Pectoralis Research Articles

COMPARISON OF POSTOPERATIVE PAIN WITH AND WITHOUT PECTORAL BLOCK IN PATIENTS UNDERGOING MODIFIED RADICAL MASTECTOMY.

Modified Radical Mastectomy is associated with significant acute postoperative pain. If this pain is not managed properly most patients will develop chronic post-mastectomy pain, which reduces quality of life. Pectoralis (PECS) block is effective in reducing pain and the consumption of analgesia in the post-operative period. The objective was to compare mean post-operative pain with or without pectoral (PECS) block in females undergoing modified radical mastectomy under general anaesthesia. A randomized controlled trial was done in the Department of General Surgery at Pakistan Institute of Medical Sciences, Islamabad. Patients who fulfilled the inclusion criteria and underwent modified radical mastectomy were included in the study. A total of 60 patients, were randomly divided into two equal groups, the PEC group and without PEC group. After surgery, patients were shifted to the postoperative care unit and were assessed for postoperative pain after 6 and 12 hours. Data was collected and descriptive analysis was done using SPSS version 22. The mean age and BMI of the patients was 51.52±10.29 years and 24.1±3.94 kg/m2, respectively. Among patients from the PEC group, the mean post-op pain after the 6 hours was 2.13±0.571 while in the without PEC group, the mean post-op pain was 2.67±1.093 (p-value=0.021). Similarly, in patients from the PEC group, the mean post-op pain after the 12 hours was 1.20±0.407 while in the without PEC group, the mean post-op pain was 1.63±0.615 (p-value=0.002). Post-operative pain with PEC block showed significantly better control as compared to the patients without PEC block group in females undergoing modified radical mastectomy under general anaesthesia.

Comment on 'Brachial plexus blockade arising from a combined pectoralis (PECS) 1 and 2 block'.

Comment on 'Brachial plexus blockade arising from a combined pectoralis (PECS) 1 and 2 block'.

Reduction of wing area affects estimated stress in the primary flight muscles of chickens.

In flying birds, the pectoralis (PECT) and supracoracoideus (SUPRA) generate most of the power required for flight, while the wing feathers create the aerodynamic forces. However, in domestic laying hens, little is known about the architectural properties of these muscles and the forces the wings produce. As housing space increases for commercial laying hens, understanding these properties is important for assuring safe locomotion. We tested the effects of wing area loss on mass, physiological cross-sectional area (PCSA), and estimated muscle stress (EMS) of the PECT and SUPRA in white-feathered laying hens. Treatments included Unclipped (N = 18), Half-Clipped with primaries removed (N = 18) and Fully-Clipped with the primaries and secondaries removed (N = 18). The mass and PCSA of the PECT and SUPRA did not vary significantly with treatment. Thus, laying hen muscle anatomy may be relatively resistant to changes in external wing morphology. We observed significant differences in EMS among treatments, as Unclipped birds exhibited the greatest EMS. This suggests that intact wings provide the greatest stimulus of external force for the primary flight muscles.

“Comparison of Postoperative Analgesic Effect of Ultrasound Guided Pectoral Vs Erector Spinae Block in Patients Undergoing Modified Radical Mastectomy”: A Randomised Controlled Study

Objectives: Post-operative pain after modified radical mastectomy ranges from moderate to severe. Pectoralis (PECS) block has been found to be more effective than Erector Spinae Pain block in reducing pain and the consumption of analgesia in the post-operative period. This study aimed to compare the effect of ESP and PECS block on the quality of recovery after modified radical mastectomy with different dosage of drugs and different time of giving blocks. Methods: The randomised controlled study was conducted at Indira Gandhi Medical College, Shimla, India, from March 2019 to March 2020. Patients were given blocks according to the computer-generated randomisation 30 minutes before shifting to the operation theatre. Group A received ESP block and group B received modified PEC block. Patient VAS score, NRS score and demand of rescue analgesia with patient satisfaction was recorded for 48hrs post-operatively. Results: A total of 60 patients were included (30 in each group). In the post-operative period, the mean VAS scores were statistically significant at 4, 8 and 24 hours postoperatively between the two groups with significantly lower VAS scores in Group A than in Group B. The total requirement of rescue analgesic was significantly lower in the ESP group than in the PECS group with p value 0.0154(<0.05). The time to first rescue analgesia was significantly higher in the ESP group (11.21±3.14) hours than in the PECS group (6.15±3.52) hours. Conclusion: Both ESP and PECS block were effective in improving the VAS score and in reducing the consumption of rescue analgesia after modified radical mastectomy.

Evaluation of the effectiveness of artificial intelligence for ultrasound guided peripheral nerve and plane blocks in recognizing anatomical structures

BackgroundWe aimed to assess the accuracy of artificial intelligence (AI) based real-time anatomy identification for ultrasound-guided peripheral nerve and plane block in eight regions in this prospective observational study. MethodsAfter obtaining ethics committee approval and written informed consent from 40 healthy volunteers (20 men and 20 women, between 18 and 72 years old), an ultrasound device installed with AI software (Nerveblox, SmartAlfa, Turkey) were used to scan regions of the cervical plexus, brachial plexus, pectoralis (PECS), rectus sheet, femoralis, canalis adductorius, popliteal, and ESP by three anesthesiology trainees. During scanning by a trainee, once software indicates 100 % scan success of associated anatomic landmarks, both raw and labeled ultrasound images were saved, assessed, and validated using a 6-point scale between 0 and 5 by two expert validators. Evaluation scores of the validators for each block were compared according to demographics (gender, age, and BMI) and block type exists. ResultsThe scores were not different except ESP, femoralis, and cervical plexus regions between the experts. The mean scores of the experts for the PECS, popliteal and rectus sheath were significant between males and females (p < 0.05). In terms of BMI, significant differences in the scores were observed only in the canalis adductorius, brachial plexus, and ESP regions (p < 0.05). ConclusionsUltrasound guided AI-based anatomy identification was performed in commonly used eight block regions by the trainees where AI technology can successfully interpret the anatomical structures in real-time sonography which would be valuable in assisting anesthesiologists.

Research Note: Expression of IGF-1 and IGF-1 receptor proteins in skeletal muscle fiber types in chickens with hepatic fibrosis

We investigated the expression of insulin-like growth factor 1 (IGF-1) and IGF-1 type 1 receptor (IGF-1R) in skeletal muscle fiber types in chickens with hepatic fibrosis induced by bile duct ligation (BDL). Eleven hens, approximately 104 weeks old, were randomly assigned to BDL (n = 4) and sham surgery (SHAM; n = 7) groups. In BDL hens, histopathology revealed marked bile duct proliferation and liver fibrosis. The cross-sectional area (CSA) of myofibers from both the pectoralis (PCT) muscles significantly decreased in the BDL group compared with the SHAM group (P < 0.01). In contrast, the CSA of myofibers from the femorotibialis lateralis (FTL) muscle did not decrease in the BDL group. Type I fibers were large, round, and hypertrophic. Elongated type IIA and IIB fibers were also present. For IGF-1 immunostaining, the immunoreaction intensity was higher in the PCT in the BDL group than the SHAM group. Within the BDL group, type I fibers from FTL had a stronger immunoreaction intensity than the type II fibers. For IGF-1R immunostaining, the intensity of the immunoreactions was similar within the PCT in the BDL group compared with the SHAM group. For FTL, type I fibers had stronger reactions to IGF-1R than type II fibers in the BDL group. These results suggest that type I fibers express both IGF-1 and IGF-1R and become hypertrophic in chickens with hepatic fibrosis.

Erector Spinae Plane Block Versus PECS Block Type II for Breast Surgery: A Randomized Controlled Trial.

BackgroundRegional anesthetic techniques are the primary analgesic techniques in breast cancer surgery. Novel techniques include the pectoralis (PECS) block and the erector spinae plane (ESP) block.ObjectivesThis study compared the analgesic efficacy of ultrasound-guided ESP and PECS-II blocks in patients undergoing unilateral modified radical mastectomy (MRM).MethodsThe current prospective randomized controlled trial investigated 60 females scheduled for unilateral MRM under general anesthesia. The participants were randomized into two groups, namely a single-shot ESP block (n = 30) and a PECS-II block (n = 30). The ESP block was conducted at the level T4 using an in-plane approach. A volume of 20 ml of bupivacaine 0.25% was administered in both blocks. The outcome measures were total morphine consumption, analgesia duration, postoperative pain intensity, and nausea and vomiting.ResultsMore ESP participants required rescue morphine analgesia than those in the PECS group (P = 0.028). The ESP group showed significantly higher total morphine consumption (P = 0.005) and a shorter time to request analgesia (P = 0.003). Pain intensity was higher in the ESP group 1, 2, and 6 hours after the surgery.ConclusionsThe PECS-II block is more effective in postoperative pain control after breast cancer surgery than the ESP block. It also prolongs the duration of analgesia and reduces the need for morphine 24 hours after the surgery.

The Use of Pectoralis Blocks in Breast Surgery: A Practice Advisory and Narrative Review from the Society for Ambulatory Anesthesia (SAMBA).

Although pectoralis (PECS) blocks are commonly used for breast surgery, recommendations regarding the efficacy of these blocks have thus far not been developed by any professional anesthesia society. Given the potential impact of PECS blocks on analgesia after outpatient breast surgery, The Society for Ambulatory Anesthesia (SAMBA) convened a task force to develop a practice advisory on the use of this analgesic technique. In this practice advisory, we compare the efficacy of PECS blocks with systemic analgesia, local infiltration anesthesia, and paravertebral blockade. Our objectives were to advise on two clinical questions. (1) Does PECS-1 and/or -2 blockade provide more effective analgesia for breast-conserving surgery than either systemic analgesics or surgeon-provided local infiltration anesthesia? (2) Does PECS-1 and/or -2 blockade provide equivalent analgesia for mastectomy compared with a paravertebral block (PVB)? Among patients undergoing breast-conserving surgery, PECS blocks moderately reduce postoperative opioid use, prolong time to analgesic rescue, and decrease postoperative pain scores when compared with systemic analgesics. SAMBA recommends the use of a PECS-1 or -2 blockade in the absence of systemic analgesia (Strength of Recommendation A). No evidence currently exists that strongly favors the use of PECS blocks over surgeon-performed local infiltration in this surgical population. SAMBA cannot recommend PECS blocks over surgical infiltration (Strength of Recommendation C). For patients undergoing a mastectomy, a PECS block may provide an opioid-sparing effect similar to that achieved with PVB; SAMBA recommends the use of a PECS block if a patient is unable to receive a PVB (Strength of Recommendation A).

Abstract No. : ABS1591: Effect of erector spinae block and PECS block on quality of recovery and analgesia after modified radical mastectomy

Background and Aims:Breast cancer is the most common malignancy in women ; modified radical mastectomy is one of the standard treatments.This study compared the effect of erector spinae block and pectoralis(PECS) block on quality of recovery and analgesia after modified radical mastectomyMethods:The present randomised controlled double-blind study was conducted on 90 patients undergoing unilateral modified radical mastectomy for breast cancer. The patients were randomised into group-I (PECS block 20ml 0.25% bupivacaine, n=30), group-II (erector spinae block 20ml 0.25% bupivacaine, n=30) and group-III (control group, n=30). Along with clinical anddemographical data, the requirement of the first dose of rescue analgesia, total rescue analgesic consumption, visual analogue scale(VAS) scores and Quality of Recovery(QoR) -40 scoreswere compared. Anaesthesia and surgical interventions were done as per standard protocol.Results:Mean first rescue analgesic requirement was significantly delayed in group-I followed by group-II compared to controls . Mean total rescue analgesic consumption was much lower in group-I and group-II as compared to group-III and the difference was statistically significant (p<0.0001)(figure 1). Mean VAS scores were also much lower in group-I followed by group-II as compared to group-III at different follow-ups, and difference was statistically significant. The global QoR-40 at 24 hours showed significantly better outcomes in group-1(table 1)Figure 1Global QoR-40 between the groupsTable 1Postoperative tramadol requirementAnalgesic requirementGroup B (n=30)Group C (n=30) P Time for 1st need of tramadol (h)8.10±1.480.7±0.38<0.001Total tramadol consumption (mg)68±48.55210±52.65<0.0001Total numberof patients requiring tramadol (%) 24 h10 (33.33%)30 (100%)<0.0001Table 1Quality of Recovery(QoR) -40 scores between the groupsGlobal QoR-40 (0-200)Group I (n=30)Group-II (n=30)Group-III (n=30) P Pre-operative186.63±7.78185.53±6.73186.34±7.56P=0.8360At 24 h183.64±6.36179.68±6.38171.37±6.88P<0.001* P t=1.63, P=0.1086t=3.455, P=0.0010*t=8.021, P<0.001*Conclusion:Both PECS and ESP block can be used efficaciously for providing analgesia in modified radical mastectomy for breast cancer. However, PECS shows better outcomes.

A COMPARISON OF POST-OPERATIVE ANALGESIA WITH INTRAOPERATIVE PECTORAL NERVE BLOCK VERSUS CONVENTIONAL TECHNIQUE IN PATIENTS UNDERGOING MODIFIED RADICAL MASTECTOMY: A PROSPECTIVE, RANDOMIZED, AND DOUBLE-BLINDED STUDY

Objective: We administered intraoperative pectoral nerve block after tissue resection was over and assessed its analgesic efficacy with conventional post-operative intravenous opioids in patients undergoing modified radical mastectomy. Methods: Sixty patients undergoing modified radical mastectomy surgery were enrolled in this prospective, randomized, and doubleblinded study. After general anesthesia and surgical resection in both groups, Group P received pectoralis (PECS) block under vision with ropivacaine at two points: 20 ml in the fascia over serratus anterior and 10 ml in the fascia between pectoral major and minor at the level of the third rib and Group T received tramadol (75 mg) in thrice daily frequency and 2% lignocaine infiltration at suture site. Primary objectives were to assess visual analog scale (VAS) scores over 24 h, time to first request for rescue analgesia (ketorolac) and total dose of analgesics needed, and secondary outcome was adverse effects and patient satisfaction score. “Mann–Whitney U test” and “Chi-square/Fischer exact test” were used for quantitative and categorical variables, respectively. Results: The mean time to the first rescue analgesia was 1175±120.21 and 1175±77.35 min and total analgesia requirement was equal (30.00±0.00 mg) in Group P and Group T, respectively. The mean VAS score over 24 h was comparable in both the groups. PECS block group had significantly less adverse effects and better satisfaction score. Conclusion: PECS block has similar analgesic efficacy as opioids but with better ability to mobilize the respective arm, better patient satisfaction score, and lesser adverse effects.

Skeletal Muscle Fibre Type Changes in an Avian Model of Hepatic Fibrosis

We investigated the susceptibility of type I and type II skeletal myofibres to atrophy in hens with hepatic fibrosis induced by bile duct ligation (BDL). Seven hens, approximately 2 years old, were randomly assigned to BDL (n=4) and sham surgery (SHAM) (n=3) groups. Mean body weight and mean liver weight as a percentage of mean body weight were significantly lower in the BDL group than in the SHAM group at 4 weeks post surgery (P=0.002, P=0.005, respectively). Mean plasma aspartate aminotransferase activity was slightly higher, while total cholesterol (P<0.001), total bilirubin (P=0.022) and NH3 (P=0.048) concentrations weresignificantly higher in the BDL group than in the SHAM group. Liver lesions were induced in all hens in the BDL group. The weights of the pectoralis (PCT) (P=0.049) and flexor perforans et perforatus digiti III (FPPD III) muscles (P=0.006) as a percentage of body weight were significantly decreased in the BDL group. A significantly reduced mean myofibre cross-sectional area in the PCT of BDL hens (P=0.005) was indicative of atrophy. No significant differences were observed in the fibre type composition of the PCT, supracoracoideus or FPPD III muscles between the SHAM and BDL groups. However, there was an approximate 43% increase in the number of type I fibres in the femorotibialis lateralis of the BDL group and small angular type II fibres and large round type I fibres in this muscle were characteristic of peripheral neuropathy. The results suggest that type II fibres are more susceptible to atrophy than type I fibres in this model of hepatic fibrosis.

Does exposure to startle impact voluntary reaching movements in individuals with severe-to-moderate stroke?

When movements of individuals with stroke (iwS) are elicited by startling acoustic stimulus (SAS), reaching movements are faster, further, and directed away from the body. However, these startle-evoked movements also elicit task-inappropriate flexor activity, raising concerns that chronic exposure to startle might also induce heightened flexor activity during voluntarily elicited movement. The objective of this study is to evaluate the impact of startle exposure on voluntary movements during point-to-point reaching in individuals with moderate and severe stroke. We hypothesize that startle exposure will increase task-inappropriate activity in flexor muscles, which will be associated with worse voluntarily initiated reaching performance (e.g. decreased distance, displacement, and final accuracy). Eleven individuals with moderate-to-severe stroke (UEFM = 8–41/66 and MAS = 0–4/4) performed voluntary point-to-point reaching with 1/3 of trials elicited by an SAS. We used electromyography to measure activity in brachioradialis (BR), biceps (BIC), triceps lateral head (TRI), pectoralis (PEC), anterior deltoid (AD), and posterior deltoid (PD). Conversely to our hypothesis, exposure to startle did not increase abnormal flexion but rather antagonist activity in the elbow flexors and shoulder horizontal adductors decreased, suggesting that abnormal flexor/extensor co-contraction was reduced. This reduction of flexion led to increased reaching distance (18.2% farther), movement onset (8.6% faster), and final accuracy (16.1% more accurate) by the end of the session. This study offers the first evidence that exposure to startle in iwS does not negatively impact voluntary movement; moreover, exposure may improve volitionally activated reaching movements by decreasing abnormal flexion activity.

Analgesic efficacy and spread of local anesthetic in ultrasound-guided paravertebral, pectoralis II, and serratus anterior plane block for breast surgeries: A randomized controlled trial.

Background:Thoracic paravertebral block (TPVB) has become the gold standard to provide postoperative analgesia in breast surgery. Recently, ultrasound-guided (USG) pectoralis (PECS) block and serratus anterior plane (SAP) block have been described as an alternative to TPVB. The objectives were to compare TPVB, PECS, and SAP block in terms of analgesic efficacy and the spread of local anesthetic by ultrasound imaging, correlating it with the sensory blockade.Materials and Methods:Prospective randomized interventional study conducted in 45 ASA grades I–II patients scheduled for the elective breast surgery. Patients were randomly allocated into three groups, i.e., Gr.1 (USG –TPVB) (ropivacaine 0.375% 20 ml), Gr.2 (USG-PECS II) block (ropivacaine 0.375% 30 ml), and Gr.3 (USG-SAP) (ropivacaine 0.375% 30 ml). Spread of the local anesthetics was seen with ultrasound imaging. Onset of sensory blockade, postoperative fentanyl consumption, and pain scores was measured.Results:TPVB and SAP group had comparatively higher spread and sensory block compared to PECS group. Postoperative fentanyl requirement (mean ± SD) was 428.33 ± 243.1 μg, 644.67 ± 260.15 μg, and 415 ± 182.44 μg in the TPVB group, PECS II group, and SAP group, respectively. SAP group had significantly lesser requirement than PECS II group (P = 0.028) but similar requirement as in TPVB group (P = 1.0). Pain scores were not significantly different among the group in the postoperative period.Conclusion:TPVB and SAP group result in a greater spread of the drug and provide equivalent analgesia and are superior to the PECS II block in providing analgesia for breast surgeries. SAP block is easier to perform than TPVB with lesser chances of complications and results in faster onset.

Comparison of pectoralis plane blocks with ketamine-dexmedetomidine adjuncts and opioid-based general anaesthesia in patients undergoing modified radical mastectomy

Background and Aims:Regional anaesthesia attenuates surgical stress-response, provides superior analgesia, reduces recovery time with early mobilisation and is opioid-sparing [addresses post-operative nausea vomiting (PONV), constipation, immunosuppression and cancer-progression concerns with opioids]. Hence, we studied pectoralis (PECS) blocks for modified radical mastectomy (MRM).Methods:A prospective, interventional, double-blind, randomised, parallel-arm, active-controlled study comparing two anaesthetic techniques for post-operative pain relief in70 adult American Society of Anesthesiologists grade I/II carcinoma breast patients undergoing MRM was conducted. Patients were randomised to Group-O (opioids, sevoflurane) and Group-P (PECS-block, pre-incisional intravenous (IV) ketamine (0.5 mg/kg), pre-incisional IVdexmedetomidine (1 μg/kg over 10 min, then 0.6 μg/kg/h). Data were subjected to statistical analysis using the Statistical Package for Social Sciences, version-23 and independent sample t-test/Welch test for equality of means and expressed as dotted box-whisker plots. Nominal categorical intergroup data was compared using Chi-squared test/Fisher's exact test. P<0.05 was considered statistically significant. Clinical significance was calculated.Results:Higher Visual Analogue Scale (VAS)-scores were recorded in Group-O versus Group-P, immediately post-extubation [mean (SD) 3.6 ± 1.5 and 0.76 ± 0.6] and at 1h (3.1 ± 1.2 and1.4 ± 0.5), 2h (2.5 ± 0.9 and 1.2 ± 0.6) and 4h (2.2 ± 0.5 and 1.7 ± 0.9) respectively. At 8h and 24h post-surgery VAS was comparable. Cumulative-VAS was lower in Group-P. Intraoperative haemodynamics were comparable. Incidence of PONV and constipation was higher in Group-O where each patient received average 27.46 mg morphine-equivalents of opioids. Time to discharge from surgical intensive care unit was 2h shorter in Group-P.Conclusion:Pre-emptive PECS-blocks supplemented with low-dose ketamine and dexmedetomidine comprise a practical and useful alternative technique to the standard opioid-based general anaesthetic technique for MRM.

Concentration of collagen fibers in the musculature of broiler chickens fed with cupuacu seed by-product

ABSTRACT In this essay, we quantify the concentration of collagen fibers in broiler chickens exposed to increasing concentrations of cupuacu seed by-product. Collection of material was carried out in five chickens per treatment at 70 days old in the groups: control, 5% and 10% inclusion of cupuacu seed by-product. Fragments of Thoracic Pectoralis (PT) and Iliotibial lateralis (ITL) muscles were prepared for light and electronic microscopy. The amount of collagen fibers in the muscle groups was 1.08±0.61% in the PTC group; 6.24±2.58% in PT5% and 7.30±2.75% in PT10%. In the Iliotibial Lateralis groups, the results were 6.96±3.14% in the ITLC; 7.43±4.22% in the ITL5% and 8.66±2.35% in ITL10%. The amount of collagen fibers in the ITL5% and ITL10% groups showed no significant statistical difference. However, when compared to the ILTC group, there was a significant statistical difference. The PT muscle responds to standard nutritional changes, unlike the ILT muscle, which requires a high-nutrient formulation. The use of 5% cupuacu seed by-product has proven to be a viable alternative source of animal feed, as it promotes an increase in the concentrations of collagen fibers in the musculature of broiler chickens and is possibly the determining factor in meat texture.

Peripheral nerve stimulator guided pectoralis (PEC-I) block: A novel approach to the chest wall block

Introduction: Thoracic epidural and paravertebral blocks, the gold standard for post-operative analgesia for chest wall surgeries have a high incidence of complications and adverse effects. The pectoralis (PEC) blocks, first described by Blanco et al., have been proven to provide good analgesia postoperatively for breast surgeries, wide pectoral dissections, upper chest injuries, pacemaker insertions, port-a-cath placements, and intercostal chest drains. To widen the scope of this simple and useful analgesia technique, which mandates the availability of ultrasound machine and indepth knowledge of the sonoanatomy of the area, we are describing the conduct of PEC-I block using peripheral nerve stimulator, which is easily available to most anesthetists. Description of the Technique: Medial and lateral pectoral nerves (LPNs) are motor nerves originating in the brachial plexus innervate the pectoral muscles. The LPN runs in between pectoralis major and pectoralis minor muscle alongside the pectoral branch of thoracoacromial artery and supplies the pectoralis major muscle. The LPN communicates with the medial pectoral nerve and is known to carry nociceptive and proprioceptive fibers. The patient lies in a supine position with ipsilateral arm slightly abducted. The injection point is the intersection of a line drawn from the angle of Louis (2nd rib) and the anterior axillary line. After local infiltration of the skin with 1% lignocaine, a 50 mm insulated nerve stimulator needle with syringe filled with local anesthetic attached to the extension tubing is inserted perpendicular to the skin. The peripheral nerve stimulators (PNS)are initially set at 1.0–1.5 mA current, 0.1ms duration, and frequency of 1Hz. The needle is slowly advanced till the pectoralis muscle contractions is noted, with a current threshold of 0.3–0.5 mA. Persistence of contraction of pectoralis muscle at this level confirms the needle placement at the target site. The LA is then slowly injected in increments with frequent negative aspirations. Discussion: An increasing numbers of breast surgeries warrant better post-operative analgesia techniques, with fewer complications.Thoracic epidural analgesia, thoracic paravertebral blocks (TPVB), and intercostal nerve blocks have all been very effective for such surgeries but, are associated with complications such as epidural hemat omas, nerve injuries, pneumothorax,and hypotension. Analgesia technique like TPVB was unreliable with a single injection, and pectoral nerves were still spared producing inadequate analgesia of the chest wall and needed post-operative monitoring. The pectoralis block (PEC block), a novel technique, was described by Blanco et al. in 2011 using ultrasound and was easy, reliable, and associated with fewer complications. Peripheral nerve stimulator for such an easy and superficial block increases the utilization and benefits wider population. We have described the use of PNS for PEC-I block that can be used as a sole analgesia technique for breast implant insertion, pacemaker implantation, porta-cath insertion, ICD insertions or removals, and pectoralis muscle flaps. The PEC-I block can be further combined with PNS guided serratus anterior plane block to achieve excellent analgesia of the chest wall for surgeries. Conclusion: The PEC-I block along with PEC-II or SA plane block has a high success rate and minimal incidence of complications and provides a consistent and reliable block for hemithorax analgesia. In this article, we describe PEC-I block using PNS which is easily available to most anesthetist,unlike US machines which are available only to very few. PNS guided PEC-I block will increase the scope of this superficial, easy, and reliable block. Keywords: Pectoralis blocks, chest wall blocks, pectoralis-I, pectoralis-II, peripheral nervous system, peripheral nervous system guided chest wall block.

Neuromuscular mechanisms of an elaborate wing display in the golden-collared manakin (Manacus vitellinus)

Many species perform elaborate physical displays to court mates and compete with rivals, but the biomechanical mechanisms underlying such behavior are poorly understood. We address this issue by studying the neuromuscular origins of display behavior in a small tropical passerine bird, the golden-collared manakin (Manacus vitellinus). Males of this species court females by dancing around the forest floor and rapidly snapping their wings together above their back. Using radio-telemetry, we collected electromyographic (EMG) recordings from the three main muscles that control avian forelimb movement, and found how these different muscles are activated to generate various aspects of display behavior. The muscle that raises the wing (supracoracoideus, SC) and the primary muscle that retracts the wing (scapulohumeralis caudalis, SH) were activated during the wing-snap, whereas the pectoralis (PEC), the main wing depressor, was not. SC activation began before wing elevation commenced, with further activation occurring gradually. By contrast, SH activation was swift, starting soon after wing elevation and peaking shortly after the snap. The intensity of this SH activation was comparable to that which occurs during flapping, whereas the SC activation was much lower. Thus, light activation of the SC likely helps position the wings above the back, so that quick, robust SH activation can drive these appendages together to generate the firecracker-like snap sonation. This is one of the first looks at the neuromuscular mechanisms that underlie the actuation of a dynamic courtship display, and it demonstrates that even complex, whole-body display movements can be studied with transmitter-aided EMG techniques.

P175. MAMMO-50: Mammographic surveillance in breast cancer patients over 50 years of age – The results of the 2 year feasibility study

S S75 Aim: To look at all our mastectomies and immediate reconstructions and see whether they have been coded properly on the OPCS system Method: All skin sparing mastectomies and immediate reconstructions with ADM/Implant that were performed over a 6 month period were taken from our central database and the OPCS and HRG codes were compared and to look at the reason why they were inappropriately coded. Results: There were 24 cases covering all 3 consultants. 9 achieved the correct HRG code (JA16Z Mastectomy and reconstruction e £6415). The remaining cases did not get a reconstruction HRG but instead JA07 and JA06 codes which are the HRGs usually assigned to mastectomies. The lost income on these 15 cases alone is about £80,000. Conclusion: Interventions were made and a re-audit will be performed of coding and HRG allocation for 3 months after these interventions. http://dx.doi.org/10.1016/j.ejso.2015.03.211 P174. Role of PEC block in recovery after mastectomy Ramkumar Dhanancheyan, Rajeeva Venkatasamy, Imtiaz Cheema James Cook University Hospital, Middlesbrough, UK Mastectomy is one of the common surgical procedures and accounts for significant bed occupancy. The aim of this audit was to review our practice of analgesic administration to the patients undergoing the procedure and its effect on the length of stay. Methods: Notes of 50 random patients who had undergone mastectomy in a 6 month period were reviewed to collect details of pain scores, analgesic requirements, duration of recovery and hospital stay. Patients having primary reconstruction were excluded. Results: A total of 47 notes were reviewed. Twenty two patients had, in addition to GA, regional analgesia (RA) in the form of Pectoralis (PEC) block. The remaining 25 did not had any PEC block but had local anaesthetic (LA) infiltration (n 1⁄4 12), LA through drain (n 1⁄4 9) or no LA (n 1⁄4 4). There was no significant difference between RA and Non RA group in terms of recovery pain scores and morphine requirement in recovery. RA group had significantly less morphine intra-operatively compared to others. Recovery stay was slightly longer and slightly more patients needed morphine on first postoperative day in Non RA group. More patients in Non RA group stayed in hospital for more than two days (Table 1). Conclusions: In this audit PEC block significantly decreased morphine requirement in perioperative period, though it did not translate to significant reduction in recovery stay. This emphasises the need for a more holistic approach in order to reduce hospital stay and regional block can be an important part of care.

Shoulder muscle activation during stable and suspended push-ups at different heights in healthy subjects

ObjectivesTo analyze shoulder muscle activation when performing push-ups under different stability conditions and heights. Study designComparative study by repeated measures. SettingValencia University laboratory. Participants29 healthy males participated. Main outcome measuresSubjects performed 3 push-ups each with their hands at 2 different heights (10 vs. 65 cm) under stable conditions and using a suspension device. Push-up speed was controlled and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the long head of the triceps brachii (TRICEP), upper trapezius (TRAPS), anterior deltoid (DELT) and clavicular pectoralis (PEC) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). ResultsSuspended push-ups at 10 cm resulted in greater activation in the TRICEP (17.14 ± 1.31 %MVIC vs. 37.03 ± 1.80 %MVIC) and TRAPS (5.83 ± 0.58 %MVIC vs. 14.69 ± 1.91 %MVIC) than those performed on the floor. For DELT and PEC similar or higher activation was found performing the push-ups on the floor, respectively. Height determines different muscle activation patterns. ConclusionsStable push-ups elicit similar PEC and higher DELT muscle activation, being greater at 10 cm; whereas suspended push-ups elicit greater TRAPS and TRICEP muscle activation, being greater at 65 cm.

Reconstruction of combined intra- extracranial defects by mycutaneuous free flap

Objective To evaluate the combined intra- extracranial defects reconstruction and to identify the reconstructive management principles that may assist in achieving successful multidisciplinary approaches.Methods The clinical records of 11 patients with recurrent tumors who required skull base reconstruction with mycutaneuous free flaps were reviewed retrospectively.The patients had undergone skull base surgery through multidisciplinary approaches with simultaneous reconstruction for the anterior and middle cranial fossa skull bases in 5 patients,and the posterior fossa in 1. Donor sites included the latissimus dorsi ( n =9) and pec toralis major muscle ( n =2 ).Results Reconstruction was performed as planned in all patients with a low incidence of complications.The necrosis of the flaps was not encountered.The postoperative recovery time was 7 to 15 days.Conclusions Mycutaneuous free flap transfer is a robust option in the repair of postoperative skull base penetrating defets.Latissimus dorsi mycutaneuous free flap is a well- vascularised flap with homogenous thickness,various types which could be harvested to cover any sizes and any locations of skull base defects. Key words: Penetrating tumor of skull base; Defect; Mycutaneuous free flap; Reconstruction