Influence of height on ED95 of intrathecal 2-chloroprocaine for knee arthroscopy: A prospective dose-response clinical trial.

BACKGROUND: Plain 2-chloroprocaine , a rapid acting amino-ester-type local anaesthetic, is used in short ambulatory procedures under spinal anaesthesia. The ED 95 of 2-chloroprocaine for lower limb surgery has not yet been defined. Moreover, patients' body height could influence the effects of the administered dose. OBJECTIVES: The aim of this study was to determine the ED 95 of plain 2-chloroprocaine based on the height of patients undergoing ambulatory knee arthroscopy under spinal anaesthesia using the continual reassessment statistical method (CRM). DESIGN: Prospective, dose-response, double blind, controlled, bi-center, clinical trial. SETTING: One university teaching hospital in Brussels and one general teaching hospital, Braine l'Alleud, Belgium. Université libre de Bruxelles. PATIENTS: ASA I-III (120 patients) scheduled for day-case knee arthroscopy under spinal anaesthesia. INTERVENTIONS: Patients were divided into three groups of 40, each comprising 10 cohorts of 4 patients, according to their respective heights (Group 1: 150-165 cm, Group 2: 166-180 cm, Group 3: 181-195 cm). Each patient enrolled into one of the 3 groups received an intrathecal dose of plain 2-chloroprocaine determined by the CRM. The starting doses for the first cohorts of four were 40 mg in group 1, 45 mg in group 2 and 50 mg in group 3. The doses for subsequent cohorts were determined by CRM of outcomes in all patients in the previous competed cohorts. Anaesthesia was considered successful when there was a lack of pinprick or cold sensation up to T12, the visual analogue scale score for tourniquet pain was < 2 and no pain during surgery. MAIN OUTCOMES: The primary outcome was the success or failure of the block. Side effects were also recorded. RESULTS: ED 95 of 2-chloroprocaine is 40 mg in group 1, 35 mg in group 2, 45 mg in group 3. Groups were different in terms of height and gender ( P  < 0.05) and similar in terms of body mass index and age ( P  > 0.05). CONCLUSION: The ED95 of intrathecal 2-chloroprocaine for patients undergoing ambulatory knee arthroscopy is between 35 and 45 mg. Height could be a factor involved in the calculation, and patient sex could partly explain the nonlinear relation between height and dose. TRIAL REGISTRY NUMBER: Clinicaltrials.gov NCT03882489.

Comparison of equipotent doses of intrathecal hyperbaric prilocaine 2% and hyperbaric bupivacaine 0.5% for elective caesarean section: A prospective, randomised, controlled, two-centre clinical trial.

BACKGROUND: Elective caesarean section is performed mainly under spinal anaesthesia using hyperbaric bupivacaine combined with opioids. Despite rapid onset, good quality anaesthesia, bupivacaine provides a long duration of motor block and is related to maternal hypotension. Current policies appeal for implementation of enhanced recovery procedures after caesarean section. Hyperbaric prilocaine is an intermediate-acting local anaesthetic known for its efficacy in ambulatory surgery. Evidence on the clinical relevance of intrathecal prilocaine use for caesarean section is currently lacking. OBJECTIVES: We aimed to investigate whether hyperbaric prilocaine would offer a shorter motor block and recovery than bupivacaine, when comparing equipotent doses. We also assessed the characteristics of sensory block, maternal haemodynamics and side effects for both mother and newborn. DESIGN: Prospective, randomised, double-blind, controlled, two-centre, clinical trial. SETTING: One university teaching hospital and one general teaching hospital in Brussels, Belgium. PATIENTS: American Society of Anesthesiologists' physical status 2 parturients (n = 40) undergoing caesarean section under spinal anaesthesia. INTERVENTIONS: Patients were randomly assigned to receive spinal anaesthesia using hyperbaric prilocaine 50 mg or hyperbaric bupivacaine 10 mg, both given with sufentanil 2.5 µg and morphine 100 µg. An epidural catheter was introduced as a backup in case of failure. MAIN OUTCOMES: The primary outcome was the motor block regression (modified Bromage scale 1 to 6). Secondary outcomes included sensory block characteristics, first unassisted ambulation, maternal side effects, newborns' parameters and overall satisfaction. RESULTS: Median [IQR] motor block was significantly shorter in the hyperbaric prilocaine group (110 [104 to 150] min versus 175 [135 to 189] min, P = 0.001). First unassisted ambulation was achieved earlier after prilocaine (204.5 [177 to 246.5] min versus 314 [209.25 to 400] min, P = 0.007), and the incidence of maternal hypotension was significantly higher with bupivacaine (P = 0.033). No supplementary epidural analgesia was needed. CONCLUSION: Prilocaine provides shorter motor block, faster recovery and better haemodynamic stability than bupivacaine while offering equivalent surgical anaesthesia. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02973048, EudraCT: 2016-003010-26.

Anesthetic Management of a Voluminous Left Atrial Myxoma Resection in a 19 Weeks Pregnant with Atypical Clinical Presentation.

We report the case of a semi-urgent cardiac surgery, in a 19 gestation age pregnant. Despite the fact that the patient was asymptomatic, except for some palpitations, a large left auricle (LA) myxoma was fortuitously diagnosed with transthoracic echocardiography (TEE). Considering the important embolic risk, the tumor was successfully removed during cardiac surgery under cardiopulmonary bypass (CPB). Fetal bradycardia following defibrillation under stable maternal and CPB conditions was successfully managed. The postoperative period and remainder of the pregnancy was smooth and the delivery uneventful.

Immune responses in relation to the type and time of thermal injury: an experimental study.

BACKGROUND: Thermal injuries are followed by a complex immune response, but the relationship between the severity of burn injury and the time exposure to the thermal injury on the extent of the immune response is still not known. OBJECTIVE: This study focuses on characterising the effect of temperature and time exposure on the post-burn immune response. METHODS: We used 120 C57BL/6 male mice divided equally in 5 burn groups and one sham operated group (groups A-E and sham). Ten mice per group were sacrificed at 24 and 48 h after burn injury and whole blood was collected; specimens of liver, lung, spleen, kidney and bowel were excised. Apoptosis and TREM-1 expression on circulating blood cells were measured. Splenocytes were isolated and stimulated for cytokine production; the rate of apoptosis of splenocytes was also measured. RESULTS: Production of IL-17 from splenocytes of mice group D was enhanced. Considerable effects were shown on the apoptosis of circulating lymphocytes and of spleen cells. The apoptotic rates varied between groups and also evolved after 24 and 48 h. To examine the origin of this differential response, quantitative bacterial cultures of liver, lung and kidney were made but no differences were observed compared with sham-operated animals. LIMITATIONS: This study was based on an experimental murine model. CONCLUSION: There is a unique response for each type of injury depending on the temperature of the thermal source and the exposure time.

ED50 and ED90 of intrathecal hyperbaric 2% prilocaine in ambulatory knee arthroscopy.

PURPOSE: Hyperbaric 2% prilocaine (HP) is increasingly used for spinal anesthesia in day-case surgery. The aim of this prospective double-blind study was to determine the effective dose (ED)50 and the ED90 of HP for patients undergoing knee arthroscopy. METHODS: Doses of HP were determined using an up-and-down sequential allocation technique. Sequences were analyzed by isotonic regression analysis. A subsequent observational study was performed with the calculated ED90 in 50 patients to confirm the initial result and to describe the induced blockade effects and side effects. Times corresponding to onset and duration of sensory and motor block, surgical data, and side effects were recorded. RESULTS: The ED50 was estimated at 28.9 mg (95% confidence interval [CI]: 26.5 to 35.3) and the ED90 was estimated to be 38.5 mg (95% CI: 35.7 to 39.5). A 40 mg dose of HP provided efficient anesthesia in 46 patients (92%, 95% CI: 82 to 98). The average (SD) time to effective anesthesia was 14.5 (3.9) min. Complete sensory block at level T12 was obtained after ten minutes in 44 of 50 patients. The average (SD) duration of the sensory block was 205 (36.1) min. Maximal level of sensory block was obtained at the T8-T11 levels in 41 of 50 patients without hemodynamic instability. A Bromage 3 score was obtained in 40 of the 46 patients who achieved successful anesthesia after 30 min. Patients did not experience urinary retention, nor were any signs of transient neurologic symptoms observed. CONCLUSION: This study determined the ED50 of HP is 28.9 mg and suggests that a 40-mg dose of HP is adequate to provide successful spinal anesthesia for outpatient knee arthroscopy.

Case report: cerebral vein thrombosis after subarachnoid analgesia for labour.

PURPOSE: We report a case of sagittal sinus thrombosis occurring after spinal analgesia for labour to highlight the difficulty of such diagnosis in the presence of postpartum atypical headache following regional anesthesia/analgesia. CLINICAL FEATURES: A previously healthy 21-yr-old, primiparous, preeclamptic parturient was admitted to the hospital at 37 weeks gestation for uterine contractions. Before pregnancy she was taking no medication other than oral contraceptives and was a non-smoker. Spinal analgesia was established on the first attempt at 8 cm of cervical dilation, in the setting of rapid progression of labour. Following an uneventful delivery, on the third day postpartum, the patient experienced gradual onset of an atypical headache with unclear postural character, followed by focal neurological signs five days later. Emergency neuroimaging revealed direct evidence of thrombosis in the posterior sagittal venous sinus. Anticoagulation was initiated with iv heparin (500 UI x kg(-1) x day(-1)). The patient's headache decreased progressively and full motor recovery was noted by day 14 postpartum. After 24 days, the patient was discharged without any neurological disability. Common inherited thrombophilic dispositions were absent, with the exception of a decrease in protein S level. CONCLUSION: Central venous thrombosis, while rare, is a recognized cause of puerperium stroke. The present case highlights the importance of considering the diagnosis in the presence of postpartum atypical headache following spinal anesthesia/analgesia. Early intervention with systemic heparinization is critical when the diagnosis is confirmed.

The replacement of graft endothelium by recipient-type cells conditions allograft rejection mediated by indirect pathway CD4+ T cells.

BACKGROUND: Whereas the participation of alloreactive T cells sensitized by indirect allorecognition in graft rejection is well documented, the nature of recipient antigen presenting cells recognized by indirect pathway CD4+ T cells within the graft has yet to be identified. The purpose of this study was to determine the role played by graft endothelium replacement in the immune recognition of cardiac allografts rejected by indirect pathway CD4+ T cells. METHODS: Transgenic RAG2-/- mice expressing I-Ab-restricted male antigen H-Y-specific TcR were studied for their capacity to reject H-2k male cardiac allografts. Chronic vascular rejection in this model was due to the indirect recognition of H-Y antigen shed from H-2k male allograft and presented by the recipient's own I-Ab APC to transgenic T cells. RESULTS: Immunohistochemical analysis of rejected grafts revealed the presence of numerous microvascular endothelial cells (EC) that expressed recipient's I-Ab MHC class II molecules. This observation suggested that graft endothelium replacement by I-Ab-positive cells of recipient origin could stimulate the rejection of male H-2k graft by I-Ab-restricted H-Y-specific T cells. To investigate further this possibility, hearts from H-2b-into-H-2k irradiation bone marrow (BM) chimera were transplanted in transgenic recipients. A direct correlation was observed between the presence of I-Ab-positive EC within myocardial microvessels and the induction of acute rejection of chimeric H-2k male cardiac allografts transplanted in transgenic recipients. CONCLUSIONS: We conclude that graft endothelium replacement by recipient-type cells is required for the rejection of cardiac allograft mediated by indirect pathway alloreactive CD4+ T cells.

The replacement of graft endothelium by recipient-type cells conditions allograft rejection mediated by indirect pathway CD4(+) T cells.

BACKGROUND: Whereas the participation of alloreactive T cells sensitized by indirect allorecognition in graft rejection is well documented, the nature of recipient antigen presenting cells recognized by indirect pathway CD4(+) T cells within the graft has yet to be identified. The purpose of this study was to determine the role played by graft endothelium replacement in the immune recognition of cardiac allografts rejected by indirect pathway CD4(+) T cells. METHODS: Transgenic RAG2(-/-) mice expressing I-A(b)-restricted male antigen H-Y-specific TcR were studied for their capacity to reject H-2(k) male cardiac allografts. Chronic vascular rejection in this model was due to the indirect recognition of H-Y antigen shed from H-2(k) male allograft and presented by the recipient's own I-A(b) APC to transgenic T cells. RESULTS: Immunohistochemical analysis of rejected grafts revealed the presence of numerous microvascular endothelial cells (EC) that expressed recipient's I-A MHC class II molecules. This observation suggested that graft endothelium replacement by I-A(b)-positive cells of recipient origin could stimulate the rejection of male H-2(k) graft by I-A(b)--restricted H-Y--specific T cells. To investigate further this possibility, hearts from H-2(b)--into--H-2(k) irradiation bone marrow (BM) chimera were transplanted in transgenic recipients. A direct correlation was observed between the presence of I-A(b)-positive EC within myocardial microvessels and the induction of acute rejection of chimeric H-2(k) male cardiac allografts transplanted in transgenic recipients. CONCLUSIONS: We conclude that graft endothelium replacement by recipient-type cells is required for the rejection of cardiac allograft mediated by indirect pathway alloreactive CD4(+) T cells.