, Okmen BM, Serkan U. Serratus anterior plane (SAP) block used for thoracotomy analgesia: a case report. Korean J Pain 2016; 29:189–192.
Takimoto K, Nishijima K, Ono M. Serratus plane block for persistent pain after partial mastectomy and axillary node dissection. Pain Physician 2016; 19:481–486.
Khalil AE, Abdallah NM, Bashandy GM, Kaddah TA. Ultrasound-guided serratus anterior plane block versus thoracic epidural analgesia for thoracotomy pain. J Thorac Cardiovasc Surg 2017; 31:152–158.
Gupta K, Srikan K, Girdhar KK, Chan V. Analgesic efficacy of ultrasound guided paravertebral block versus serratus plane block for modified radical mastectomy: a randomized controlled trial. Indian J Anaesth 2017; 61:381–386.
Renes SH, Bruhn J, Gielen MJ, Scheffer GJ, van Geffen GJ. In-plane ultrasound-guided thoracic paravertebral block: a preliminary report of 36 cases with radiologic confirmation of catheter position. Reg Anesth Pain Med 2010; 35:212–216.
Krediet AC, Moayeri N, Geffen GJ, Bruhn J, Renes S, Biegeleisen PE, Groen GJ. Different approaches to ultrasound-guided thoracic paravertebral block. Anesthesiology 2015; 123:459–474.
Carassiti M, Cappiello D, Galli B. One shot six centres: a new strategy in ultrasound guided paravertebral block. J Anesth Clin Res 2015; 6:580–583.
Kaya FN, Turker G, Mogol EB, Bayraktar S. Thoracic paravertebral block for video-assisted thoracoscopic surgery: single injection versus multiple injections. J Cardiothorac Vasc Anesth 2012; 26:90–94.
Raveglia F, Alessandro R, Leporati A, Di Mauro P, Cioffi U, Baisi A. Analgesia in patients undergoing thoracotomy: epidural versus paravertebral technique. A randomized, double-blind, prospective study. J Thorac Cardiovasc Surg 2014; 147:469–473.
Messina M, Boroli F, Landoni G, Bignami E, Dedola E, N′ZepaBatonga J et al.
A comparison of epidural vs paravertebral blockade in thoracic surgery. Minerva Anestesiol 2009; 75:616–621.
Weijs TJ, Ruurda JP, Nieuwenhuijzen GA, van Hillegersberg R, Luyer MD. Strategies to reduce pulmonary complications after esophagectomy. World J Gastroenterol 2016; 19:6509–6514.
Kotze A, Seally A, Howell S. Efficacy and safety of different techniques of paravertebral block for analgesia after thoracotomy: a systematic review and metaregression. Br J Anaesth 2009; 103:626–636.
Ammar AS, Mahmoud KM. Dose the addition of magnesium to bupivacaine improve postoperative analgesia of ultrasound-guided thoracic paravertebral block in patients undergoing thoracic surgery? J Anesth 2014; 28:58–63.
Kolettas A, Lazaridis G, Baka S, Mpoukovinas I, Karavasilis V, Kioumis L et al.
Postoperative pain management. J Thorac Dis 2015; 7:62–72.
Ben-Ari A, Moreno M, Chelly JE, Bigeleisen PE. Ultrasound-guided paravertebral block using an intercostal approach. Anesth Analg 2009; 109:1691–1694.
Marhofer D, Marhofer P, Kettner SC, Fleischmann E, Prayer D, Schernthaner M et al.
Magnetic resonance imaging analysis of the spread of local anesthetic solution after ultrasound-guided lateral thoracic paravertebral blockade: a volunteer study. Anesthesiology 2013; 118:1106–1112.
Kulkarni KRR. Single needle thoracic paravertebral block with ropivacaine and dexmeditomidine for radical mastectomy: experience in 25 cases. Int J Anesth Pain Med 2016; 2:1–4.
Koh D, Khai L. The use of single-injection thoracic paravertebral block in breast cancer surgeries in our Asian population: The Singapore General Hospital Experience. Proc Singapore Healthcare 2013; 22:107–113.
Cheema S, Richardson J, McGurgan P. Factors affecting the spread of bupivacaine in the adult thoracic paravertebral space. Anaesthesia 2003; 58:684–687.
Naja Z, Lӧnnqvist PA. Somatic paravertebral nerve blockade: incidence of failed block and complications. Anaesthesia 2001; 56:1181–1201.
Richardson J, Lӧnnqvist PA, Naja Z. Bilateral thoracic paravertebral block: potential and practice. Br J Anaesth 2011; 106:164–171.
Shelley B, Macfie A. Where now for thoracic paravertebral blockade? Anaesthesia 2012; 67:1317–1320.
Baidya DK, Khanna P, Maitra S. Analgesic efficacy and safety of thoracic paravertebral and epidural analgesia for thoracic surgery: a systematic review and meta-analysis. Interact Cardiovasc Thorac Surg 2014; 18:626–635.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]