Dose Of Lidocaine Research Articles

Changes in plasma alpha-1 acid glycoprotein following hemorrhagic trauma: Possible role in dose differences of ALM drug therapy in rat and pig resuscitation.

The binding of drugs to plasma proteins is an important consideration in drug development. We have reported that the dose of adenosine, lidocaine, and magnesium (ALM) fluid therapy for resuscitation from hemorrhagic shock is nearly 3-times higher for pigs than rats. Since lidocaine strongly binds to serum alpha-1-acid glycoprotein (AGP), the aim of the study was to investigate the effect of hemorrhagic shock on levels of AGP in rats and pigs. Healthy adult male Sprague-Dawley rats and female crossbred pigs (n = 33 each) underwent tail vein and peripheral ear vein blood sampling, respectively, to collect plasma for AGP measurements. Rats (n = 17) and pigs (n = 16) underwent surgical instrumentation and uncontrolled hemorrhage via liver resection, and were treated with 3% NaCl ± ALM IV bolus followed 60 min later by 4 h 0.9% NaCl ± ALM IV drip. Rats were monitored for 72 h with blood samples taken post-surgery, and at 5.25, 24, and 72 h. Pigs were monitored for 6 h with blood samples taken post-surgery, and at 60 min and 6 h. Plasma AGP was measured with rat- and pig-specific enzyme-linked immunosorbent assay kits. Baseline AGP levels in rats were 3.91 μg/mL and significantly 83-fold lower than in pigs (325 μg/mL). Surgical instrumentation was associated with ~10-fold increases in AGP in rats and a 21% fall in pigs. AGP levels remained elevated in rats after hemorrhage and resuscitation (28-29 μg/mL). In contrast, no significant differences in plasma AGP were found in ALM- or Saline-treated pigs over the monitoring period. We conclude that the trauma of surgery alone was associated with significant increases in AGP in rats, compared to a contrasting decrease in pigs. Higher levels of plasma AGP in pigs prior to hemorrhagic shock is consistent with the higher ALM doses required to resuscitate pigs compared with rats.

Clinical dosage of lidocaine does not impact the biomedical outcome of sepsis-induced acute respiratory distress syndrome in a porcine model.

Sepsis is a common disease in intensive care units worldwide, which is associated with high morbidity and mortality. This process is often associated with multiple organ failure including acute lung injury. Although massive research efforts have been made for decades, there is no specific therapy for sepsis to date. Early and best treatment is crucial. Lidocaine is a common local anesthetic and used worldwide. It blocks the fast voltage-gated sodium (Na+) channels in the neuronal cell membrane responsible for signal propagation. Recent studies show that lidocaine administered intravenously improves pulmonary function and protects pulmonary tissue in pigs under hemorrhagic shock, sepsis and under pulmonary surgery. The aim of this study is to show that lidocaine inhalative induces equivalent effects as lidocaine intravenously in pigs in a lipopolysaccharide (LPS)-induced sepsis with acute lung injury. After approval of the local State and Institutional Animal Care Committee, to induce the septic inflammatory response a continuous infusion of lipopolysaccharide (LPS) was administered to the pigs in deep anesthesia. Following induction and stabilisation of sepsis, the study medication was randomly assigned to one of three groups: (1) lidocaine intravenously, (2) lidocaine per inhalation and (3) sham group. All animals were monitored for 8 h using advanced and extended cardiorespiratory monitoring. Postmortem assessment included pulmonary mRNA expression of mediators of early inflammatory response (IL-6 & TNF-alpha), wet-to-dry ratio and lung histology. Acute respiratory distress syndrome (ARDS) was successfully induced after sepsis-induction with LPS in all three groups measured by a significant decrease in the PaO2/FiO2 ratio. Further, septic hemodynamic alterations were seen in all three groups. Leucocytes and platelets dropped statistically over time due to septic alterations in all groups. The wet-to-dry ratio and the lung histology showed no differences between the groups. Additionally, the pulmonary mRNA expression of the inflammatory mediators IL-6 and TNF-alpha showed no significant changes between the groups. The proposed anti-inflammatory and lung protective effects of lidocaine in sepsis-induced acute lung injury could not be proven in this study.

The impact of intraoperative intravenous lidocaine infusion on early postoperative pain after complex spine surgeries

BackgroundThis study aimed to assess the effect of intravenous lidocaine infusion affected on early postoperative pain control after complex spin surgeries.Ninety patients who were scheduled for complex spine surgery were included in this prospective double-blinded controlled trial. They were randomly assigned to one of two groups: L and P. Patients in group L received a loading dose of lidocaine 1 mg/kg then followed by 1.5 mg/kg/h infusion till the end of the surgery, while in group P, lidocaine was replaced with normal saline.ResultsThe pain score assessed by VAS at rest showed statistically significant lower values in group L at 30 min, 8, 12, and 24 h postoperatively. VAS during movement was significantly higher in group P only after 24 h postoperatively. The entire dose of intraoperative fentanyl consumed was significantly lower in group L. The time elapsed to ask for the first dose of rescue analgesia was significantly longer in group L. The first rescue dose of nalbuphine was significantly lower in group L. In group P, the overall dose of narcotics consumed in the first postsurgical day was significantly higher.ConclusionsWhen compared to placebo, lidocaine infusion significantly reduced the postoperative pain scores, as well as the entire dose of intraoperative and postoperative narcotics used.

Five Versus 10 Pharyngeal Sprays of 10% Lignocaine for Topical Anesthesia During Flexible Bronchoscopy: A Multicenter, Randomized Controlled Trial.

Ensuring adequate patient comfort is crucial during bronchoscopy. Although lidocaine spray is recommended for topical pharyngeal anesthesia, the optimum dose of sprays is unclear. We compared 5 versus 10 sprays of 10% lidocaine for topical anesthesia during bronchoscopy. In this investigator-initiated, prospective, multicenter, randomized clinical trial, subjects were randomized to receive 5 (group A) or 10 sprays (group B) of 10% lidocaine. The primary objective was to compare the operator-rated overall procedure satisfaction between the groups. Two hundred eighty-four subjects were randomized (143 group A and 141 group B). The operator-rated overall procedure satisfaction, VAS [mean (SD)] was similar between the groups [group A, 74.1 (19.9) and group B, 74.3 (18.5), P=0.93]. The VAS scores of patient-rated cough [group A, 32.5 (22.9) and group B, 32.3 (22.2), P=0.93], and operator-rated cough [group A, 29.8 (22.3) and group B, 26.9 (21.5), P=0.26] were also similar. The time to reach vocal cords, overall procedure duration, mean doses of sedatives, the proportion of subjects willing to return for a repeat procedure (if required), and complications were not significantly different. Subjects in group A received significantly less cumulative lidocaine (mg) [group A, 293.9 (11.6) and group B, 343.5 (10.6), P<0.001]. During bronchoscopy, topical anesthesia with 5 sprays of 10% lidocaine is preferred as it is associated with a similar operator-rated overall procedure satisfaction at a lower cumulative lidocaine dose compared with 10 sprays.

A Multi-Centered Case Series Highlighting the Clinical Use and Dosing of Lidocaine and Mexiletine for Refractory Cancer Pain (Sci202)

A Multi-Centered Case Series Highlighting the Clinical Use and Dosing of Lidocaine and Mexiletine for Refractory Cancer Pain (Sci202)

Multimodal Analgesia with Local Wound Infiltration and Intravenous Parecoxib for Thyroidectomy.

Background and objective: Adequate postoperative pain control is an important component to enhance recovery. Multimodal analgesia with various pain control techniques has been widely used to alleviate postoperative pain. The use of either wound infiltration or a superficial cervical plexus block has been reported to be effective for pain management after thyroid surgery. The present study evaluated the effect of multimodal analgesia using lidocaine wound infiltration combined with intravenous parecoxib for patients monitored after thyroidectomy. Materials and Methods: A total of 101 patients with a multimodal analgesia protocol being monitored after thyroidectomy were enrolled. After the induction of anesthesia, multimodal analgesia was performed through wound infiltration of 1% lidocaine and epinephrine at a ratio of 1:200,000 (5 μg/mL) combined 40 mg intravenous parecoxib before skin excision. Patients were divided into two groups for this retrospective analysis based on the injection dose of lidocaine they received. Patients in Group I (the control, n = 52) received a 5 mL injection solution, while those in Group II (the study, n = 49) received a 10 mL dosage in a time-sequential manner, in accordance with a previous clinical trial. The primary outcome was measuring postoperative pain intensity at rest, as well as during motion and coughing, which was measured at the postoperative anesthetic care unit (PACU) and on the first day after the operation (POD 1) in the ward. Pain intensity was assessed using a numerical rating scale (NRS). The secondary outcomes were postoperative adverse events including anesthetic-related side effects, as well as airway and pulmonary complications. Results: Most of the patients reported no pain or mild pain during the observation period. The patients in Group II had a lower pain intensity during motion than Group I (NRS 1.47 ± 0.89 vs. 1.85 ± 0.96, p = 0.043) when measured at the postoperative anesthetic care unit. Pain intensity during coughing was also significantly lower in the study group than in the control group (NRS 1.61 ± 0.95 vs. 1.96 ± 0.79, p = 0.049) when measured at the postoperative anesthetic care unit. There were no severe adverse events in either of the groups. Only one patient (1.9%) in Group I experienced temporary vocal palsy. Conclusions: The use of lidocaine with an equal volume of intravenous parecoxib provided comparable analgesia with minimal adverse events when monitoring thyroidectomy.

A Systematic Review of the Usage of Lidocaine in Hip Replacement Surgery.

Hip replacement procedures, professionally known as hip arthroplasty, are one of the most common orthopedic procedures. Due to the variation in this procedure, the use and types of anesthetics differ. One such commonly used anesthetic is lidocaine. Since there are currently no standardized or general procedures for the application of lidocaine for perioperative hip arthroplasty procedures, this review aims to delve into this topic. A literature review surrounding the key terms "hip replacement" and "lidocaine" was performed on PubMed. After reviewing 24 randomized control trials, statistical analyses between groups that had no lidocaine versus groups that did were performed. The results showed that there was no statistical significance between various age groups and the use of lidocaine. One percent (1%) and 2% injected into the lumbar region were the most commonly reported doses of lidocaine, with 2% often being the first test dose. Other conclusions were that lidocaine was used for general anesthesia for individuals that underwent hip arthroplasty due to an underlying condition (cauda equina syndrome, ankylosing spondylitis, etc.). Lidocaine was also used for postoperative pain relief, which is a potential concern from its addictive qualities. This investigation outlines the current stance and usage of lidocaine in perioperative hip arthroplasty while noting its limitations.

Comparison of 40 and 100 mg of laryngotracheal lidocaine instillation to prevent cough during emergence from general anesthesia: A randomized controlled trial

BackgroundPrevious studies have found that laryngotracheal instillation of 100–160 mg of lidocaine could alleviate cough. The objective of this study was to examine whether a smaller dosage (40 mg) of lidocaine can produce a noninferior result compared with the usual dosage. MethodThis study included 275 patients aged 18–60 years with an American Society of Anesthesiologists class I-III who were undergoing elective surgery under general anesthesia with a tracheal tube. All patients were randomly divided into two groups. Two milliliters of 2% lidocaine (40 mg) diluted with 3 ml of sterile water to make up a 5-ml solution for the L40 group was prepared to be identical with a 5-ml solution of 2% lidocaine (100 mg) for the L100 group. The 5-ml solutions were divided into halves and injected using 3-ml syringes through each of the two ports of a laryngotracheal instillation of the topical anesthesia tube at the end of surgical closure. The severity of cough and complications during extubation and stay in the postanesthetic care unit were recorded. ResultsA total of 275 patients were enrolled, and five patients were excluded. The incidence of total cough was significantly higher in the L40 group (71.1%) than in the L100 group (52.6%) (P = 0.003). However, the incidence of cough grades 1 and 2 was comparable between the two groups (75.6% and 76.8%, respectively; P = 0.464). Sore throat and swallowing difficulty were common complications, but there were no statistical differences. ConclusionThe incidence of cough with lidocaine 40 mg administered intratracheally was significantly higher than that with lidocaine 100 mg during extubation. Thai Clinical Trial Registry numberTCTR 20200811001 (www.thaiclinicaltrials.org).

Intravenous lidocaine for attenuation of pressor response after endotracheal intubation. A randomized, double-blinded dose-finding study

ABSTRACT Introduction Endotracheal intubation (ETI) is one of the commonly used maneuvers in the daily anesthetic practice, it is commonly associated with hemodynamic stimulation leading to marked tachycardia, hypertension, and myocardial ischemia. Aim and objectives In this study, we compared three doses of lidocaine for prophylaxis against pressor response of ETI. We hypothesized that the larger dose (2 mg/Kg) will be more effective for attenuation of the pressor response. Methods After randomization, post induction of anesthesia patients were categorized into three groups according to the dose of lidocaine: group A received 1 mg/Kg, group B received 1.5 mg/Kg, and group C received 2 mg/Kg. To achieve blinding, the study drug was prepared by a research assistant and was diluted to 10 mL in all groups. Heart rate measurement after 1 minute of lidocaine injection was carried out. Heart rate, cardiac output and stroke volume were continuously measured and were recorded every 30 seconds starting from baseline pre-induction reading till 5 minutes zafter ETI, systolic and diastolic blood pressure were measured at 1-minute intervals starting from baseline reading till 5-minute after ETI. Results Pressor response was lower in group C receiving 2 mg/Kg with P value = 0.021 defined by an increase in the heart rate, cardiac output, or systolic blood pressure by 20% or more which was evaluated after ETI continuously for 5 minutes. Conclusion Lidocaine in the dose of (2mg/Kg) is more effective than lower doses in attenuation of the pressor response of the ETI.

Effect of local administration of eicosapentaenoic acid on the jaw-opening reflex in rats.

Although eicosapentaenoic acid (EPA) application in vitro inhibits voltage-gated Na+ (Nav) channels in excitable tissues, the acute local effect of EPA on the jaw-opening reflex in vivo remains unknown. The aim of the present study was to determine whether local administration of EPA to adult male Wistar rats could attenuate the excitability of the jaw-opening reflex in vivo, including nociception. The jaw-opening reflex evoked by electrical stimulation of the tongue was recorded by a digastric muscle electromyogram (dEMG) in pentobarbital-anesthetized rats. The amplitude of the dEMG response was significantly increased in proportion to the electrical stimulation intensity (1×-5× threshold). At 3×, local administration of EPA dose-dependently inhibited the dEMG response, lasting 60min, with maximum inhibition observed within approximately 10min. The mean magnitude of dEMG signal inhibition by EPA was almost equal to that observed with a local anesthetic, 1% lidocaine, and with a half dose of lidocaine plus a half dose of EPA. These findings suggest that EPA attenuates the jaw-opening reflex, possibly by blocking Nav channels of primary nerve terminals, and strongly support the idea that EPA is a potential therapeutic agent and complementary alternative medicine for the prevention of acute trigeminal nociception.

Evaluation of Efficacy of Two Different Doses of Intravenous Lidocaine in Patients with Chronic Pain

Background: An intravenous infusion of lidocaine has been used on numerous occasions to produce analgesia in neuropathic pain. It has been shown to be beneficial for the treatment of variety of neuropathic pain states in a wide range of dosage, from 2 to 7.5 mg/kg. The aim of our study was to evaluate the efficacy of two different doses of intravenous lidocaine (3 and 4 mg/kg) in patients with chronic pain. Methods: Patients above the age of 18 years suffering from chronic pain due to postherpetic neuralgia, post-surgical scar pain, chronic low back pain having numeric analogue scale (NAS) pain score of ≥3 without satisfactory pain relief from conservative treatment were randomised to receive either 3 mg/kg or 4 mg/kg intravenous lidocaine in 250 mL normal saline infusions weekly over a period of 1 hour for 3 weeks. NAS was measured before starting each infusion, immediately after completion of infusion, 2 and 24 hours, 7th day, 14th day, 21st day, and 28th day. Results: NAS score at first hour and 24th hour was significantly reduced (P = 0.001), after each infusion [7th, 14th day] in both the groups. There was no statistical difference in pain score among both groups except for day 7 (P value 0.04). Reduction in NAS score was also present on 21st and 28th day in both groups, but it did not reach a significant value. On 28th day, NAS score values showed increasing trend. Duration of pain relief was around 1 week after each infusion in both groups. Conclusion: Intravenous lidocaine at a dose of 3 mg/kg or 4 mg/kg was effective in reducing pain in patients with chronic pain. The analgesic effect was not different among both groups. Trend of greater response was observed with 4 mg/kg dose.

The role of ultrasound-guided perineural injection of the tibial nerve with a sub-anesthetic dosage of lidocaine for the diagnosis of tarsal tunnel syndrome.

Tarsal tunnel syndrome (TTS) involves entrapment of the tibial nerve at the medial ankle beneath the flexor retinaculum and its branches, the medial and lateral plantar nerves, as they course through the porta pedis formed by the deep fascia of the abductor hallucis muscle. TTS is likely underdiagnosed, because diagnosis is based on clinical evaluation and history of present illness. The ultrasound-guided lidocaine infiltration test (USLIT) is a simple approach that may aid in the diagnosis of TTS and predict the response to neurolysis of the tibial nerve and its branches. Traditional electrophysiological testing cannot confirm the diagnosis and only adds to other findings. We performed a prospective study of 61 patients (23 men and 38 women) with a mean age of 51 (29-78) years who were diagnosed with idiopathic TTS using the ultrasound guided near-nerve needle sensory technique (USG-NNNS). Patients subsequently underwent USLIT of the tibial nerve to assess the effect on pain reduction and neurophysiological changes. USLIT led to an improvement in symptoms and nerve conduction velocity. The objective improvement in nerve conduction velocity can be used to document the pre-operative functional capacity of the nerve. USLIT may also be used as a possible quantitative indicator of whether the nerve has the potential to improve in neurophysiological terms and ultimately inform prognosis after surgical decompression. USLIT is a simple technique with potential predictive value that can help the clinician to confirm the diagnosis of TTS before surgical decompression.

Efficacy of dexmedetomidine-based opioid-free anesthesia on the control of surgery-induced inflammatory response and outcomes in patients undergoing open abdominal hysterectomy

ABSTRACT Objectives To compare the effect of opioid-based (OB-GA) versus opioid-free intraoperative analgesia during general anesthesia (OF-GA) and epidural anesthesia (EA) during open abdominal hysterectomy on pro-inflammatory cytokines’ levels estimated in blood samples obtained at end of surgery (S2) and 24-hr (S3) postoperative (PO). Patients Patients of OF-GA group received loading doses of dexmedetomidine (DEX; 0.6 µg/kg) and Lidocaine (LID; 1.5 mg/kg) and intraoperative (IO) DEX (1 µg/kg) and LID (20 mg/ ml) infusions. GA was provided as sevoflurane inhalational anesthesia and EA was provided as loading dose (15 ml) of 0.5% bupivacaine and intermittent doses if required. The study outcome is the effect of anesthetic techniques on S2 and S3-samples’ serum cytokines’ levels. Results PO serum cytokines’ levels were significantly higher than preoperative levels with significantly higher levels in S2-sample of patients OB-GA patients compared to patients of other groups. In the S3 sample, serum cytokines’ levels were decreased after OB-GA but increased after OF-GA and EA. OF-GA provided better IO hemodynamic control and PO lower cytokines’ levels, pain scores and consumption of rescue analgesia. Satisfaction scores were significantly higher by OF-GA and LA. Conclusion DEX-based OF-GA provided better IO and PO control on surgical inflammatory response with improved PO outcomes regarding analgesia and adverse effects. EA also allowed IO control on cytokines’ levels but PO rebound was detected.

Effectivity of Intravenous Lidocaine in Pain of Neuropathic Origin

Background: In order to accomplish the goals of this research project, lidocaine was administered intravenously (IV) to patients who were experiencing neuropathic pain. The researchers had an interest in gaining a deeper understanding of the connections that exist between effect and concentration, as well as graded and quanta1 dose-response. Study Place: Kulsoom International Hospital Islamabad Study Duration: 6months (Feb 2021 To July 2021) Methods and Materials: Fifteen patients received an intravenous dose of lidocaine at a rate of 8.35 milligrams per minute for a total of one hour. During the course of the study, both venous blood samples and visual analog pain scores were collected at regular intervals of ten minutes for duration of sixty minutes. In addition, blood samples were taken in order to determine the concentrations of lidocaine in the serum as well as the amount of water in the serum both at the start of the analgesia as well as when the patient had reached their maximum level of pain relief. In order to determine the levels of lidocaine, a technique known as gas chromatography was performed. Result: In addition to graded dose-response curves for each participant and the group, a quanta1 dose-response curve was created. Besides graded dose-response curves, this was done. Also done: graded dose-response curves. The dose-response relationship for IV lidocaine showed large pain relief for modest dose changes. Despite moderate dosage increases, this was true. This was when the drug was given. The ED administered 370.0 mg of lidocaine, but the ED administered 415.5 mg (5 min of infusion). Similar to the link between concentration and effect, 0.60 pg/mL of lidocaine significantly reduced pain. It's intriguing that serum lidocaine concentration didn't correlate better with analgesia onset or end than free lidocaine concentration did. Free lidocaine concentration correlated with analgesic effect. Lidocaine concentration in the serum was a stronger predictor of analgesia. Conclusion: This suggests that IV lidocaine's analgesic mechanism may not follow a concentration-effect connection. The evidence shows this. Intravenous lidocaine is significantly stronger than oral. The analgesic response to intravenous lidocaine is a quick "break in pain" over a narrow dosage and concentration range. This was true independent of lidocaine dose. It doesn't matter how much lidocaine is given.

Spotlight in Plastic Surgery: January 2023.

Spotlight in Plastic Surgery: January 2023.

"Can Perioperative Intravenous Lidocaine Decrease Postoperative Pain After Oral and Maxillofacial Surgeries?": A Randomized Clinical Trial.

To determine the efficacy of perioperative intravenous lidocaine in decreasing postoperative pain after oral and maxillofacial surgeries. Forty patients undergoing various oral and maxillofacial surgeries under general anesthesia were recruited in this prospective, randomized, double blinded controlled trial. Lidocaine group received Lidocaine 2.0%, whereas the control group received Normal saline 0.9% infusion. Pain intensity, sedation, vitals and side effects were assessed at 2h, 4h, 6h, 12h and 24h postoperatively. Twenty patients were assigned to each group. There were no significant differences between the groups for the study variables at baseline. The median Numeric Rating Scale (NRS) pain scores were higher in normal saline group than lidocaine group at 2h, 4h and 6h and same at 12and 24h; however, the differences were not statistically significant. Mean (± SD) analgesic consumed in lidocaine group was 47.37 (± 42.80) mg and 69.47(± 36.13) mg in saline group, which was not significant either. Similarly, no statically significant difference was observed for sedation and vitals at all the time intervals. Perioperative infusion of low dose lidocaine does not have significant effect on reduction in postoperative pain intensity and analgesic consumption, in patients undergoing oral and maxillofacial surgeries. Trail registered at clinicaltrials.gov (NCT03479320).

Comparison of Amiodarone with Combined Doses of Magnesium Sulphate and Lidocaine for Prevention of Ventricular Fibrillation Following Coronary Clamp Release During Coronary Artery Bypass Graft Surgery

Objective: To compare the effects of amiodarone with effects of combined doses of magnesium sulphate and lidocaine for prevention of ventricular fibrillation following coronary clamp release during (coronary artery bypass grafting) CABG.&#x0D; Study Design: Comparative cross sectional study.&#x0D; Place and Duration of Study: Army Cardiac Centre, Lahore Pakistan, from Jun 2021 to Dec 2021.&#x0D; Methodology: One hundred patients who reported at Army Cardiac Centre Lahore, Pakistan for coronary artery bypass grafting surgery, were involved in comparative study. Patients satisfying the inclusion criteria were allocated into the LM(Lidocaine Magnesium) and A (Amiodarone) groups. Following aortic cross clamp release, the incidence of ventricular fibrillation (VF) and other arrhythmias was calculated in first 30 minutes and up to 24 hours later. The ionotropic agent used was epinephrine at a rate of 0.05 to 0.1 micrograms/kg/minute. Within 15 minutes of anesthetic induction and 15 minutes after the CPB pump was removed, hemodynamic parameters were assessed and recorded.&#x0D; Results: Arrhythmias within 30 minutes and up to 24 hours after aortic cross clamp ACC release in A and LM group were compared. The difference between two groups, having arrhythmias and no arrhythmias was statistically insignificant (p≥0.050) except VF up to 24 hours after ACC release. The highest voltage for defibrillation was used in Group-A n=20 (40.0%) and n=27 (54.0%) in L.M group, (p=0.004). The average electrical defibrillations in group-A was less than that of group L.M,(p=0.000). While, the use of ionotropic agent was almost equal in both the groups, (p=0.975).&#x0D; Conclusion: Overall, the amiodarone group had a decreased incidence of VF when the ACC was released, while the difference was not statistically significant.

Evaluation of lidocaine for brachial plexus blockade in eastern box turtles (Terrapene carolina carolina)

ObjectiveTo evaluate latency and duration of a brachial plexus block technique in eastern box turtles performed with 2% lidocaine at three dose rates. Study designProspective, randomized, blinded crossover study. AnimalsAdult eastern box turtles, two for drug dose evaluation and a group of six (three male, three female) weighing 432 ± 40 g (mean ± standard deviation) for the main study. MethodsAnimals were randomly assigned to four brachial plexus blocks with lidocaine at 5, 10 and 20 mg kg–1 or 0.9% saline (treatments LID5, LID10, LID20 and CON, respectively), separated by 1 week. Treatment side was randomized and blocks were performed unilaterally. Baseline observations of mentation, heart rate (HR), respiratory rate (fR), skin temperature and limb response to manipulation or toe pinch were evaluated. Assessments were made every 10 minutes until 1 hour of normal sensory and motor function to the treated thoracic limb, or for a total of 2 hours if no block was evident. ResultsMotor and sensory blockade was achieved in treatments LID10 and LID20 in one turtle, with a latency of 10 minutes and duration of 50 minutes for both doses. Raising of the ipsilateral lower palpebra occurred with both blocks. Turtles administered lidocaine experienced higher HR compared with CON, and HR decreased over time for all individuals. Mentation and fR were not changed with any lidocaine dose. ConclusionsThe technique was unreliable in producing brachial plexus motor and sensory blockade at the lidocaine doses evaluated in this study. HR was higher in lidocaine-administered turtles but remained within normal limits for the species. No change in mentation or fR was observed among treatments. Clinical relevanceGeneral anesthesia with systemic analgesia is recommended for surgical procedures involving the chelonian thoracic limb. Further studies are needed to optimize a brachial plexus block in this species.

Effects of two continuous infusion doses of lidocaine on isoflurane minimum anesthetic concentration in chickens

ObjectiveTo assess the effect of two intravenous (IV) doses of lidocaine on the minimum anesthetic concentration (MAC) of isoflurane in chickens. Study designBlinded, prospective, randomized, experimental crossover study. AnimalsA total of six adult female chickens weighing 1.90 ± 0.15 kg. MethodsChickens were anesthetized with isoflurane and mechanically ventilated. Isoflurane MAC values were determined (T0) in duplicate using an electrical noxious stimulus and the bracketing method. After MAC determination, a low dose (LD; 3 mg kg–1 followed by 3 mg kg–1 hour–1) or high dose (HD; 6 mg kg−1 followed by 6 mg kg−1 hour–1) of lidocaine was administered IV. MAC determination was repeated at 1.5 (T1.5) and 3 (T3) hours of lidocaine administration and blood was collected for analysis of plasma lidocaine and monoethylglycinexylidide (MEGX) concentrations. Pulse rate, peripheral hemoglobin oxygen saturation, noninvasive systolic arterial pressure and cloacal temperature were recorded at T0, T1.5 and T3. Treatments were separated by 1 week. Data were analyzed using mixed-effects model for repeated measures. ResultsMAC of isoflurane (mean ± standard deviation) at T0 was 1.47 ± 0.18%. MAC at T1.5 and T3 was 1.32 ± 0.27% and 1.26 ± 0.09% (treatment LD); and 1.28 ± 0.06% and 1.30 ± 0.06% (treatment HD). There were no significant differences between treatments or times. Maximum plasma lidocaine concentrations at T3 were 496 ± 98 and 1200 ± 286 ng mL–1 for treatments LD and HD, respectively, and were not significantly different from T1.5. With treatment HD, plasma concentration of MEGX was significantly higher at T3 than at T1.5. Physiological variables were not significantly different among times with either treatment. Conclusions and clinical relevanceAdministration of lidocaine did not significantly change isoflurane MAC in chickens. Within treatments, plasma lidocaine concentrations were not significantly different at 1.5 and 3 hours.

Abstract 156: Clinical Significance Of Left Ventricular Systolic Dysfunction After Cardiac Arrest

Introduction: Post-resuscitative transthoracic echocardiography (TTE) in cardiac arrest survivors has led to increased identification of left ventricular systolic dysfunction (LVSD). We sought to evaluate the association between LVSD and in-hospital outcomes. Methods: This is a retrospective review of all cardiac arrest patients with TTE documenting left ventricular systolic function during admission to a single tertiary care center between 2015 and 2020. We used a multivariable logistic regression adjusted for age, sex, race, cardiac arrest location, witnessed arrest, initial rhythm, etiology, and Charlson Comorbidity Index to evaluate the association between LVSD and in-hospital outcomes. LVSD was defined as ejection fraction (EF) &lt; 40% on TTE. Good neurologic outcome was defined as Cerebral Performance Categories 1-2. High vasopressor need was defined as peak norepinephrine-equivalent dose &gt; 1mcg/kg/min within 72 hours of arrest. Use of antiarrhythmic was defined as any dose of amiodarone, esmolol, or lidocaine within 72 hours of arrest. Results: Of 477 cardiac arrest patients, 321 (67.3%) met inclusion and were included in the analysis. Mean age was 60.4 ± 16.9 years with most being male (n= 192, 59.8%) and Caucasian (n=203, 63.2%). The majority had out-of-hospital cardiac arrest (n=212, 66%) and presented with a non-shockable rhythm (n=220, 68.5%). LVSD was more common in patients with shockable rhythm (48.5% (n =49) vs 22.6% (n= 49), p&lt;0.001). There was no difference in survival to hospital discharge, good neurologic outcome, or progression to brain death for patients with LVSD compared to those without (OR [95% CI] 1.04 [0.57-1.86], 0.87 [0.46-1.62], and 1.84 [0.70-4.79], respectively). LVSD was associated with increased use of antiarrhythmics (OR 2.85 [1.55-5.26]) and high vasopressor requirement (OR 1.81 [1.08-3.05]). Conclusion: LVSD was common in cardiac arrest patients, particularly those with shockable rhythm arrest, and was associated with increased vasopressor or antiarrhythmic use. There was no association between LVSD and survival to hospital discharge, functional neurologic outcome, or progression to brain death.