The effects of intrathecal morphine on urinary bladder function and recovery in patients having a cesarean delivery - A randomized clinical trial

INTRODUCTION

Spinal anesthesia with intrathecal morphine (ITM) is a common anesthesia technique for cesarean delivery. The hypothesis was that the addition of ITM will delay micturition in women undergoing cesarean delivery.

METHODS

Fifty-six ASA physical status I and II women scheduled to undergo elective cesarean delivery under spinal anesthesia were randomized to the PSM group (50 mg prilocaine + 2.5 mcg sufentanil + 100 mcg morphine; n = 30) or PS group (50 mg prilocaine + 2.5 mcg sufentanil; n = 24). The patients in the PS group received a bilateral transverse abdominal plane (TAP) block. The primary outcome was the effect of ITM on the time to micturition and the secondary outcome was the need for bladder re-catheterization.

RESULTS

The time to first urge to urinate (8 [6-10] hours in the PSM group versus 6 [4-6] hours in the PS group) and the time to first micturition (10 [8-12] hours in the PSM group versus 6 [6-8] hours in the PS group) were significantly (p < 0.001) prolonged in the PSM group. Two patients in the PSM group met the 800 mL criterium for urinary catheterization after 6 and 8 h respectively.

CONCLUSION

This study is the first randomized trial to demonstrate that the addition of ITM to the standardized mixture of prilocaine and sufentanil significantly delayed micturition.

[Interscalene block and shoulder surgery. Literature review and new method of infiltration]

Nowadays, interscalene block is the gold standard for intra- and post-operative analgesia for shoulder surgery. It consists of distributing a sufficient volume of local anesthetics, within the interscalenic space which contains the C5 to C7 nerve roots. Due to its proximity to the area where the anesthetic is injected, the phrenic nerve can be transiently blocked causing a kind of paralysis of an hemidiaphragm. First, the use of ultrasound has reduced the incidence of diaphragmatic hemiparesis especially when the injection is performed at the C7 level rather than the C5 or C6 level. Then, decreasing the doses of local anesthetics has reduced the diffusion to the non-targeted structures, such as the phrenic nerve, causing less diaphragmatic hemiparesis. Finally, Palhais and Lee et al discovered that injecting LA at distance from the nerves roots can be useful in reducing this side effect. Based on their work, we decided to inject the local anesthetic into the muscle fascia. Our experience with this injection into the muscle itself seems to confirm the results described in the literature with less diaphragmatic hemiparesis. Further studies are needed to support our hypothesis and will be the subject of future researches in our institution.

[Treatment of post-total knee replacement gonalgy by radiofrequency ablation of the genicular nerves]

Neurotomy of genicular nerves by radiofrequency is a technique efficient to reduce mecanic knee pain and pain after total knee replacement. In this article, we describe the case of a patient that has suffered from chronic knee pain after total knee replacement. The patient has successfully benefited of a neurotomy of genicular nerves by radiofrequency in the inferior right limb.

Cardiac Biomarkers and Prediction of Early Outcome After Heart Valve Surgery: A Prospective Observational Study

OBJECTIVES

Circulating cardiac biomarkers may improve the prediction of long-term outcomes after cardiac surgery. The authors sought to assess if cardiac biomarkers also help better predict short-term morbidity.

DESIGN

Prospective observational study.

SETTING

Single academic hospital.

PARTICIPANTS

A total of 250 patients undergoing aortic or mitral valve surgery with or without associated coronary artery bypass grafts.

INTERVENTION

None MEASUREMENT AND MAIN RESULTS: Relationships between preoperative plasma concentrations of four cardiac biomarkers (sST2, Galectin-3, GDF-15, and NT-proBNP) and postoperative outcome were assessed using logistic regressions and Cox proportional hazards models. The primary outcome was a composite of 30-day mortality, an inotropic support longer than 48 hours and an initial length of stay in the intensive care >five days. Secondary outcome measures were postoperative acute kidney injury, inotropic support duration, lengths of intensive care unit and hospital stays, and 30-day and one-year mortality. No association was observed between any of the four cardiac biomarkers and the primary outcome. The preoperative levels of Galectin-3 (hazard ratio = 1.2; p < 0.001) and sST2 (hazard ratio = 1.01, p < 0.001) were significantly associated with one-year survival, and their addition to the EuroSCORE II significantly improved the prediction of one-year mortality (p < 0.001). Similarly, Galectin-3 was associated with postoperative acute kidney injury (odds ratio = 1.15, p = 0.001) and improved the prediction of this complication when added to the EuroSCORE II (p = 0.002).

CONCLUSIONS

These results suggested that the ability of cardiac biomarkers to predict short-term outcome after cardiac surgery, though of interest, appears limited. Conversely, cardiac biomarkers may have the potential to refine the prediction of long-term outcome. Admittedly, all positive results were obtained on secondary outcomes and must be regarded with caution.

[Predictive scores used during the anesthetic preoperative visit. Part 2. Assessment of perioperative risk]

Anesthesia remains a high-risk specialty, even though the discipline has evolved considerably over the last few decades. Independently of postoperative complications, some risks are inherent to the perioperative period itself. In this narrative review of the literature, we describe these risks and the predictive scores, allowing an assessment of these complications. All these scores are designed to detect high-risk patients and to promote personalized medicine and individualized anesthesia. They also increase the objectivity of the preoperative assessment. Finally, using these scores, the practitioner can more accurately respond to the patient who presents anxiety regarding the perioperative period.

[Predictive scores used during the anesthetic preoperative visit. Part 1. Assessment of postoperative complications]

Anesthesia is changing, moving from an intraoperative medicine to a transversal perioperative medicine. The evolution of the preoperative anesthetic consultation is part of this evolution. Recently, anesthesiologists attempt to categorize their patients to detect as early as possible those at risk of short, medium, and long-term complications. In that way, a personalized (individualized) anesthesia could be performed considering the patient's comorbidities as well as the type of surgery. Respect for the guidelines is easier to achieve with such personalized medicine. For this purpose, anesthesiologists can use predictive scores. In the last few years, there was an increase in the availability of these validated scores. A shared feature of these scores is to provide objectivity but also efficiency in their ability to be predictive while being easy and quick to apply in clinical practice. Thereby, anesthesiologists can inform the patient with more accurate information concerning their perioperative risks. Finally, these scores are part of a public health care policy that aims to reduce expenses by optimizing patient management and preoperative testing. These scores provide a global vision of the patient, which can be shared and understandable by the different practitioners.

Teaching humanitarian surgery: Filling the gap between NGO needs and subspecialized surgery through a novel inter-university certificate

Background: Access to surgical care is a global health burden. A broad spectrum of surgical competences is required in the humanitarian context whereas current occidental surgical training is oriented towards subspecialties. We proposed to design a course addressing the specificities of surgery in the humanitarian setting and austere environment.Method: The novelty of the course lies in the implication of academic medical doctors alongside with surgeons working for humanitarian non-governmental organizations (NGO). The medical component of the National Defense participated regarding particular topics of war surgery. The course is aimed at trained surgeons and senior residents interested in participating to humanitarian missions.Results: The program includes theoretical teaching on surgical knowledge and skills applied to the austere context. The course also covers non-medical aspects of humanitarian action such as international humanitarian law, logistics, disaster management and psychological support. It comprises a large-scale mass casualty exercise and a practical skills lab on surgical techniques, ultrasonography and resuscitation. Attendance to the four teaching modules, ATLS certification and succeeding final examinations provide an interuniversity certificate.30 participants originating from 11 different countries joined the course. Various surgical backgrounds, training levels as well as humanitarian experience were represented.Feedback from the participants was solicited after each teaching module and remarks were applied to the following session. Overall participant evaluations of the first course session are presented.Conclusion: Teaching humanitarian surgery joining academic and field actors seems to allow filling the gap between high-income country surgical practice and the needs of the humanitarian context.

Quadratus lumborum block: an imaging study of three approaches

BACKGROUND AND OBJECTIVES

Different injection techniques for the quadratus lumborum (QL) block have been described. Data in human cadavers suggest that the transverse oblique paramedian (TOP) QL3 may reach the thoracic paravertebral space more consistently than the QL1 and QL2. However, the distribution of injectate in cadavers may differ from that in patients. Hence, we assessed the distribution of the injectate after the QL1, QL2, and TOP QL3 techniques in patients.

MATERIALS AND METHODS

Thirty-four patients scheduled for abdominal surgery received QL blocks postoperatively; 26 patients received bilateral and 8 patients received unilateral blocks. Block injections were randomly allocated to QL1, QL2, or TOP QL3 techniques (20 blocks per each technique). The injections consisted of 18 mL of ropivacaine 0.375% with 2 mL of radiopaque contrast, injected lateral or posterior to the QL muscle for the QL1 and QL2 techniques, respectively. For the TOP QL3, the injection was into the plane between the QL and psoas muscles, proximal to the L2 transverse process. Two reviewers, blinded to the allocation, reviewed three-dimensional computed tomography (3D-CT) images to assess the distribution of injectate.

RESULTS AND DISCUSSION

The QL1 block spread in the transversus abdominis plane (TAP), QL2 in the TAP, and posterior aspect of the QL muscle, whereas TOP QL3 spread consistently in the anterior aspect of the QL muscle with occasional spread to the lumbar and thoracic paravertebral areas.

CONCLUSIONS

The spread of injectate after QL1, QL2, and QL3 blocks, resulted in different distribution patterns, primarily in the area of injection. The TOP QL3 did not result in consistent interfascial spread toward the thoracic paravertebral space.

[Autonomic hyperreflexia after spinal cord injury : perioperative management]

Spinal cord injury can have widespread consequences beyond the disruption of sensory and motor functions. Injury at or above the sixth thoracic spinal cord segment frequently leads to dysregulation of the autonomic nervous system, which results in a syndrome called autonomic hyperreflexia or dysreflexia. It is a hypertensive crisis triggered by visceral or somatic stimuli below the level of the injury and caused by sympathetic spinal reflexes not modulated by regulatory centers in the brain. Patients with spinal cord injuries frequently undergo surgery for multiple reasons. Because of the potentially lethal complications of autonomic hyperreflexia, physicians, and in particular anaesthesiologists, must be aware of the underlying pathophysiological mechanisms and adequate perioperative management.

[Preoperative fasting : state of the art]

Inhalation of gastric content is a significant risk factor for perioperative complications. Preoperative fasting reduces this risk. The preanesthesia fasting time is variable and is subject to recommendations from different scientific societies. The clinician can identify some risk factors for inhalation during the preoperative anesthetic consultation. On the day of the procedure, the gastric ultrasound allows quantitative or semi-quantitative assessment of the gastric content. In that way, the anesthesiologist can adapt the anesthesia, in particular by using a so-called rapid sequence induction and esophageal compression.

[An unexpected discovery of laryngeal neurofibroma during intubation for elective surgery]

We report the unexpected discovery of a large laryngeal neurofibroma during a direct laryngoscopy for intubation in a 18-year old female with a medical history of neurofibromatosis type 1. The most striking feature of this case report is the discrepancy between the absence of clinical manifestations and the size and location of the neurofibroma. This case highlights the importance of a careful preoperative assessment, especially in the context of multisystemic disease. Knowledge of the disease, recognition of related complications and adequate preoperative evaluation are crucial to establish the safest anesthesia strategy.

A fast and general method to empirically estimate the complexity of brain responses to transcranial and intracranial stimulations

BACKGROUND

The Perturbational Complexity Index (PCI) was recently introduced to assess the capacity of thalamocortical circuits to engage in complex patterns of causal interactions. While showing high accuracy in detecting consciousness in brain-injured patients, PCI depends on elaborate experimental setups and offline processing, and has restricted applicability to other types of brain signals beyond transcranial magnetic stimulation and high-density EEG (TMS/hd-EEG) recordings.

OBJECTIVE

We aim to address these limitations by introducing PCI^ST, a fast method for estimating perturbational complexity of any given brain response signal.

METHODS

PCI^ST is based on dimensionality reduction and state transitions (ST) quantification of evoked potentials. The index was validated on a large dataset of TMS/hd-EEG recordings obtained from 108 healthy subjects and 108 brain-injured patients, and tested on sparse intracranial recordings (SEEG) of 9 patients undergoing intracranial single-pulse electrical stimulation (SPES) during wakefulness and sleep.

RESULTS

When calculated on TMS/hd-EEG potentials, PCI^ST performed with the same accuracy as the original PCI, while improving on the previous method by being computed in less than a second and requiring a simpler set-up. In SPES/SEEG signals, the index was able to quantify a systematic reduction of intracranial complexity during sleep, confirming the occurrence of state-dependent changes in the effective connectivity of thalamocortical circuits, as originally assessed through TMS/hd-EEG.

CONCLUSIONS

PCI^ST represents a fundamental advancement towards the implementation of a reliable and fast clinical tool for the bedside assessment of consciousness as well as a general measure to explore the neuronal mechanisms of loss/recovery of brain complexity across scales and models.

[Anesthetist facing ethylic patient : management and precaution]

The anesthetic management of the patient with unhealthy alcohol use is challenging. Chronic alcohol intake results in numerous co-morbid diseases, physiologic changes and pharmacologic alterations leading to increased perioperative morbidity and mortality. Hence anesthesiologists should search for chronic and acute effects of alcohol abuse when managing such patients. Also, the anesthetic approach of these patients must be adapted to prevent perioperative complications, including withdrawal symptoms. Last, the preoperative period is on opportunity to initiate alcohol withdrawal, with patient's agreement and collaboration.

Propofol-induced unresponsiveness is associated with impaired feedforward connectivity in cortical hierarchy

BACKGROUND

Impaired consciousness has been associated with impaired cortical signal propagation after transcranial magnetic stimulation (TMS). We hypothesised that the reduced current propagation under propofol-induced unresponsiveness is associated with changes in both feedforward and feedback connectivity across the cortical hierarchy.

METHODS

Eight subjects underwent left occipital TMS coupled with high-density EEG recordings during wakefulness and propofol-induced unconsciousness. Spectral analysis was applied to responses recorded from sensors overlying six hierarchical cortical sources involved in visual processing. Dynamic causal modelling (DCM) of induced time-frequency responses and evoked response potentials were used to investigate propofol's effects on connectivity between regions.

RESULTS

Sensor space analysis demonstrated that propofol reduced both induced and evoked power after TMS in occipital, parietal, and frontal electrodes. Bayesian model selection supported a DCM with hierarchical feedforward and feedback connections. DCM of induced EEG responses revealed that the primary effect of propofol was impaired feedforward responses in cross-frequency theta/alpha-gamma coupling and within frequency theta coupling (F contrast, family-wise error corrected P<0.05). An exploratory analysis (thresholded at uncorrected P<0.001) also suggested that propofol impaired feedforward and feedback beta band coupling. Post hoc analyses showed impairments in all feedforward connections and one feedback connection from parietal to occipital cortex. DCM of the evoked response potential showed impaired feedforward connectivity between left-sided occipital and parietal cortex (T contrast P=0.004, Bonferroni corrected).

CONCLUSIONS

Propofol-induced loss of consciousness is associated with impaired hierarchical feedforward connectivity assessed by EEG after occipital TMS.

Sedation of Patients With Disorders of Consciousness During Neuroimaging: Effects on Resting State Functional Brain Connectivity

BACKGROUND

To reduce head movement during resting state functional magnetic resonance imaging, post-coma patients with disorders of consciousness (DOC) are frequently sedated with propofol. However, little is known about the effects of this sedation on the brain connectivity patterns in the damaged brain essential for differential diagnosis. In this study, we aimed to assess these effects.

METHODS

Using resting state functional magnetic resonance imaging 3T data obtained over several years of scanning patients for diagnostic and research purposes, we employed a seed-based approach to examine resting state connectivity in higher-order (default mode, bilateral external control, and salience) and lower-order (auditory, sensorimotor, and visual) resting state networks and connectivity with the thalamus, in 20 healthy unsedated controls, 8 unsedated patients with DOC, and 8 patients with DOC sedated with propofol. The DOC groups were matched for age at onset, etiology, time spent in DOC, diagnosis, standardized behavioral assessment scores, movement intensities, and pattern of structural brain injury (as assessed with T1-based voxel-based morphometry).

RESULTS

DOC were associated with severely impaired resting state network connectivity in all but the visual network. Thalamic connectivity to higher-order network regions was also reduced. Propofol administration to patients was associated with minor further decreases in thalamic and insular connectivity.

CONCLUSIONS

Our findings indicate that connectivity decreases associated with propofol sedation, involving the thalamus and insula, are relatively small compared with those already caused by DOC-associated structural brain injury. Nonetheless, given the known importance of the thalamus in brain arousal, its disruption could well reflect the diminished movement obtained in these patients. However, more research is needed on this topic to fully address the research question.

Quality of life at home and satisfaction of patients after enhanced recovery protocol for colorectal surgery

BACKGROUND

Quality of life of patients at home after an enhanced recovery protocol (ERP) for surgery has been least studied especially in elderly patients.

METHODS

Our first 41 patients entered in the colorectal GRACE database were interviewed through telephone about their postoperative stress, fatigue, pain, difficulty in feeding, home autonomy, and satisfaction. We compared the responses of the elderly patients (>70 years, n = 19) with those of the younger patients.

RESULTS

The time between the surgery and the questionnaire was 79 ± 48 days. Early return was experienced as stressful by ±20% of the patients. Fatigue and pain were low (respectively: simple numerical scale [SNS] = 4.2 ± 3.2 and 2.5 ± 2.9). When present, pain was relieved by the prescribed treatment. One-third of the patients described some difficulty in feeding. Fifty percent of the patients felt completely autonomous when returned at home, 80% attributed the rapid recovery of autonomy to the ERP. Finally, 87% were globally satisfied (SNS: 8.5 ± 1.0). The characteristics of the 'elderly' group (77 ± 6 years) and their questionnaire responses were similar to those of the younger patients.

CONCLUSIONS

Despite some limitations (retrospective, different time between surgery and the telephone survey), our study suggests that quality of life at home after ERP for colorectal surgery is very satisfactory for over 80% of patients. Furthermore, this study confirms that elderly patients benefit from an ERP for colorectal surgery like younger patients.

Preoperative adherence to continuous positive airway pressure among obstructive sleep apnea patients

BACKGROUND

Obstructive Sleep Apnea (OSA) increases the perioperative risk of complications. Chronic use of Continuous Positive Airway Pressure (CPAP) by patients decreases the importance of comorbidities caused by the OSA. However, many patients do not adhere to the treatment. Given the postoperative complications, it is important for the anesthesiologist to identify non-adherent patients. This prospective study was designed to identify factors that would predict patient adherence.

METHODS

Ninety patients who were treated by CPAP for more than one year were recruited. Among them, and based on objective criteria such as length of use of CPAP during the night, 75 were considered as being adherent to CPAP, while the other 15 were not. Sixty-two potential causes of non-adherence were investigated (some have not been tested before), and further divided into five categories. Those categories included cultural, intellectual, or economic factors, OSA comorbidities, patient belief about health, ENT-related problems, and pathophysiological features estimating the degree of improvement afforded by CPAP introduction.

RESULTS

Multivariate binary logistic regression analysis identified one criterion of non-adherence to treatment, namely the feeling of breathlessness, and three criteria of adherence, namely awareness of the risk of complications, awareness of treatment efficacy, and feeling of being less tired with CPAP therapy.

CONCLUSIONS

These four new criteria should preoperatively be sought, in order to detect non-adherent patients more efficiently.

[When diagnostic imaging is misleading: a case of subacute liver failure]

We report the case of a 67 year old woman presenting with a mixed alteration of liver function tests. Despite normal results of tomodensitometry and positon emission tomography, a liver biopsy was performed due to the development of acute liver failure: it showed a diffuse infiltration of liver sinusoids by a breast adenocarcinoma, unfortunately fatal for the patient. The tumour infiltration was responsible for portal hypertension and hepatic perfusion disorders leading to liver failure.

[Perioperative management of direct oral anticoagulants: not much evidence but several different approaches]

New oral anticoagulants (NOACs) are a major step forward in the field of anticoagulation. As a consequence, the number of patients treated with NOACs that have to undergo surgery constantly increases. The optimal management of such patients is not clearly determined so far as scientifically established data are lacking. A first proposal is to mimic the perioperative management of patients on vitamin-K antagonists. When the risk of perioperative bleeding is low, NOAC intake is stopped 24 hours before surgery. If the risk of postoperative hemorrhage is moderate or high, NOAC treatment is interrupted 5 days before surgery with a low molecular weight heparin bridging whenever necessary. A second option is based on pharmacokinetic data. When the risk of perioperative bleeding is low, NOAC intake is stopped the day before surgery. If the risk of perioperative bleeding is higher, NOAC intake is suspended for 5 half lives before surgery, 48-72 hours or more. This interruption should be for a longer period in the presence of renal failure. When an unforeseen surgery is needed, the procedure must be delayed as late as possible. In case of emergency, non specific pro-hemostatic agents such as prothrombin complexes or recombinant factor VIIa have not strongly proven useful and must only be used in last ditch effort.

Posterior cingulate cortex-related co-activation patterns: a resting state FMRI study in propofol-induced loss of consciousness

Background

Recent studies have been shown that functional connectivity of cerebral areas is not a static phenomenon, but exhibits spontaneous fluctuations over time. There is evidence that fluctuating connectivity is an intrinsic phenomenon of brain dynamics that persists during anesthesia. Lately, point process analysis applied on functional data has revealed that much of the information regarding brain connectivity is contained in a fraction of critical time points of a resting state dataset. In the present study we want to extend this methodology for the investigation of resting state fMRI spatial pattern changes during propofol-induced modulation of consciousness, with the aim of extracting new insights on brain networks consciousness-dependent fluctuations.

Methods

Resting-state fMRI volumes on 18 healthy subjects were acquired in four clinical states during propofol injection: wakefulness, sedation, unconsciousness, and recovery. The dataset was reduced to a spatio-temporal point process by selecting time points in the Posterior Cingulate Cortex (PCC) at which the signal is higher than a given threshold (i.e., BOLD intensity above 1 standard deviation). Spatial clustering on the PCC time frames extracted was then performed (number of clusters = 8), to obtain 8 different PCC co-activation patterns (CAPs) for each level of consciousness.

Results

The current analysis shows that the core of the PCC-CAPs throughout consciousness modulation seems to be preserved. Nonetheless, this methodology enables to differentiate region-specific propofol-induced reductions in PCC-CAPs, some of them already present in the functional connectivity literature (e.g., disconnections of the prefrontal cortex, thalamus, auditory cortex), some others new (e.g., reduced co-activation in motor cortex and visual area).

Conclusion

In conclusion, our results indicate that the employed methodology can help in improving and refining the characterization of local functional changes in the brain associated to propofol-induced modulation of consciousness.

[Alpha-2 adrenoreceptor agonists in anaesthesia and intensive care medicine]

Alpha-2 adrenoreceptor agonists have long been used in the treatment of arterial hypertension. However, in that indication they have progressively been replaced by antihypertensive drugs with a more interesting therapeutic profile. Nonetheless, pharmacological activation of alpha-2 adrenoreceptors leads to a variety of clinical effects that are of major interest for anaesthesia and intensive care practice. Indeed, the sedative and analgesic properties of alpha-2 adrenoreceptor agonists allow a reduction of hypnotic and opioid needs during general anaesthesia. In addition, they induce a down-regulation of the level of consciousness comparable to that of natural slow-wave sleep during post-anaesthesia and intensive care unit stay. These drugs may also prevent some deleterious effects of the sympathetic discharge in response to surgical stress. Furthermore, alpha-2 adrenoreceptor agonists are potent adjuncts for locoregional anaesthesia. In this article, we will summarize the most frequent applications of alpha-2 adrenoreceptor agonists in anaesthesia and intensive care medicine. We will focus on the clinical data available for the two most representative molecules of this pharmacological class: clonidine and dexmedetomidine.

Preeclampsia: an update

Preeclampsia was formerly defined as a multisystemic disorder characterized by new onset of hypertension (i.e. systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg) and proteinuria (> 300 mg/24 h) arising after 20 weeks of gestation in a previously normotensive woman. Recently, the American College of Obstetricians and Gynecologists has stated that proteinuria is no longer required for the diagnosis of preeclampsia. This complication of pregnancy remains a leading cause of maternal morbidity and mortality. Clinical signs appear in the second half of pregnancy, but initial pathogenic mechanisms arise much earlier. The cytotrophoblast fails to remodel spiral arteries, leading to hypoperfusion and ischemia of the placenta. The fetal consequence is growth restriction. On the maternal side, the ischemic placenta releases factors that provoke a generalized maternal endothelial dysfunction. The endothelial dysfunction is in turn responsible for the symptoms and complications of preeclampsia. These include hypertension, proteinuria, renal impairment, thrombocytopenia, epigastric pain, liver dysfunction, hemolysis-elevated liver enzymes-low platelet count (HELLP) syndrome, visual disturbances, headache, and seizures. Despite a better understanding of preeclampsia pathophysiology and maternal hemodynamic alterations during preeclampsia, the only curative treatment remains placenta and fetus delivery. At the time of diagnosis, the initial objective is the assessment of disease severity. Severe hypertension (SBP ≥ 160 mm Hg and/or DBP ≥ 110 mmHg), thrombocytopenia < 100.000/μL, liver transaminases above twice the normal values, HELLP syndrome, renal failure, persistent epigastric or right upper quadrant pain, visual or neurologic symptoms, and acute pulmonary edema are all severity criteria. Medical treatment depends on the severity of preeclampsia, and relies on antihypertensive medications and magnesium sulfate. Medical treatment does not alter the course of the disease, but aims at preventing the occurrence of intracranial hemorrhages and seizures. The decision of terminating pregnancy and perform delivery is based on gestational age, maternal and fetal conditions, and severity of preeclampsia. Delivery is proposed for patients with preeclampsia without severe features after 37 weeks of gestation and in case of severe preeclampsia after 34 weeks of gestation. Between 24 and 34 weeks of gestation, conservative management of severe preeclampsia may be considered in selected patients. Antenatal corticosteroids should be administered to less than 34 gestation week preeclamptic women to promote fetal lung maturity. Termination of pregnancy should be discussed if severe preeclampsia occurs before 24 weeks of gestation. Maternal end organ dysfunction and non-reassuring tests of fetal well-being are indications for delivery at any gestational age. Neuraxial analgesia and anesthesia are, in the absence of thrombocytopenia, strongly considered as first line anesthetic techniques in preeclamptic patients. Airway edema and tracheal intubation-induced elevation in blood pressure are important issues of general anesthesia in those patients. The major adverse outcomes associated with preeclampsia are related to maternal central nervous system hemorrhage, hepatic rupture, and renal failure. Preeclampsia is also a risk factor for developing cardiovascular disease later in life, and therefore mandates long-term follow-up.

Thalamus, brainstem and salience network connectivity changes during propofol-induced sedation and unconsciousness

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based on independent component analysis and a classical seed-based analysis. Contrary to previous propofol research, which mainly emphasized the importance of connectivity in the default mode network (DMN) and external control network (ECN), we focused on the salience network, thalamus, and brainstem. The importance of these brain regions in brain arousal and organization merits a more detailed examination of their connectivity response to propofol. We found that the salience network disintegrated during propofol-induced unconsciousness. The thalamus decreased connectivity with the DMN, ECN, and salience network, while increasing connectivity with sensorimotor and auditory/insular cortices. Brainstem regions disconnected from the DMN with unconsciousness, while the pontine tegmental area increased connectivity with the insulae during mild sedation. These findings illustrate that loss of consciousness is associated with a wide variety of decreases and increases of both cortical and subcortical connectivity. It furthermore stresses the necessity of also examining resting state connectivity in networks representing arousal, not only those associated with awareness.

Neural correlates of consciousness during general anesthesia using functional magnetic resonance imaging (fMRI)

This paper reviews the current knowledge about the mechanisms of anesthesia-induced alteration of consciousness. It is now evident that hypnotic anesthetic agents have specific brain targets whose function is hierarchically altered in a dose-dependent manner. Higher order networks, thought to be involved in mental content generation, as well as sub-cortical networks involved in thalamic activity regulation seems to be affected first by increasing concentrations of hypnotic agents that enhance inhibitory neurotransmission. Lower order sensory networks are preserved, including thalamo-cortical connectivity into those networks, even at concentrations that suppress responsiveness, but cross-modal sensory interactions are inhibited. Thalamo-cortical connectivity into the consciousness networks decreases with increasing concentrations of those agents, and is transformed into an anti-correlated activity between the thalamus and the cortex for the deepest levels of sedation, when the subject is non responsive. Future will tell us whether these brain function alterations are also observed with hypnotic agents that mainly inhibit excitatory neurotransmission. The link between the observations made using fMRI and the identified biochemical targets of hypnotic anesthetic agents still remains to be identified.

[Obstetrical epidural analgesia and postpartum backache]

Backache is a common problem in the general population. The prevalence of backpain is increased during pregnancy and after delivery. Early studies have suggested that labor epidural analgesia might be associated with an increased incidence of backache in the postpartum period. However, these initial studies were retrospective and their design included several methodological deficiencies. All the prospective studies published afterwards (prospective cohort studies and 3 randomized controlled trials) yield the same result: there is no relationship between labor epidural analgesia and long-term postpartum backpain. Pregnant women must be aware of this in order to make an informed and appropriate choice about labor epidural analgesia, the most effective technique for intrapartum pain relief.

Opioids and protection against ischemia-reperfusion injury: from experimental data to potential clinical applications

Ischemic preconditioning, first demonstrated in animal myocardium, is an intrinsic and ubiquitous mechanism of marked protection against ischemia. Accumulating evidences have established that endogenous opioid peptides and their receptors play an important role in this adaptive phenomenon in the heart and other major organs. Of interest for therapeutic developments, opioid receptor agonists have been administered successfully to improve tolerance against experimental ischemia-reperfusion in various tissues. Recent human studies now raise the possibility to exploit this opioid-induced protection in clinical cardiac ischemia. These remarkable anti-ischemic properties of opioids and their emerging potential for organ protection in perioperative medicine will be reviewed at the light of pertinent results from basic and clinical researches.

[Post-dural puncture headache: treatment and prevention]

Post-dural puncture headache (PDPH) is a common iatrogenic and incapacitating complication. Dural puncture can be intentional (spinal block, myelography,...) or accidental (epidural block). Risk factors are well described and the obstetric patient is at high risk for PDPH. The treatment of PDPH is not standardised. Many options have been proposed, but only the epidural blood patch has apparent benefits. A few measures have been suggested to prevent PDPH after unintentional dural puncture, but none has been shown to work with certainty.

[Pseudoxanthoma elasticum and obstetric epidural analgesia: report of a case]

Pseudoxanthoma elasticum is a rare inherited disorder of the elastic tissue characterised by multisystem manifestations. Skin, eyes, gastro-intestinal system and cardiovascular system are the major affected systems. We describe the anaesthetic management of a parturient affected by this disease.

[Pediatric anesthesia: little children, big problems]

Infants and children are patients who are the most susceptible to benefit from a procedure in the ambulatory setting. However, some of these patients are at risk. They include infants, especially if premature, and children with sleep apnea syndrome or with current or recent upper respiratory infection. The present paper gives advices for an optimal anesthesic management of these young patients.

[Anesthesia and safety of procedures outside the operating room: "everyone's responsibility"]

Due to important technological improvements, anesthesiological activity outside the operating theatre is increasing. Most of these procedures are performed for gastroenterology procedures; other procedures include medical imaging, electroconvulsive therapy or cardioversion. The practice of anesthesia at alternative sites is associated with logistical difficulties with many constraints. Anesthesia will be requested if the procedure is likely to be unpleasant or painful, if the patient is not cooperative, or if the patient's hemodynamic condition is unstable. The pre-anesthesia assessment, an adequate monitoring and an appropriate choice of the anesthetic technique and drugs will be helpful in managing an anesthetic procedure too frequently neglected despite it is associated with risks similar to procedures performed in the operating theatre.

Lipomatous hypertrophy of the interatrial septum: the typical echographic aspect is worth being known

A 65-year-old man was scheduled for an on-pump coronary artery bypass graft procedure because of a three-vessels coronary artery disease. A right atrial mass appended to the interatrial septum was discovered during intraoperative transoesophageal echocardiography. Therefore, the right atrium was opened. Gross examination revealed a fatty lesion of the interatrial septum. A biopsy was performed before the atrium was closed. A histological diagnosis of lipomatous hypertrophy of the interatrial septum was made. Lipomatous hypertrophy of the interatrial septum is a mass of adipocytes infiltrating the interatrial septum. The aspect of "dumbbell" produced by the sparing of the Fossa Ovalis is typical. The lesion is benign and remains asymptomatic most of the time although it can be responsible for cardiac arrhythmias or circulatory obstruction. The typical echographic aspect should be known to avoid unnecessary surgical resection.

Linking sleep and general anesthesia mechanisms: this is no walkover

This review aims at defining the link between physiological sleep and general anesthesia. Despite common behavioral and electrophysiological characteristics between both states, current literature suggests that the transition process between waking and sleep or anesthesia-induced alteration of consciousness is not driven by the same sequence of events. On the one hand, sleep originates in sub-cortical structures with subsequent repercussions on thalamo-cortical interactions and cortical activity. On the other hand, anesthesia seems to primarily affect the cortex with subsequent repercussions on the activity of sub-cortical networks. This discrepancy has yet to be confirmed by further functional brain imaging and electrophysiological experiments. The relationship between the observed functional modifications of brain activity during anesthesia and the known biochemical targets of hypnotic anesthetic agents also remains to be determined.

Comparison of the surgical Pleth Index™ with haemodynamic variables to assess nociception-anti-nociception balance during general anaesthesia

BACKGROUND

The Surgical Pleth Index (SPI) is proposed as a means to assess the balance between noxious stimulation and the anti-nociceptive effects of anaesthesia. In this study, we compared SPI, mean arterial pressure (MAP), and heart rate (HR) as a means of assessing this balance.

METHODS

We studied a standard stimulus [head-holder insertion (HHI)] and varying remifentanil concentrations (CeREMI) in a group of patients undergoing neurosurgery. Patients receiving target-controlled infusions were randomly assigned to one of the three CeREMI (2, 4, or 6 ng m⁻¹), whereas propofol target was fixed at 3 µg ml⁻¹. Steady state for both targets was achieved before HHI. Intravascular volume status (IVS) was evaluated using respiratory variations in arterial pressure. Prediction probability (Pk) and ordinal regression were used to assess SPI, MAP, and HR performance at indicating CeREMI, and the influence of IVS and chronic treatment for high arterial pressure, as possible confounding factors.

RESULTS

The maximum SPI, MAP, or HR observed after HHI correctly indicated CeREMI in one of the two patients [accurate prediction rate (APR)=0.5]. When IVS and chronic treatment for high arterial pressure were taken into account, the APR was 0.6 for each individual variable and 0.8 when all of them predicted the same CeREMI. That increase in APR paralleled an increase in Pk from 0.63 to 0.89.

CONCLUSIONS

SPI, HR, and MAP are of comparable value at gauging noxious stimulation-CeREMI balance. Their interpretation is improved by taking account of IVS, treatment for chronic high arterial pressure, and concordance between their predictions.

Effect of an intravenous infusion of lidocaine on cisatracurium-induced neuromuscular block duration: a randomized-controlled trial

BACKGROUND

Intravenous lidocaine can be used intraoperatively for its analgesic and antihyperalgesic properties but local anaesthetics may also prolong the duration of action of neuromuscular blocking agents. We hypothesized that intravenous lidocaine would prolong the time to recovery of neuromuscular function after cisatracurium.

METHODS

Forty-two patients were enrolled in this randomized, double-blind, placebo-controlled study. Before induction, patients were administered either a 1.5 mg/kg bolus of intravenous lidocaine followed by a 2 mg/kg/h infusion or an equal volume of saline. Anaesthesia was induced and maintained using propofol and remifentanil infusions. After loss of consciousness, a 0.15 mg/kg bolus of cisatracurium was administered. No additional cisatracurium injection was allowed. Neuromuscular function was assessed every 20 s using kinemyography. The primary endpoint was the time to spontaneous recovery of a train-of-four (TOF) ratio ≥ 0.9.

RESULTS

The time to spontaneous recovery of a TOF ratio ≥ 0.9 was 94 ± 15 min in the control group and 98 ± 16 min in the lidocaine group (P=0.27).

CONCLUSIONS

No significant prolongation of spontaneous recovery of a TOF ratio ≥ 0.9 after cisatracurium was found in patients receiving intravenous lidocaine.

[Perioperative tobacco cessation: potential benefits and principles of management]

Thirty percent of surgical patients undergoing routine surgery are smokers, and smoking is an additional risk for these patients. During the perioperative period, smokers are more prone than non smokers to present either systemic complications interesting the cardiovascular and pulmonary functions or specific complications related to the surgical procedure, such as infections, wound problems and delayed osteosynthesis. Therefore, coming-off from smoking addiction is an obvious prerequisite in these patients. Diagnosing smoking habit, evaluating its severity and its systemic repercussions on vital functions, as well as proposing an efficacious and appropriate help to smokers before surgery become one essential objective of pre-anesthetic assessment.

Management of severe preeclampsia

Features of severe preeclampsia include severe proteinuric hypertension and symptoms of central nervous system dysfunction, hepatocellular injury, thrombocytopenia, oliguria, pulmonary oedema, cerebrovascular accident and severe intrauterine growth restriction. Women with severe preeclampsia must be hospitalized to confirm the diagnosis, to assess the severity of the disease, to monitor the progression of the disease and to try to stabilize the disease. Severe preeclampsia may be managed expectantly, in selected cases. The objective of expectant management in these patients is to improve neonatal outcome. Expectant management is based on antihypertensive treatment and prevention of end organ dysfunction. Antihypertensive treatment improves maternal outcome but has the potential to be deleterious for the foetus. Plasma volume expansion has been suggested for severe preeclampsia but trials failed to show any benefit. Magnesium sulfate is the anticonvulsivant of choice to treat or prevent eclampsia when indicated. Antenatal corticosteroids are recommended in severely preeclamptic women with 26-34 weeks gestation. Timing of delivery is based upon gestational age, severity of preeclampsia, maternal and foetal risks.

[Perioperative tobacco cessation: a crucial period to overcome clinical inertia and poor compliance]

Smoking concerns 30% of the patients scheduled to anesthesia. Tobacco is one of the most important risk factors for postoperative complications. There are two classes of complications: those induced by the smoking habits on the cardiovascular and the respiratory systems, and those that predispose to other complications by direct interference with processes required for the success of surgery: healing and immune responses. The preoperative period represents a crucial period to overcome clinical inertia and profit of a better compliance. Some strategies applicable by the general practitioner and the anesthesiologist during the preoperative consultation to establish smoking cessation and help the patient to comply with are proposed.

[Is a coagulation blood test compulsory before neuraxial blockade for labor analgesia?]

Neuraxial blockade such as epidural, spinal or combined spinal-epidural analgesia is considered to be the best technique for labour analgesia. Even if epidural hematoma is a very rare complication of neuraxial blockade, it may result in severe and definitive neurological injuries. This rare complication is usually associated with coagulation abnormalities. This is the reason why many physicians order routine coagulation screening tests before performing neuraxial blockade. This practice is questionable from the evidence-based medicine and the economic point of view. According to the guidelines published by several scientific societies, no routine coagulation screening tests are required in the absence of any history or clinical suspicion of coagulation impairment. The aim of the present article is to delineate the appropriate attitude in this context.

Default network connectivity reflects the level of consciousness in non-communicative brain-damaged patients

The 'default network' is defined as a set of areas, encompassing posterior-cingulate/precuneus, anterior cingulate/mesiofrontal cortex and temporo-parietal junctions, that show more activity at rest than during attention-demanding tasks. Recent studies have shown that it is possible to reliably identify this network in the absence of any task, by resting state functional magnetic resonance imaging connectivity analyses in healthy volunteers. However, the functional significance of these spontaneous brain activity fluctuations remains unclear. The aim of this study was to test if the integrity of this resting-state connectivity pattern in the default network would differ in different pathological alterations of consciousness. Fourteen non-communicative brain-damaged patients and 14 healthy controls participated in the study. Connectivity was investigated using probabilistic independent component analysis, and an automated template-matching component selection approach. Connectivity in all default network areas was found to be negatively correlated with the degree of clinical consciousness impairment, ranging from healthy controls and locked-in syndrome to minimally conscious, vegetative then coma patients. Furthermore, precuneus connectivity was found to be significantly stronger in minimally conscious patients as compared with unconscious patients. Locked-in syndrome patient's default network connectivity was not significantly different from controls. Our results show that default network connectivity is decreased in severely brain-damaged patients, in proportion to their degree of consciousness impairment. Future prospective studies in a larger patient population are needed in order to evaluate the prognostic value of the presented methodology.

[Regional analgesia after lower limb orthopaedic surgery]

To provide postoperative analgesia, the anaesthesist has at his disposal a panel of different medications and also regional techniques of neural blockade. Loco-Regional analgesia (epidural or peripheral nerve block), by the use of local anaesthetics, blocks conduction of the painful influx to th central nervous system. Pain relief using peripheral nerve blocks after lower limb surgery represents as good alternative to the epidural analgesia and is superior to controlled analgesia with morphine. Peripheral nerve blocks, by decreasing the use of opioids in the postoperative period, reduce the incidence of side effects related to these molecules. They are also devoided of the adverse events due to the epidural analgesia like urinary retention or need for continuous monitoring. Analgesia after total knee prosthesis and hallux valgus surgery has considerably evolved. Postoperative analgesia is important in these cases: it facilitates physical therapy and improves patient's rehabilitation and satisfaction, it also shortens hospital stay. The aim of this review is to explain the different techniques of peripheral neural blockade and assess the value of this technique for the postoperative period after these two surgeries.

[Treatment of severe preeclampsia: until when and for what risks/benefits?]

The four major hypertensive disorders related to pregnancy are preeclampsia, chronic hypertension, preeclampsia superimposed upon chronic hypertension, and gestational hypertension. The development of hypertension and proteinuria in pregnancy is usually due to preeclampsia, particularly in a primigravida. These findings typically become apparent in the latter part of the third trimester and progress until delivery, but some women develop symptoms in the latter half of the second trimester, or intrapartum, or the early postpartum period. Preeclampsia is characterized as mild or severe. Severe hypertension, coagulopathy, thrombocytopenia, liver function abnormalities, and fetal growth restriction are features of severe disease. Laboratory evaluation should assess haemoglobin/hematocrit and platelet count, renal and hepatic function, as well as assessment of fetal well-being and growth. Timing of delivery is based upon gestational age, maternal and fetal condition, and the severity of preeclampsia. Maternal end organ dysfunction and nonreassuring tests of fetal well-being are indications for delivery at any gestational age. Antihypertensive treatment aims at protecting the mother from severe hypertensive encephalopathy, but may jeopardize the fetus. We recommend antenatal corticosteroids (betamethasone) be given to women with preeclampsia at 26 to 34 weeks of gestation. Magnesium sulfate is more effective than phenytoin for prevention of eclamptic seizures.

[Heparin-induced thrombocytopenia]

Heparin-induced thrombopenia (HIT) may occur as a complication of any type of heparin but is more frequently observed after administration of unfractioned heparins. Such a complication is scarce but potentially severe and may cause life-threatening thromboembolic and hemorrhagic disorders. Tow types of HIT are described. Type I HIT are of non immunologic origin. They have no clinical expression and spontaneously resolve after heparin therapy has been stopped. Type II HIT which are potentially severe and of immunologic origin, are related to the formation of a IgG-platelet factor 4 complex which activates platelets. They are characterized by an absolute or relative reduction of the platelet number observed on two successive assays. Once other causes of thrombopenia have been ruled out, the diagnostic relies on immunologic or functional tests evidencing the platelet anti-factor 4. Stopping heparin administration is mandatory and surrogate anti-thombotic measures must be instituted. An early diagnosis and an appropriate treatment of this complication result in a significant reduction of morbidity and mortality.

Pain and non-pain processing during hypnosis: a thulium-YAG event-related fMRI study

The neural mechanisms underlying the antinociceptive effects of hypnosis still remain unclear. Using a parametric single-trial thulium-YAG laser fMRI paradigm, we assessed changes in brain activation and connectivity related to the hypnotic state as compared to normal wakefulness in 13 healthy volunteers. Behaviorally, a difference in subjective ratings was found between normal wakefulness and hypnotic state for both non-painful and painful intensity-matched stimuli applied to the left hand. In normal wakefulness, non-painful range stimuli activated brainstem, contralateral primary somatosensory (S1) and bilateral insular cortices. Painful stimuli activated additional areas encompassing thalamus, bilateral striatum, anterior cingulate (ACC), premotor and dorsolateral prefrontal cortices. In hypnosis, intensity-matched stimuli in both the non-painful and painful range failed to elicit any cerebral activation. The interaction analysis identified that contralateral thalamus, bilateral striatum and ACC activated more in normal wakefulness compared to hypnosis during painful versus non-painful stimulation. Finally, we demonstrated hypnosis-related increases in functional connectivity between S1 and distant anterior insular and prefrontal cortices, possibly reflecting top-down modulation.

[Contribution of functional neuroimaging studies to the understanding of the mechanisms of general anesthesia]

Since the early beginning of anesthesia, almost 2 centuries ago, ignorance has prevailed regarding the cerebral mechanisms of the loss of consciousness induced by general anesthesia. The recent contribution of functional brain imaging studies has allowed considerable progress in that domain. Similarly, the study of brain function under general anesthesia is currently a major tool for the understanding of conscious phenomena. This functional approach leads to conceptual changes about the functioning brain and may ultimately provide tracks for new treatments and practical applications. All these aspects are reviewed in this paper, at the light of the most recent literature.