Midbrain and pons MRI shape analysis and its clinical and CSF correlates in degenerative parkinsonisms: a pilot study.

OBJECTIVES: To conduct brainstem MRI shape analysis across neurodegenerative parkinsonisms and control subjects (CS), along with its association with clinical and cerebrospinal fluid (CSF) correlates. METHODOLOGY: We collected demographic and clinical variables, performed planimetric and shape MRI analyses, and determined CSF neurofilament-light chain (NfL) levels in 84 participants: 11 CS, 12 with Parkinson's disease (PD), 26 with multiple system atrophy (MSA), 21 with progressive supranuclear palsy (PSP), and 14 with corticobasal degeneration (CBD). RESULTS: MSA featured the most extensive and significant brainstem shape narrowing (that is, atrophy), mostly in the pons. CBD presented local atrophy in several small areas in the pons and midbrain compared to PD and CS. PSP presented local atrophy in small areas in the posterior and upper midbrain as well as the rostral pons compared to MSA. Our findings of planimetric MRI measurements and CSF NfL levels replicated those from previous literature. Brainstem shape atrophy correlated with worse motor state in all parkinsonisms and with higher NfL levels in MSA, PSP, and PD. CONCLUSION: Atypical parkinsonisms present different brainstem shape patterns which correlate with clinical severity and neuronal degeneration. In MSA, shape analysis could be further explored as a potential diagnostic biomarker. By contrast, shape analysis appears to have a rather limited discriminant value in PSP. KEY POINTS: • Atypical parkinsonisms present different brainstem shape patterns. • Shape patterns correlate with clinical severity and neuronal degeneration. • In MSA, shape analysis could be further explored as a potential diagnostic biomarker.

Ultrasound-guided genicular nerves block vs. local infiltration analgesia for total knee arthroplasty: a randomised controlled non-inferiority trial.

Genicular nerves block is a promising technique to treat acute postoperative pain in total knee arthroplasty. Similar to surgeon-administered local infiltration analgesia, it targets sensory branches from the knee capsule, but through a selective ultrasound-guided injection that reduces local anaesthetic dose (150 ml ropivacaine 0.2% with local infiltration analgesia vs. 20 ml with genicular nerves block). This randomised non-inferiority trial compared the analgesic efficacy of genicular nerves block vs. local infiltration analgesia in the first 24 h following total knee arthroplasty. Sixty patients were randomly allocated to receive either ultrasound-guided block of five genicular nerves or local infiltration analgesia. The primary outcome was rest pain numeric rating scale (0-10) at 24 h. Secondary outcomes included pain numeric rating scale (rest and movement) and cumulative opioid consumption during the first 24 h. We analysed 29 patients in the genicular nerves block group and 30 in the local infiltration analgesia group. We found that the median difference (95%CI) in postoperative rest pain at 24 h (non-inferiority criteria, Δ = 1) was -1.0 (-2.0 to 1.0, p < 0.001). Median difference in cumulative opioid consumption was 0.0 mg (-3.0-5.0, p < 0.001) meeting the non-inferiority criteria, Δ = 23 mg. We conclude that genicular nerves block of five nerves provides non-inferior analgesia in the first 24 h following surgery compared with local infiltration analgesia, but with a considerable reduction in the local anaesthetic dose.

Intraoperative tranexamic acid use in major spine surgery in adults: a multicentre, randomized, placebo-controlled trial†.

Background: Perioperative tranexamic acid (TXA) use can reduce bleeding and transfusion requirements in several types of surgery, but level I evidence proving its effectiveness in major spine surgery is lacking. This study was designed to investigate the hypothesis that TXA reduces perioperative blood loss and transfusion requirements in patients undergoing major spine procedures. Methods: We conducted a multicentre, prospective, randomized double-blind clinical trial, comparing TXA with placebo in posterior instrumented spine surgery. Efficacy was determined based on the total number of blood units transfused and the perioperative blood loss. Other variables such as the characteristics of surgery, length of hospital stay, and complications were also analysed. Results: Ninety-five patients undergoing posterior instrumented spine surgery (fusion of >3 segments) were enrolled and randomized: 44 received TXA (TXA group) and 51 received placebo (controls). The groups were comparable for duration of surgery, number of levels fused, and length of hospitalization. Transfusion was not required in 48% of subjects receiving TXA compared with 33% of controls (P = 0.05). Mean number of blood units transfused was 0.85 in the TXA group and 1.42 with placebo (P = 0.06). TXA resulted in a significant decrease in intraoperative bleeding (P = 0.01) and total bleeding (P = 0.01) relative to placebo. The incidence of adverse events was similar in the two groups. Conclusions: TXA did not significantly reduce transfusion requirements, but significantly reduced perioperative blood loss in adults undergoing major spinal surgery. Clinical trial registration: NCT01136590.

Should all patients be optimized to the same preoperative hemoglobin level to avoid transfusion in primary knee arthroplasty?

BACKGROUND AND OBJECTIVE: Optimization of the preoperative hemoglobin (Hb) level is an effective way to reduce allogeneic transfusion in total knee arthroplasty (TKA) though the procedure is expensive, requires close monitoring and is often inconvenient for patients with reduced mobility. Our aim was to investigate the value of preoperative Hb levels to predict transfusion and thereby tailoring Hb optimization to patient characteristics. MATERIALS AND METHODS: All consecutive patients who undergone primary TKA in our center over 2 years, and received tranexamic acid intraoperatively, were reviewed. The adjusted association between preoperative Hb levels and transfusion was assessed by multivariate logistic regression, and the estimated probability of transfusion for individual patients was derived from the logistic model. RESULTS: Out of the 784 patients who meet the inclusion criteria, risk of transfusion was associated with poorer performance status, as measured by the America Association of Anestesiology (ASA) score III/IV (OR: 3·3, P < 0·001) and lower preoperative Hb level (OR 3·8 for each g/dl below 13 g/dl; P < 0·001). According to the Hb level, the estimated probability of transfusion was 0·03 (range: 0·03-0·64) for ASA I/II patients and 0·10 (range: 0·10-0·84) for ASA III/IV. CONCLUSION: Not all the patients undergoing TKA who receive tranexamic acid need the same preoperative Hb optimization target. Two easily available factors, such as the ASA score and the Hb level, can help individualize the Hb optimization target.

[The 2013 Seville Consensus Document on alternatives to allogenic blood transfusion. An update on the Seville Document]. / 2013. Documento Sevilla de Consenso sobre Alternativas a la Transfusión de Sangre Alogénica. Actualización del Documento Sevilla.

Since allogeneic blood transfusion (ABT) is not harmless, multiple alternatives to ABT (AABT) have emerged, though there is great variability in their indications and appropriate use. This variability results from the interaction of a number of factors, including the specialty of the physician, knowledge and preferences, the degree of anemia, transfusion policy, and AABT availability. Since AABTs are not harmless and may not meet cost-effectiveness criteria, such variability is unacceptable. The Spanish Societies of Anesthesiology (SEDAR), Hematology and Hemotherapy (SEHH), Hospital Pharmacy (SEFH), Critical Care Medicine (SEMICYUC), Thrombosis and Hemostasis (SETH) and Blood Transfusion (SETS) have developed a Consensus Document for the proper use of AABTs. A panel of experts convened by these 6 Societies have conducted a systematic review of the medical literature and have developed the 2013 Seville Consensus Document on Alternatives to Allogeneic Blood Transfusion, which only considers those AABT aimed at decreasing the transfusion of packed red cells. AABTs are defined as any pharmacological or non-pharmacological measure aimed at decreasing the transfusion of red blood cell concentrates, while preserving patient safety. For each AABT, the main question formulated, positively or negatively, is: « Does this particular AABT reduce the transfusion rate or not?¼ All the recommendations on the use of AABTs were formulated according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) methodology.

Research priorities in perioperative fluid therapy and hemodynamic monitoring: A Delphi Consensus Survey from the Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR).

BACKGROUND: Research in fluid therapy and perioperative hemodynamic monitoring is difficult and expensive. The objectives of this study were to summarize these topics and to prioritize these topics in order of research importance. METHODS: Electronic structured Delphi questionnaire over three rounds among 30 experts in fluid therapy and hemodynamic monitoring identified through the Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section of the Spanish Society of Anesthesiology and Critical Care. RESULTS: 77 topics were identified and ranked in order of prioritization. Topics were categorized into themes of crystalloids, colloids, hemodynamic monitoring and others. 31 topics were ranked as essential research priority. To determine whether intraoperative hemodynamic optimization algorithms based on the invasive or noninvasive Hypotension Prediction Index versus other management strategies could decrease the incidence of postoperative complications. As well as whether the use of renal stress biomarkers together with a goal-directed fluid therapy protocol could reduce hospital stay and the incidence of acute kidney injury in adult patients undergoing non-cardiac surgery, reached the highest consensus. CONCLUSIONS: The Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section of the Spanish Society of Anesthesiology and Critical Care will use these results to carry out the research.

Combined CSF α-SYN RT-QuIC, CSF NFL and midbrain-pons planimetry in degenerative parkinsonisms: From bedside to bench, and back again.

INTRODUCTION: Differential diagnosis between Parkinson's disease (PD) and atypical parkinsonisms (APs: multiple system atrophy[MSA], progressive supranuclear palsy[PSP], corticobasal degeneration[CBD]) remains challenging. Lately, cerebrospinal fluid (CSF) studies of neurofilament light-chain (NFL) and RT-QuIC of alpha-synuclein (α-SYN) have shown promise, but data on their combination with MRI measures is lacking. OBJECTIVE: (1) to assess the combined diagnostic ability of CSF RT-QuIC α-SYN, CSF NFL and midbrain/pons MRI planimetry in degenerative parkinsonisms; (2) to evaluate if biomarker-signatures relate to clinical diagnoses and whether or not unexpected findings can guide diagnostic revision. METHODS: We collected demographic and clinical data and set up α-SYN RT-QuIC at our lab in a cross-sectional cohort of 112 participants: 19 control subjects (CSs), 20PD, 37MSA, 23PSP, and 13CBD cases. We also determined CSF NFL by ELISA and, in 74 participants (10CSs, 9PD, 26MSA, 19PSP, 10CBD), automatized planimetric midbrain/pons areas from 3T-MRI. RESULTS: Sensitivity of α-SYN RT-QuIC for PD was 75% increasing to 81% after revisiting clinical diagnoses with aid of biomarkers. Sensitivity for MSA was 12% but decreased to 9% with diagnostic revision. Specificities were 100% against CSs, and 89% against tauopathies raising to 91% with diagnostic revision. CSF NFL was significantly higher in APs. The combination of biomarkers yielded high diagnostic accuracy (PD vs. non-PD AUC = 0.983; MSA vs. non-MSA AUC = 0.933; tauopathies vs. non-tauopathies AUC = 0.924). Biomarkers-signatures fitted in most cases with clinical classification. CONCLUSIONS: The combination of CSF NFL, CSF RT-QuIC α-SYN and midbrain/pons MRI measures showed high discriminant ability across all groups. Results opposite to expected can assist diagnostic reclassification.

Intraoperative warming and post-operative cognitive dysfunction after total knee replacement.

BACKGROUND: Post-operative cognitive dysfunction (POCD) can affect 30% of orthopedic surgery patients. We hypothesized that perioperative temperature has an impact on POCD. METHODS: We included 150 patients over 65 years of age scheduled for total knee replacement under spinal anesthesia. They were randomized to receive standard care (sheet cover) or active warming. Neurocognitive assessment (11 subtests) was performed pre-operatively and at day 4 (three subtests) and 3 months (10 subtests). A control group of 55 nonsurgical patients took the same tests at equivalent times. POCD was defined as an individual score decrease of more than 2 standard deviations (SDs) below the baseline on at least two subtests or 2 SDs in the combined z-score, in both cases using control-adjusted changes. RESULTS: Tympanic temperature declined below 35 °C in 88% of standard-care patients; 25.3% of warmed patients had a temperature ≥36 °C. On day 4, 3.2% of standard-care patients and 19.4% of warmed patients had POCD (P=0.0058). At 3 months, there were no between-group differences (standard care, 14.3%; warmed, 6.5%) (P=0.2440). CONCLUSIONS: Perioperative warming was associated with a higher incidence of cognitive dysfunction at 4 days after total knee replacement in patients >65 years of age.

Allogeneic blood transfusion does not increase the risk of wound infection in total knee arthroplasty.

BACKGROUND AND OBJECTIVE: Allogeneic blood transfusion has been reported to increase the risk of postoperative infection in arthroplasty though the results are inconclusive. Data from a previous clinical trial on antibiotic prophylaxis in knee arthroplasty were analysed to gain further insight into the relationship between wound infection and both blood transfusion and the storage time of transfused RBCs. MATERIALS AND METHODS: A total of 910 consecutive patients undergoing primary knee arthroplasty were prospectively followed for 12 months after surgery. The main outcome was wound infection, either superficial or deep-tissue. Possible predictors for wound infection included the patient's age and sex, preoperative physical status, time under leg ischaemia, postoperative fluid drainage, and the number and length of storage of transfused RBCs. RESULTS: Deep tissue infection was diagnosed in 28 (3%) patients, superficial infection in 25 (2.7%) and cellulitis in eight (0.8%) patients. Transfusion of at least one blood unit had been given to 22 (36%) of the 61 patients who later developed wound infection and 313 (36%) of those who did not (P > 0.05). Patients who developed wound infection had a significantly poorer physical status and longer time of leg ischaemia. There was no significant difference between both groups of patients in either the amount or the length of storage of transfused RBC units. CONCLUSION: This study failed to find any association between the incidence of wound infection after knee arthroplasty and allogeneic transfusion.

[Survey of perioperative hemostasis and transfusion management in cardiac surgery: how do anesthesiologists practice?]. / Encuesta de hemostasia y transfusión perioperatoria en cirugía cardiaca: cómo actuamos los anestesólogos?

OBJECTIVE: To determine practices related to control of perioperative hemostasis and transfusion in patients undergoing cardiac surgery in Spain, including the extent to which protocols are being used. METHODS: A questionnaire was created to collect information from physicians in anesthesiology and postoperative recovery care between July 1 and September 20, 2007. The physicians were asked about practice in the 12 months prior to the survey. RESULTS: Thirty-four hospitals responded. Seventy percent reported that they did not have protocols or guidelines for the control of hemostasis during cardiac surgery. Forty-four percent did not have information on the proportion of patients who received transfusions; 47% gave transfusions to 75% of patients. The standard preoperative tests were platelet counts, activated partial thromboplastin time, and prothrombin time. Acetylsalicylic acid and clopidogrel were suspended before surgery at 15 (44%) and 25 (73%) hospitals, respectively. In cases of resistance to heparin, additional doses of the drug were injected, in combination with plasma or antithrombin in 29% and 12% of the hospitals, respectively. In the intensive postoperative recovery care unit, only 1 hospital used thromboelastography. Only 1 other hospital used a platelet function analyzer. CONCLUSIONS: Hemostasis, perioperative coagulation, and criteria for transfusion vary widely among the hospitals surveyed. Few guidelines are available and they are not often being followed. A high percentage of patients receive transfusions, although not all hospitals can cite a figure. New technology has not been widely applied.

Patient Blood Management for primary hip and knee replacement. A survey among POWER.2 study researchers. / Patient Blood Management en artroplastia primaria de cadera y rodilla. Encuesta entre los investigadores del estudio POWER.2.

BACKGROUND: Implementation of Patient Blood Management programs remain variable in Europe, and even in centres with well-established PBM programs variability exists in transfusion practices. OBJECTIVES AND METHODS: We conducted a survey in order to assess current practice in perioperative Patient Blood Management in patients undergoing total hip and knee replacement among researchers involved in POWER.2 Study in Spain (an observational prospective study evaluating enhanced recovery pathways in orthopaedic surgery). RESULTS: A total of 322 responses were obtained (37.8%). Half of responders check Haemoglobin levels in patients at least 4 weeks before surgery; 35% treat all anaemic patients, although 99.7% consider detection and treatment of preoperative anaemia could influence the postoperative outcomes. Lack of infrastructure (76%) and lack of time (51%) are the main stated reasons not to treat anaemic patients. Iron status is routinely checked by 19% before surgery, and 36% evaluate it solely in the anaemic patient. Hb<9.9 g/dl is the threshold to delay surgery for 61% of clinicians, and 22% would consider transfusing preoperatively clinically stable patients without active bleeding. The threshold to transfuse patients without cardiovascular disease is 8 g/dl for 43%, and 7 g/dl for 34% of the responders; 75% of clinicians consider they use "restrictive thresholds", and 90% follow the single unit transfusion policy. CONCLUSIONS: The results of our survey show variability in clinical practice in Patient Blood Management in major orthopaedic surgery, despite being the surgery with the greatest tradition in these programs.

Effectiveness and safety of tranexamic acid administration during total knee arthroplasty.

BACKGROUND: The administration of tranexamic acid (TA) is associated with a decrease in the number of red blood cell (RBC) units transfused. However, concerns about its safety have hindered its broader use. STUDY DESIGN AND METHODS: We evaluated the effect of TA on RBC transfusion and thromboembolic complications in total knee arthroplasty. We retrospectively studied 414 patients, 215 immediately before introducing TA treatment (control group) and after, in 199 patients without history of thromboembolic diseases (TA group). In a subgroup of patients, a lower extremities contrast venography was performed. RESULTS: Fifty-four per cent of control group patients were transfused with RBC while only 17.6% of TA group patients received RBCs. In the TA that group, those transfused received less units (2.83 vs. 1.89), showed smaller mean calculated perioperative blood loss and haemoglobin values at discharge were higher compared to control group (10.1 vs. 9.3 g/dl). Thromboembolic complications were diagnosed in 2.8% of the patients in the control group and in 1.5% in the TA group. Asymptomatic distal deep venous thrombosis was found in 54 (14.8%) of TA group patients and 54 (30.1%) of control patients. TA administration reduced the expenditure for RBC transfusion plus the cost of TA from 148.94 to 33.87 euro per patient. CONCLUSION: Routine administration of TA during total knee arthroplasty to patients without history of thromboembolic disease is associated with a 67% reduction in RBC transfusions and, in those transfused, with a reduction in the number of units administered. TA treatment was not associated with an increase in thromboembolic complications. Transfusion costs are significantly reduced.

[Perioperative colloid administration: a survey of Spanish anesthesiologists' attitudes]. / Utilización perioperatoria de coloides por los anestesiólogos españioles: encuesta de opinión.

OBJECTIVES: To determine the availability of intravascular fluid volume replacement solutions in Spanish hospitals, to survey the extent of use of colloids by anesthesiologists, to ascertain the possible adverse effects they seek to prevent when using each solution, and to assess their level of knowledge about the subject. MATERIAL AND METHODS: A questionnaire was administered over a period of 6 months (July 2004-January 2005). The questionnaire was available online at www.encuestacoloides.com. The address was distributed by e-mail to anesthesiologists of all the Spanish autonomous communities and published in the Revista Española de Anestesiología y Reanimación. RESULTS: One hundred forty-two anesthesiologists responded. Crystalloids and colloids were widely available in most hospitals. Hydroxyethyl starch (HES) solutions were the colloids most often used (73%), followed by gelatins (28%). Dextran solutions, on the other hand, were no longer being used. The reasons the respondents gave for using these solutions were related to the time they remained in the vascular system, their greater effect of volume expansion, and the preservation of hemostasis. The most-feared complication was anaphylactic reaction to gelatins and there were concerns about the dose limit for infusion of HES solutions and about hemodynamic instability caused by dextran solutions. Fifty-four percent felt that scientific meetings provide little information about colloids and volume replacement. CONCLUSIONS: There is widespread use of colloids other than dextran along with crystalloids for plasma volume replacement. Spanish anesthesiologists are clear about important concepts related to colloid use. However, a high percentage have doubts about certain fundamental issues. Continuing professional development opportunities related to intravascular fluid replacement therapy should be increased.

Cost-effectiveness of post-operative cell salvage in total knee arthroplasty. Should we continue to recommend its use today? / Análisis de coste-eficacia del recuperador postoperatorio de sangre de drenajes en cirugía protésica primaria de rodilla. ¿Debemos seguir recomendando su empleo en la actualidad?

OBJECTIVES: Total knee arthroplasty (TKA) has a high transfusion rate. In our protocol, the use of postoperative cell salvage is indicated in patients with contraindications to tranexamic acid (TA). An analysis was performed on the effect of post-operative cell salvage (POCS) regarding transfusion rate and costs in patients undergoing TKA. MATERIAL AND METHODS: A prospective analysis was conducted on 518 patients, of whom 434 received TA, and 84 were contraindicated. The red cell mass, blood volume, and the percentage of lost blood volume were calculated. Incidents associated with the use of post-operative re-perfusion of drained blood and the rate of transfusion were recorded. An analysis was performed on the costs associated with allogeneic transfusion prevention methods. RESULTS: A POCS drain was not inserted in 10 out of the 84 patients not candidates for TA. In the 74 in which it was placed, 158±72ml of red cell mass was reinfused. The allogeneic transfusion rate was 36%, and was 52% in those with no drain inserted. Relative risk of transfusion using POCS was 0.69 (0.41 to 1.16) with an absolute risk reduction of 16% (-8 to 40%). The number needed to treat to avoid allogeneic transfusion was 7. The direct costs to avoid allogeneic transfusion were €1,610. No complications associated with blood re-infusion were observed. CONCLUSIONS: The use of POCS would be required in 7 patients after TKA to avoid one allogeneic transfusion with a cost over 10 times that of a transfusion of red cell concentrates.

Clinical practice guide for the choice of perioperative volume-restoring fluid in adult patients undergoing non-cardiac surgery.

The present Clinical practice guide responds to the clinical questions about security in the choice of fluid (crystalloid, colloid or hydroxyethyl starch 130) in patients who require volume replacement during perioperative period of non-cardiac surgeries. From the evidence summary, recommendations were made following the GRADE methodology. In this population fluid therapy based on crystalloids is suggested (weak recommendation, low quality evidence). In the events where volume replacement is not reached with crystalloids, the use of synthetic colloids (hydroxyethyl starch 130 or modified fluid gelatin) is suggested instead of 5% albumin (weak recommendation, low quality evidence). The choice and dosage of the colloid should be based in the product characteristics, patient comorbidity and anesthesiologist's experience.

Optimizing preoperative haemoglobin in major orthopaedic surgery using intravenous iron with or without erythropoietin. An epidemiologic study.

AIM: To evaluate the effectiveness of intravenous iron treatment, with or without associated erythropoietin (rHuEPO), measured as haemoglobin (Hb) increase. The relationships between the Hb increase and parameters used to evaluate anaemia were analysed. MATERIAL AND METHOD: Retrospective observational study carried out in two third-level hospitals between January 2005 and December 2009. The study included patients with iron deficiency anaemia scheduled for elective orthopaedic surgery and treated with intravenous iron sucrose alone or associated with rHuEPO. Treatment efficacy was analysed based on the Hb increase from baseline to just before surgery. RESULTS: A total of 412 patients who received a median of 800mg of iron sucrose were included; 125 of them (30.4%) additionally received 2.4 vials of rHuEPO. The Hb increase was 0.8 (1.1) g/dL in patients treated with intravenous iron and 1.5 (1.3) g/dL in those additionally given rHuEPO(P<.01). The percentage of hypochromic red blood cells (r=0.52) and soluble transferrin receptor (r=0.59) value were significantly correlated to the Hb increase in patients receiving iron. CONCLUSIONS: In patients with iron deficiency anaemia, the effectiveness of iron sucrose treatment to optimize Hb before surgery was moderate; adjuvant administration of erythropoietin improved the results. Determination of functional iron status parameters may improve the treatment effectiveness.

[Changes in oxygen saturation in the jugular bulb during cardiac surgery]. / Cambios de la saturación de oxígeno en el bulbo de la yugular durante la cirugía cardíaca.

OBJECTIVE: Heart surgery with cardiopulmonary bypass (CPB) leads to changes in supply and consumption of cerebral oxygen (DO2 and VO2C). Monitoring jugular bulb oxygen saturation (SjO2) detects changes in the DO2C/VO2C ratio that occur in patients undergoing heart surgery. The objective of this study was to determine the evolution of SjO2, of the arteriovenous difference of cerebral oxygen and of cerebral oxygen extraction, as well as the possible relation between those variables and changes in mean arterial pressure, hemoglobin counts and temperature in patients undergoing heart surgery with CPB. PATIENTS AND METHOD: A prospective study carried out in 31 patients who underwent coronary valve surgery. To monitor SjO2, each patient's internal jugular vein was cannulated with an oximetric catheter in a retrograde direction to monitor SjO2. RESULTS: Baseline SjO2 (68 +/- 7.4%), obtained after anesthetic induction, was similar to SjO2 before (65 +/- 6%) and after (67 +/- 8.2%) CPB. However, SjO2 upon starting CPB (60 +/- 8.6%) and during rewarming (63 +/- 3%) were significantly lower than at baseline. SjO2 was significantly higher during hypothermic bypass (78 +/- 5%) than at baseline. SjO2 ranged from a low of 60 +/- 8% as CPB was initiated to a high of 78 +/- 5% during hypothermic CPB. Mean arterial pressure was significantly lower at the start of bypass (44 +/- 6 mmHg) than anesthetic induction (83.5 +/- 13.1 mmHg) and the decrease correlated with a significant decrease in SjO2. Changes in mean arterial pressure were unrelated to significant changes in SjO2 at other moments, however. Nor was there a significant relation between changes in temperature or hemoglobin and the evolution of SjO2. At least one episode of SjO2 desaturation (= 50%) occurred in 29% of the patients, with the lowest values being recorded at the start of CPB and during rewarming. CONCLUSIONS: The greatest risk of cerebral oxygen imbalance between supply and demand occurs at the start of CPB and during rewarming, as shown by decreases in SjO2 levels below baseline at those times.

[Learning cardiopulmonary resuscitation using conventional external cardiac massage or active compression-decompression in simulated cardiopulmonary resuscitation]. / Aprendizaje de la reanimación cardíaca mediante masaje cardíaco externo convencional o compresión-descompresión activa en reanimación cardiopulmonar simulada.

OBJECTIVE: To compare medical students' simulated learning of two different techniques of cardiopulmonary resuscitation (CPR). One was conventional external cardiac massage (ECM) and the other was active compression-decompression (ACD-CPR). MATERIAL AND METHODS: The study group (group S) comprised 111 students enrolled in their fourth year of medical studies who had no prior experience of CPR. Group R, the control group, was made up of 32 medical residents in anesthesiology and post-anesthetic intensive care. Before the study, group S received 5 hours of theoretical classes on CPR and both groups saw a video explaining each technique just before performing the test. All subjects applied each method to an adult dummy for one minute. The variables evaluated were frequency of complete and effective thoracic compressions and the body weight of the resuscitator. RESULTS: Each group performed similarly using the two techniques in terms of frequency of total compressions achieved. For each technique, the number of effective compressions achieved by group S (49.4 +/- 22.9 with ECM and 42.5 +/- 20.7 with ACD-CPR) was significantly lower (p < 0.05) than the number attained by group R (71.2 +/- 18.6 with ECM and 58.8 +/- 12 with ACD-CPR). Group R's frequency of effective compressions was significantly higher (p < 0.05) with CPR than with ACD-CPR. Body weight had no influence on the number of total compressions or efficacy in group R, whereas lower body weight in group S was significantly related to lower frequency of effective compressions with ECM p < 0.05). Neither group achieved a frequency of 80 total compressions in one minute. CONCLUSIONS: With the present teaching method, the medical students' performance was poor for both types of CPR and was affected by body weight. The residents' performance was less effective with ACD-CPR, a technique that was new to them, than with conventional ECM, with which they were expert and on which body weight had no impact.