The social representations of diagnosing Lyme disease.

Social science studies on the controversy surrounding Lyme disease (LD) focused on the opposition between the "mainstream" and biomedical approach on one side and the "Lyme-literate" one on the other side, the latter claiming the existence of the chronic form of LD. The qualitative and exploratory study 'C18-48 Quali-Explo-PIQTIQ' (2019) investigated the social representations of LD in patients bitten by a tick. Twenty-four semi-structured interviews were conducted in three French medical units. Thematic and patient trajectory analyses were performed. Our results showed that, after the tick bite, some patients presented an "illness without disease" condition, characterised by uncertainty. In some cases, they consulted "Lyme-literate" health providers and received a diagnosis of chronic LD. This diagnosis was obtained by prescribing unassessed biological testing, providing an objective result and clinical categorisation. Unlike literature on the "Lyme-literate" approach, this diagnostic procedure involved some biomedical operations.

How PrEP users constitute a community in the MSM population through their specific experience and management of stigmatization. The example of the French ANRS-PREVENIR study.

The ANRS-PREVENIR (2017-2020) prospective cohort study aims to reduce the number of new HIV infections in the "Ile-de-France" region in France, by enrolling individuals at high risk of HIV infection and proposing daily and on-demand pre-exposure prophylaxis (PrEP). The qualitative component of the ANRS-PREVENIR study aimed to investigate social and relational evolutions associated with PrEP use in men who have sex with men (MSM). In 2018, 12 focus groups with MSM (n = 68) were conducted by a social sciences researcher in Paris. A thematic analysis was performed. Results showed that stigma concerning PrEP use is a complex issue, with various kinds of stigmatization being practiced, sometimes even by the wider MSM population and PrEP users themselves. All types of stigma identified were expressed in forms of verbal abuse which made PrEP use taboo. Inside the wider MSM population a PrEP-user "community" was identified which shared a certain complicity in terms of values and a positive attitude towards PrEP. The emergence of new intragroup and intergroup social norms should be taken into account by policy makers to promote a more positive image of PrEP users.

Cerebral Critical Closing Pressure: Is the Multiparameter Model Better Suited to Estimate Physiology of Cerebral Hemodynamics?

BACKGROUND: Cerebral critical closing pressure (CrCP) is the level of arterial blood pressure (ABP) at which small brain vessels close and blood flow stops. This value is always greater than intracranial pressure (ICP). The difference between CrCP and ICP is explained by the tone of the small cerebral vessels (wall tension). CrCP value is used in several dynamic cerebral autoregulation models. However, the different methods for calculation of CrCP show frequent negative values. These findings are viewed as a methodological limitation. We intended to evaluate CrCP in patients with severe traumatic brain injury (TBI) with a new multiparameter impedance-based model and compare it with results found earlier using a transcranial Doppler (TCD)-ABP pulse waveform-based method. METHODS: Twelve severe TBI patients hospitalized during September 2005-May 2007. Ten men, mean age 32 years (16-61). Four had decompressive craniectomies (DC); three presented anisocoria. Patients were monitored with TCD cerebral blood flow velocity (FV), invasive ABP, and ICP. Data were acquired at 50 Hz with an in-house developed data acquisition system. We compared the earlier studied "first harmonic" method (M1) results with results from a new recently developed (M2) "multiparameter method." RESULTS: M1: In seven patients CrCP values were negative, reaching -150 mmHg. M2: All positive values; only one lower than ICP (ICP 60 mmHg/ CrCP 57 mmHg). There was a significant difference between M1 and M2 values (M1 < M2) and between ICP and M2 (M2 > ICP). CONCLUSION: M2 results in positive values of CrCP, higher than ICP, and are physiologically interpretable.

Consensus summary statement of the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care: a statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine

Neurocritical care depends, in part, on careful patient monitoring but as yet there are little data on what processes are the most important to monitor, how these should be monitored, and whether monitoring these processes is cost-effective and impacts outcome. At the same time, bioinformatics is a rapidly emerging field in critical care but as yet there is little agreement or standardization on what information is important and how it should be displayed and analyzed. The Neurocritical Care Society in collaboration with the European Society of Intensive Care Medicine, the Society for Critical Care Medicine, and the Latin America Brain Injury Consortium organized an international, multidisciplinary consensus conference to begin to address these needs. International experts from neurosurgery, neurocritical care, neurology, critical care, neuroanesthesiology, nursing, pharmacy, and informatics were recruited on the basis of their research, publication record, and expertise. They undertook a systematic literature review to develop recommendations about specific topics on physiologic processes important to the care of patients with disorders that require neurocritical care. This review does not make recommendations about treatment, imaging, and intraoperative monitoring. A multidisciplinary jury, selected for their expertise in clinical investigation and development of practice guidelines, guided this process. The GRADE system was used to develop recommendations based on literature review, discussion, integrating the literature with the participants' collective experience, and critical review by an impartial jury. Emphasis was placed on the principle that recommendations should be based on both data quality and on trade-offs and translation into clinical practice. Strong consideration was given to providing pragmatic guidance and recommendations for bedside neuromonitoring, even in the absence of high quality data

Comparison between magnetic resonance imaging and rigid rectoscopy in the preoperative identification of intra- and extraperitoneal rectal cancer.

AIM: Accurate preoperative discrimination between extra- and intraperitoneal rectal cancer has important treatment implications. Our main objective was to compare the diagnostic performance of MRI with rigid rectoscopy (RRS) in assessing the location of rectal cancers above or below the peritoneal reflection (PR), using the findings obtained during abdominal surgery for treatment of the cancer as the reference standard. We also compared the accuracy of MRI and RRS in assessing the level of the lower border of the tumour from the anal verge. METHOD: Patients with rectal carcinoma awaiting surgery underwent MRI and RRS. The MRI images were reviewed by two abdominal radiologists who determined the location of the inferior border of the tumour in relation to the PR. Receiver-operating characteristics (ROC) curve analysis was performed to determine the diagnostic performance of RRS at different cut-off values. RESULTS: The sensitivity and specificity were 98.15% and 100%, respectively, for MRI, and 100% and 76.92%, respectively, for RRS at a cut-off value of < 10 cm. The mean level of the lower border of the tumour from the anal verge was 68 ± 44.3 mm on RRS and 73.5 ± 42.4 mm on MRI (P = 0.25), with a trend towards overestimation with MRI. CONCLUSION: RRS is still the main means of assessing the level of a rectal tumour from the anal verge, but MRI has value in determining the level of the tumour in relation to the PR, which cannot be seen on endoscopy.

Development of a multimodal monitoring platform for medical research.

A low cost multimodal monitoring and signal processing platform is presented. A modular and flexible system was developed, aimed to continuous acquisition of several biological variables at patient bed-head and further processing with application specific algorithms. System hardware is made of a six-channel isolation and signal conditioning front-end along with a high resolution analog-to-digital converter board connected to a standard laptop. Whole system hardware is compact and light weight, which ensures portability and ease of use at intensive care units. System software is divided in three modules: Acquisition, Signal Processing and Patients Data Management. The first one allows configuring each acquisition channel parameters, depending on the biological variable connected to it, and to store up to several hours of continuous data. Signal processing module implements novel algorithms for research purposes like dynamic cerebral autoregulation, optimal perfusion pressure, critical closing pressure or pulsatility index. It is flexible enough to easily add new processing algorithms, export data to different formats and create graphical reports. Patients data management module organizes acquired records, which allows selecting cases for new studies based on different criteria like monitored variables or pathological information. In this work, whole system architecture is described and algorithms included into the cerebral hemodynamics toolbox are presented along with experimental results.

Cerebral CO2 reactivity in severe head injury. A transcranial Doppler study.

BACKGROUND: Cerebral circulation is profoundly affected by changes in PaCO2. CO2 manipulation plays a basic role in the management of intracranial hypertension; CO2 reactivity (CO2R) defines the changes in CBF in response to changes in PaCO2. Transcranial Doppler has allowed exploring its effects "on line". MATERIALS AND METHODS: We conducted a prospective clinical trial, with the objective of studying CO2R in severe head injury patients. Sixteen severe traumatic brain injury patients, mechanically ventilated, were included. Monitoring of MAP, ICP, CPP, SjO2, ETCO2, and cerebral blood flow velocity (CBFV) was performed. Taking into account basal cerebral hemodynamic pattern, minute ventilation was modified to attain a negative ("A") or positive ("B") deltaPCO2. CO2R was calculated as: CO2R = % deltaCBFV/deltaETCO2 in mmHg (normal value 3.7 +/- 1%/mmHg). CO2R was compared with deltaICP/ deltaPCO2 in each patient. FINDINGS: Three patients were excluded because the change in ETCO2 was too low (deltaETCO2 < 3 mmHg). The median value of CO2R in the total group of 13 patients was 3.38. In "A" the values tended to be lower than in "B". There were four low CO2R values in "A" and none in "B". There was no significant correlation between CO2R and deltaICP/deltaPCO2. CONCLUSIONS: The different "A" and "B" behavior might be due to dissimilar mechanisms involved in the basis of vasodilatation and vasoconstriction. Changes in ventilation must be performed with caution, avoiding sudden increases in CO2 that may increase ICP. The absence of correlation between CO2R and deltaICP/deltaPCO2 is explained, at least partially, by different cranio-cerebral compliance in each patient. Therefore, induced blood volume changes are not directly transmitted to ICP, but their effects depend on the shape of the pressure-volume curve and the position on the curve in which each situation is working.

Indomethacin and cerebral autoregulation in severe head injured patients: a transcranial Doppler study.

OBJECTIVE: To assess the effect of indomethacin on cerebral autoregulation, systemic and cerebral haemodynamics, in severe head trauma patients. DESIGN: Prospective, controlled clinical trial, with repeated measurements. SETTINGS: A 12-bed adult general intensive care unit in a third level referral university hospital. PATIENTS: 16 severely head injured patients, 14 males, age range 17-60. INTERVENTIONS: Indomethacin was administrated as a load plus continuous infusion. Indomethacin reactivity was assessed as the estimated cerebral blood flow change elicited by the load. Dynamic and static cerebral autoregulation tests were performed before indomethacin administration, and during its infusion. MEASUREMENTS AND MAIN RESULTS: Systemic and cerebral haemodynamic changes were assessed through continuous monitoring of mean arterial pressure, transcranial Doppler cerebral blood flow velocity, intracranial pressure, cerebral perfusion pressure, and jugular venous oxygen saturation. Indomethacin loading dose was immediately followed by a cerebral blood flow median decrease of 36 or 29% (p = ns) evaluated by two different methods, by an ICP decrease and by an AVDO(2) increase from 3.52 to 6.15 mL/dL (p = 0.002). Dynamic autoregulation increased from a median of 28 to 57% (p<0.05) during indomethacin infusion; static autoregulation also increased, from a median of 72 to 89% (p = ns). CONCLUSIONS: Indomethacin decreased intracranial pressure and cerebral blood flow, and increased cerebral perfusion pressure, while maintaining tissue properties of further extracting O(2). The increase in both autoregulatory values reveals an enhancement of cerebral microvasculature reactivity under indomethacin, during hypertensive and--especially--during hypotensive situations.

Comparison between two static autoregulation evaluation methods.

Cerebral static autoregulation (AR) was evaluated at bedside in 14 severely head injured patients. 16 investigations were performed. Cerebral perfusion pressure (CPP) was increased by infusing vasopressors during one hour, and registered every 2-5 minutes. CBF was simultaneously estimated by: 1) middle cerebral artery mean flow velocity (FV) monitoring with Transcranial Doppler (TDC), and 2) the reciprocal of arteriovenous oxygen content difference, calculated from basal and hypertensive arterial and jugular bulb blood samples. AR assessment: For TCD results, linear regression method was used, studying two pairs of variables: a) %FV-CPP (the regression slope was the main AR value adopted) and b) % cerebrovascular resistance (CVR)-%CPP. For the AVDO2 method, autoregulation was considered preserved if estimated % delta CBF/delta PPE < 1%/mm Hg. TCD method clearly defined three groups. Group 1 and 2 (8 and 5 investigations) were considered as two grades of preserved AR, and the third one (3 cases) as impaired AR. AVDO2 method: 12 studies were evaluated. 10 showed preserved AR, and 2 impaired AR. There was coincidence of results from both methods in 10 out of 12 studies. (0.83).

[Cytomegalovirus encephalitis in an immunocompetent patient: clinical, neuropathological and ultrastructural analysis]. / Encefalitis a citomegalovirus en un paciente inmunocompetente: análisis clinico, neuropatologico y ultraestructural.

Cytomegalovirus encephalitis is rarely diagnosed in immunocompetent patients. It is more frequent among immunocompromised hosts. We present a case of a young male patient without evidence of immunosupression who had a cytomegalovirus encephalitis. The diagnosis was made by detection of viral DNA in cerebral tissue obtained by biopsy. Neuropathologic and ultrastructural changes are described and compared with the descriptions in immunocompromised patients.

Use of vasopressors to raise cerebral perfusion pressure in head injured patients.

Cerebral ischemia due to low cerebral perfusion pressure (CPP) is the most important secondary effect of severe head injury. There is consensus regarding the maintenance of this pressure at levels above 70 mm Hg. One way to elevate CPP is by increasing mean arterial pressure (MAP). In this study, the authors attain this target by using adrenergic vasopressors investigating the effectiveness of dopamine, noradrenaline and methoxamine in 16 severe head injured patients. The results were: a) the increase of MAP effectively increased CPP without changes in intracranial pressure (ICP) and cerebral extraction of oxygen (CEO2); b) noradrenaline at a dose of 0.5 mg to 5 mg/h was effective and safe and might be considered the drug of choice; c) dopamine was not as effective at a high dose of 10 to 42.5 micrograms/kg/min; d) methoxamine given as a bolus was an effective way to control sudden decreases in MAP. It made the patients more responsive to dopamine. No important undesirable reactions occurred during the study.

Use of indomethacin in brain-injured patients with cerebral perfusion pressure impairment: preliminary report.

The effect of indomethacin, a cyclooxygenase inhibitor, was studied in the treatment of 10 patients with head injury and one patient with spontaneous subarachnoid hemorrhage, each of whom presented with high intracranial pressure (ICP) (34.4 +/- 13.1 mm Hg) and cerebral perfusion pressure (CPP) impairment (67.0 +/- 15.4 mm Hg), which did not improve with standard therapy using mannitol, hyperventilation, and barbiturates. The patient had Glasgow Coma Scale scores of 8 or less. Recordings were made of the patients' ICP and mean arterial blood pressure from the nurse's end-hour recording at the bedside, as well as of their CPP, rectal temperature, and standard therapy regimens. The authors assessed the effects of an indomethacin bolus (50 mg in 20 minutes) on ICP and CPP; an indomethacin infusion (21.5 +/- 11 mg/hour over 30 +/- 9 hours) on ICP, CPP, rectal temperature, and standard therapy regimens (matching the values before and during infusion in a similar time interval); and discontinuation of indomethacin treatment on ICP, CPP, and rectal temperature. The indomethacin bolus was very effective in lowering ICP (p < 0.0005) and improving CPP (p < 0.006). The indomethacin infusion decreased ICP (p < 0.02), but did not improve CPP and rectal temperature. The effects of standard therapy regimens before and during indomethacin infusion showed no significant changes, except in three patients in whom mannitol reestablished its action on ICP and CPP. Sudden discontinuation of indomethacin treatment was followed by significant ICP rebound. The authors suggest that indomethacin may be considered one of the frontline agents for raised ICP and CPP impairment.

Electromyography of the small bowel following inversion of a jejunal segment in dogs

A atividade mioeletrica do intestino delgado foi estudada apos a inversao de um segmento jejunal em sete caes. Sete pares de eletrodos bipolares foram implantados na camada seromuscular do intestino delgado em diferentes locais, incluindo a alca jejunal invertida. Os registros eletromiograficos foram obtidos no 7§ e 10§ dias pos-operatorios, durante os periodos de jejum e alimentar. O complexo mioeletrico migratorio (CMM) estava presente em todos os locais registrados, inclusive na alca jejunal invertida. A duracao do CMM duodenal foi 70,3ñ14,8 minutos...