Faut-il modifier ou optimiser le traitement préopératoire ?

Mild therapeutic hypothermia (32–34 °C) has been recently introduced into the international guidelines of cardiac arrest management, considering that the patient survival without neurological sequellae for out-of-hospital cardiac arrests following ventricular fibrillation has been improved with induced and controlled hypothermia. The benefit of therapeutic hypothermia is largely related to its neuroprotective effects. However, several issues remain unsolved to date. Consistently, the therapeutic window for applying hypothermia and the exact mechanism of the hypothermia effects on the ischemia-reperfusion syndrome and the cerebral anoxia are only partially understood. Furthermore, this efficient treatment is associated with some side effects that could counterbalance its benefits. Although recommended by all international committees, the exact implementation modalities of hypothermia still remain to be clarified, including the patient-to-treat selection criteria, the most efficient cooling and rewarming devices, the cooling duration and depth, the optimal temperature monitoring, and the usefulness of the associated treatments. Beneficial or deleterious extraneurological hypothermia effects, mainly regarding the cardiovascular and the respiratory systems, have also not been yet completely elucidated. Taking into accounts its risk-benefit balance and treating its potential complications should enhance hypothermia benefits. Only a better understanding of its precise effects and its optimal implementation modalities would be helpful in order to improve the final cardiac arrest prognosis.

Le monitorage de la pression intracrânienne améliore-t-il le devenir des traumatisés crâniens graves ?

Raised intracranial pressure (ICP) is frequent and associated with poor outcome after severe traumatic brain injury (TBI). Information obtained by ICP monitoring allows early detection of high ICP and goal-directed therapy. There is a large body of clinical evidence showing that protocol driven neurocritical care improves outcomes after TBI. A monitoring method cannot be separated from therapeutic implications, which may have beneficial or deleterious consequences. ICP monitoring and guided therapy are not risk-free. A rational use of ICP as a guide to therapy must take into account of the absolute threshold for treatment, but also of the risk/benefit balance of the used intervention.     

Quelle pression de perfusion cérébrale après traumatisme crânien chez l’enfant ?

The management of cerebral perfusion pressure (CPP) is the one of the main preoccupation for the care of paediatric traumatic brain injury (TBI). The physiology of cerebral autoregulation, CO₂ vasoreactivity, cerebral metabolism changes with age as well as the brain compliance. Low CPP leads to high morbidity and mortality in pediatric TBI. The recent guidelines for the management of CPP for the paediatric TBI indicate a CPP threshold 40–50 mmHg (infants for the lower and adolescent for the upper). But we must consider the importance of age-related differences in the arterial pressure and CPP. The best CPP is the one that allows to avoid cerebral ischaemia and oedema. In this way, the adaptation of optimal CPP must be individual. To assess this objective, interesting tools are available. Transcranial Doppler can be used to determine the best level of CPP. Other indicators can predict the impairment of autoregulation like pressure reactivity index (PRx) taking into consideration the respective changes in ICP and CPP. Measurement of brain tissue oxygen partial pressure is an other tool that can be used to determine the optimal CPP.     

Peut-on prédire l’aggravation neurologique des patients traumatisés crâniens mineurs et modérés par le dosage sanguin de la protéine S-100β ?

Introduction

Patients with moderate traumatic brain injury (TBI) (Glasgow Coma Scale, GCS, 9–13) or minor TBI (GCS 14–15) are at risk for subsequent neurological deterioration. Serum protein S-100 is believed to reflect brain damage following TBI. In patients with normal or minor CT scan abnormalities on admission, we tested whether the determination of serum protein S-100 beta could predict secondary neurological deterioration.

Methods

Sixty-seven patients with moderate or minor TBI were prospectively studied. Serum samples were collected on admission within 12 hours postinjury to measure serum protein S-100 levels. Neurological outcome was assessed up to seven days after trauma. Secondary neurological deterioration was defined as two points or more decrease from the initial GCS, or any treatment for neurological deterioration.

Results

Nine patients had a secondary neurological deterioration after trauma. No differences in serum levels of protein S-100 were found between these patients and those without neurological aggravation (n = 58 patients): 0.93 μg/l (0.14–4.85) vs 0.39 μg/l (0.04–6.40), respectively. The proportion of patients with abnormal levels of serum protein S-100 at admission according to two admitted cut-off levels (> 0.1 and > 0.5 μg/l) was comparable between the two groups of patients. Elevated serum levels of protein S-100 were found in patients with Injury Severity Score (ISS) of more than 16 (n = 23 patients): 1.26 μg/l (0.14–6.40) vs 0.22 μg/l (0.04–6.20) in patients with ISS less than 16 (n = 44 patients).

Discussion

The dosage of serum protein S-100 on admission failed to predict patients at risk for neurological deterioration after minor or moderate TBI. Extracranial injuries can increase serum protein S-100 levels, then limiting the usefulness of this dosage in this clinical setting.     

Hypernatrémie chez le patient cérébrolésé : utile ou dangereux ?

Hypernatremia is defined by a serum sodium concentration of more than 145 mmol/L and reflects a disturbance of the regulation between water and sodium. The high incidence of hypernatremia in patients with severe brain injury is due various causes including poor thirst, diabetes insipidus, iatrogenic sodium administration, and primary hyperaldosteronism. Hypernatremia in the intensive care unit is independently associated with increased mortality and complications rates. Because of the rapid brain adaptation to extracellular hypertonicity, sustained hypernatremia exposes the patient to an exacerbation of brain edema during attempt to normalize natremia. Like serum glucose, serum sodium concentration must be tightly monitored in the intensive care unit.     

Analgésie péridurale pour le traitement chirurgical des carcinoses péritonéales : une pratique à risque ?

Background

To study the risks of haemodynamic instability, and the possible occurrence of spinal haematoma, meningitis and epidural abscess when epidural analgesia is performed for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

Methods

We retrospectively analyzed the data of 35 patients treated by HIPEC with oxaliplatin or cisplatin. An epidural catheter was inserted before induction of general anaesthesia. Postoperatively, a continuous epidural infusion of ropivacain, then a patient-controlled epidural analgesia were started.

Results

The epidural catheter was used peroperatively before HIPEC in 12 subjects (34%), and after HIPEC in 23 subjects (66%). The median dose of ropivacain given peroperatively in the epidural catheter was 40 mg (30–75). Norepinephrin was used in two subjects (6%) peroperatively (median infusion rate 0.325 μg/kg per minute [0.32–0.33]), and in four subjects (11%) in the postoperative 24 hours. No spinal haematoma, meningitis or epidural abscess were noted. Five subjects (14%) had a thrombopenia or a prothrombin time less than 60% before catheter removal. Two subjects (6%) had a leukopenia before catheter removal. No thrombopenia or blood coagulation disorders were recorded the day of catheter removal.

Conclusion

In this series of 35 patients, the use of epidural analgesia for HIPEC does not seem to be associated with a worse risk of haemodynamic instability, spinal haematoma, meningitis or epidural abscess. HIPEC with platinum salt is not incompatible with the safety of epidural analgesia, with an optimized fluid management peroperatively and the following of perimedullary anesthesia practice guidelines.     

Trachéotomie et traumatisme crânien grave : pour qui ? Pourquoi ? Quand ? Comment ?

The aim of this study is to determine, from the data available in the literature, the indications of tracheostomy in brain injured patients, the incidence and risk factors for complications and the follow-up required until decannulation. The incidence of tracheostomy is 10% in TBI and 50 to 70% in subpopulations with a Glasgow Coma Scale (GCS) below 9. Early complications are not specific. The most frequent late complication is laryngotracheal stenosis, which occurs in 15% and is more frequently observed in the most severe patients with major hypertonia. It is likely that tracheostomy, if needed, should be performed early and the prognosis as to whether it will be required, can be made at the end of the first week. The follow-up of these patients includes surveillance of multiresistant colonisations and systematic performance of fibroscopy before decannulation. Cuffless, small diameters, soft tracheostomy tubes, are preferred on the long-term unless the risk of aspiration remains high.     

La période périopératoire de chirurgie carcinologique : un moment crucial ! L’anesthésie locorégionale prévient-elle la récidive des cancers ?

Surgical treatment of cancer is usually necessary but it can paradoxically aggravate the patient outcome by increasing the risk of recurrence. Many perioperative factors have been shown to contribute to the dissemination of the tumor: surgery itself, stress, inflammation, pain, anaesthetic drugs, blood transfusion, etc. The type of anaesthesia chosen in the cancer patient could then be crucial and influence the evolution of the disease. Experimental, preclinical and retrospective studies have suggested that a regional anesthesia associated or not with a general anesthesia for carcinologic surgery might reduce the risk of cancer recurrence. This text reviews the factors promoting the recurrence of tumors after carcinologic surgery and the potential possibilities of protection associated with the type of anaesthesia chosen.     

La chirurgie de l’hallux valgus en 2005. Chirurgie conventionnelle,mini-invasive ou percutanée ? Uni- ou bilatérale ? Hospitalisation ou ambulatoire ?

There remains a good deal of controversy concerning forefoot surgery. Certain concepts such as conventional procedures, minimally invasive surgery, or percutaneous surgery are promoted because of their specific advantages including rapid recovery and compatibility with a short hospital stay or even outpatient surgery. Nevertheless, in 2005 many questions remain unanswered and highly variable practices have been basically founded on personal experience rather than scientific evidence. In addition, financial and lobbying pressure appears to have an influence on our choices, affecting the freedom of our therapeutic decision-making. Developed over a long period, conventional surgery has proven reliability, reproducibility and adaptability. Procedures termed minimally invasive are defined by the limited incision. Percutaneous surgery is not less invasive than other procedures; the techniques are performed under indirect visual control and often assisted with more or less sophisticated radioscopic techniques depending on the surgeon's own experience. In our opinion, percutaneous surgery should be considered as a new concept based on rapid and functional results. Patients often raise the question of a bilateral procedure. For hallux valgus, there is no consensus on whether unilateral or bilateral procedures are better, the best solution depending on postoperative weight bearing and thus on the technique employed. From a cost expenditures point of view, bilateral procedures have an impact. For the advantages in terms of macroeconomy for professional incapacity, the question is less univocal for healthcare authorities. Advances in perioperative anesthesia and analgesia have enabled a broader approach to ambulatory surgery. Outpatient surgery appears to have benefits in terms of organization and economics. Variables studied were as follows: duration of hospital stay, postoperative edema, number of days of sick leave and preoperative and early and late postoperative pain. Patients who underwent minimally invasive procedures had a significantly shorter hospital stay compared with three other groups. For bilateral procedures, hospital stay on average was longer than in the two other groups. There was no correlation between postoperative edema and pain or between the degree of edema at 15 days and two months. Mean sick leave was 54.6 days. This was significantly shorter for percutaneous procedures compared with conventional surgery or minimally invasive techniques. Preoperative pain was noted four to five on the Visual Analogue Scale (VAS). There was no significant difference between the different groups as a function of the type of surgery performed. Statistically, there is very little difference in the short term between the different techniques. A much longer study would be necessary to obtain evidence to guide our practices. While there is certainly no reason to condemn one method or another, surgeons must be careful about the promises given to patients which are generally based on personal experience but not necessarily supported by rigorous scientific data.     

Analgésie péridurale obstétricale chez une parturiente atteinte d’un déficit en facteur XI : défi inconsidéré ou risque raisonné ?

The authors report the performance of a labour epidural analgesia in a 26-year-old parturient presenting a moderate factor XI (FXI) deficiency. If haemostasis disorders usually contraindicate an epidural analgesia (with a risk of epidural haematoma), a moderate FXI deficiency is not an absolute contraindication to perform such an epidural analgesia. Desmopressin, sometimes used in surgery to reduce the bleeding, was administered to withdraw the catheter in better haemostasis conditions. No neurological signs were observed.     

Le mystère des trépanations préhistoriques : la neurochirurgie serait-elle le plus vieux métier du monde ?

Trepanation is known to be the first surgical procedure ever performed. Its origins date from the Neolithic Age in Europe and the operation was particularly performed in South America at the Pre-Colombian era, a few thousand years later. Based on many archeological studies on trepanned skulls, we compare the differences and similarities of these two periods through epidemiological, topographical, and technical approaches. Signs of bony regeneration are assessed in an attempt to understand the postoperative survival of trepanned patients. The literature in surgery and archeology does not mention the possible relation between trepanations and growing skull fractures. However, it is reasonable to think that these cranial holes, occurring after a pediatric skull fracture, could mimic real trepanation orifices. The possible connections between these two entities are discussed. The etiological hypotheses on prehistoric trepanation are reviewed.     

Optimisation de l’administration des agents anesthésiques inhalés : débit de gaz frais ou fraction délivrée ?

Introduction

During volatile closed-circuit anaesthesia, a chosen end-tidal fraction (Fet) could be achieved by setting either delivered fraction (Fd) or fresh gas flow (FGF). This study compared the efficacy of both strategies and the resulting drug consumption.

Patients and methods

Sixty patients (10 per group) were administered, after intravenous induction and intubation, desflurane, sevoflurane or isoflurane + 50% N₂O, to achieve a target Fet equal to one minimal alveolar concentration (MAC), according to one strategy: high FGF (HFGF) Fd fixed 20% above target Fet, FGF 10 l/min then 1 l/min after achieving the target, FGF opened at 10 l/min at the end of surgery; low FGF (LFGF) FGF fixed at 1 l/min, Fd at the maximal value on the vaporizer, then set at target Fet + 20% after achieving Fet equal to one MAC, FGF maintained at 1 l/min until extubation.

Results

The target Fet was achieved in all patients in LFGF within 2.1 ± 0.9 min followed by 15% (isoflurane) to 57% (sevoflurane) overdosage, but only in nine patients out of 30 after 10 min in HFGF. Delays were similar between desflurane and sevoflurane. Volatile consumption was decreased by 75% in LFGF. Fifty percent decrement and extubation times were shorter with HFGF, similarly for the three agents.

Conclusion

Massive overdosage of Fd is the fastest, reproducible and cheapest strategy to achieve (or to increase) a chosen Fet. High FGF is the fastest to decrease Fet during or at the end of anaesthesia. Combining Fd and FGF adjustments in order to maximize Fd/Fet gradients overwrites pharmacokinetic differences between desflurane and sevoflurane and reduces differences with isoflurane. Automatic adjustments based on volatile pharmacockinetics would be helpful to achieve a target Fet without overdosage.