Anesthetic Technique Research Articles

Anatomical Studies Evaluating Pediatric Regional Anesthesia: A Scoping Review

Background: Pediatric regional anesthesia has been driven by the gradual rise in the adoption of opioid-sparing strategies and the growing concern over the possible adverse effects of general anesthetics on neurodevelopment. Nonetheless, performing regional anesthesia studies in a pediatric population is challenging and accounts for the scarce evidence. This study aimed to review the scientific foundation of studies in cadavers to assess regional anesthesia techniques in children. Methods: We searched the following databases MEDLINE, EMBASE, and Web of Science. We included anatomical cadaver studies assessing peripheral nerve blocks in children. The core data collected from studies were included in tables and comprised block type, block evaluation, results, and conclusion. Results: The search identified 2409 studies, of which, 16 were anatomical studies on the pediatric population. The techniques evaluated were the erector spinae plane block, ilioinguinal/iliohypogastric nerve block, sciatic nerve block, maxillary nerve block, paravertebral block, femoral nerve block, radial nerve block, greater occipital nerve block, infraclavicular brachial plexus block, and infraorbital nerve block. Conclusion: Regional anesthesia techniques are commonly performed in children, but the lack of anatomical studies may result in reservations regarding the dispersion and absorption of local anesthetics. Further anatomical research on pediatric regional anesthesia may guide the practice.

Peripheral Nerve Blocks for Hip Fractures.

The incidence of hip fractures has continued to increase as life expectancy increases. Hip fracture is one of the leading causes of increased morbidity and mortality in the geriatric population. Early surgical treatment (<48 h) is often recommended to reduce morbidity/mortality. In addition, adequate pain management is crucial to optimize functional recovery and early mobilization. Pain management often consists of multimodal therapy which includes non-opioids, opioids, and regional anesthesia techniques. In this review, we describe the anatomical innervation of the hip joint and summarize the commonly used peripheral nerve blocks to provide pain relief for hip fractures. We also outline literature evidence that shows each block's efficacy in providing adequate pain relief. The recent discovery of a nerve block that may provide adequate sensory blockade of the posterior capsule of the hip is also described. Finally, we report a surgeon's perspective on nerve blocks for hip fractures.

Anesthesia Techniques for Vitreoretinal Surgery in the United States: A Report from the Multicenter Perioperative Outcomes Group Research Consortium

PurposeTo explore the patterns of anesthesia use and their determinants during vitreoretinal (VR) surgeries in academic and community hospitals across the US, using data from the Multicenter Perioperative Outcomes Group (MPOG). DesignA retrospective, multicenter, cohort study. MethodsWe queried the MPOG database of 107,066 patients undergoing VR surgeries. Patients (≥18 yrs.) undergoing VR surgery with monitored anesthesia care (MAC) or general anesthesia (GA) from January 1, 2015, to December 31, 2021 were included. Patient-level, case-based, and institutional-level covariates were collected. We performed multivariable mixed-effects models to determine predictors of anesthesia type use. The primary outcome was the type of anesthesia (MAC or GA) used during VR surgeries. As a secondary outcome, MAC cases were further classified based on the additional use of sedation into MAC with or without sedation. ResultsWe found that 67.45% of VR surgery cases received MAC, and 73.63% of institutions administered MAC to more than half of cases. Random effect modeling revealed that 47.76% of the variation in MAC use was attributed to institutions. A trend toward increased use of MAC with increasing age was observed. Patients diagnosed with chronic pulmonary disease, liver disease, or a history of drug abuse were less likely to receive MAC. Conversely, we found that patients with reported alcohol abuse disorder, diabetes with complications, and those with American Society of Anesthesiologists (ASA) physical status of 4 (vs. 1, 2, or 3) were more likely to use MAC. Compared to non-complex VR surgeries, there was a notably decreased likelihood of MAC use in complex PPV (P = 0.004), PPV + scleral buckle (SB) for retinal detachment (P < 0.0001), and primary SB surgery (P < 0.0001). ConclusionsApproximately 2/3 of VR anesthesia is under MAC, but GA is still preferred for SBs, complex vitrectomy, and younger patients. We show that large interinstitutional variation for using MAC in practice exists.

Pharmacokinetics in regional anesthesia.

Pharmacokinetics of local anesthetics are one of the main determinants of success and safety of regional anesthesia and comprise local and systemic distribution phases. This review aims to summarize the latest research findings on this topic in the context of various regional blocks performed for different surgeries and patient populations. Research into local kinetics and systemic absorption of local anesthetics has chiefly been focused on novel fascial plane blocks, especially the erector spinae plane block, as these are increasingly adopted for regional anesthesia and pain management. As their clinical efficacy is very dependent on injection of large volumes of local anesthetic, doses over typically recommended limits are often administered. Fascial plane blocks are the regional anesthesia techniques in need of the most pharmacokinetic characterization, not only to better understand their complex mechanisms of action but also to avoid harm from excessive doses of local anesthetics. Further mapping of risk factors for systemic toxicity from administration in different block sites is crucial. Extremes of age and pregnancy are vulnerable patient populations but in whom regional anesthesia, including novel techniques, has been performed with few complications.

Ultrasound-guided regional anesthesia by orthopaedic surgeons in fixation of distal radius fracture

The technique of ultrasound-guided regional anesthesia has demonstrated satisfactory efficacy and safety in fixation of various fractures. There are limited studies performed concerning the applicability of a surgeon self-performed ultrasound-guided regional anesthesia. This study aimed to evaluate the efficacy of a self-performed ultrasound-guided regional anesthesia by surgeon for distal radius fracture fixation in terms of intraoperative and post-operative characteristics. Material and Methods: Patients with distal radius fracture who underwent surgery under the surgeon-performed ultrasound-guided regional anesthesia were evaluated in this retrospective study. A total of 12 patients (2 male/10 female) with a mean age of 60.6 were evaluated for the type of injury by AO classification, American Society of Anesthesiologists Classification (ASA), intraoperative visual analog scale pain (VAS) scores, duration of operation, post-operative pain control, complications and duration of hospitalisation. Result: Average age of the study population was 60.6, of which four of them were of ASA I, six of them ASA II and two of them ASA III. We provided complete pain control during the operation with all of the patient experience no pain (VAS = 0) throughout the operation. Average operative time was 77.5 min. Average blood loss was 7.7 mL. Early post-operative pain control at 6 h after operation was well with majority of patients experience pain of VAS 1. Average post-operative hospital length of stay is 2.08 days. There was no complication arising from the application of regional anesthesia. Conclusion: Ultrasound-guided regional anesthesia can provide excellent efficacy and pain control during and after operation. Occurrence of complication was well avoided. Distal radius fracture fixation can be performed safely by orthopaedic surgeons under this technique.

Description and Evaluation of Dye and Contrast Media Distribution of Ultrasound-Guided Rectus Sheath Block in Cat Cadavers.

The rectus sheath block is an ultrasound-guided anaesthetic technique which aims to provide analgesia to the abdominal midline. This study aimed to assess the distribution of 0.4 mL kg-1 of a mixture of methylene blue and iopromide injected into each hemiabdomen in the internal rectus sheath in cat cadavers. We hypothesise that this technique would be feasible and would cover the rami ventrales of the last thoracic and the first lumbar spinal nerves. The study was divided into two phases. Phase 1 aimed to study the anatomical structures of the ventral abdominal wall (four cats were dissected). Phase 2 (ten cadavers) consisted of an ultrasound-guided injection of the mixture mentioned above and the assessment of its distribution by computed tomography and anatomical dissection. The results showed the staining of the cranioventral abdominal wall with a craniocaudal spread of four (three to eight) vertebral bodies. Methylene blue stained three (one to four) rami ventrales, affecting T10 (60%), T11 (100%), T12 (90%), T13 (50%) and L1 (5%). Based on these results, it could be stated that this technique could supply anaesthesia to the midline of the abdominal midline cranial to the umbilicus in clinical patients, but it may not be able to provide anaesthesia to the middle and caudal midline abdominal region.

Retrospective Study of Anesthesia-Related Complications in Elderly Patients Undergoing Surgery.

Anesthesia administration in elderly surgical patients presents unique challenges due to age-related physiological changes and comorbidities. Knowing anesthesia-related complications is crucial for optimizing perioperative care in this vulnerable population. A retrospective review of electronic medical records was conducted to identify anesthesia-related complications in elderly subjects aged 65 and above undergoing surgery between January 2018 and December 2020. Data collection included demographic characteristics, comorbidities, anesthesia techniques, and postoperative outcomes. There were a total of 100 elderly patients. Cardiovascular events (35%) were the most common complication, followed by respiratory issues (20%) and adverse drug reactions (15%). Statistical analysis revealed significant associations between cardiovascular events, respiratory issues, adverse drug reactions, and anesthesia. Anesthesia-related complications pose significant risks in elderly surgical patients. Tailored anesthesia management strategies, including comprehensive preoperative assessment and vigilant intraoperative monitoring, are essential for mitigating perioperative risks and improving outcomes in this vulnerable population.

The efficacy of wound catheter infusion with local anesthetics for the treatment of postoperative pain in children: A systematic review

AbstractWound catheter infusion (WCI) with local anesthetics (LA) is a regional anesthesia technique, which has shown to produce effective postoperative analgesia in adults, without any adverse effects on wound healing. To investigate the efficacy and safety of WCI with LA for the treatment of postoperative pain in children, we conducted a systematic review of literature published until 2020. The literature search included articles concerning subcutaneous WCI with LA, in the surgical wound, as treatment of postoperative pain, in children &lt;18 years of age. Exclusion criteria were studies describing peripheral nerve blocks, intercostal, abdominal or thoracic wall blocks and single local anesthetic infiltration of the surgical wound. The articles were appraised for quality and only randomized controlled trials with a Jadad score ≥3 were included for evaluation of results concerning postoperative pain scores and opioid use. All relevant original studies, including observational studies and case reports, were assessed for adverse events and measurements of LA plasma concentrations during WCI. A total of 1907 articles were found, leading to 92 relevant abstracts selected for further review. After exclusion of articles of which full texts could not be retrieved or because of exclusion criteria, 28 articles remained. Thirteen articles described randomized controlled trials, of which 10 were assessed as good or excellent in quality. Due to the small number and heterogeneity of the studies, the data could not be pooled. Instead, results were described per type of procedure: abdominal surgery, extremity surgery, thoracic surgery and iliac crest bone harvesting. Reduced pain scores and opioid needs were demonstrated after abdominal and extremity surgery. In five studies, plasma levels of LA were measured, which all remained below toxic thresholds. In all relevant studies, no serious adverse events concerning the use of WCI were reported.

Precision in practice: An audit study on low-flow anesthesia techniques with desflurane and sevoflurane for cost-effective and sustainable care.

In the backdrop of escalating healthcare costs and an increasing focus on resource optimization, this audit study delves into the realm of anesthesia management, specifically exploring the application of low-flow anesthesia (LFA). The primary objective was to assess adherence to hospital standards and evaluate the economic implications of LFA (<1 L/min). This retrospective audit focused on 700 adult patients undergoing elective surgeries with general anesthesia. Data sources included anesthesia records, electronic recording systems, and audits by a dedicated team. Fresh gas flow rates (FGFRs), minimum alveolar concentration (MAC), and volatile anesthetic consumption were analyzed. Cost comparisons between low-flow and high-flow anesthesia were conducted, employing specific cost per milliliter metrics. The average FGFR during the maintenance phase was found to be 0.45 ± 0.88 L/min. Adherence to hospital standards was notably high, with 94.29% of patients being maintained on low-flow gas rates. The differences in anesthetic consumption between low-flow and high-flow FGFR were statistically significant for both desflurane (12.17 ± 10.84 ml/MAC hour versus 43.12 ± 27.25 ml/MAC hour) and sevoflurane (3.48 ± 7.22 ml/MAC hour versus 5.20 ± 5.20 ml/MAC hour, P < 0.001). The calculated savings per patient with low-flow desflurane and sevoflurane anesthesia compared to high flow were found to be 109.25 AED and 6.74 AED, respectively. This audit advocates for the widespread adoption of LFA as a standard practice. Beyond aligning with hospital standards, the study highlights the multi-faceted benefits of LFA, encompassing economic savings, environmental safety, and enhanced patient care.

Awake Combined Spinal Caudal Anesthesia for Longer-Duration Urologic Surgery in Infants: A Case Series.

Awake combined spinal caudal anesthesia has been used as an anesthetic technique for longer-duration infraumbilical surgeries in infants. Literature on the safety and feasibility of this technique is limited. We share our experience with 27 infants undergoing longer-duration urologic surgery using awake combined spinal and caudal anesthesia without the use of systemic sedatives or inhalational agents. We describe our technique, safety considerations, and details surrounding the optimal timing of caudal catheter activation for prolongation of surgical anesthesia.

Methods of prolonging the effect of caudal block in children.

Caudal epidural blockade is one of the most frequently administered regional anesthesia techniques in children. It is a supplement during general anesthesia and for providing postoperative analgesia in pediatrics for sub-umbilical surgeries, especially for genitourinary surgeries. However, the duration of the analgesic effect is occasionally unsatisfactory. In this review, we discuss the main advantages and disadvantages of different techniques to prolong postoperative analgesia for single-injection caudal blockade in children. A literature search of the keywords "caudal", "analgesia", "pediatric", and "children" was performed using PubMed and Web of Science databases. We highlight that analgesic quality correlates substantially with the local anesthetic's type, dose, the timing relationship between caudal block and surgery, caudal catheterization, and administration of epidural opioids or other adjuvant drugs.

The effects of anaesthesia and analgesia on short- and long-term outcomes following colorectal cancer surgery

BACKGROUND Colorectal cancer (CRC) is the second most frequent cause of global cancer mortality. Most patients with CRC require surgical tumour resection, with certain stages of CRC (Stage II/III) also requiring postoperative chemotherapy. The timing of postoperative chemotherapy is largely determined by postoperative recovery. Delayed return to intended oncologic therapy (RIOT) by &gt;8 weeks results in worse oncologic outcomes. RIOT is thus an important surrogate marker of outcome for patients with stage II/III CRC. We will test the hypothesis that anaesthetic technique during CRC resection surgery may affect RIOT. OBJECTIVE To test the association between anaesthetic and analgesic technique during CRC surgery and RIOT. To document Short-term Secondary outcomes including individual postoperative complications and a composite of all postoperative complications, the Comprehensive Complications Index (CCI) and to measure the time to recurrence (TTR) of cancer at 3 years. DESIGN This is a prospective, international, multicentre, observational cohort study. SETTING Global healthcare setting, with &gt;140 centres in &gt;30 nations. PATIENTS Inclusion criteria: All patients age &gt;18 years, ASA I–III, with CRC stage I–III scheduled for elective CRC surgery (open or minimally invasive). Exclusion criteria: Uncontrolled renal or liver disease, restrictive (limiting mobility) heart failure or ischemic heart disease (ASA IV–V). Speech, language, or cognitive difficulties precluding signing informed consent to participate and Stage IV CRC. PRIMARY OUTCOME MEASURES Short -term: The duration from day of surgery to RIOT among patients expected to receive postoperative chemotherapy. Long-term: incidence of recurrence and time to recurrence (TTR) at 3 years after primary curative surgery SECONDARY OUTCOMES Postoperative complications within 30 days of surgery, length of hospital stay, Days at Home at 30 and 90 days (DAH-30, DAH-90) after surgery, and adverse events related to oncological treatment. We will also assess the burden of preoperative modifiable comorbid disease in patients. Exploratory endpoints will assess practice variation (including incidence of RIOT by demographic e.g. gender of patient, type of institution, country). RESULTS N/A. CONCLUSIONS N/A. TRIAL REGISTRATION The Effects of aNesthesia in COloREctal cancer outcome study: ENCORE, ClinicalTrials.gov Identifier: NCT04493905.

Dental treatments under sedation-analgesia in patients who are unable to collaborate: a prospective observational study.

Excessive fear of dental procedures leads to disruptive behavior during dental examinations and treatments. Dental examinations and treatments of these patients usually require additional techniques, such as sedation. The most commonly used techniques are inhalation of nitrous oxide, infusion of propofol with fentanyl, and premedication and infusion of midazolam. A prospective observational epidemiological study was conducted on patients who required sedoanalgesia techniques for dental exploration and procedures. The reasons for the inability of patients to cooperate (excessive fear or intellectual disability), age, sex, weight, systemic pathology, oral pathology, treatment performed, time of intervention, anesthetic technique performed, and occurrence of complications were recorded. In total, 218 patients were studied. Sixty-five patients came for fear of dental treatment and 153 for presenting with a diagnosis of intellectual disability and not collaborating in the treatment with local anesthesia. The average age of all patients was 30.54 ± 17.30 years. The most frequent oral pathologies found in patients with excessive fear were tartar (6.8%) and wisdom teeth (6.4%), followed by missing teeth (5%). In patients with disabilities, a combination of tartar and cavities appeared most frequently (41.3%), followed by cavities (15.6%). The most frequently used sedoanalgesia technique was the infusion of propofol with fentanyl in both groups of patients, followed by nitrous oxide. The combination of propofol and fentanyl was the most frequently used alternative in patients who were unable to collaborate because of intellectual disability or carry out longer or more complex treatments. Inhaled nitrous oxide and midazolam were the sedative techniques of choice for simpler oral treatments, such as tartrectomies, shallow obturations, and shorter interventions, or in younger patients.

Monitored Anesthesia Care (MAC) as an Alternative to General Anesthesia (GA): Prospective Double-Blinded Randomized Controlled Study Comparing Efficacy and Safety of Dexmedetomidine and Ketamine Infusions with Ultrasonography (USG) Guided Pectoral Nerve Block (PECs) for Postoperative Analgesia in Breast Surgery.

PECs blocks are usually combined for breast surgery under general anesthesia (GA) to provide postoperative analgesia rather than primary anesthesia technique. A prospective, interventional, single-center, double-blind, randomized, parallel-group, active-controlled, Helsinki protocol-compliant clinical study was conducted in a tertiary care teaching center after obtaining the Ethics Committee's approval and patients' written informed consent. Forty-eight American Society of Anesthesiologists physical status I/II patients aged 18-60 years, undergoing elective unilateral breast surgery were enrolled. Patients were block-randomized (computer-generated) to two equal groups (24 patients each), with one of them receiving Dexmedetomidine and the other one Ketamine. For concealment, sequentially numbered, sealed, opaque envelopes were used. The study was double-blinded for both the anesthesiologist and outcome assessor anesthesiologist. Obese patients (body mass index > 30), those with infection at block site, coagulopathy and known hypersensitivity to local anesthetics or study medications as well as individuals who refused participation in research were all excluded. The Dexmedetomidine group received a bolus of 0.5 mcg/kg over ten minutes, followed by an infusion of 0.3 mcg/kg/hour, while the Ketamine group received a bolus of 0.5 mg/kg over ten minutes, followed by an infusion of 0.3 mg/kg/hour. Postoperative analgesia was compared using a visual analogue scale (VAS) at regular intervals. When VAS exceeded four, 1 mg/kg intravenous Pethidine was administered as a rescue analgesic. Sub-anesthetic low-dose Ketamine was more effective than low-dose Dexmedetomidine in prolonging PECs block analgesia, which was statistically significant (p value < 0.001). The Ketamine group had lower rescue analgesic Pethidine consumption and longer first-rescue analgesia demand time. There was no significant hemodynamic difference between the study groups. Ketamine was more efficient than Dexmedetomidine for postoperative analgesia.

Local Infiltration Anesthesia Versus Ultrasound-Guided Pectoralis (PEC1) + Serratus Anterior Plane (SAP) Blocks on Postanesthetic Care Unit Pain Control in Patients Undergoing Primary Submuscular Augmentation Mammoplasty

Background Ultrasound-guided regional field blocks are not widely used in outpatient plastic surgeries. The efficacy of truncal blocks (PEC1 + SAP) has not been established in plastic surgery. The purpose of this study was to analyze the outcomes of these newer anesthetic techniques compared with traditional blind local anesthetic infiltration in patients undergoing breast augmentation. Methods This retrospective institutional review board-approved cohort study compared the outcomes of the different practices of 2 plastic surgeons at the same accredited outpatient surgery center between 2018 and 2022. Group 1 received an intraoperative blind local infiltration anesthetic. Group 2 underwent surgeon-led, intraoperative, ultrasound-guided PEC1 (Pectoralis 1) + SAP (serratus anterior plane) blocks. Patients who underwent any procedure other than primary submuscular augmentation mammoplasty were excluded from the study. The outcomes measured included operative time, opioid utilization in morphine milligram equivalents (MME), pain level at discharge, and time spent in the post anesthetic care unit (PACU). Results Sixty patients met the inclusion criteria for each group for a total of 120 patients. The study groups were similar to each other. Patients receiving PEC1 + SAP blocks (group 2) had significantly lower average MME requirements in the PACU (3.04 MME vs 4.52 MME, P = 0.041) and required a shorter average PACU stay (70.13 minutes vs 80.38 minutes, P = 0.008). There were no significant differences in the pain level at discharge, operative time, or implant size between the 2 groups. Conclusions Surgeon-led, intraoperative, ultrasound-guided PEC1 + SAP blocks significantly decreased opioid utilization in the PACU by 33% and patient time in the PACU by 13%, while achieving similar patient pain scores and operating times.

Perioperative Management of Neuroanesthesia in Patients with Supratentorial Tumors Who Have Excised Tumors Using Neuroprotection Technique and Total Intravenous Anesthesia

Background: Neuroanesthesia management presents a unique challenge for anesthesiologists. They must provide an optimal surgical condition without worsening the patient's neurological deficits. Therefore, we need drugs with neuroprotective abilities. This case report explains the perioperative management of neuroanesthesia in patients with supratentorial tumors who have excised tumors using a neuroprotection technique and total intravenous anesthesia (TIVA). Case: A 43-year-old female patient with space-occupying process cerebri with the differential diagnosis of meningioma frontotemporal dextra, post trepanation frontal sinistra tumor excision, edema cerebri, and hydrocephalus on ventriculoperitoneal shunt. On physical examination, Glasgow coma scale E3M6Vaphasia, aphasia and left hemiparesis were found. She underwent a tumor excision procedure with total intravenous anesthesia modified with neuroprotection techniques and total intravenous anesthesia techniques using 300 mg thiopental, 2 mg midazolam, 150 µg fentanyl, 80 mg lidocaine, and 50 mg rocuronium. Intraoperative anesthesia management was carried out by administering propofol 50 mg/hour, fentanyl 50 µg/hour, and atracurium 15 mg/hour. Conclusion: Total intravenous anesthesia is a complete general anesthesia method used in all intravenous agents, where the benefits of this method are used in neurosurgery, including accelerating the patient's return from the effects of anesthesia, faster recovery of cognitive function, as well as reducing intracranial pressure and the risk of ischemia.

The Anesthetic Technique for Clavicle Surgery in Remote Areas: Clavicopectoral Plane Block With Landmark Technique

The Anesthetic Technique for Clavicle Surgery in Remote Areas: Clavicopectoral Plane Block With Landmark Technique

Preoperative examination of inflammatory biomarkers in relation to the prognosis of postoperative complications after heart transplantation

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Semmelweis University Heart transplantation (HTX) is the definitive therapy for end-stage heart failure. Although complications have drastically decreased with modern immunosuppressive therapy, surgical and anesthetic techniques, significant complications such as graft failure, acute rejection or infection must still be expected. The purpose of the study is to examine cytokine pathways linked to inflammation from direct preoperative serum samples, which can serve as prognostic factors in relation to septic events and mortality in the early postoperative period. The study was conducted using the blood samples of 102 patients who underwent HTX. Blood samples were taken from the patients immediately before HTX. The amounts of a total of 32 cytokines and related proteins were determined using LEGENDplex assays. After that, we correlated the biomarker amounts determined in the serum samples with the end points we indicated. In patients undergoing HTX who developed septic events during postoperative intensive care, the preoperative MMP2 serum concentration was significantly higher compared to other patients undergoing HTX (n=23, p=0.04). Independent predictors of mortality in the intensive care unit (n=5) were preoperative MRP8/14 (AUC=0.8), NGAL (AUC=0.75), IGFBP-4 (AUC=0.73), cystatin C (AUC=0.7) and the MMP2 (AUC=0.74) serum concentrations. Patients transplanted from left ventricular mechanical circulatory support (LVAD) (n=11) were examined as a separate group, where early postoperative mortality was significantly higher (n=4, p=0.02), the independent predictor of which was the concentration of IGFBP-4 (p=0.04 , AUC=0.73). Based on our results, it can be said that the differences in the preoperative concentration of certain inflammatory biomarkers that can be measured in the serum show correlations with the postoperative septic events and mortality of patients undergoing HTX.

Axillary Brachial Plexus Block Compared with Other Regional Anesthesia Techniques in Distal Upper Limb Surgery: A Systematic Review and Meta-Analysis.

Background: Several regional anesthesia (RA) techniques have been described for distal upper limb surgery. However, the best approach in terms of RA block success rate and safety is not well recognized. Objective: To assess and compare the surgical anesthesia and efficacy of axillary brachial plexus block with other RA techniques for hand and wrist surgery. The attainment of adequate surgical anesthesia 30 min after block placement was considered a primary outcome measure. Additionally, successful block outcomes were required without the use of supplemental local anesthetic injection, systemic opioid analgesia, or the need to convert to general anesthesia. Methods: We performed a systematic search in the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and CENTRAL. RCTs comparing axillary blocks with other brachial plexus block techniques, distal peripheral forearm nerve block, intravenous RA, and the wide-awake local anesthesia no tourniquet (WALANT) technique were included. Results: In total, 3070 records were reviewed, of which 28 met the inclusion criteria. The meta-analysis of adequate surgical anesthesia showed no significant difference between ultrasound-guided axillary block and supraclavicular block (RR: 0.94 [0.89, 1.00]; p = 0.06; I2 = 60.00%), but a statistically significant difference between ultrasound-guided axillary block and infraclavicular block (RR: 0.92 [0.88, 0.97]; p < 0.01; I2 = 53.00%). Ultrasound-guided infraclavicular blocks were performed faster than ultrasound-guided axillary blocks (SMD: 0.74 [0.30, 1.17]; p < 0.001; I2 = 85.00%). No differences in performance time between ultrasound-guided axillary and supraclavicular blocks were demonstrated. Additionally, adequate surgical anesthesia onset time was not significantly different between ultrasound-guided block approaches: ultrasound-guided axillary blocks versus ultrasound-guided supraclavicular blocks (SMD: 0.52 [-0.14, 1.17]; p = 0.12; I2 = 86.00%); ultrasound-guided axillary blocks versus ultrasound-guided infraclavicular blocks (SMD: 0.21 [-0.49, 0.91]; p = 0.55; I2 = 92.00%). Conclusions: The RA choice should be individualized depending on the patient, procedure, and operator-specific parameters. Compared to ultrasound-guided supraclavicular and infraclavicular block, ultrasound-guided axillary block may be preferred for patients with significant concerns of block-related side effects/complications. High heterogeneity between studies shows the need for more robust RCTs.

A Review on Techniques of Blood Withdrawal in Experimental Small Animals

In preclinical research, experimental studies in small animals like pharmacokinetics/ toxicokinetics, serum biochemistry and hematology necessitate the biological matrix sampling to estimate drug level, serum enzyme, and blood parameters respectively. The biological matrix is withdrawn from experimental animals by employing the recommended blood collection technique and must be conducted in compliance with the ethical guidelines. It has demanded a minimal painful and least stressful procedures, which can be achieved using inhalant/parenteral anesthesia and/or proper restraint technique. This leads to better experimental outcome. The study personnel conducting blood withdrawal must be well-versed. All these procedures must be approved by IAEC protocol and should include scientist and study personnel names who are involved in animal handling and blood withdrawal. In this review, the different techniques of blood withdrawal from small animals, including collection guidelines, limit volumes and recovery periods, and advantages and disadvantages of sites used for blood collection are demonstrated and discussed.