Phrenic Nerve Block Research Articles

Determination of the Optimal Volume of 0.5% Ropivacaine in Single-Injection Retroclavicular Brachial Plexus Block for Arthroscopic Shoulder Surgery: A Phase I/II Trial.

A brachial plexus block plays an important role in providing perioperative analgesia for shoulder surgery; however, the inherent risk of phrenic nerve block and resulting hemidiaphragmatic paralysis may limit its use in patients with compromised pulmonary function. This study aimed to evaluate safety, efficacy, the maximum tolerated volume, and the optimal biological volume of 0.5% ropivacaine used in a single-injection retroclavicular brachial plexus block for arthroscopic shoulder surgery. In this seamless single-arm exploratory phase I/II trial, a novel Bayesian optimal interval design was used to guide volume escalation for determination of the maximum tolerated volume, followed by sequential volume expansion using Bayesian optimal phase 2 design to establish the optimal biological volume. Fifty-four patients who underwent arthroscopic shoulder surgery received a single-injection retroclavicular brachial plexus block with 0.5% ropivacaine ranging from 15 mL to 40 mL. The primary outcomes were complete or partial hemidiaphragmatic paralysis in phase I, measured using ultrasound 30 min after block completion, and the block success in phase II, defined as achieving a total sensorimotor score ≥12 points and the total sensory score ≥3, measured through manual sensorimotor testing. The maximum tolerated volume for the single-injection retroclavicular brachial plexus block was determined to be 35 mL of 0.5% ropivacaine, with a hemidiaphragmatic paralysis rate of 0.09 (95% credible interval, 0 to 0.29). The optimal biological volume was found to be 25 mL, with a block success rate of 1.0 (95% credible interval, 0.95 to 1.0) and a negligible hemidiaphragmatic paralysis rate of 0.01 (95% credible interval, 0 to 0.06). A single-injection retroclavicular brachial plexus block using 25 mL of 0.5% ropivacaine produced consistent block success with a minimal HDP rate, suggesting the need for further studies to confirm this result in arthroscopic shoulder surgery.

Ultrasound Guided Phrenic Nerve Block for Percutaneous Computer Tomography Guided Lung Biopsy

Abstract The aim of this paper is to present the technique of the ultrasound (US) guided phrenic nerve block (PNB). This is an important adjuvant technique for percutaneous computer-tomography (CT) lung biopsy of nodules situated in the lower lobes, in proximity of the diaphragm, with a diameter of less than 2 cm. These types of nodules have a high location variability during respiration, which makes them hard to be approached for a successful biopsy. US visualization of the nerve is possible after identifying specific landmarks as the sternocleidomastoid and scalene muscle, interval jugular vein and brachial plexus. The phrenic nerve is seen as an oval hypoechogenic structure with no Doppler signal, superficial to the anterior scalene muscle. Ropivacaine can be used as a local anesthetic to induce the PNB. Results: Success of the phrenic nerve block can be assessed by CT scanogram, which shows the ipsilateral hemidiaphragm elevated, and by subsequent lung scans that show little to no location variability of the target lesion. Conclusion. US-guided PNB is a safe and efficient procedure that can help during percutaneous CT-guided lung biopsy of small basal nodules.

Phrenic nerve block: the key to managing acute biliary pain?

Phrenic nerve block: the key to managing acute biliary pain?

Combined Infraclavicular-Suprascapular Nerve Blocks Compared With Interscalene Block for Arthroscopic Rotator Cuff Repair: A Prospective, Randomized, Double-blind, and Comparative Clinical Trial

BACKGROUND: The gold standard postoperative analgesia protocol for arthroscopic rotator cuff repair procedures is the interscalene block (ISB), which prevents the significant consequences of phrenic nerve block associated with hemidiaphragmatic paralysis (HDP). The infraclavicular brachial plexus block (BPB) combined with the suprascapular nerve block (SSNB) had the same analgesic efficacy as the infraclavicular BPB alone, with no effect on respiration. OBJECTIVES: Therefore, the study aimed to assess the HDP and analgesic efficacy of both approaches in controlling pain following arthroscopic rotator cuff repair surgeries. STUDY DESIGN: A prospective, randomized, double-blind, and comparative clinical trial. SETTING: The study comprised 66 patients. They were separated into 2 equal parallel groups 33 patients each: the ISB group and the costoclavicular and suprascapular block (CSB) group. METHODS: The ISB group obtained the ISB followed by the general anesthesia. The CSB group received infraclavicular blockade using the costoclavicular approach and SSNB followed by general anesthesia. RESULTS: Considering morphine utilization during the first day following the operation, the groups demonstrated an insignificant difference. The CSB group showed a decreased rate of diaphragmatic paralysis. LIMITATIONS: There was no control group. And, the blocks might take a long time to be performed up to 30 minutes. Also, there were no validated criteria to define HDP based on M-mode ultrasound measurements. CONCLUSIONS: The employment of the costoclavicular block in combination with the suprascapular block may provide a comparable analgesic potency to the sole use of the standard ISB with no HDP. KEY WORDS: Interscalene block, costoclavicular block, suprascapular nerve block, hemidiaphragmatic paralysis

ULTRASONOGRAPHIC EVALUATION OF DIAPHRAGMATIC PARALYSIS FOLLOWING SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK BY DIFFERENT VOLUMES OF 0.5% BUPIVACAINE

Background: Ultrasound guidedsupraclavicular brachial plexus block is widely used technique in anaesthesiafor upper limb surgeries. However it can block phrenic nerve to cause diaphragmatic palsy. It is difficult to avoid even with ultrasound-guided supraclavicular brachial plexus block. Objectives: Our primary objective was to assess the incidence of hemidiaphragmatic paralysis following ultrasound-guided supraclavicular brachial plexus block using different volumes of 0.5% bupivacaine. Methods: Sixty patients with American Society of Anesthesiologists (ASA) physical status I and II were randomized to receive 20ml (group A) and 30 ml (group B) of 0.5% bupivacaine in a double blinded fashion. Ultrasound guided supraclavicular brachial plexus block was performed. Diaphragmatic excursion was studied using a curvilinear 3.5 MHz transducer before and 20 min after giving the block. Results: The incidence of partial diaphragmatic paralysis in the group A and group B were 33% and 40% respectively. None of the patient in group A had complete paralysis whereas only 2(6.6%) patients had complete paralysis in group B. Conclusion: Risk of phrenic nerve block was involved even in ultrasound guided supraclavicular brachial plexus block. Hemidiaphragmatic paralysis is volume dependent, and the overall incidence is higher at greater volumes. Hence, caution is required in patients with pre-existing cardiorespiratory dysfunction.

Intractable hiccups after VNS implantation: a case report

BackgroundHiccups (medically termed, “singultus”), when intractable, can cause significant medical consequences such as aspiration, malnutrition, and depression, leading to poor quality of life. Several case reports have shown that vagus nerve stimulator (VNS) implantation can help treat central idiopathic intractable hiccups. However, we present a contrary case of a patient who developed intractable singultus following VNS placement for medically refractory epilepsy.Case presentationWe report a 71-year-old male patient with drug-resistant epilepsy who underwent VNS implantation and developed intractable hiccups shortly thereafter. The hiccups were severe and persistent, such that the patient developed a Mallory-Weiss tear, which required intensive care, invasive intubation and mechanical ventilation, and a prolonged rehabilitation course. Despite multiple therapies including phrenic nerve block and Nissen fundoplication, the patient’s hiccups persisted and only stopped once the VNS was permanently deactivated.ConclusionsLittle is known about the incidence of hiccups after VNS implantation. We present one case of hiccups as a direct consequence of VNS implantation. The clinical impact of this report is significant given the relative unfamiliarity of hiccups as an adverse effect of VNS implantation. Neurologists and epileptologists, who present VNS implantation as a surgical option for seizure control to their patients, should be aware of the possibility of singultus development and its significant physical and emotional ramifications.

Influence of extent of surgical resection on post-hepatectomy shoulder pain: an observational study

Shoulder pain frequently follows hepatectomy. However, the influence of surgical procedures on shoulder pain is unclear. In this observational study, patients who underwent hepatectomy were enrolled in Shanghai Cancer Center. Shoulder pain and surgical pain were assessed using the numeric rating scale 2 days after surgery. The incidence of shoulder pain was the outcome of the cohort study. Nested case–control analyses were further applied. Three hundred and twelve patients were finally enrolled in this study. Nested case–control analysis showed that there were no significant differences in the number of surgical segments between the two groups (P = 0.09). In addition, minor hepatectomy did not reduce the incidence of shoulder pain compared with major hepatectomy (P = 0.37). The drainage volume within 2 days after surgery was significantly more in those patients with shoulder pain (P = 0.017). In open surgery, surgical sites involving the right anterior lobe (OR (95% CI) 2.021 (1.075, 3.802), P = 0.029) and right posterior lobe (OR (95% CI) 2.322 (1.193, 4.522), P = 0.013) were both independent risk factors for shoulder pain. Left shoulder pain also occurred in patients who did not receive left lateral hepatectomy. The preventive phrenic nerve block was not suitable for post-hepatectomy shoulder pain. Stronger preventative intervention should be used in those high-risk patients.

Modern possibilities of upper extremity regional anesthesia

Today, regional anesthesia is widely used during surgical interventions in orthopedic surgery. Blockades of individual nerves and plexuses are used. Objective. To introduce readers: surgeons, orthopedists-traumatologists with the possibilities of regional anesthesia like an adequate method of analgesia during upper limb interventions. Methods. Relevant literature from PubMed, Scopus, Google Scholar databases and own experience of regional anesthesia were analyzed. The results. The work describes the effect of regional anesthesia on the nervous, respiratory, cardiovascular and coagulation systems. Information about blocks of peripheral nerves of the upper extremities: interscalene, supraclavicular, subclavian, axillary. Their advantages and disadvantages were analyzed. Interscalene block is not recommended for patients with severe lung disease due to the risk of respiratory failure. Complications of this analgesia include: phrenic nerve block (up to 100 %), sympathetic chain block and Horner's syndrome. Also, possible accidental injection into the vertebral artery. Indications for the supraclavicular block are operations on the hand, forearm, elbow and shoulder. Complications — phrenic nerve block (17‒50 %), recurrent laryngeal blockade (22 %), pneumothorax (0.6‒6.1 %). When planning anesthesia, the accompanying pathology of the patient and his general condition should be taken into account. Particular care is required when the patient is taking anticoagulants. Risk of bleeding and thrombosis should be carefully assessed. Special attention should be paid to the toxicity of local anesthetics and ways to eliminate it. Conclusions. Regional anesthesia can be used in the pre-, intra- and postoperative periods. Sometimes it’s the only method that permit surgical intervention. It is necessary to understand all the advantages and limitations to ensure high quality of patient care.

Phrenic Nerve Impingement and Effect of Superficial Neck Flexors Stretching in Improving Diaphragmatic Function among Patient with Chronic Neck Pain

Background: The phrenic nerve is formed on the lateral border of scalenus anterior. It runs vertically downward on the anterior surface of the scalenus anterior. The muscle is oblique and nerve cross it obliquely from its lateral to medial border. In this part the nerve is related anteriorly sternocleidomastoid. The decline in the diaphragm function can occur due to phrenic nerve block but to the best of our search, there is dearth of literature pertaining to involvement of phrenic nerve in patient with chronic neck pain secondary to superficial neck flexors tightness. So, evaluation of these muscle for tightness may be considered which may affect the maximum inspiratory pressure (MIP). Objective: To find the change in diaphragmatic function secondary to phrenic nerve impingement measured through maximum inspiratory pressure (MIP) following stretching of superficial neck flexors in patient with chronic neck pain Methods: An experimental (pre-post design) study involving 40 subjects with mean (±SD) age 22.4 ± 2.8 years was performed. Using purposive sampling 40 subjects (77.5% female and 22.5% male) were used to check phrenic nerve impingement by looking at the effect of superficial neck flexors stretching (sternocleidomastoid and anterior scalene) in improving diaphragmatic function in patient with chronic neck pain. The included subject’s diaphragmatic function was measured through maximum inspiratory pressure using a device capsule sensing pressure gauge followed by stretching of superficial neck flexors on both sides. After two minutes of stretching diaphragmatic function was again measured. Results: There was increase in diaphragmatic function following stretching of superficial neck flexors by 13.2cm H2O which was found to be highly significant statistically with p value < 0.01 Conclusion: The result of present study concluded that superficial neck flexors stretching was effective in treating the impingement of phrenic nerve as measured through maximum inspiratory pressure in patients with chronic neck pain.

Efficacy of Phrenic Nerve Block and Suprascapular Nerve Block in Amelioration of Ipsilateral Shoulder Pain after Thoracic Surgery: A Systematic Review and Network Meta-Analysis

Background and Objectives: Ipsilateral shoulder pain (ISP) is a common complication after thoracic surgery. Severe ISP can cause ineffective breathing and impair shoulder mobilization. Both phrenic nerve block (PNB) and suprascapular nerve block (SNB) are anesthetic interventions; however, it remains unclear which intervention is most effective. The purpose of this study was to compare the efficacy and safety of PNB and SNB for the prevention and reduction of the severity of ISP following thoracotomy or video-assisted thoracoscopic surgery. Materials and methods: Studies published in PubMed, Embase, Scopus, Web of Science, Ovid Medline, Google Scholar and the Cochrane Library without language restriction were reviewed from the publication's inception through 30 September 2022. Randomized controlled trials evaluating the comparative efficacy of PNB and SNB on ISP management were selected. A network meta-analysis was applied to estimate pooled risk ratios (RRs) and weighted mean difference (WMD) with 95% confidence intervals (CIs). Results: Of 381 records screened, eight studies were eligible. PNB was shown to significantly lower the risk of ISP during the 24 h period after surgery compared to placebo (RR 0.44, 95% CI 0.34 to 0.58) and SNB (RR 0.43, 95% CI 0.29 to 0.64). PNB significantly reduced the severity of ISP during the 24 h period after thoracic surgery (WMD -1.75, 95% CI -3.47 to -0.04), but these effects of PNB were not statistically significantly different from SNB. When compared to placebo, SNB did not significantly reduce the incidence or severity of ISP during the 24 h period after surgery. Conclusion: This study suggests that PNB ranks first for prevention and reduction of ISP severity during the first 24 h after thoracic surgery. SNB was considered the worst intervention for ISP management. No evidence indicated that PNB was associated with a significant impairment of postoperative ventilatory status.

Neuropathies Following an Ultrasound-Guided Axillary Brachial Plexus Block.

Ultrasound-guided brachial plexus block (UGBPB) has interscalene, supraclavicular, infraclavicular, and axillary approaches. The axillary block is considered to be the safest and with fewer adverse events compared to the interscalene (eg, phrenic nerve block, spinal cord or vertebral artery puncture) and supraclavicular (eg, pneumothorax). However, with regard to postoperative neurological symptoms (PONS), it is controversial whether its incidence after an axillary block was higher than that after non-axillary approaches". In this study, we investigated whether the incidence of a neuropathy after an axillary block was higher than that after non-axillary approaches. This was a single-center, retrospective cohort study. All UGBPBs were performed under general anesthesia between January 2014 and March 2020. The outcomes included the overall incidence of PONS and neuropathies for axillary and non-axillary approaches. The etiology, symptoms, and outcomes of patients were investigated. Of the 992 patients, 143 (14%) and 849 (86%) were subjected to axillary and non-axillary approaches, respectively. Among 19 cases (19.2:1000; 95% confidence interval [CI], 18.2-20.1) of PONS, four (4.0:1000; 95% CI, 3.8-4.2) were neuropathies attributed to the UGBPB, three (21.0:1000; 95% CI, 18.1-23.8) to the axillary and one (2.8:1000; 95% CI, 2.6-3.1) to non-axillary approaches. The incidence of neuropathies after an axillary block was significantly higher than that after non-axillary approaches (P = 0.005). The incidence of neuropathies after US-guided axillary block under general anesthesia was significantly higher than that after non-axillary approaches.

The Minimum Effective Analgesic Volume of 0.5% Bupivacaine for Ultrasound-Guided Anterior Suprascapular Nerve Block.

Objective The interscalene brachial plexus block (ISBB) constitutes the gold standard for analgesia after shoulder procedures. Ipsilateral phrenic nerve block remains the most common adverse effect after ISBB. Alternative nerve blocks are performed in shoulder surgery in order to prevent hemi-diaphragmatic paralysis (HDP). The purpose of the present study was to investigate the minimum effective local anesthetic volume of 0.5% bupivacaine for postoperative analgesia with an anterior suprascapular nerve block (ASSB). The secondary aim was to investigate diaphragm functions with the local anesthetic doses used while conducting effective volume research. Method This prospective observational study was conducted at the American Hospital of Istanbul, Turkey, from March to July 2022. The initial injected volume of 0.5% bupivacaine was 10 ml. Our clinical experience indicates that this yields a complete sensory block of the anterior suprascapular nerve. In accordance with the up-and-down method, the volume of 0.5% bupivacaine used for a particular patient was determined by the outcome of the preceding block, which represented block success. In case of effective ASSB being achieved, the volume of 0.5% bupivacaine to be administered to the next patient was lowered by 1 ml. In case of block failure, however, the volume of 0.5% bupivacaine to be applied in the subsequent case was increased by 1 ml. Ipsilateral hemi-diaphragmatic movement measurements were taken before (baseline) and 30 minutes after the block. General anesthesia was induced 60 minutes after the completion of the block performance by means of a standardized protocol. Results Sixty-seven patients were included in the study. The ED50 and ED95 calculated for anterior suprascapular nerve block using probit transformation and logistic regression analysis were 2.646 (95% CI, 0.877-2.890) and 3.043 ml (95% CI, 2.771-4.065), respectively. When complete paralysis was defined as 75% or above, partial paralysis as 25-50%, and no paralysis as 25% or less, volumes of 6 ml or lower appeared to cause no paralysis for the anterior suprascapular nerve block. Conclusion We, therefore, recommend using a volume of 6 ml or less in order to achieve diaphragm-sparing features for anterior suprascapular nerve blocks.

Hiccups in patients with cancer: a multi-site, single-institution study of etiology, severity, complications, interventions, and outcomes

BackgroundTo our knowledge, previous studies have not investigated hiccups in patients with cancer with detailed patient-level data with the goal of capturing a broad spectrum of hiccup symptomatology.MethodsThis multi-site, single institution study examined consecutive medical records to better understand hiccups in patients with cancer.ResultsA total of 320 patients are the focus of this report. The median age of patients when hiccups were first reported in the medical record was 63 years (range: 21, 97 years) with 284 (89%) men and 36 (11%) women. The most common diagnose was gastrointestinal cancer. Hiccups most frequently occurred daily, as seen in 194 patients (62%), and the most common duration was less than 1 week, as seen in 146 patients (47%). However, nine patients had had daily hiccups for greater than 6 weeks, and 5 had symptoms for years. Cited etiology was non-chemotherapy medications in 36 (11%) and cancer chemotherapy in 19 (6%). Complications occurred in approximately a third and included insomnia in 51 patients (16%); hospitalization or emergency department visit in 34 (11%); and musculoskeletal pain in 23 (7%). Baclofen was the single most prescribed agent for hiccup palliation, but 100 patients received more than one medication. Medical procedures, which included acupuncture, paracentesis, or phrenic nerve block, were performed in 5 patients. In 234 patients (73%), the medical record documented hiccup cessation.ConclusionsHiccups appear to be highly problematic in a small subset of patients with cancer with no well-defined palliative approaches.

Injection of local anesthetic lateral to vertebral transverse process instead of conventional method for interscalene block in difficult cases with poor view

Ultrasound guided (USG) peripheral nerve block techniques have become increasingly popular in regional anesthesia in the recent few years. USG interscalene brachial plexus block provides effective analgesia after a variety of of surgeries and have been shown to reduce opioid consumption, decrease postoperative nausea and vomiting (PONV), improve patient satisfaction, and decrease recovery room length of stay.1 Regardless of all of these advantages, there have been some complications associated with this technique. The most important complication is the phrenic nerve block. Therefore, impaired respiratory function is considered a relative contraindication to interscalene plexus block. It has been shown to cause ipsilateral hemidiaphragmatic paresis almost always due to phrenic nerve block.2, 3
 Key words: Nerve Block/methods; Anesthetics, Local; Peripheral Nerves / diagnostic imaging; Ultrasonography, Interventional / methods 
 Citation: Heidarifar R, Amini SM, Lotfi S, Ahmadi A. Injection of local anesthetic lateral to vertebral transverse process instead of conventional method for interscalene block in difficult cases with poor view. Anaesth. pain intensive care 2021;26(1):126-127.
 DOI: 10.35975/apic.v26i1.1783

Phrenic Nerve Block and Respiratory Effort in Pigs and Critically Ill Patients with Acute Lung Injury.

Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular blockade, the authors hypothesized that perineural administration of lidocaine around the phrenic nerve would reduce tidal volume (VT) and peak transpulmonary pressure in spontaneously breathing patients with acute respiratory distress syndrome. An established animal model of acute respiratory distress syndrome with six female pigs was used in a proof-of-concept study. The authors then evaluated this technique in nine mechanically ventilated patients under pressure support exhibiting driving pressure greater than 15 cm H2O or VT greater than 10 ml/kg of predicted body weight. Esophageal and transpulmonary pressures, electrical activity of the diaphragm, and electrical impedance tomography were measured in pigs and patients. Ultrasound imaging and a nerve stimulator were used to identify the phrenic nerve, and perineural lidocaine was administered sequentially around the left and right phrenic nerves. Results are presented as median [interquartile range, 25th to 75th percentiles]. In pigs, VT decreased from 7.4 ml/kg [7.2 to 8.4] to 5.9 ml/kg [5.5 to 6.6] (P < 0.001), as did peak transpulmonary pressure (25.8 cm H2O [20.2 to 27.2] to 17.7 cm H2O [13.8 to 18.8]; P < 0.001) and driving pressure (28.7 cm H2O [20.4 to 30.8] to 19.4 cm H2O [15.2 to 22.9]; P < 0.001). Ventilation in the most dependent part decreased from 29.3% [26.4 to 29.5] to 20.1% [15.3 to 20.8] (P < 0.001). In patients, VT decreased (8.2 ml/ kg [7.9 to 11.1] to 6.0 ml/ kg [5.7 to 6.7]; P < 0.001), as did driving pressure (24.7 cm H2O [20.4 to 34.5] to 18.4 cm H2O [16.8 to 20.7]; P < 0.001). Esophageal pressure, peak transpulmonary pressure, and electrical activity of the diaphragm also decreased. Dependent ventilation only slightly decreased from 11.5% [8.5 to 12.6] to 7.9% [5.3 to 8.6] (P = 0.005). Respiratory rate did not vary. Variables recovered 1 to 12.7 h [6.7 to 13.7] after phrenic nerve block. Phrenic nerve block is feasible, lasts around 12 h, and reduces VT and driving pressure without changing respiratory rate in patients under assisted ventilation.

Comments on: “Phrenic Nerve Block, the Rescue Management for Pneumothorax after Retrolaminar Block”

The Sri Lankan Journal of Anaesthesiology is the official journal of the College of Anaesthesiologists of Sri Lanka. It publishes clinical investigations, research articles, audits, case reports, review articles and CME articles relating to anaesthesiology, critical care and pain. It is published bi annually in January and June. Sri Lankan Journal of Anaesthesiology is included on DOAJ and Scopus.

S2184 Intractable Hiccups Treated With Phrenic Nerve Block

S2184 Intractable Hiccups Treated With Phrenic Nerve Block

Respiratory Failure Following Interscalene Block for the Treatment of Shoulder Dislocation in a Patient with COVID-19

Introduction: Guidelines recommend the use of regional anesthesia for patients with COVID-19, when possible. Interscalene block (ISB) is the standard care for analgesia of shoulder surgery. Hemidiaphragmatic paresis due to phrenic nerve block is expected in ISB but is usually well-compensated. We present a patient with pulmonary involvement of COVID-19 candidate for the surgery of shoulder dislocation under ISB who experienced respiratory failure after the block. Case Presentation: A 36-year-old female patient with COVID-19 developed a shoulder dislocation following a seizure. Relocating the joint was successfully attempted under intravenous sedation and ultrasound-guided ISB. The patient developed respiratory distress due to hemidiaphragmatic paresis after the block. She was managed using a continuous positive airway pressure (CPAP) mask for 48 hours until the pulmonary condition improved. Conclusions: Anesthetists should prepare themselves to replace ISB with diaphragm-sparing blocks or apply techniques to reduce the chance of hemidiaphragmatic paresis after ISB in patients with COVID-19.

Phrenic nerve block during nonintubated video-assisted thoracoscopic surgery: a single-centre, double-blind, randomized controlled trial

There has been interest in the use of nonintubated techniques for video-assisted thoracoscopic surgery (VATS) in both awake and sedated patients. The authors’ centre developed a nonintubated technique with spontaneous ventilation for use in a patient under general anaesthesia using a phrenic nerve block. This treatment was compared with a case-matched control group. The authors believe that this technique is beneficial for optimizing anaesthesia for patients undergoing VATS. The patients were randomly allocated (1:1) to the phrenic nerve block (PNB) group and the control group. Both groups of patients received a laryngeal mask airway (LMA) that was inserted after anaesthetic induction, which permitted spontaneous ventilation and local anaesthesia in the forms of a paravertebral nerve block, a PNB and a vagal nerve block. However, the patients in the PNB group underwent procedures with 2% lidocaine, whereas saline was used in the control group. The primary outcome included the propofol doses. Secondary outcomes included the number of propofol boluses, systolic blood pressure (SBP), pH values of arterial blood gas and lactate (LAC), length of LMA pulled out, length of hospital stay (length of time from the operation to the time of discharge) and complications after 1 month. Intraoperatively, there were increases in lactate (F = 12.31, P = 0.001) in the PNB group. There was less propofol (49.20 ± 8.73 vs. 57.20 ± 4.12, P = 0.000), fewer propofol boluses (P = 0.002), a lower pH of arterial blood gas (F = 7.98, P = 0.006) and shorter hospital stays (4.10 ± 1.39 vs. 5.40 ± 1.22, P = 0.000) in the PNB group. There were no statistically significant differences in the length of the LMA pulled out, SBP or complications after 1 month between the groups. PNB optimizes the anaesthesia of nonintubated VATS.

Phrenic nerve block on severe post-hepatectomy shoulder pain: A randomized, double-blind, placebo-controlled, pilot study.

Severe shoulder pain occurs frequently after surgery close to the diaphragm, potentially caused by referred pain via the ipsilateral phrenic nerve. We aimed to assess the analgesic effect of an ultrasound-guided phrenic nerve block on moderate to severe right-sided shoulder pain after open partial hepatectomy. This was a randomized, double-blind, placebo-controlled, pilot study, comparing ultrasound-guided phrenic nerve block (ropivacaine 0.75mg/mL) versus placebo (isotonic sodium chloride 0.9mg/mL) on severe post-hepatectomy shoulder pain (NRS ≥6). Pre- and postoperative spirometry and arterial blood gas analyses were used to assess respiratory function. Subjects with chronic lung disease were excluded. Unfortunately, due to lack of funding, the trial was ended prematurely and therefore presented as a pilot study. One hundred and one subjects were screened for eligibility; 14 subjects were randomized, and two subjects were later excluded; thus, 12 subjects were analyzed with six in each group. A statistically significant difference in reduction in median pain intensity between groups was observed 15minutes after phrenic nerve block ("ropivacaine first" ΔNRS: -6.0 [-6.0 to -3.0] vs. "saline first" ΔNRS: 0 [-6.0 to 1.0], P=.026). Spirometry results and arterial blood gas analyses were not clinically impacted by the block. Postoperative phrenic nerve block significantly reduced severe post-hepatectomy shoulder pain. Larger studies are warranted to confirm the lack of clinically relevant block-related impairment of respiratory function.