Automated titration of propofol and remifentanil decreases the anesthesiologist's workload during vascular or thoracic surgery: a randomized prospective study.

Closed loop target-control infusion systems using a Bispectral (BIS) signal as an input (TCI Loop) can automatically maintain intravenous anesthesia in a BIS range of 40-60 %. Our purpose was to assess to what extent such a system could decrease anesthesia workload in comparison to the use of a stand alone TCI system manually adjusted to fit the same BIS range of 40-60 % (TCI Manual). Patients scheduled for elective vascular or thoracic surgery were randomized to the TCI Loop or TCI Manual method for administering propofol and remifentanil during both induction and maintenance of general anesthesia. Assessment of workload was performed by an independent observer who quoted each time the physician looked at the BIS monitor. The number of propofol and remifentanil target modifications, the percentage of time of adequate anesthesia i.e. BIS in the range 40-60 and hemodynamic data were recorded. Eighteen patients per group were enrolled. Characteristics, duration of surgery and propofol-remifentanil consumption were similar between groups. However, the percentage of time in the BIS range 40-60 % was higher in the TCI Loop versus TCI Manual groups (94 % ± 12 vs. 74 % ± 19, p < 0.001). Mean arterial pressure was lower with TCI Manual (78 ± 6 vs. 88 ± 13 mmHg, p < 0.001). The number of times the anesthesiologist watched the controller or BIS monitor (p < 0.05) and the number of manual adjustments (p < 0.001) performed in each group was lower with TCI Loop group during induction and maintenance of anesthesia. An automated controller strikingly frees the anesthesiologist from manual intervention to adjust drug delivery.

Dissociating anticipation from perception: Acute pain activates default mode network.

Few studies have explored the effect of acute pain on attentional networks and on the default mode network. Moreover, these studies convey conflicting results, seemingly caused by design. To reassess this issue, we studied 20 healthy subjects with functional magnetic resonance imaging while delivering painful electric shocks. The design was purposely constructed to separate rest, anticipation, and pain perception. We found that default mode network activity in response to pain was biphasic. It deactivated during anticipation when the dorsal attentional network was activated. During pain perception, the default mode network was activated, as were attentional networks. The left posterior fusiform gyrus showed the same dynamics as the default mode network, and its activity was negatively correlated to the subject's pain intensity rating. The associative pregenual anterior cingulate cortex seemed to play a key role in these coactivations. These results concur with data from the literature showing that enhanced pain perception results in greater default mode network activity and that the anticorrelation between the default mode network and the dorsal attentional network disappears in chronic pain patients.

Closed-loop coadministration of propofol and remifentanil guided by bispectral index: a randomized multicenter study.

BACKGROUND: We have developed a proportional-integral-derivative controller allowing the closed-loop coadministration of propofol and remifentanil, guided by a Bispectral Index (BIS) monitor, during induction and maintenance of general anesthesia. The controller was compared with manual target-controlled infusion. METHODS: In a multicenter study, 196 surgical patients were randomly assigned to dual closed-loop or manual administration of propofol and remifentanil. Comparison between groups was evaluated by calculating a global score that characterized the overall performance of the controller including the percentage of adequate anesthesia, defined as BIS between 40 and 60, the median absolute performance error, and wobble. Secondary outcomes included occurrence of burst suppression ratio, time to tracheal extubation, and drug consumption. RESULTS: Eighty-three patients assigned to dual-loop control and 84 patients assigned to manual control completed the study. The global score and the percentage of time with BIS between 40 and 60 were better in the dual-loop group (26 ± 11 vs 43 ± 40, P < 0.0001; 82% ± 12% vs 71% ± 19%, P < 0.0001). Overshoot (BIS <40), undershoot (BIS >60), and burst suppression ratio were all significantly less common in the dual-loop group. Modifications to the propofol and remifentanil infusions were more frequent, and adjustments smaller in the dual-loop group. Remifentanil consumption was greater (0.22 ± 0.07 vs 0.16 ± 0.07 µg · kg(-1) · min(-1); P < 0.0001) and the speed to tracheal extubation was shorter (10 ± 4 vs 11 ± 5 minutes; P = 0.02) in the dual-loop group. CONCLUSION: The controller allows the automated delivery of propofol and remifentanil and maintains BIS values in predetermined boundaries during general anesthesia better than manual administration.

Adverse events with medical devices in anesthesia and intensive care unit patients recorded in the French safety database in 2005-2006.

BACKGROUND: French regulations require that adverse events involving medical devices be reported to the national healthcare safety agency. The authors evaluated reports made in 2005-2006 for patients in anesthesiology and critical care. METHODS: For each type of device, the authors recorded the severity and cause of the event and the manufacturer's response where relevant. The authors compared the results with those obtained previously from the reports (n = 1,004) sent in 1998 to the same database. RESULTS: The authors identified 4,188 events, of which 91% were minor, 7% severe, and 2% fatal. The cause was available for 1,935 events (46%). Faulty manufacturing was the main cause of minor events. Inappropriate use was the cause in a significantly larger proportion of severe events than minor events (P < 0.001) and was usually considered preventable via improved knowledge or device verification before use. Compared to with that in 1998, the annual number of reported events doubled and the rate of severe events decreased slightly (12-10%, P = 0.03). The rate of events related to manufacturing problems remained stable (59-60%, P = nonsignificant), and the rate of events caused by human errors was 32-42% (P = 0.01). There were no changes in the mortality rate (2% in both studies). CONCLUSIONS: The number of adverse events related to medical devices indicates a need for greater attention to these complex pieces of equipment that can suffer from faulty design and manufacturing and from inappropriate use. Improvements in clinician knowledge of medical devices, and to a lesser extent improvement in manufacturing practices, should improve safety.

Changes in R-Wave amplitude in DII lead is less sensitive than pulse pressure variation to detect changes in stroke volume after fluid challenge in ICU patients postoperatively to cardiac surgery.

OBJECTIVE: The amplitude of R-wave in DII lead (RDII) has been shown to correlate to central blood volume in animal and healthy volunteers. The aim of this study was to assess if change in RDII (DeltaRDII) after passive leg rise (PLR) and fluid loading would allow detecting preload dependence in intensive care ventilated patients. This parameter was compared to concomitant changes in pulse arterial pressure (DeltaPP). METHODS: Observational study in 40 stable sedated and ventilated cardiac surgery patients studied postoperatively. In line with our routine practice we performed a 45 degrees passive leg rise (PLR1) to detect preload dependence. If cardiac index or DeltaPP rose more than 12 and 13%, respectively, the patient was declared as non-responder (NR) to fluid loading. If these criteria were not met, they were declared as responders (R) and received a 500 ml of gelatin fluid loading (FL) followed by a second passive leg rise (PLR2). Hemodynamic parameters were assessed during each maneuver using their indwelling Swan-Ganz and radial catheter. RESULTS: We identified 16 R and 24 NR whose hemodynamic parameters did not differ at basal condition, except DeltaPP (19% +/- 7 in R vs. 7% +/- 4 in NR, P < 0.001). PLR1 did not elicit any hemodynamic change in NR. In R, DeltaPP decreased and SV rose, both significantly (P < 0.001) whereas DeltaRDII did not vary. FL induced a more pronounced change in these parameters. CONCLUSIONS: DeltaRDII in response to PLR does not successfully help identifying preload dependent patients contrarily to DeltaPP or change in stroke volume.

Blue Dye Embolization of Renal Tumor: A New Technique to Improve Tumor Localization During Laparoscopic Partial Nephrectomy.

Purpose: To improve the tumor localization during laparoscopic surgery, we describe an innovative technique involving superselective intra-arterial injection of blue dye in tumoral vessels to color the tumor before surgical enucleation. Materials and Methods: The dye injection was performed at the same time as superselective embolization, immediately before laparoscopic surgery in a hybrid operating room. We used this new treatment sequence on 50 consecutive patients. Results: The selective intra-arterial injection of an emulsion of blue dye and lipiodol was feasible in 46 (92%) cases and well tolerated, followed by superselective embolization of the tumor vessels with glue or coils. The tumor was easily localized during surgery due to the blue coloration. Tumor coloration was not associated with postoperative complication, especially allergic reaction or renal failure. Pathologic analysis of the tumor was not modified by the coloration and all tumors had negative surgical margins. Conclusions: The preoperative dye localization is a feasible, safe, and accurate procedure. This combined approach reduces the difficulty of surgery and increases patient safety.

Written information that relatives of adult intensive care unit patients would like to receive--a comparison to published recommendations and opinion of staff members.

OBJECTIVE: Information booklets have not been assessed by the families of intensive care unit (ICU) patients. This study explored the information that the relatives of adult ICU patients wanted to find in the information booklets. DESIGN: Multicenter survey. SETTING: Twenty-three French ICUs. SUBJECTS: One close relative of each of 250 consecutive adult patients. METHODS: Relatives were asked about the desirability of finding information on each of the 24 topics identified by ICU physicians and listed in guidelines as deserving inclusion in information booklets. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The 250 patients (61% men) had a mean age of 60 +/- 18 years and a mean Simplified Acute Physiology Score II of 48 +/- 19; 57% had chronic comorbidities and 41% were surgical patients. At least 72% of the relatives felt that booklets should discuss nosocomial infections, treatment-limitation decisions, access to medical information on the patient, access to medical records, and the meaning of medical terms. Overall, relatives wanted more information than that anticipated by ICU physicians, suggested in guidelines, or found in booklets. However, for at least one of the 24 topics, 38% of relatives indicated that fear or poor comprehension made them unwilling to receive written information. These relatives were younger and had fewer years of formal education than did the other relatives, and they were more likely to be visiting conscious unrestrained patients. CONCLUSIONS: Opinions of relatives should be taken into account when designing ICU information booklets. Relatives want more information than that anticipated by physicians or suggested in guidelines, but the youngest or the less-educated ones may respond less favorably to written information.

Pneumococcal urinary antigen test: A tool for pneumococcal aortitis diagnosis?

Introduction: Aortitis is rare. The etiological diagnosis is difficult but essential for treatment. Even with appropriate treatment mortality remains high. We present a case of pneumococcal aortitis followed by a brief review of the literature. Presentation of Case: In this case, the aortic disease was characterized by multiple inflammatory aneurysms. Blood cultures were negative but urine was tested for the presence of pneumococcal urinary antigen postoperatively was positive. Treatment consisted of antibacterial therapy and both surgical and endovascular procedures. The patient was discharged and is well. Discussion: Preoperative determination of etiology is crucial in implementing a specific treatment. Pneumococcus is a common bacterium in infectious aortitis. Identification of the causative microbe is necessary to guide antimicrobial therapy. Blood cultures are frequently sterile. The pneumococcal urinary antigen test may be more sensitive than blood cultures, as is the case in pneumococcal pneumonia. Conclusions: The pneumococcal urinary antigen test may was a useful diagnostic tool in establishing the cause for aortitis in this case. Its potential value should be assessed in furthers studies.

AnaConDa reflection filter: bench and patient evaluation of safety and volatile anesthetic conservation.

BACKGROUND: The AnaConDa filter permits administration of volatile anesthetic without the use of an anesthesia machine. It is intended for use in the intensive care unit. METHODS: We studied the AnaConDa reflection filter on the bench and in anesthetized patients. The bench analysis used a test lung, a gas analyzer, an intensive care ventilator, the AnaConDa filter, and a syringe pump. We studied a range of tidal volume, respiratory rate, and positive end-expiratory pressure values. We simulated errors during syringe refilling and patient transportation. In 15 anesthetized patients, we used the AnaConDa with constant ventilation variables, a constant sevoflurane infusion rate (4-5 mL/h), and two consecutive fresh gas flow levels. RESULTS: In the bench study, the expired volatile anesthetic fraction decreased linearly with respiratory frequency at constant minute ventilation, and decreased markedly in a hyperbolical manner when tidal volume increased at a constant respiratory rate. Changing the positive end-expiratory pressure level and inspiration/expiration ratio did not modify the AnaConDa's performance. Several safety failures were observed: refilling caused a transient change in AnaConDa output because of a pumping effect, and a standard Luer lock made it possible to connect the halogenate syringe on an IV infusion line. In anesthetized patients, reducing fresh gas flow from 8 to 1 L/min led to a median 40% increase in the expired volatile anesthetic fraction. CONCLUSIONS: This study shows that the device is generally reliable, but that there are several conditions under which it might deliver more anesthetic than intended.

Laparoscopic partial nephrectomy following tumor embolization in a hybrid room. Feasibility and clinical outcomes.

PURPOSE: In order to limit ischemia and operative bleeding during and after partial nephrectomy we developed a clampless laparoscopic technique, in a hybrid operating room, immediately after super-selective arterial embolization of the renal tumor. We evaluated feasibility and morbidity of this new approach of zero ischemia in partial nephrectomy. METHODS: We included prospectively 50 consecutive patients treated in a hybrid operating room by this new technique for a localized renal tumor in a university hospital between May 2015 and January 2017. We evaluated perioperative data, postoperative complications, surgical margin and modification of renal function one month after surgery. Renal tumor complexity was evaluated by the R.E.N.A.L. score. RESULTS: We included 30 (60%) men and 20 (40%) women with a median age of 61 years (32-84) and a median BMI of 26.85 kg/m2 (20.1-46.4). Tumors were at low, median and high complexity in respectively 11 (22%), 32 (64%) and 7 (14%) cases. Median endovascular and surgical procedures durations were 43 min (16-120) and 80 min (32-150). Median blood loss was 100 mL (10-850). Two Clavien II complications occurred. Median length of hospital stay was 3 days (2-7). Renal function was not modified one month after partial nephrectomy. Median tumor size was 3 cm (1.2-8). Forty tumors (80%) were malignant and surgical margins were positive in one (2%). CONCLUSIONS: Clampless laparoscopic partial nephrectomy in a hybrid operating room without pedicular dissection after previous tumoral embolization is a technically safe and carcinologically efficient mini-invasive alternative for the management of localized renal tumors.

Sedative premedication before surgery--A multicentre randomized study versus placebo.

OBJECTIVE: Anxiolytic premedication before non-ambulatory surgery in adult patients may have become of less importance in an era of better preoperative patient information. Moreover, an oral hypnotic given the night before surgery may be as efficient as an anxiolytic for relieving patient anxiety. These two strategies were compared for superiority to a placebo and to each other for non-inferiority. STUDY DESIGN: Double-blind, randomized, multicentre study versus placebo. Eight hospitals in France. June 2011 to February 2013. PATIENTS: Non-ambulatory consecutive surgical patients undergoing general surgery. METHODS AND INTERVENTIONS: Patients received either zopiclone 7.5mg the night before surgery (n=204), or alprazolam 0.5mg the morning of surgery (n=206) and controls received placebo (n=68). Demographic data, preoperative anxiety, fear of surgery and anaesthesia, and mood were assessed the day before surgery using a visual analogue scale, the Spielberger scale and the APAIS scale. In the operating room, anxiety and comfort were assessed in addition to physiological data. RESULTS: Preoperative data did not differ between groups. In the operating room, anxiety and comfort were moderate and did not differ significantly between groups on a 1-10 scale (median [25-75 percentile]): zopiclone: 2 [1-4] and 2.5 [1-5]; alprazolam: 2 [1,4] and 2 [1-5]; placebo: 3 [1-5] and 3 [1-5]. The patients who were more anxious preoperatively remained so in the operating room, irrespective of the treatment received (r=0.31, p<0.001). A placebo effect was observed in 38% of patients in the corresponding group. Patients receiving zopiclone reported a significantly better sleep the night before surgery compared to other groups (median: 2 vs. 1, p<0.001). CONCLUSIONS: Premedication in non-ambulatory surgery is no more effective than a placebo, owing to the very moderate level of anxiety experienced by patients.

The presupplementary area within the language network: a resting state functional magnetic resonance imaging functional connectivity analysis.

The presupplementary motor area (pre-SMA) is involved in volitional selection. Despite the lateralization of the language network and different functions for both pre-SMA, few studies have reported the lateralization of pre-SMA activity and very little is known about the possible lateralization of pre-SMA connectivity. Via functional connectivity analysis, we sought to understand how the language network may be connected to other intrinsic connectivity networks (ICNs) through the pre-SMA. We performed a spatial independent component analysis of resting state functional magnetic resonance imaging in 30 volunteers to identify the language network. Subsequently, we applied seed-to-voxel functional connectivity analyses centered on peaks detected in the pre-SMA. Three signal peaks were detected in the pre-SMA. The left rostral pre-SMA intrinsic connectivity network (LR ICN) was left lateralized in contrast to bilateral ICNs associated to right pre-SMA peaks. The LR ICN was anticorrelated with the dorsal attention network and the right caudal pre-SMA ICN (RC ICN) anticorrelated with the default mode network. These two ICNs overlapped minimally. In contrast, the right rostral ICN overlapped the LR ICN. Both right ICNs overlapped in the ventral attention network (vATT). The bilateral connectivity of the right rostral pre-SMA may allow right hemispheric recruitment to process semantic ambiguities. Overlap between the right pre-SMA ICNs in vATT may contribute to internal thought to external environment reorientation. Distinct ICNs connected to areas involved in lexico-syntactic selection and phonology converge in the pre-SMA, which may constitute the resolution space of competing condition-action associations for speech production.

Early lung ultrasonography predicts the occurrence of acute respiratory distress syndrome in blunt trauma patients.

PURPOSE: Extent of lung contusion on initial computed tomography (CT) scan predicts the occurrence of acute respiratory distress syndrome (ARDS) in blunt chest trauma patients. We hypothesized that lung ultrasonography (LUS) on admission could also predict subsequent ARDS. METHODS: Forty-five blunt trauma patients were prospectively studied. Clinical examination, chest radiography, and LUS were performed on arrival at the emergency room. Lung contusion extent was quantified using a LUS score and compared to CT scan measurements. The ability of the LUS score to predict ARDS was tested using the area under the receiver operating characteristic curve (AUC-ROC). The diagnostic accuracy of LUS was compared to that of combined clinical examination and chest radiography for pneumothorax, lung contusion, and hemothorax, with thoracic CT scan as reference. RESULTS: Lung contusion extent assessed by LUS on admission was predictive of the occurrence of ARDS within 72 h (AUC-ROC = 0.78 [95 % CI 0.64-0.92]). The extent of lung contusion on LUS correlated well with CT scan measurements (Spearman's coefficient = 0.82). A LUS score of 6 out of 16 was the best threshold to predict ARDS, with a 58 % [95 % CI 36-77] sensitivity and a 96 % [95 % CI 76-100] specificity. The diagnostic accuracy of LUS was higher than that of combined clinical examination and chest radiography: (AUC-ROC) 0.81 [95 % CI 0.50-1.00] vs. 0.74 [0.48-1.00] (p = 0.24) for pneumothorax, 0.88 [0.76-1.00] vs. 0.69 [0.47-0.92] (p < 0.05) for lung contusion, and 0.84 [0.59-1.00] vs. 0.73 [0.51-0.94] (p < 0.05) for hemothorax. CONCLUSIONS: LUS on admission identifies patients at risk of developing ARDS after blunt trauma. In addition, LUS allows rapid and accurate diagnosis of common traumatic thoracic injuries.

Comparison of infection rate with the use of antibiotic-impregnated vs standard extraventricular drainage devices: a prospective, randomized controlled trial.

BACKGROUND: External ventricular drainage (EVD) catheters provide reliable and accurate means of monitoring intracranial pressure and alleviating elevated pressures via drainage of cerebrospinal fluid (CSF). CSF infections occur in approximately 9% of patients. Antibiotic-impregnated (AI) EVD catheters were developed with the goal of reducing the occurrence of EVD catheter-related CSF infections and their associated complications. OBJECTIVE: To present an international, prospective, randomized, open-label trial to evaluate infection incidence of AI vs standard EVD catheters. METHODS: Infection was defined as (1) proven infection, positive CSF culture and positive Gram stain or (2) suspected infection: (A) positive CSF culture with no organisms identified on initial Gram stain; (B) negative CSF culture with a gram-positive or -negative stain; (C) CSF leukocytosis with a white blood cell/red blood cell count >0.02. RESULTS: Four hundred thirty-four patients underwent implantation of an EVD catheter. One hundred seventy-six patients in the AI-EVD cohort and 181 in the standard EVD catheter cohort were eligible for evaluation of infection. The 2 groups were similar in all clinical characteristics. Proven infection was documented in 9 (2.5%) patients (AI: 4 [2.3%] vs standard: 5 [2.8%], P = 1.0). Suspected infection was documented in 31 (17.6%) patients receiving AI and 37 (20.4%) patients receiving standard EVD catheters, P = .504. Duration of time to suspected infection was prolonged in the AI cohort (8.8 ± 6.1 days) compared with the standard EVD cohort (4.6 ± 4.2 days), P = .002. CONCLUSION: AI-EVD catheters were associated with an extremely low rate of catheter-related infections. AI catheters were not associated with risk reduction in EVD infection compared to standard catheters. Use of AI-EVD catheters is a safe option for a wide variety of patients requiring CSF drainage and monitoring, but the efficacy of AI-EVD catheters was not supported in this trial.

Changes in intracranial pressure and cerebral autoregulation in patients with severe traumatic brain injury.

BACKGROUND: Impaired cerebral autoregulation is frequent after severe traumatic head injury. This could result in intracranial pressure fluctuating passively with the mean arterial pressure. OBJECTIVE: This study examines the influence of autoregulation on the amplitude and direction of changes in intracranial pressure in patients with severe head injuries during the management of cerebral perfusion pressure. DESIGN: Prospective study. SETTING: Neurosurgical intensive care unit PATIENTS: A total of 42 patients with severe head injuries. INTERVENTIONS: Continuous recording of cerebral blood flow velocity, intracranial pressure, and mean arterial pressure during the start or change of continuous norepinephrine infusion. MEASUREMENTS AND MAIN RESULTS: Cerebrovascular resistance was calculated from the cerebral perfusion pressure and middle cerebral artery blood flow velocity. The strength of autoregulation index was calculated as the ratio of the percentage of change in cerebrovascular resistance by the percentage of change in cerebral perfusion pressure before and after 121 changes in mean arterial pressure at constant ventilation between day 1 and day 18 after trauma. The strength of autoregulation index varied widely, indicating either preserved or severely perturbed autoregulation during hypotensive or hypertensive challenge in patients with or without intracranial hypertension at the basal state (strength of autoregulation index, 0.51 +/- 0.32 to 0.71 +/- 0.25). The change in intracranial pressure varied linearly with the strength of autoregulation index. There was a clinically significant change in intracranial pressure (> or =5 mm Hg) in the same direction as the change in mean arterial pressure in five tracings of three patients. This was caused by the mean arterial pressure dropping below the identified lower limit of autoregulation in three tracings for two patients. It seemed to be caused by a loss of cerebral autoregulation in the remaining two tracings for one patient. CONCLUSION: Cerebral perfusion pressure-oriented therapy can be a safe way to reduce intracranial pressure, whatever the status of autoregulation, in almost all patients with severe head injuries.

Comparison of local measurement of cerebral metabolism and to cerebral PvO2 during alterations in intracranial pressure, PaCO2 and arterial pressure--an experimental study in goat.

OBJECTIVE: to assess the changes in local brain PO2, PCO2, pH (PO2br, PCO2br, pHbr) measured by a intraparenchymal probe (Neurotrend, Codeman) and compare them to simultaneous recording of cerebral PvO2 and blood flow (CBF). METHODS: Arterial, venous longitudinal sinus blood samples and CBF were analyzed in 8 adult anesthetized, ventilated goats. Three step increase of intracranial pressure (ICP) (16, 22, 29 mm Hg) were performed by inflation of an epidural balloon. At each ICP level, similar changes in MAP and in PaCO2 were performed. RESULTS: At constant PaCO2 and MAP, balloon inflation induced a fast response: a decrease of PO2br, PCO2br and pHbr (starting 14 +/- 12 sec, 45 +/- 23 sec and 55 +/- 19 sec after the peak ICP, respectively). Since the second inflation level, PO2br decreased (p < 0.05) despite an ICP returning at 22 mm Hg and a cerebral perfusion pressure (CPP) larger than 90 mmHg. During changes in PaCO2, PO2br paralleled CBF and PvO2 before the second balloon inflation but diverged at higher ICP. In the same time pH-pHbr gradient rose. Hypotension did not induce sizeable changes. CONCLUSIONS: The direct metabolic monitoring of cerebral tissue locally compressed show fast response. At steady state, it shows alterations which are not detected by the measurement of the oxygen saturation in the longitudinal sinus or that of CBF. It confirms that the threshold for ICP which may require therapy in presence of focal brain compression is around 20 mm Hg even in the presence of a CPP > 90 mm Hg.