Unilateral Anesthesia Research Articles

Comparison of a fixed dose of 0.15% Hypobaric and 0.5% Hyperbaric Bupivacaine for shortterm unilateral lower limb orthopedic surgeries.Retrospective study with two videos

Background: Unilateral spinal anesthesia in orthopedic surgery of a limb has its advantages, especially in patients undergoing outpatient basis surgeries. Low dose, slow speed of administration and remaining in lateral decubitus for a certain period facilitate unilateral distribution in spinal anesthesia. Isobaric solutions of local anesthetics are not suitable for this type of anesthesia. Hypobaric and hyperbaric solutions of bupivacaine were compared in unilateral spinal anesthesia in patients undergoing orthopedic surgeries of one limb on an outpatient basis. Methods: Retrospective study carried out between 2002 and 2020 with 497 patients were randomly divided into two groups to receive 6 mg of 0.15% hypobaric bupivacaine or 6 mg of 0.5% hyperbaric bupivacaine. The solutions were administered in the L3-L4 space with the patient in the left lateral decubitus and remaining in this position for 15 minutes. Sensitive anesthesia was evaluated by the pin prick test. Motor blockade was determined by the modified Bromage scale. Both blockades were compared with the opposite side and among themselves. Results: There was a significant difference between the side of the surgery and the opposite side in all two groups at 15 minutes, but the frequency of unilateral spinal anesthesia was 90.9% with the 0.15% hypobaric bupivacaine versus 93.2% with the 0.5% hyperbaric bupivacaine. Patients did not develop any hemodynamic changes. Post puncture headache and transitory neurological symptoms were not observed. Conclusion: Spinal anesthesia with hypobaric and hyperbaric solutions present a higher frequency of unilateral anesthesia, without cardiocirculatory alteration, and patient satisfaction in remaining with a limb without anesthesia.

Comparison Of Hemodynamic Effect Caused By Intrathecal Low Dose Administration Of 0.5% Against 0.75% Hyperbaric Bupivacaine In Patients Undergoing Lower Limb Surgery Under Unilateral Spinal Anaesthesia.

Spinal anaesthesia has its unique place in modern anaesthetic practice. In past, most of the surgeries, irrespective of the site of surgery, were performed in general anaesthesia but now in the modern anaesthetic field, spinal anaesthesia has markedly replaced general anaesthesia, specifically in obstetrics, lower limbs, and abdominal surgeries. A total of 100 patients fit to undergo lower limb surgery between the ages of 20 to 70 years were included in the study. 50 patients were in 0.5% hyperbaric bupivacaine (Group A) while 50 patients were in the 0.75% hyperbaric bupivacaine group (Group B). Patients with a history of allergies to local anaesthetics, ischemic heart disease and contraindications to spinal anaesthesia were excluded. At the end of the injection, the patient was immediately laid down and tilted to 30 degrees lateral on the operative side for unilateral anaesthesia. Mean arterial pressure at baseline, 15, 30, 45 and 60 minutes was recorded by trainee anaesthesia. A baseline was taken of mean arterial pressure measured 15 minutes before induction of spinal anaesthesia in a lying position. The mean baseline arterial pressure of patients in group A was 88.72±1.71 mmHg and in group B was 88.94±1.95 mmHg. Mean arterial pressure MAP at 15, 30, 45 and 60 minutes in both groups was as follows; 86.22±2.55 vs 81.78±1.52 mmHg, 83.72±3.36 vs 75.84±1.34 mmHg, 80.02±3.40 vs 70.90±0.97 mmHg and 77.14±4.24 vs 66.06±1.62 mmHg respectively (p-value <0.05). This study concluded that the hemodynamic parameters in terms of mean arterial pressure remained more stable by deviating less from the baseline value with the use of a low dose of 0.5% hyperbaric bupivacaine instead of 0.75% hyperbaric bupivacaine in patients undergoing lower limb surgery under unilateral spinal anaesthesia.

Comparative assessment of effect of two methods of spinal anesthesia on central hemodynamic parameters in elderly and senile patients in emergency vascular surgery

Objective. To improve the results of treatment of comorbid patients with acute arterial ischemia by substantiating the optimal type of spinal anesthesia for surgical intervention on the affected limb.Materials and methods. The study involved 70 patients who were treated in the Department of Vascular Surgery of Clinical Hospital of ‘Russian Railways-Medicine Co.’ in Barnaul. The patients were divided into two groups: group 1 – patients operated under conditions of bilateral (bilateral) spinal anesthesia, group 2 – patients operated under conditions of monolateral (unilateral) spinal anesthesia. All patients underwent an assessment of the level of spinal block on the Bromage scale, monitoring of central hemodynamics using a MARG-10–01 rheograph, postoperative assessment of myocardial ischemia on the ECG, acute kidney damage to control diuresis.Results. In the 2nd group, there was a sufficient sensory and motor block to perform surgery. In the intraoperative period in the group of patients who underwent unilateral blockade, the mean arterial pressure decreased by 3 mm Hg. In this regard, there was no clinically significant increase in heart rate and a decrease in the stroke index and the index of total peripheral vascular resistance. In the 1st group, the decrease in mean arterial pressure reached 20% of the original, which led to an increase in heart rate by 12% and a decrease in stroke index by 11%.Conclusions. During the perioperative period, the indicators of central hemodynamics in the group 2 were more stable compared to the group 1, they did not need the use of vasopressor drugs and crystalloids. And in the early postoperative period, patients who underwent unilateral anesthesia did not show signs of acute kidney injury. Monolateral spinal anesthesia, compared with conventional spinal anesthesia, provides more stable hemodynamics in elderly patients with acute arterial ischemia.

Electrical Stimulation of Distal Tibial Nerve During Stance Phase of Walking May Reverse Effects of Unilateral Paw Pad Anesthesia in the Cat.

Cutaneous feedback from feet is involved in regulation of muscle activity during locomotion, and the lack of this feedback results in motor deficits. We tested the hypothesis that locomotor changes caused by local unilateral anesthesia of paw pads in the cat could be reduced/reversed by electrical stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve during stance. Several split-belt conditions were investigated in four adult female cats. In addition, we investigated the effects of similar distal tibial nerve stimulation on overground walking of one male cat that had a transtibial, bone-anchored prosthesis for 29months and, thus, had no cutaneous/proprioceptive feedback from the foot. In all treadmill conditions, cats walked with intact cutaneous feedback (control), with right fore- and hindpaw pads anesthetized by lidocaine injections, and with a combination of anesthesia and electrical stimulation of the ipsilateral distal tibial nerve during the stance phase at 1.2× threshold of afferent activation. Electrical stimulation of the distal tibial nerve during the stance phase of walking with anesthetized ipsilateral paw pads reversed or significantly reduced the effects of paw pad anesthesia on several kinematic variables, including lateral center of mass shift, cycle and swing durations, and duty factor. We also found that stimulation of the residual distal tibial nerve in the prosthetic hindlimb often had different effects on kinematics compared with stimulation of the intact hindlimb with paw anesthetized. We suggest that stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve provides functionally meaningful motion-dependent sensory feedback, and stimulation responses depend on limb conditions.

Способ минимизации типичных осложнений при спинальной анестезии

Целью работы было исследовать влияние низкодозовой спинальной монолатеральной анестезии с использованием гипербарических растворов бупивакаина на кардиогемодинамику, респираторную депрессию, мышечную дрожь, постпункционную головную боль, транзиторный ишемический синдром и потребность в дополнительной внутривенной седации. Низкодозовая спинальная анестезия выявила больший протективный эффект в отношении кардиогемодинамики: стабильное состояние гемодинамики на этапах оперативного лечения при выполнении низкодозовой спинальной монолатеральной анестезии наблюдали в среднем в 3 раза чаще, чем при стандартной спинномозговой анестезии. Использование монолатеральной техники предотвращало опасные изменения респираторной функции на основном этапе в среднем в 2 раза больше, а по окончании операции — в 4 раза. Озноб и дрожь после монолатеральной спинномозговой анестезии наблюдали на основном этапе в 1,5 раза реже, а по окончании оперативного лечения — в 2,4 раза реже, чем при ортодоксальной спинномозговой анестезии.

Anesthesia for knee arthroscopy: which nerves should be blocked?

Nowadays knee arthroscopy is the most common orthopedic procedure. It is used to diagnose and treat various pathological conditions. Usually knee arthroscopy can be performed using spinal anesthesia. The article presents a successful experience of using a combined technique, which consist in a unilateral subarachnoid anesthesia with additional adductor canal block and blocks of the articular branches of the sciatic and obturator nerves.

Monolateral spinal anesthesia

Spinal anesthesia is a simple and affordable method of anesthesia that provides a sufficient level of intraoperative and postoperative analgesia, muscle relaxation, and early activation of patients. Like all other techniques, it has advantages and disadvantages. The most common side effect of anesthesia is the central hemodynamic disturbance, such as hypotension, which is prevented by unilateral anesthesia. Thus, presented herein are the most common complications and their prevention methods.

Changes in measures of consciousness during anaesthesia of one hemisphere (Wada test)

BackgroundIn the Wada test, one hemisphere is selectively anaesthetised by unilateral intracarotid injection of a fast-acting anaesthetic agent. This gives a unique opportunity to observe the functions and physiological activity of one hemisphere while anaesthetising the other, allowing direct comparisons between brain states and hemispheres that are not possible in any other setting. AimTo test whether potential measures of consciousness would be affected by selective anaesthesia of one hemisphere, and reliably distinguish the states of the anesthetised and non-anesthetised hemispheres. MethodsWe analysed EEG data from 7 patients undergoing Wada-tests in preparation for neurosurgery and computed several measures reported to correlate with the state of consciousness: power spectral density, functional connectivity, and measures of signal diversity. These measures were compared between conditions (normal rest vs. unilateral anaesthesia) and hemispheres (injected vs. non-injected), and used with a support vector machine to classify the state and site of injection objectively from individual patient's recordings. ResultsAlthough brain function, assessed behaviourally, appeared to be substantially altered only on the injected side, we found large bilateral changes in power spectral density for all frequency bands tested, and functional connectivity changed significantly both between and within both hemispheres. Surprisingly, we found no statistically significant differences in the measures of signal diversity between hemispheres or states, for the group of 7 patients, although 4 of the individual patients showed a significant decrease in signal diversity on the injected side. Nevertheless, including signal diversity measures improved the classification results, indicating that these measures carry at least some non-redundant information about the condition and injection site. We propose that several of these results may be explained by conduction of activity, via the corpus callosum, from the injected to the contralateral hemisphere and vice versa, without substantially affecting the function of the receiving hemisphere, thus reflecting what we call “cross-state unreceptiveness”.

Unilateral Spinal Anaesthesia in Calves

In this study, we aimed to evaluate the effects of unilateral anaesthesia by the administration of hyperbaric bupivacaine through the lumbosacral space into the subarachnoid space in calves. A total of 10 calves with unilateral femoral fractures were included in the study. After each calf was placed in a lateral position on the side intended for surgery, 15 mg of hyperbaric bupivacaine was slowly injected into the subarachnoid space. The onset, duration and depth of anaesthesia were determined by the pinprick test (scale 1–4). In addition, heart rate, diastolic arterial blood pressure, systolic arterial blood pressure, mean arterial blood pressure, respiratory rate and body temperature of the calves were monitored and recorded from the onset to 120 min after anaesthesia. The onset of unilateral spinal anaesthesia was within 20 s and the mean duration of anaesthesia was 155.40 min. Although there were statistical differences between hemodynamic values in the study, they were within the reference values. As a result, we believe that unilateral spinal anaesthesia in calves provides adequate anaesthesia for use in orthopaedic procedures; thus, it can be used in practice.

Comparison of unilateral versus bilateral spinal anaesthesia using hyperbaric bupivacaine with clonidine in unilateral inguinal hernia surgery - A randomized controlled trial

Introduction: Unilateral spinal anaesthesia can be used for inguinal hernia surgery. The advantage is that it provides a stronger block on the side of surgery, accelerated recovery of the nerve block with better maintenance of cardiovascular stability. Hence it can be a valuable technique for high risk patients. Materials and Methods: The study design was randomized controlled trial including 60 patients undergoing elective hernioplasty. Patients were allocated to either group unilateral (U) or group bilateral (B) and received Inj Bupivacaine 0.5% heavy 12.5mg + inj Clonidine 15 microgram in sub-arachnoid block. Patients were kept in lateral position for 10min for group U & made supine immediately on the OT table for group B. Variation in hemodynamic parameters, onset, peak level, duration of sensory and motor block were noted. Results: At 10, 15 and 20 min minutes after giving anaesthesia, the mean heart rate, systolic and diastolic blood pressures, mean arterial pressure were significantly higher in patients receiving unilateral anaesthesia. Mean duration of sensory and motor block, total duration of analgesia were significantly more in bilateral anaesthesia. Conclusion: Unilateral spinal anaesthesia achieved stable hemodynamics, adequate duration of block for surgery and rapid recovery. So it can be a valuable technique in high risk patients. Keywords: Spinal anaesthesia, Unilateral spinal anaesthesia.

Central Connections of the Lacrimal Functional Unit.

To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia. A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were as follows: 1) bilateral saline (control), 2) unilateral anesthesia (ipsilateral anesthetic; contralateral saline), and 3) bilateral anesthesia. There was no difference in between-eye wetting lengths in the saline control eyes (P = 0.394) or the bilaterally anesthetized eyes (P = 0.171). The wetting length was reduced in both eyes after bilateral anesthesia compared with saline controls (P = 0.001; P ≤ 0.0005). After unilateral anesthesia, the wetting length was reduced in the anesthetized eye compared with its saline control by 51.4% (P ≤ 0.0005) and compared with its fellow, unanesthetized eye (P = 0.005). The fellow eye value was also reduced compared with its saline control (P = 0.06). The wetting length was reduced by topical anesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanesthetized fellow eye, the reduction compared with its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal fellow eye, in cases of unilateral corneal anesthesia.

Acute unilateral anesthesia mumps after hysteroscopic surgery under general anesthesia: a case report.

Acute unilateral parotid gland swelling after general anesthesia, anesthesia mumps is rare and when occurred, it is associated with the patient's position and with long-lasting surgery. The exact mechanism or etiology has not been fully established but stasis of gland secretion, blockage of Stensen's duct by direct compression, or retrograde flow of air by increased the oral cavity pressure are suspicious reasons. We experienced a case of soft tissue swelling in the left preauricular and submandibular regions in a 40-year-old female patient after short-lasting, hysteroscopic myomectomy performed in the lithotomy position with no suspicious predisposing factor. It is required to pay attention on the fact that even with the usual face mask ventilation can lead to the development of anesthesia mumps.

Thoracic paravertebral anesthesia for percutaneous radiofrequency ablation of hepatic tumors

Study ObjectiveTo present our preliminary experience using a thoracic paravertebral block (TPVB) as the sole anesthetic in percutaneous hepatic radiofrequency ablation (RFA). DesignRetrospective case series of 12 ASA physical status 1, 2, and 3 patients of average risk scheduled for RFA. SettingUniversity medical center. MeasurementsThe first 12 procedures performed using TPVB were analyzed to evaluate the efficacy and safety of this anesthetic technique. Data collected included patients’ characteristics, procedure, pain referred during paravertebral punctures, and RFA (verbal numerical scale; VNS). Anesthesia and medical records also were reviewed for any major complications that occurred during or after the RFA. Main ResultsTen of the 12 patients presented for hepatocellular carcinoma; the other two patients had melanoma metastasis. Nine patients were ASA physical status 1 or 2; the other three patients were ASA physical status 3. Nine had liver cirrhosis. All patients had normal coagulation profiles. The TPVBs were performed in a median time of 6.5 (4–15) minutes. Onset of sensory loss to pinprick test occurred approximately 15 to 20 minutes after the injections. No evidence of bilateral blockade was seen in any patient. In most cases, the extent of anesthesia ranged from T6 to T11 or T12. In one patient (no. 2), the stimulating needle elicited no sensory or motor response at the T7 level; the local anesthetic was then injected one cm beyond the transverse process. All patients were very pleased with their anesthetic care; all were discharged from the hospital with no procedure-related complications. ConclusionThe use of thoracic paravertebral block as the sole anesthetic for RFA of liver produced satisfactory unilateral anesthesia and minor adverse events.

UNILATERAL SPINAL ANESTHESIA FOR LOWER EXTREMITY SURGERY

Objective: To compare the efficacy of unilateral spinal anesthesia by heavy bupivacaine with conventional bilateral anesthesia for lower extremity surgery. Methods: In this prospective randomized study, eighty two patients undergoing elective lower extremity orthopedic surgery were randomly allocated into two groups, unilateral and bilateral. All patients received intrathecally 8 mg of hyperbaric bupivacaine 0.5% over 40 seconds at the L3-4 intervertebral space. A lateral decubitus position after spinal injection was maintained in the unilateral group for 15 min. The onset and recovery of sensory and motor block and perioperative side effects were recorded. Results: Success rate of unilateral anesthesia was 82.9%. In the unilateral group, the sensory block for surgery (above L1) (181.5 ± 18.9 versus 150.0 ± 20.1 min), motor block time (149.3 ± 18.4 versus 121.5 ± 16.4 min) were longer and incidence of hypotension (2.4 versus 29.3%) was lower than those in the bilateral group. Onset of sensory block (3.5 ± 1.1 versus 3.3 ± 0.9 min), succes rate of anesthesia (100% in both groups), incidences of intraoperative nausea, vomiting and agitation and postoperative nausea, vomiting, headache and heart rate, respiratory changes were not significant between two groups. Conclusion: Unilateral spinal anesthesia provided longer sensory and motor block, lower incidence of hypotention in comparison with conventional bilateral anesthesia. This is a suitable technique for lower limb orthopedic procedures. Key words: Unilateral spinal anesthesia, lower extremity surgery

Clots and cauda equina: aortic obstruction as a rare cause of cauda equina syndrome

Cauda equina syndrome (CES) is a rare clinical entity with an incidence of two per million people annually [1]. Symptoms and signs are very variable. Amongst them are severe low back pain, bilateral or unilateral sciatica, saddle anaesthesia, motor weakness, sensory deficit, and bladder and bowel dysfunction [1, 2]. None of these features has a high predictive value for CES in its own right, and many are common complaints with a variety of possible causes [3]. A high level of suspicion for CES is needed in any clinician who may come across it. Unfortunately, CES is all too often mis-managed [4, 5], resulting in not only devastating consequences for the patient’s quality of life, but also a disproportionately high medico-legal profile and significant risk of litigation [3, 6]. CES is a true spinal surgical emergency which, if untreated, may progress to paraplegia and/or permanent incontinence [2]. Debate as to the optimum timing for decompressive surgery, where cauda equina compression is the cause, is ongoing [2, 7], but prompt diagnosis is mandatory. Although magnetic resonance imaging (MRI) scanning is the diagnostic tool of choice [3], the percentage of patients being scanned for a clinical diagnosis of CES and in whom a compressive lesion is found on imaging is only 22 % [8]. It is important, therefore, to keep an open mind as to the aetiology of the patient’s symptoms. A thorough history and examination should underpin the diagnostic process and should guide further investigation, particularly in those patients whose lumbar spine MRI scans are unremarkable. We present two cases of aortic occlusion mimicking compressive CES that presented to our unit.

Radiographic evidence of unilateral epidural anesthesia

Radiographic evidence of unilateral epidural anesthesia

Effects of Epidural Needle Rotation and Different Speeds of Injection on the Distribution of Epidural Block

This prospective, randomised study examined the effect of injection speeds for unilateral epidural anesthesia on block characteristics, hemodynamic parameters, and discharge criteria in 60 patients. Levobupivacaine 5% was administered to Group F over 1 min (fast) and to Group S over 3 min (slow) (n=30 each) with the needle angulated at 5°-10° from the midline. Unilateral epidural block was significantly more successful in Group S than in Group F (70.3% vs. 16%; p<0.001). On the non-operated sides in group S, the maximal sensorial block time was shorter and the regression time for 2 segments was longer (p<0.05). And the walk-out time was longer in group F (p<0.05). We consider that the slow administration of local anesthetic in unilateral epidural anesthesia is more effective than rapid administration.

Ropivacaine for Unilateral Spinal Anesthesia; Hyperbaric or Hypobaric?

The aim of this study was to compare the unilaterality of subarachnoid block achieved with hyperbaric and hypobaric ropivacaine. The prospective, randomized trial was conducted in an orthopedics surgical suite. In all, 60 ASA I-III patients scheduled for elective total knee arthroplasty were included in the study. Group Hypo (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL of distilled water (density at room temperature was 0.997) and group Hyper (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL (5mg.mL(-1)) of dextrose (density at room temperature was 1,015). Patients in the hyperbaric group were positioned with the operated side down and in the 15° Fowler position, versus those in the hypobaric group with the operated side facing up and in the 15° Trendelenburg position. Combined spinal epidural anesthesia was performed midline at the L(3-4) lumbar interspace. Hemodynamic and spinal block parameters, regression time, success of unilateral spinal anesthesia, patient comfort, surgical comfort, surgeon comfort, first analgesic requirement time, and adverse effects were assessed. Time to reach the T10 dermatome level on the operated side was shorter in group Hyper (612.00±163.29s) than in group Hypo (763.63±208.35s) (p<0.05). Time to 2-segment regression of the sensory block level on both the operated and non-operated sides was shorter in group Hypo than in group Hyper. Both hyperbaric and hypobaric ropivacaine (11.25mg) provided adequate and dependable anesthesia for total knee replacement surgery, with a high level of patient and surgeon comfort. Hypobaric local anesthetic solutions provide a high level of unilateral anesthesia, with rapid recovery of both sensory and motor block, and therefore may be preferable in outpatient settings.

Congenital Unilateral Corneal Anaesthesia with Microphthalmos: A Case Report

Congenital corneal anaesthesia (CCA) is an uncommon condition difficult to diagnose. We report the case of a 20-month-old boy who presented with unilateral congenital corneal anaesthesia. The child was referred with a persistent corneal epithelial defect, unresponsive to symptomatic local treatment for over 10 months. Intensive topical treatment and strict corneal protection led to quick corneal healing. Congenital corneal anaesthesia occurs either alone or in association with neurological diseases or systemic congenital abnormalities. It is important to search for corneal anaesthesia in children with chronic ulcerations of the cornea and self-inflicted injuries. Early diagnosis and treatment are important due to the risk of poor visual prognosis. Management of CCA should aim for the prevention of epithelial defects and is a life-long process.

Characteristics of unilateral spinal anesthesia at different speeds of intrathecal injection

Unilateral spinal anesthesia is performed to provide restriction of sympathetic and motor block. The purpose of this study is to compare the effect of different speeds of intrathecal injection on unilateral spinal anesthesia. The patient cohort comprised 66 patients who were placed in the lateral position with the side to be operated on dependent. After dural puncture, the needle aperture was turned towards the dependent side, and hyperbaric 0.5% bupivacaine was injected at a rate of 1 ml/min in Group Slow patients (Group S, n = 33) or 0.5 ml/min in Group Extra Slow patients (Group ES, n = 33). The lateral position was maintained for 15 min. Skin temperature, loss of pinprick sensation, and degree of motor block were recorded. There were significant differences in the characteristics of the non-operative side between the groups when on the block. Sensorial block was unilateral in 25 (75.8%) patients in Group S and in 29 patients in Group ES (87.9%) 15 min post-injection. At the end of the operation (approximately 50 min after spinal anesthesia), strictly unilateral anesthesia was present in 31 patients in Group ES (93.9%) and in 22 patients in Group S (66.6%) (p < 0.05). Unilateral sensory and motor block were observed in both groups, and the incidence of strict unilateral block was significantly higher in group ES patients. The result of the study show that the extra-slow injection of hyperbaric bupivacaine provided strictly unilateral sensorial and sympathetic block in 93.9 and 87.9% of the patients, respectively, and that a slow injection of low doses of hyperbaric 0.5% bupivacaine 1 ml was sufficient to provide unilateral spinal anesthesia.