Subarachnoid space of the optic nerve sheath and intracranial hypertension: a macroscopic, light and electron microscopic study

PURPOSE

The optic nerve (ON) is an extension of the central nervous system via the optic canal to the orbital cavity. It is accompanied by meninges whose arachnoid layer is in continuity with that of the chiasmatic cistern. This arachnoid layer is extended along the ON, delimiting a subarachnoid space (SAS) around the ON. Not all forms of chronic intracranial hypertension (ICH) present papilledema. The latter is sometimes asymmetric, unilateral, or absent. The radiological signs of optic nerve sheath (ONS) dilation, in magnetic resonance imaging, are inconsistent or difficult to interpret. The objective of this study was to analyze the anatomy, the constitution, and the variability of the SAS around the ON in its intraorbital segment to improve the understanding of the pathophysiologic mechanism of asymmetric or unilateral or absent papilledema in certain ICH.

METHODS

The study was carried out on nine cadaveric specimens. In four embalmed specimens, macroscopic analysis of the SAS of the ONS were performed, with description about density of the arachnoid trabecular meshwork in three distinct areas (bulbar segment, mid-orbital segment and the precanal segment). In three other embalmed specimens, after staining of SAS by methylene blue (MB), we performed macroscopic analysis of MB progression in the SAS of the ONS. Then, in two non-embalmed specimens, light and electron microscopy (EM) analysis were also done.

RESULTS

On the macroscopic level, after staining of SAS, we found in all cases that MB progressed on 16 mm average throughout the SAS of the ONS without reaching the papilla. In four embalmed specimens, in the SAS of the ONS, the density of the arachnoid trabecular meshwork showed inter-individual variability (100%) and intra-individual variability with bilateral variability (50%) and/or variability within the same ONS (88%). On the microscopic level, the arachnoid trabeculae of the ONS are composed of dense connective tissue. The EM perfectly depicted its composition which is mainly of collagen fibers of parallel orientation.

CONCLUSION

The variability of the SAS around the ONS probably impacts the symmetrical or asymmetrical nature of papilledema in ICH.

A retrospective study of indications and consequences of monitoring direct oral anticoagulant plasma concentrations on patient care in a university hospital: The Retro-AOD study

INTRODUCTION

The use of direct oral anticoagulants (DOAC) is increasing. Specific concentrations are available and have been proven to be reliable and reproducible in optimising patient care. This retrospective, monocentric study aimed to describe the indications and consequences of monitoring DOAC plasma levels on patient care.

MATERIALS AND METHODS

We collected data of patients hospitalised at the Bordeaux University Hospital between January 2017 and December 2018. These included demographics, indications, type, dose of DOAC, standard coagulation tests, creatinine clearance and DOAC plasma concentration using specifically calibrated rivaroxaban and apixaban anti-Xa and dabigatran anti-IIa assays. The date of last DOAC intake, the time between intake and plasma level measurement were also collected and analysed.

RESULTS

A total of 2197 DOAC assays in 1488 patients were obtained in various clinical situations: urgent or elective procedures, context of acute renal failure, suspicion or occurrence of ischemic strokes, intra-cranial and other bleeding sites. Interpretation of these assays led physicians to maintain, postpone or cancel invasive and high haemorrhagic risk procedures in 757, 261 and 56 cases respectively. The remaining 1123 assays were associated with no significant modification of patient care. DOAC plasma concentration was ≤30 ng ml^-1 (sensitivity 85.4%, specificity 73.6%, positive predictive value 71.1%, negative predictive value 86.7%, AUC 0.81) after a last intake of at least 2 days.

CONCLUSIONS

Our study is, to date, the largest report of real-life measurement of specific DOAC plasma level at a single institution. Patient care was not modified in more than half of the assays.

Pre-operative peripheral intravenous cannula insertion failure at the first attempt in adults: Development of the VENSCORE predictive scale and identification of risk factors

STUDY OBJECTIVE

Our objective was to develop a clinical scale (the VENSCORE) to predict pre-operative peripheral intravenous cannula (PIVC) insertion failure at the first attempt in adults.

DESIGN

This was a prospective multicenter cohort study that included internal validation with bootstrapping.

SETTING

The operating rooms of 14 hospitals in southern France from June 2016 to June 2018.

PATIENTS

Consecutive adult patients aged 18 years or older were recruited upon arrival to the operating room, regardless of American Society of Anaesthesiology (ASA) physical status.

INTERVENTIONS

PIVC insertion on arrival to the OR.

MEASUREMENTS

PIVC insertion failure at the first attempt was the outcome of interest. Data collected included the number of PIVC insertion attempts and potential predictors of the risk of failure (including pre-operative patient characteristics and data relative to the procedure). Uni- and multivariable logistic analyses were performed. Based on these results, the VENSCORE scale was developed to predict the risk of failure of the first PIVC insertion.

MAIN RESULTS

In total, 3394 patients were included, and 27 were excluded because of protocol violations. The PIVC insertion failure rate at the first attempt was 20.3%. Based on multivariable analysis, a history of difficult PIVC insertions, high-risk surgery, poor vein visibility, and moderate to poor vein palpability were identified as risk factors for insertion failure at the first attempt. The area under the curve of the predictive model was 0.82 (95% confidence interval: 0.80-0.84). A VENSCORE value of 0 points was associated with a failure rate of 7%, versus 97% for a score of 6.

CONCLUSIONS

The four-item VENSCORE scale could be useful for prospectively identifying adults at risk of first PIVC insertion attempt failure.

Peri-operative management of pheochromocytoma with intravenous urapidil to prevent hemodynamic instability: A 17-year experience

Background and Aims

Surgery for pheochromocytoma (PCC) can cause excessive catecholamine release with severe hypertension. Alpha blockade is the mainstay of preoperative management. The aim of this study was to evaluate the efficacy and tolerance of intra-venous (IV) urapidil, a competitive short acting α1 receptor antagonist, in the prevention of peri-operative hemodynamic instability of patients with PCC.

Material and Methods

This retrospective observational study included 75 patients (79 PCC) for PCC removal surgery from 2001 to 2017 at the Bordeaux University Hospital. They received, 3 days before surgery, continuous intravenous infusion of urapidil with stepwise increase to the maximum tolerated dose. Urapidil was maintained during the procedure and stopped after clamping the adrenal vein. Plasma catecholamine concentrations were measured during surgery. Hypertensive peaks (SAP >160 mmHg) and tachycardia >100 beats/min were treated with boluses of nicardipine 2 mg and esmolol 0.5 mg/kg.

Results

We recorded 20/79 (25%) cases with systolic arterial pressure (SAP) >180 mmHg. Only 11/79 (14%) had hypotension with SAP <80 mmHg. Peaks of catecholamine secretions were observed preferentially during peritoneal insufflation and tumor dissection (P < 0.05). A correlation was found between tumor size (mm) and the highest norepinephrine levels [r = 0.288, P = 0.015], and between hypertensive peaks (mmHg) and the highest norepinephrine levels [r = 0.45, P = 0.017]. No mortality was reported. The median [range] postoperative hospital stay was 4 [2-9] days.

Conclusion

IV urapidil limits hypertensive and hypotensive peaks during PCC surgery, and corresponds to surgical imperatives allowing a short hospital stay, due to its "on-off" effect.

Evaluation of least significant changes of pulse contour analysis-derived parameters

Background

Many maneuvers assessing fluid responsiveness (minifluid challenge, lung recruitment maneuver, end-expiratory occlusion test, passive leg raising) are considered as positive when small variations in cardiac index, stroke volume index, stroke volume variation or pulse pressure variation occur. Pulse contour analysis allows continuous and real-time cardiac index, stroke volume, stroke volume variation and pulse pressure variation estimations. To use these maneuvers with pulse contour analysis, the knowledge of the minimal change that needs to be measured by a device to recognize a real change (least significant change) has to be studied. The aim of this study was to evaluate the least significant change of cardiac index, stroke volume index, stroke volume variation and pulse pressure variation obtained using pulse contour analysis (ProAQT^®, Pulsion Medical System, Germany).

Methods

In this observational study, we included 50 mechanically ventilated patients undergoing neurosurgery in the operating room. Cardiac index, stroke volume index, pulse pressure variation and stroke volume variation obtained using ProAQT^® (Pulsion Medical System, Germany) were recorded every 12 s during 15-min steady-state periods. Least significant changes were calculated every minute.

Results

Least significant changes statistically differed over time for cardiac index, stroke volume index, pulse pressure variation and stroke volume variation (p < 0.001). Least significant changes ranged from 1.3 to 0.7% for cardiac index, from 1.3 to 0.8% for stroke volume index, from 10 to 4.9% for pulse pressure variation and from 10.8 to 4.3% for stroke volume variation.

Conclusion

To conclude, the present study suggests that pulse contour analysis is able to detect rapid and small changes in cardiac index and stroke volume index, but the interpretation of rapid and small changes of pulse pressure variation and stroke volume variation must be done with caution.

Changes in dynamic arterial elastance induced by volume expansion and vasopressor in the operating room: a prospective bicentre study

BACKGROUND

Dynamic arterial elastance (Eadyn), defined as the ratio between pulse pressure variations and stroke volume variations, has been proposed to assess functional arterial load. We evaluated the evolution of Eadyn during volume expansion and the effects of neosynephrine infusion in hypotensive and preload-responsive patients.

METHODS

In this prospective bicentre study, we included 56 mechanically ventilated patients in the operating room. Each patient had volume expansion and neosynephrine infusion. Stroke volume and stroke volume variations were obtained using esophageal Doppler, and pulse pressure variations were measured through the arterial line. Pressure response to volume expansion was defined as an increase in mean arterial pressure (MAP) ≥ 10%.

RESULTS

Twenty-one patients were pressure responders to volume expansion. Volume expansion induced a decrease in Eadyn (from 0.69 [0.58-0.85] to 0.59 [0.42-0.77]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after volume expansion were related to age, history of arterial hypertension, net arterial compliance and effective arterial elastance. Eadyn value before volume expansion > 0.65 predicted a MAP increase ≥ 10% with a sensitivity of 76% (95% CI 53-92%) and a specificity of 60% (95% CI 42-76%). Neosynephrine infusion induced a decrease in Eadyn (from 0.67 [0.48-0.80] to 0.54 [0.37-0.68]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after neosynephrine infusion were only related to heart rate.

CONCLUSION

Eadyn is a potential sensitive marker of arterial tone changes following vasopressor infusion.

Postoperative Thrombotic Microangiopathy following Radical Cystectomy for Bladder Cancer

This report describes the perioperative management of disseminated intravascular coagulation occurring abruptly during a planned cystectomy for non-metastatic bladder papillary carcinoma. Peroperatively, profuse bleeding and an acute decrease in blood pressure were effectively treated by blood transfusions and fresh frozen plasma. Haematological tests indicated the presence of disseminated intravascular coagulation. On the following three days, acute renal failure, peripheral disseminated intravascular coagulation-related thrombocytopenia and haemolytic anemia with schistocytes were suggestive of thrombotic microangiopathy. Treatment by plasma exchange along with haemodialysis was commenced. An aetiological work-up remained negative. After 21 days of treatment, haemodialysis and plasma exchange were stopped. Urological outcome was favourable. The one-year follow-up did not show any residual renal insufficiency and laboratory parameters returned to normal. In the absence of evidence in favour of an infectious, drug-related or immunological aetiology, we postulated that this thrombotic microangiopathy was caused by disseminated intravascular coagulation and that the tumour manipulation during the surgical procedure was the triggering factor.

Immediate Hypersensitivity to Contrast Agents: The French 5-year CIRTACI Study

BACKGROUND

Iodinated and gadolinium-based contrast media (ICM; GBCM) induce immediate hypersensitivity (IH) reactions. Differentiating allergic from non-allergic IH is crucial; allergy contraindicates the culprit agent for life. We studied frequency of allergic IH among ICM or GBCM reactors.

METHODS

Patients were recruited in 31 hospitals between 2005 and 2009. Clinical symptoms, plasma histamine and tryptase concentrations and skin tests were recorded. Allergic IH was diagnosed by intradermal tests (IDT) with the culprit CM diluted 1:10, "potentially allergic" IH by positive IDT with pure CM, and non-allergic IH by negative IDT.

FINDINGS

Among 245 skin-tested patients (ICM = 209; GBCM = 36), allergic IH to ICM was identified in 41 (19.6%) and to GBCM in 10 (27.8%). Skin cross-reactivity was observed in 11 patients with ICM (26.8%) and 5 with GBCM (50%). Allergy frequency increased with clinical severity and histamine and tryptase concentrations (p < 0.0001). Cardiovascular signs were strongly associated with allergy. Non-allergic IH was observed in 152 patients (62%) (ICM:134; GBCM:18). Severity grade was lower (p < 0.0001) and reaction delay longer (11.6 vs 5.6 min; p < 0.001). Potentially allergic IH was diagnosed in 42 patients (17.1%) (ICM:34; GBCM:8). The delay, severity grade, and mediator release were intermediate between the two other groups.

INTERPRETATION

Allergic IH accounted for < 10% of cutaneous reactions, and > 50% of life-threatening ones. GBCM and ICM triggered comparable IH reactions in frequency and severity. Cross-reactivity was frequent, especially for GBCM. We propose considering skin testing with pure contrast agent, as it is more sensitive than the usual 1:10 dilution criteria.

End-expiratory occlusion maneuver to predict fluid responsiveness in the intensive care unit: an echocardiographic study

BACKGROUND

In mechanically ventilated patients, an increase in cardiac index during an end-expiratory-occlusion test predicts fluid responsiveness. To identify this rapid increase in cardiac index, continuous and instantaneous cardiac index monitoring is necessary, decreasing its feasibility at the bedside. Our study was designed to investigate whether changes in velocity time integral and in peak velocity obtained using transthoracic echocardiography during an end-expiratory-occlusion maneuver could predict fluid responsiveness.

METHODS

This single-center, prospective study included 50 mechanically ventilated critically ill patients. Velocity time integral and peak velocity were assessed using transthoracic echocardiography before and at the end of a 12-sec end-expiratory-occlusion maneuver. A third set of measurements was performed after volume expansion (500 mL of saline 0.9% given over 15 minutes). Patients were considered as responders if cardiac output increased by 15% or more after volume expansion.

RESULTS

Twenty-eight patients were responders. At baseline, heart rate, mean arterial pressure, cardiac output, velocity time integral and peak velocity were similar between responders and non-responders. End-expiratory-occlusion maneuver induced a significant increase in velocity time integral both in responders and non-responders, and a significant increase in peak velocity only in responders. A 9% increase in velocity time integral induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 89% (95% CI 72% to 98%) and specificity of 95% (95% CI 77% to 100%). An 8.5% increase in peak velocity induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 64% (95% CI 44% to 81%) and specificity of 77% (95% CI 55% to 92%). The area under the receiver operating curve generated for changes in velocity time integral was significantly higher than the one generated for changes in peak velocity (0.96 ± 0.03 versus 0.70 ± 0.07, respectively, P = 0.0004 for both). The gray zone ranged between 6 and 10% (20% of the patients) for changes in velocity time integral and between 1 and 13% (62% of the patients) for changes in peak velocity.

CONCLUSIONS

In mechanically ventilated and sedated patients in the neuro Intensive Care Unit, changes in velocity time integral during a 12-sec end-expiratory-occlusion maneuver were able to predict fluid responsiveness and perform better than changes in peak velocity.

Functional variability of sacral roots in bladder control

Object

Sacral roots are involved in sensory, autonomic, and motor innervation of the lower limbs and perineum. Theoretically, it can be assumed that the S-3 root level innervates the bladder; however, clinical practice shows that this distribution can vary. Few researchers have studied this variability.

Methods

The authors conducted a retrospective study involving 40 patients who underwent surgery requiring an electrophysiological exploration of the sacral roots. They performed stimulations for the monitoring of muscular (3 Hz, 1 V) and bladder responses under cystomanometry (30 Hz, 10 V).

Results

Although the S-3 roots were involved in bladder innervation in all cases, they were exclusively involved (i.e., the only nerve roots involved) in only 8 of 40 cases. In the remaining 32 cases, other sacral nerve roots were involved. The most common association was S-3+S-4 (12 cases), followed by S-2+S-3 (6 cases), S-2+S-3+S-4 (5 cases), and S-3+S-4+S-5 (2 cases). Stimulation of S-2 could sometimes induce bladder contraction (15 cases, 40%); however, the amplitude was often low. S-4 nerve roots were involved in 24 of 40 cases (60%) in the bladder motor function, whereas S-5 roots were only involved 7 times (17%). Occasionally, we noticed a horizontal asymmetry in the response, with a predominant response from the right side in 6 of 7 cases, always with a major S-3 response.

Conclusions

This is the first study showing a significant horizontal and vertical variability in the functional distribution of sacral roots in bladder innervation. These results show the variability of cauda equina syndromes and their forensic implications. These data should help with the monitoring of sacral roots and the performance of several tasks during surgery, including neurostimulation and neuromodulation.

Benefits of intravenous lidocaine on post-operative pain and acute rehabilitation after laparoscopic nephrectomy

BACKGROUND AND AIMS

Intravenous (I.V.) lidocaine has analgesic, antihyperalgesic and anti-inflammatory properties and is known to accelerate the return of bowel function after surgery. We evaluated the effects of I.V. lidocaine on pain management and acute rehabilitation protocol after laparoscopic nephrectomy.

MATERIALS AND METHODS

A total of 47 patients scheduled to undergo laparoscopic nephrectomy were included in a two-phase observational study where I.V. lidocaine (1.5 mg/kg/h) was introduced, in the second phase, during surgery and for 24 h post-operatively. All patients underwent the same post-operative rehabilitation program. Post-operative pain scores, opioid consumption and extent of hyperalgesia were measured. Time to first flatus and 6 min walking test (6MWT) were recorded.

RESULTS

Patient demographics were similar in the two phases (n = 22 in each group). Lidocaine significantly reduced morphine consumption (median [25-75% interquartile range]; 8.5 mg[4567891011121314151617] vs. 25 mg[1920212223242526272829303132]; P < 0.0001), post-operative pain scores (P < 0.05) and hyperalgesia extent on post-operative day 1-day 2-day 4 (mean ± standard deviation (SD); 1.5 ± 0.9 vs. 4.3 ± 1.2 cm (P < 0.001), 0.6 ± 0.5 vs. 2.8 ± 1.2 cm (P < 0.001) and 0.13 ± 0.3 vs. 1.2 ± 1 cm (P < 0.001), respectively). Time to first flatus (mean ± SD; 29 ± 7 h vs. 48 ± 15 h; P < 0.001) and 6MWT at day 4 (189 ± 50 m vs. 151 ± 53 m; P < 0.001) were significantly enhanced in patients with i.v. lidocaine.

CONCLUSION

Intravenous (I.V.) lidocaine could reduce post-operative morphine consumption and improve post-operative pain management and post-operative recovery after laparoscopic nephrectomy. I.V. lidocaine could contribute to better post-operative rehabilitation.

Management program decreases postoperative nausea and vomiting in high-risk and in general surgical patients: a quality improvement cycle

BACKGROUND

Preventing postoperative nausea and vomiting (PONV) is a major priority for postsurgical patient care. Our objective was to assess the efficacy of a multimodal postoperative nausea and vomiting (PONV) approach, which was associated with a continuous quality improvement program, in maintaining a low PONV incidence in the PACU.

METHODS

Consecutive adult patients scheduled for surgery (ambulatory surgery or not) were prospectively included. PONV data were recorded in the PACU and over a 24-hour period. The management program was based on a multimodal approach with both changes in anesthetic techniques and anti-emetics, and on a three-stage protocol including: 1) phase I: institutional practice phase based on prospective observational study; 2) protocol implementation; 3) phase II: prospective observational study associated with feedback, scientific session and evaluation to guideline adherence. We used the Apfel risk scoring system to identify patients at high risk of PONV. Feedback with audit results and didactic sessions were scheduled quarterly in the Phase II.

RESULTS

Thirty-seven/395 (9.4%) and 151/3864 (3.9%) patients experienced PONV in the PACU during Phase I and Phase II respectively (P<0.001). Among the patients with an Apfel risk score that included at least two risk factors, 16.6% and 4.2% experienced PONV in the PACU during Phase I and Phase II respectively (P<0.001).

CONCLUSION

We highlight the association with a sharp decrease in PONV incidence over a one-year period and a multimodal PONV approach using feedback to clinicians associated with continuous quality improvement program.

Cerebral blood flow modulation by transcutaneous cranial electrical stimulation with Limoge's current

OBJECTIVES

Transcutaneous cranial electrical stimulation (TCES) delivers a high-frequency (166 kHz) pulsed biphasic balanced current with a pulse repetition frequency of 100 Hz with 40% duty cycle through a negative electrode and two positive electrodes over the skull. TCES has a proven ability to potentiate anesthesia and analgesia, although the physiological mechanisms of this effect remain unclear. We hypothesized that the mechanism is a modulation of CBF in the central endogenous opioid system. This study aimed at determining the effects of TCES on CBF to elucidate its physiological mechanism.

METHODS

Thirty-six healthy volunteers were randomly assigned to active or placebo TCES, and all assessments were double blind. TCES was performed using the Anesthelec™ device. In the stimulated group, an active cable was used, and in the control group (sham), the cable was inactive. CBF was measured by XeCT™ before and after two hours of TCES.

RESULTS

Globally, CBF was unchanged by TCES. However, locally, TCES induced a significant CBF decrease in the brainstem and thalamus, which are structures involved in pain and anxiety (TCES and control CBF decrease were 18.5 and 11.9 mL/100g brain tissue/min, respectively).

CONCLUSION

TCES can modulate local CBF but it has no effect on overall CBF. [Clinical Trials. gov number: NCT00273663].

Awake Craniotomy vs Surgery Under General Anesthesia for Resection of Supratentorial Lesions4

BACKGROUND:

The use of an awake craniotomy in the treatment of supratentorial lesions is a challenge for both patients and staff in the operation theater.

OBJECT:

To assess the safety and effectiveness of an awake craniotomy with brain mapping in comparison with a craniotomy performed under general anesthesia.

METHODS:

We prospectively compared 2 groups of patients who underwent surgery for supratentorial lesions: those in whom an awake craniotomy with intraoperative brain mapping was used (AC group, n = 214) and those in whom surgery was performed under general anesthesia (GA group, n = 361, including 72 patients with lesions in eloquent areas). The AC group included lesions in close proximity to the eloquent cortex that were surgically treated on an elective basis.

RESULTS:

Globally, the 2 groups were comparable in terms of sex, age, American Society of Anesthesiologists score, pathology, size of lesions, quality of resection, duration of surgery, and neurological outcome, and different in tumor location and preoperative neurological deficits (higher in the AC group). However, specific data analysis of patients with lesions in eloquent areas revealed a significantly better neurological outcome and quality of resection (P &lt; .001) in the AC group than the subgroup of GA patients with lesions in eloquent areas. Surgery was uneventful in AC patients and they were discharged home sooner.

CONCLUSION:

AC with brain mapping is safe and allows maximal removal of lesions close to functional areas with low neurological complication rates. It provides an excellent alternative to craniotomy under GA.

Hemangioblastoma of the corpus callosum: A case report and review of the literature on its origin

A third case of corpus callosum hemangioblastoma (HB) is presented. With no preoperative embolization, surgery was uneventful and the postoperative course was excellent. Based on the literature, we attempted to clarify the histogenesis of HB and to explain why they are exceptional in the supratentorial region in contrast to the posterior cranial fossa. The VHL gene is expressed particularly in Purkinje cells of the cerebellum, but this expression is also possible in supratentorial structures. Its mutation leads to developmental arrest of angioblasts that become potentially neoplastic cells. These CD133-positive pluripotent neoplastic angioblasts, similar to stem cells, may be immature HB in the brain. They also express VEGF, coexpress Epo/EpoR, and are capable of differentiation into primitive vascular structures. This coexpression may not only mediate developmental stagnation, but may also induce HB proliferation. Therefore, HB tumorigenesis may be initiated during embryogenesis and may originate from angiomesenchyma because of the expression of three cell types (stromal cells, pericytes, and endothelial cells) in vimentin. Their capacity for proliferation and differentiation in HB depends on the microenvironment.

Wound infiltration with magnesium sulphate and ropivacaine mixture reduces postoperative tramadol requirements after radical prostatectomy

PURPOSE

This prospective, randomized, double-dummy study was undertaken to compare the effects of magnesium sulphate (MgSO(4)) administered by the intravenous vs. the infiltration route on postoperative pain and analgesic requirements.

METHODS

Forty ASA I or II men scheduled for radical retropubic prostatectomy under general anaesthesia were randomized into two groups (n=20 each). Two medication sets A and B were prepared at the pharmacy. Each set contained a minibag of 50 ml solution for IV infusion and a syringe of 45 ml for wound infiltration. Group MgSO(4).IV patients received set A with 50 mg/kg MgSO(4) in the minibag and 190 mg of ropivacaine in the syringe. Group MgSO(4)/L received set B with isotonic saline in the minibag and 190 mg of ropivacaine +750 mg of MgSO(4) in the syringe. The IV infusion was performed over 30 min at induction of anaesthesia and the surgical wound infiltration was performed during closure. Pain was assessed every 4 h, using a 100-point visual analogue scale (VAS). Postoperative analgesia was standardized using IV paracetamol (1 g/6 h) and tramadol was administered via a patient-controlled analgesia system. The follow-up period was 24 h.

RESULTS

The total cumulative tramadol consumption was 221 +/- 64.1 mg in group MgSO4.IV and 134 +/- 74.9 mg in group MgSO(4).L (P<0.01). VAS pain scores were equivalent in the two groups throughout the study. No side-effects, due to systemic or local MgSO(4) administration, were observed.

CONCLUSION

Co-administration of MgSO(4) with ropivacaine for postoperative infiltration analgesia after radical retropubic prostatectomy produces a significant reduction in tramadol requirements.

SPINAL MENINGIOMA SURGERY IN ELDERLY PATIENTS WITH PARAPLEGIA OR SEVERE PARAPARESIS

OBJECTIVE

In a multicenter study, 102 patients aged 70 years or older with paraplegia or severe paraparesis, and who underwent operation for spinal meningiomas, are presented to correlate surgery and outcome and to determine the most influential factors that affected this outcome.

METHODS

Five French neurosurgical centers participated in this retrospective study between 1990 and 2007. Pre- and postoperative neurological status were assessed using a grading system. All patients underwent operation, and neurological evaluations were conducted 3 months and 1 year after surgery. The median follow-up period was 49.5 months (range, 12–169 months). Data were analyzed using a multiple logistic regression model.

RESULTS

Twenty-six patients were paraplegic (Grade 4). Complete tumor removal was obtained in 93 patients. There was no surgical mortality, and morbidity was 9%. Three months after surgery, 7 of the patients were unchanged, 87 patients had improved, and 8 were not evaluated. One year after surgery, 7 of the 100 surviving patients were clinically unchanged and 93 had improved. Of those who had improved, 49 patients experienced complete recovery.

CONCLUSION

Advanced age did not seem to contraindicate surgery, even in patients with severe preoperative neurological deficits and/or an American Society of Anesthesiologists class of III. Quality of life can be improved in most cases.

INTRACRANIAL MENINGIOMA SURGERY IN THE NINTH DECADE OF LIFE

OBJECTIVE

The aims of this study are to assess the surgical outcome of elderly patients aged 80 years or more, to analyze the factors influencing postoperative course, and to propose a grading system to standardize the surgical indication of intracranial meningioma in the elderly.

METHODS

Between 1990 and 2005, we surgically treated 74 consecutive patients aged 80 years or more for intracranial meningiomas (47 women, 27 men; mean age, 82 yr; age range, 80–90 yr). The median follow-up period was 94 months (range, 15–147 mo). We retrospectively analyzed the factors influencing surgical outcome and retained the significant factors to form the Sex, Karnofsky Performance Scale, American Society of Anesthesiology Class, Location of Tumor, and Peritumoral Edema (SKALE) grading system.

RESULTS

There was no perioperative mortality, and the 1-year mortality rate was 9.4%. Postoperative mortality was lower in women with a Karnofsky Performance Scale score of 60 or greater, an American Society of Anesthesiology Class of 1 or 2, a noncritical tumor location, and a moderate or absent peritumoral edema. Patients with a SKALE score of more than 8 had an excellent outcome, whereas those with a SKALE score of less than 8 had a poor outcome. The rate of postoperative complications was 9.4%. Large tumors, critical locations, severe peritumoral edema, and total surgical excision were associated with a higher risk of postoperative complications.

CONCLUSION

Surgery of intracranial meningioma in elderly patients is feasible when the SKALE score is 8 or greater. Prospective studies are required to validate this grading system.

Sublingual oxybutynin reduces postoperative pain related to indwelling bladder catheter after radical retropubic prostatectomy †

BACKGROUND

Bladder discomfort related to an indwelling catheter can exacerbate postoperative pain. It mimics overactive bladder syndrome that is resistant to conventional opioid therapy. Muscarinic receptor antagonists are effective for treatment of the overactive bladder. The aim of this study was to assess the efficacy of oxybutynin in the management of postoperative pain after radical prostatectomy.

METHOD

Forty-six ASA I or II men undergoing radical retropubic prostatectomy under general anaesthesia were randomly assigned to two groups, in a double-blind fashion: Group O and Group P (n = 23 each). Group O and Group P received, respectively, sublingual oxybutynin 5 mg or placebo every 8 h during the 24 h after surgery. A 16F Foley catheter was placed during the vesico-urethral anastomosis and the balloon inflated with 10 ml of saline. Pain was assessed in the recovery room starting 10 min after extubation using a 100-point visual analogue scale (VAS). The patients were asked to specify whether pain was related to the surgical incision or bladder pain. Standardized postoperative analgesia included acetaminophen and tramadol administered via a patient-controlled analgesia system.

RESULTS

The incidence of bladder catheter pain was 65% (15 of 23 patients) in Group P compared with 17% (4 of 23 patients) in Group O (P < 0.01). Overall VAS scores at rest were significantly lower in Group O. Cumulative tramadol consumption was 322.9(124.3) mg [mean(sd)] in Group P and 146(48) mg in Group O (P < 0.01). No oxybutynin-related side-effects were reported.

CONCLUSIONS

Sublingual oxybutynin is an effective treatment for postoperative pain after radical retropubic prostatectomy and produces a significant reduction in tramadol requirements.

Intravenous magnesium sulphate decreases postoperative tramadol requirement after radical prostatectomy*

BACKGROUND

The purpose of this study was to assess whether the addition of intravenous magnesium sulphate (Mg) at the induction of anaesthesia to a balanced anaesthetic protocol including wound infiltration, paracetamol and tramadol resulted in improved analgesic efficiency after radical prostatectomy.

METHODS

We conducted a randomized, double-blind, controlled study. Thirty ASA I or II males scheduled to undergo radical retropubic prostatectomy with general anaesthesia were prospectively assigned to one of the two groups (n = 15 each). The Mg group (Gr Mg) received 50 mg kg-1 of MgSO4 in 100 mL of isotonic saline over 20 min immediately after induction of anaesthesia and before skin incision. The patients in the control group (Gr C) received the same volume of saline over the same period. At the time of abdominal closure, wound infiltration with 190 mg (40 mL) of ropivacaine was performed in both groups. Pain was assessed by a 10-point visual analogue scale in the recovery room starting from the time of tracheal extubation. Standardized postoperative analgesia included paracetamol and tramadol administered via a patient-controlled analgesia device.

RESULTS

In the postoperative period, both groups experienced an identical pain course evolution. Cumulative mean tramadol dose after 24 h was 226 mg in the magnesium group and 446 mg in the control group (P < 0.001). Postoperative nausea occurred in two patients in each group. Two vs. eight patients required analgesic rescue in magnesium and control groups, respectively (P = 0.053).

CONCLUSIONS

This study shows that intravenous magnesium sulphate reduces tramadol consumption when used as a postoperative analgesic protocol in radical prostatectomy.

Comparative overview of brain perfusion imaging techniques

Numerous imaging techniques have been developed and applied to evaluate brain hemodynamics. Among these are: Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), Xenon-enhanced Computed Tomography (XeCT), Dynamic Perfusion-computed Tomography (PCT), Magnetic Resonance Imaging Dynamic Susceptibility Contrast (DSC), Arterial Spin-Labeling (ASL), and Doppler Ultrasound. These techniques give similar information about brain hemodynamics in the form of parameters such as cerebral blood flow (CBF) or volume (CBV). All of them are used to characterize the same types of pathological conditions. However, each technique has its own advantages and drawbacks. This article addresses the main imaging techniques dedicated to brain hemodynamics. It represents a comparative overview, established by consensus among specialists of the various techniques. For clinicians, this paper should offers a clearer picture of the pros and cons of currently available brain perfusion imaging techniques, and assist them in choosing the proper method in every specific clinical setting.

Comparison of the anaesthetic requirement with target-controlled infusion of propofol to insert the laryngeal tube vs. the laryngeal mask

BACKGROUND AND OBJECTIVE

The target effect-site concentration of propofol to insert a laryngeal mask airway was recently reported as almost 5 microg mL(-1). The present study aimed to determine the target effect-site concentration with target-controlled infusion of propofol to place classical larnygeal mask airway or current laryngeal tube in adult patients.

METHODS

We included 40 patients scheduled for short gynaecological and radiological procedures under general anaesthesia in a randomized, double-blind manner using the Dixon's up-and-down statistical method. Monitoring included standard cardiorespiratory monitors, and bispectral index monitoring was used for all patients. Anaesthesia was conducted with a target-controlled infusion system: Diprifusor. The initial target plasma concentration of propofol was 5 microg mL(-1), and was changed stepwise by 0.5 microg mL(-1) increments according to Dixon's up-and-down method. Criteria for acceptable insertion were: Muzi's score < or = 2, and mean arterial blood pressure, heart rate or bispectral index variation <20% the baseline values.

RESULTS

Target effect-site concentration of propofol required to insert laryngeal tube was 6.3 +/- 0.3 microg mL(-1) with Dixon method and ED50 was 6.1 microg mL(-1) (5.9-6.4) with logistic regression method. In the case of larnygeal mask airway they were 7.3 +/- 0.2 microg mL(-1) (Dixon method) and 7.3 microg mL(-1) (7.1-7.5; with logistic regression) respectively (P < 0.05). ED95 (logistic regression) was 6.8 microg mL(-1) (5.9-7.6) for laryngeal tube and 7.7 microg mL(-1) (7.3-8.0) for larnygeal mask airway (P < 0.05). Haemodynamic incidents were 55% in the larnygeal mask airway group vs. 30% in the laryngeal tube group (P < 0.05).

CONCLUSIONS

The target effect-site concentration of propofol for insertion of laryngeal tube was lower than for larnygeal mask airway (P < 0.05), with a consequent reduction of the propofol induced haemodynamic side-effects.

Comparative overview of brain perfusion imaging techniques

BACKGROUND AND PURPOSE

Numerous imaging techniques have been developed and applied to evaluate brain hemodynamics. Among these are positron emission tomography, single photon emission computed tomography, Xenon-enhanced computed tomography, dynamic perfusion computed tomography, MRI dynamic susceptibility contrast, arterial spin labeling, and Doppler ultrasound. These techniques give similar information about brain hemodynamics in the form of parameters such as cerebral blood flow or cerebral blood volume. All of them are used to characterize the same types of pathological conditions. However, each technique has its own advantages and drawbacks.

SUMMARY OF REVIEW

This article addresses the main imaging techniques dedicated to brain hemodynamics. It represents a comparative overview established by consensus among specialists of the various techniques.

CONCLUSIONS

For clinicians, this article should offer a clearer picture of the pros and cons of currently available brain perfusion imaging techniques and assist them in choosing the proper method for every specific clinical setting.

Effects of perioperative alpha1 block on haemodynamic control during laparoscopic surgery for phaeochromocytoma

BACKGROUND

Laparoscopic surgery for phaeochromocytoma can cause excessive catechol amine release with severe hypertension and sinus tachycardia. i.v. calcium antagonists may be used to prevent increases in blood pressure during phaeochromocytoma resection. We investigated the effects of perioperative alpha(1) adrenergic block with urapidil on intraoperative haemodynamic events. The aim was to block the alpha(1) adrenergic receptors before any acute catecholamine release, to prevent any severe rise in blood pressure.

METHODS

Eighteen patients with a phaeochromocytoma received a continuous i.v. infusion of urapidil 10-15 mg h(-1) for 3 days before surgery and until the adrenal gland had been removed. Plasma catecholamine concentrations were measured before surgery, after induction of anaesthesia, at the end of pneumoperitoneal insufflation, during gland manipulation, after gland resection, and in the recovery room after extubation. Arterial pressure was recorded concomitantly. Hypertensive events were treated with boluses of nicardipine with or without esmolol.

RESULTS

All patients had the adrenal tumour removed without any severe rise in blood pressure or other complication. Creation of a pneumoperitoneum and adrenal gland manipulation induced significant catecholamine release associated with hypertension in 6 and 12 patients, respectively. No correlation was found between hypertensive events and plasma catecholamine levels suggesting alpha(1) receptor block with urapidil is efficacious.

CONCLUSIONS

Perioperative alpha(1) block using i.v. urapidil is a safe and efficient alternative during surgical management of phaeochromocytoma.

[Anterior sacral root stimulation with dorsal rhizotomy (Brindley technique)]

Patients with spinal cord lesions are exposed to vesico-sphincter dysfunctions which can aggravate the vital or functional prognosis. The pathophysiological characteristics of these neurogenic bladders explains the usefulness of surgical treatment. The objective of the Brindley technique is to improve both voiding and effective continence. Any patient with a stable supra-sacral spinal cord lesion (paraplegia, tetraplegia) with a reflex bladder (incontinence, vesico-sphincter dyssynergia resistant to medical treatment with the risk of upper urinary tract involvement) can benefit from the Brindley technique. The electrodes are placed on the anterior sacral roots in order to obtain the desired micturation. Posterior sacral rhizotomies are indispensable to the technique as they suppress detrusor and sphincter hyperreflexia and improve continence thereby protecting the upper urinary tract. About 90% of the patients considered have an improved quality of life after implantation of the Brindley stimulator. The bladder capacity was constantly improved and the majority of the patients become continent. Micturation was excellent with low residual volume and low rate of urinary tract infections. Complications are analyzed in this review of the literature. The Brindley technique is an excellent alternative to medical treatment in these highly distressed patients. It restores satisfactory continence and improves psychological as well as economical constraints related to auto/hetero catheterisations performed several times a day.

[Osmotic cerebral oedema: the role of plasma osmolarity and blood brain barrier]

There are five types of oedema: vasogenic, cytotoxic, interstitial, hyperemic and osmotic. The differences lie on the type and localization of the oedema, the state of the blood-brain barrier (BBB) and the pathological context. Under physiological conditions, the osmolarity of extra cellular fluids (ECFs) is equal on both sides of the BBB. However, the pathophysiological variations of circulating osmolarity (including acute hyponatremia and hypernatremia) do not affect, at the same time, the osmolarity of cerebral ECFs. This situation generates an osmotic gradient on either side of the BBB. The latter, if intact, behaves like a semi-permeable membrane allowing water transport according to the osmotic laws. Depending on its direction, water movement could induce cerebral liquid inflation (i.e. osmotic oedema) or cerebral dehydration. In case of osmotic insult, cerebral cell modify their active osmotic molecular contents in order to limit volume variation. There are two types of osmoactive molecules, organic (i.e. ideogenic osmoles: amino acids, polyols and trimethylamines) and non organic (i.e. electrolytes). In the event of plasma hypotonicity, cerebral cells expel active osmotic molecules to reduce the osmotic gradient and water movement thereby reducing edema. The opposite reaction is observed in the case of hypertonic insult. This cerebral osmoregulation becomes more effective, the slower the osmotic disorder. It explains, for example, why patients with chronic and severe hyponatremia could be asymptomatic. Severe osmotic oedema is observed mainly in water intoxication, acute hyponatremia or too rapid reduction of hyperosmolarity. However, osmotic oedema is not limited to extreme clinical circumstances. Hyponatremia, even modest, could modify cerebral blood volume and impair osmoregulation. Generally these minor modifications do not affect normal brain tissue. In the presence of cerebral lesion, osmoregulation operates only in areas of preserved BBB. The pathological zones are therefore exposed to osmotic oedema (even in cases of moderate hyponatremia) with deterioration of both clinical status and intracranial pressure. This authentic phenomenon could be insidious and difficult to differentiate from osmotic central oedema. Hyponatremia constitutes an authentic secondary cerebral insult of systemic origin, an entity clearly identified by experimental studies to justify the choice between crystalloids and colloids in neuroanaesthesia and neurointensive care. These studies have revealed an increase in water content in normal brain tissues after administration of hypotonic solutions. The increase in plasma osmolarity as a treatment modality using mannitol or hypertonic saline is based on the same concepts. The most remote indication is the occurrence of a reactive mydriasis in the context of trauma for example. More recently, therapeutic hypernatremia has been proposed to control intracranial hypertension.

Dorsal rhizotomy with anterior sacral root stimulation for neurogenic bladder

A spinal cord lesion above the sacral micturition center results in a loss of voluntary control and development of bladder sphincter dysynergia with hyperreflexia of the detrusor and spasticity of the sphincter. Sacral rhizotomy and implantation of an anterior sacral root stimulator appears as an effective method for the treatment not only of voiding dysfunction but also of defecation and sexual disturbance. The surgical technique is described as are the clinical and electrophysiological controls. The results of our series of operated patients with intradural implantation and sacral deaffentation show a constant improvement. 90% have satisfactory continence and no longer require an incontinence appliance. Bladder capacity and compliance have increased to 120% and urethral closure pressure has decreased. 80% have complete voiding or a post-void residue of not more than 50 ml. So, urinary infection rate is dramatically decreased.

[Autonomic hyperreflexia induced by sacral root stimulation is detected by spectral analysis of the EEG]

PURPOSE

To compare spectral analysis of the electrocardiogram (ECG) with mean arterial pressure (MAP) and heart rate (HR) monitoring in the detection of autonomic hyperreflexia (AHR) induced by sacral root stimulation.

METHODS

Ten spinal cord injured patients scheduled for implantation of a sacral root stimulator for bladder retention were included. Under target controlled anesthesia with propofol 4 micro g*mL(-1) and remifentanil 4 ng*mL(-1), the patients were placed in the knee chest position. The sacral roots were exposed by laminectomy (L2-S1) and their function assessed by electrostimulation under urodynamic and cardiovascular monitoring. Online power spectrum densities were calculated from the ECG R-R interval by the MemCalc(TM) software using the maximum entropy method. Low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4 Hz) spectra were associated with sympathetic and parasympathetic activities respectively. The most extreme value of each variable was noted before and during each stimulation. A difference ( triangle up ) of more than 10% signified AHR. The comparison ( triangle up LF vs triangle up MAP and triangle up HF vs triangle up HR) was done by a concordance test with a kappa coefficient (k): -1 = total discordance to 1 = total concordance.

RESULTS

AHR was detected in six patients as an increase in LF and MAP (n = 4); an increase in LF, HF, MAP with a decrease in HR (n = 2). The detection delay was 5.3 +/- 1 sec (LF, HF) and 10.4 +/- 1.2 sec (MAP and HR). Concordance was 85% (LF vs MAP: k = 0.7) and 90% (HF vs HR: k = 0.8).

CONCLUSION

AHR induced by sacral root stimulation is detected by spectral analysis of the ECG earlier than MAP and HR. Other studies are needed to confirm these results.