Lung ultrasound as a screening tool for SARS-CoV-2 infection in surgical patients.

PURPOSE: To evaluate the diagnostic performance of lung ultrasound (LUS) in screening for SARS-CoV-2 infection in patients requiring surgery. METHODS: Patients underwent a LUS protocol that included a scoring system for screening COVID-19 pneumonia as well as RT-PCR test for SARS-CoV-2. The receiver operator characteristic (ROC) curve was determined for the relationship between LUS score and PCR test results for COVID-19. The optimal threshold for the best discrimination between non-COVID-19 patients and COVID-19 patients was calculated. RESULTS: Among 203 patients enrolled (mean age 48 years; 82 males), 8.3% were COVID-19-positive; 4.9% were diagnosed via the initial RT-PCR test. Of the patients diagnosed with SARS-CoV-2, 64.7% required in-hospital management and 17.6% died. The most common ultrasound findings were B lines (19.7%) and a thickened pleura (19.2%). The AUC of the ROC curve of the relationship of LUS score with a cutoff value >8 versus RT-PCR test for the assessment of SARS-CoV-2 pneumonia was 0.75 (95% CI 0.61-0.89; sensitivity 52.9%; specificity 91%; LR (+) 6.15, LR (-) 0.51). CONCLUSION: The LUS score in surgical patients is not a useful tool for screening patients with potential COVID-19 infection. LUS score shows a high specificity with a cut-off value of 8.

Effect of High-Flow Oxygen Therapy vs Conventional Oxygen Therapy on Invasive Mechanical Ventilation and Clinical Recovery in Patients With Severe COVID-19: A Randomized Clinical Trial.

IMPORTANCE: The effect of high-flow oxygen therapy vs conventional oxygen therapy has not been established in the setting of severe COVID-19. OBJECTIVE: To determine the effect of high-flow oxygen therapy through a nasal cannula compared with conventional oxygen therapy on need for endotracheal intubation and clinical recovery in severe COVID-19. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label clinical trial conducted in emergency and intensive care units in 3 hospitals in Colombia. A total of 220 adults with respiratory distress and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen of less than 200 due to COVID-19 were randomized from August 2020 to January 2021, with last follow-up on February 10, 2021. INTERVENTIONS: Patients were randomly assigned to receive high-flow oxygen through a nasal cannula (n = 109) or conventional oxygen therapy (n = 111). MAIN OUTCOMES AND MEASURES: The co-primary outcomes were need for intubation and time to clinical recovery until day 28 as assessed by a 7-category ordinal scale (range, 1-7, with higher scores indicating a worse condition). Effects of treatments were calculated with a Cox proportional hazards model adjusted for hypoxemia severity, age, and comorbidities. RESULTS: Among 220 randomized patients, 199 were included in the analysis (median age, 60 years; n = 65 women [32.7%]). Intubation occurred in 34 (34.3%) randomized to high-flow oxygen therapy and in 51 (51.0%) randomized to conventional oxygen therapy (hazard ratio, 0.62; 95% CI, 0.39-0.96; P = .03). The median time to clinical recovery within 28 days was 11 (IQR, 9-14) days in patients randomized to high-flow oxygen therapy vs 14 (IQR, 11-19) days in those randomized to conventional oxygen therapy (hazard ratio, 1.39; 95% CI, 1.00-1.92; P = .047). Suspected bacterial pneumonia occurred in 13 patients (13.1%) randomized to high-flow oxygen and in 17 (17.0%) of those randomized to conventional oxygen therapy, while bacteremia was detected in 7 (7.1%) vs 11 (11.0%), respectively. CONCLUSIONS AND RELEVANCE: Among patients with severe COVID-19, use of high-flow oxygen through a nasal cannula significantly decreased need for mechanical ventilation support and time to clinical recovery compared with conventional low-flow oxygen therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04609462.

Persistently high venous-to-arterial carbon dioxide differences during early resuscitation are associated with poor outcomes in septic shock.

INTRODUCTION: Venous-to-arterial carbon dioxide difference (Pv-aCO2) may reflect the adequacy of blood flow during shock states. We sought to test whether the development of Pv-aCO2 during the very early phases of resuscitation is related to multi-organ dysfunction and outcomes in a population of septic shock patients resuscitated targeting the usual oxygen-derived and hemodynamic parameters. METHODS: We conducted a prospective observational study in a 60-bed mixed ICU in a University affiliated Hospital. 85 patients with a new septic shock episode were included. A Pv-aCO2 value ≥ 6 mmHg was considered to be high. Patients were classified in four predefined groups according to the Pv-aCO2 evolution during the first 6 hours of resuscitation: (1) persistently high Pv-aCO2 (high at T0 and T6); (2) increasing Pv-aCO2 (normal at T0, high at T6); (3) decreasing Pv-aCO2 (high at T0, normal at T6); and (4) persistently normal Pv-aCO2 (normal at T0 and T6). Multiorgan dysfunction at day-3 was compared for predefined groups and a Kaplan Meier curve was constructed to show the survival probabilities at day-28 using a log-rank test to evaluate differences between groups. A Spearman-Rho was used to test the agreement between cardiac output and Pv-aCO2. Finally, we calculated the mortality risk ratios at day-28 among patients attaining normal oxygen parameters but with a concomitantly increased Pv-aCO2. RESULTS: Patients with persistently high and increasing Pv-aCO2 at T6 had significant higher SOFA scores at day-3 (p < 0.001) and higher mortality rates at day-28 (log rank test: 19.21, p < 0.001) compared with patients who evolved with normal Pv-aCO2 at T6. Interestingly, a poor agreement between cardiac output and Pv-aCO2 was observed (r2 = 0.025, p < 0.01) at different points of resuscitation. Patients who reached a central venous saturation (ScvO)2 ≥ 70% or mixed venous oxygen saturation (SvO2) ≥ 65% but with concomitantly high Pv-aCO2 at different developmental points (i.e., T0, T6 and T12) had a significant mortality risk ratio at day-28. CONCLUSION: The persistence of high Pv-aCO2 during the early resuscitation of septic shock was associated with more severe multi-organ dysfunction and worse outcomes at day-28. Although mechanisms conducting to increase Pv-aCO2 during septic shock are insufficiently understood, Pv-aCO2 could identify a high risk of death in apparently resuscitated patients.

Rapid Intubation Sequence: 4-Year Experience in an Emergency Department.

BACKGROUND: The rapid intubation sequence is advanced airway management that effectively ensures an adequate supply of oxygen in critically ill patients. The medical personnel in the emergency department performed this procedure. OBJECTIVE: To describe the main characteristics of the rapid intubation sequence in an emergency department of a high complexity hospital. METHODS: This is a descriptive, cross-sectional, retrospective study. We included all older patients with a rapid intubation sequence requirement in the emergency department from 2014 to 2017. We used central tendency measures for numerical variables and proportions for categorical variables. RESULTS: A total of 401 patients were eligible for this analysis. The main indication for intubation was the Glasgow Coma Scale = <8 in 170 patients (42.4%), followed by hypoxemia in 142 patients (35.4%). In 36 patients, at least one complication occurred. RSI was performed in 54.4% by emergency physician. RSI was successful on the first attempt in 90.5%. Only 36 patients (9%) presented complications. CONCLUSION: In this study, we found that the rapid intubation sequence was not related to a high proportion of complications. Perhaps, this is attributed to the degree of medical training and the use of emergency department protocols in our hospital.

Impact of red blood cell transfusion on oxygen transport and metabolism in patients with sepsis and septic shock: a systematic review and meta-analysis. / Impacto da transfusão de eritrócitos no transporte e no metabolismo de oxigênio em pacientes com sepse e choque séptico: uma revisão sistemática e metanálise.

Red blood cell transfusion is thought to improve cell respiration during septic shock. Nevertheless, its acute impact on oxygen transport and metabolism in this condition remains highly debatable. The objective of this study was to evaluate the impact of red blood cell transfusion on microcirculation and oxygen metabolism in patients with sepsis and septic shock. We conducted a search in the MEDLINE®, Elsevier and Scopus databases. We included studies conducted in adult humans with sepsis and septic shock. A systematic review and meta-analysis were performed using the DerSimonian and Laird random-effects model. A p value < 0.05 was considered significant. Nineteen manuscripts with 428 patients were included in the analysis. Red blood cell transfusions were associated with an increase in the pooled mean venous oxygen saturation of 3.7% (p < 0.001), a decrease in oxygen extraction ratio of -6.98 (p < 0.001) and had no significant effect on the cardiac index (0.02L/minute; p = 0,96). Similar results were obtained in studies including simultaneous measurements of venous oxygen saturation, oxygen extraction ratio, and cardiac index. Red blood cell transfusions led to a significant increase in the proportion of perfused small vessels (2.85%; p = 0.553), while tissue oxygenation parameters revealed a significant increase in the tissue hemoglobin index (1.66; p = 0.018). Individual studies reported significant improvements in tissue oxygenation and sublingual microcirculatory parameters in patients with deranged microcirculation at baseline. Red blood cell transfusions seemed to improve systemic oxygen metabolism with apparent independence from cardiac index variations. Some beneficial effects have been observed for tissue oxygenation and microcirculation parameters, particularly in patients with more severe alterations at baseline. More studies are necessary to evaluate their clinical impact and to individualize transfusion decisions.

Considera-se que a transfusão de eritrócitos melhora a respiração celular durante o choque séptico. Contudo, seu impacto agudo no transporte e no metabolismo de oxigênio nessa condição ainda é amplamente debatido. O objetivo deste estudo foi avaliar o impacto da transfusão de eritrócitos na microcirculação e no metabolismo do oxigênio em pacientes com sepse e choque séptico. Conduzimos um levantamento nas bases de dados MEDLINE®, Elsevier e Scopus. Incluímos estudos realizados com seres humanos adultos com sepse e choque séptico. Realizamos uma revisão sistemática e metanálise com utilização do modelo de efeitos aleatórios de DerSimonian e Laird. Consideramos significante valor de p < 0,05. Incluíram-se na análise 19 manuscritos, correspondentes a 428 pacientes. As transfusões de eritrócitos se associaram com aumento de 3,7% na média combinada de saturação venosa mista de oxigênio (p < 0,001), diminuição de razão de extração de oxigênio de -6,98 (p < 0,001) e nenhum efeito significante no índice cardíaco (0,02 L/minuto; p = 0,96). Obtiveram-se resultados similares em estudos que incluíram mensurações simultâneas de saturação venosa mista de oxigênio, razão de extração de oxigênio e índice cardíaco. As transfusões de eritrócitos levaram a aumento significante na proporção de pequenos vasos perfundidos (2,85%; p = 0,553), enquanto os parâmetros de oxigenação tissular revelaram aumento significante no índice de hemoglobina tissular (1,66; p = 0,018). Estudos individuais relataram melhoras significantes na oxigenação tissular e nos parâmetros microcirculatórios sublinguais em pacientes com microcirculação alterada na avaliação inicial. A transfusão de eritrócitos pareceu melhorar o metabolismo sistêmico de oxigênio com aparente independência de variações no débito cardíaco. Observaram-se alguns efeitos benéficos para a oxigenação tissular e parâmetros microcirculatórios, em particular em pacientes com alterações iniciais mais graves. São necessários mais estudos para avaliar seu impacto clínico e individualizar as decisões relativas à transfusão.

Recommendations of the Colombian Consensus Committee for the Management of Traumatic Brain Injury in Prehospital, Emergency Department, Surgery, and Intensive Care (Beyond One Option for Treatment of Traumatic Brain Injury: A Stratified Protocol [BOOTStraP]).

Background Traumatic brain injury (TBI) is a global public health problem. In Colombia, it is estimated that 70% of deaths from violence and 90% of deaths from road traffic accidents are TBI related. In the year 2014, the Ministry of Health of Colombia funded the development of a clinical practice guideline (CPG) for the diagnosis and treatment of adult patients with severe TBI. A critical barrier to the widespread implementation was identified-that is, the lack of a specific protocol that spans various levels of resources and complexity across the four treatment phases. The objective of this article is to present the process and recommendations for the management of patients with TBI in various resource environments, across the treatment phases of prehospital care, emergency department (ED), surgery, and intensive care unit. Methods Using the Delphi methodology, a consensus of 20 experts in emergency medicine, neurosurgery, prehospital care, and intensive care nationwide developed recommendations based on 13 questions for the management of patients with TBI in Colombia. Discussion It is estimated that 80% of the global population live in developing economies where access to resources required for optimum treatment is limited. There is limitation for applications of CPGs recommendations in areas where there is low availability or absence of resources for integral care. Development of mixed methods consensus, including evidence review and expertise points of good clinical practices can fill gaps in application of CPGs. BOOTStraP (Beyond One Option for Treatment of Traumatic Brain Injury: A Stratified Protocol) is intended to be a practical handbook for care providers to use to treat TBI patients with whatever resources are available. Results Stratification of recommendations for interventions according to the availability of the resources on different stages of integral care is a proposed method for filling gaps in actual evidence, to organize a better strategy for interventions in different real-life scenarios. We develop 10 algorithms of management for building TBI protocols based on expert consensus to articulate treatment options in prehospital care, EDs, neurological surgery, and intensive care, independent of the level of availability of resources for care.

Impacto da transfusão de eritrócitos no transporte e no metabolismo de oxigênio em pacientes com sepse e choque séptico: uma revisão sistemática e metanálise / Impact of red blood cell transfusion on oxygen transport and metabolism in patients with sepsis and septic shock: a systematic review and meta-analysis

RESUMO Considera-se que a transfusão de eritrócitos melhora a respiração celular durante o choque séptico. Contudo, seu impacto agudo no transporte e no metabolismo de oxigênio nessa condição ainda é amplamente debatido. O objetivo deste estudo foi avaliar o impacto da transfusão de eritrócitos na microcirculação e no metabolismo do oxigênio em pacientes com sepse e choque séptico. Conduzimos um levantamento nas bases de dados MEDLINE®, Elsevier e Scopus. Incluímos estudos realizados com seres humanos adultos com sepse e choque séptico. Realizamos uma revisão sistemática e metanálise com utilização do modelo de efeitos aleatórios de DerSimonian e Laird. Consideramos significante valor de p < 0,05. Incluíram-se na análise 19 manuscritos, correspondentes a 428 pacientes. As transfusões de eritrócitos se associaram com aumento de 3,7% na média combinada de saturação venosa mista de oxigênio (p < 0,001), diminuição de razão de extração de oxigênio de -6,98 (p < 0,001) e nenhum efeito significante no índice cardíaco (0,02 L/minuto; p = 0,96). Obtiveram-se resultados similares em estudos que incluíram mensurações simultâneas de saturação venosa mista de oxigênio, razão de extração de oxigênio e índice cardíaco. As transfusões de eritrócitos levaram a aumento significante na proporção de pequenos vasos perfundidos (2,85%; p = 0,553), enquanto os parâmetros de oxigenação tissular revelaram aumento significante no índice de hemoglobina tissular (1,66; p = 0,018). Estudos individuais relataram melhoras significantes na oxigenação tissular e nos parâmetros microcirculatórios sublinguais em pacientes com microcirculação alterada na avaliação inicial. A transfusão de eritrócitos pareceu melhorar o metabolismo sistêmico de oxigênio com aparente independência de variações no débito cardíaco. Observaram-se alguns efeitos benéficos para a oxigenação tissular e parâmetros microcirculatórios, em particular em pacientes com alterações iniciais mais graves. São necessários mais estudos para avaliar seu impacto clínico e individualizar as decisões relativas à transfusão.

ABSTRACT Red blood cell transfusion is thought to improve cell respiration during septic shock. Nevertheless, its acute impact on oxygen transport and metabolism in this condition remains highly debatable. The objective of this study was to evaluate the impact of red blood cell transfusion on microcirculation and oxygen metabolism in patients with sepsis and septic shock. We conducted a search in the MEDLINE®, Elsevier and Scopus databases. We included studies conducted in adult humans with sepsis and septic shock. A systematic review and meta-analysis were performed using the DerSimonian and Laird random-effects model. A p value < 0.05 was considered significant. Nineteen manuscripts with 428 patients were included in the analysis. Red blood cell transfusions were associated with an increase in the pooled mean venous oxygen saturation of 3.7% (p < 0.001), a decrease in oxygen extraction ratio of -6.98 (p < 0.001) and had no significant effect on the cardiac index (0.02L/minute; p = 0,96). Similar results were obtained in studies including simultaneous measurements of venous oxygen saturation, oxygen extraction ratio, and cardiac index. Red blood cell transfusions led to a significant increase in the proportion of perfused small vessels (2.85%; p = 0.553), while tissue oxygenation parameters revealed a significant increase in the tissue hemoglobin index (1.66; p = 0.018). Individual studies reported significant improvements in tissue oxygenation and sublingual microcirculatory parameters in patients with deranged microcirculation at baseline. Red blood cell transfusions seemed to improve systemic oxygen metabolism with apparent independence from cardiac index variations. Some beneficial effects have been observed for tissue oxygenation and microcirculation parameters, particularly in patients with more severe alterations at baseline. More studies are necessary to evaluate their clinical impact and to individualize transfusion decisions.

Can venous-to-arterial carbon dioxide differences reflect microcirculatory alterations in patients with septic shock?

PURPOSE: Septic shock has been associated with microvascular alterations and these in turn with the development of organ dysfunction. Despite advances in video microscopic techniques, evaluation of microcirculation at the bedside is still limited. Venous-to-arterial carbon dioxide difference (Pv-aCO2) may be increased even when venous O2 saturation (SvO2) and cardiac output look normal, which could suggests microvascular derangements. We sought to evaluate whether Pv-aCO2 can reflect the adequacy of microvascular perfusion during the early stages of resuscitation of septic shock. METHODS: Prospective observational study including 75 patients with septic shock in a 60-bed mixed ICU. Arterial and mixed-venous blood gases and hemodynamic variables were obtained at catheter insertion (T0) and 6 h after (T6). Using a sidestream dark-field device, we simultaneously acquired sublingual microcirculatory images for blinded semiquantitative analysis. Pv-aCO2 was defined as the difference between mixed-venous and arterial CO2 partial pressures. RESULTS: Progressively lower percentages of small perfused vessels (PPV), lower functional capillary density, and higher heterogeneity of microvascular blood flow were observed at higher Pv-aCO2 values at both T0 and T6. Pv-aCO2 was significantly correlated to PPV (T0: coefficient -5.35, 95 % CI -6.41 to -4.29, p < 0.001; T6: coefficient, -3.49, 95 % CI -4.43 to -2.55, p < 0.001) and changes in Pv-aCO2 between T0 and T6 were significantly related to changes in PPV (R (2) = 0.42, p < 0.001). Absolute values and changes in Pv-aCO2 were not related to global hemodynamic variables. Good agreement between venous-to-arterial CO2 and PPV was maintained even after corrections for the Haldane effect. CONCLUSIONS: During early phases of resuscitation of septic shock, Pv-aCO2 could reflect the adequacy of microvascular blood flow.

Variations in the anatomical relationship between the common carotid artery and the internal jugular vein: an ultrasonographic study.

INTRODUCTION: The internal jugular vein locates anterior or anterolateral to the common carotid artery in two-thirds of the subjects studied by ultrasound when the head is in a rotated position. AIM: To identify variables associated with the anterior location of the internal jugular vein. METHODS: Ultrasound examinations were performed with the patients in the supine position, with the head rotated to the opposite side. The proximal third of the neck was visualized transversely with a 7.5-mHz transducer. The relationship between the vessels was described in accordance with the proportion of the artery overlapped by the vein. Univariate comparisons and a multivariate analysis of potential variables that may affect the anatomic relationships were performed. RESULTS: Seventy-eight patients were included, 44 of whom were men. The patients' ages ranged from 17 to 90 years (median 64.0, interquartile range 41-73). The right and left sides were studied 75 and 73 times, respectively. The vein was located lateral to the artery in 24.3% (95%CI= 17.4-32.2) of the studies, anterolateral in 33.8% (95%CI= 26.2-41.4) and anterior in 41.9% (95%CI= 33.9-49.8). The multivariate analysis identified age group (OR= 3.7, 95% CI 2.1-6.4) and, less significantly, the left side (OR= 1.7, 95%CI= 0.8-3.5) and male gender (OR= 1.2, 95%CI= 0.6-2.7) as variables associated with the anterior position of the vein. CONCLUSIÓN: The anterior position of the internal jugular vein relative to the common carotid artery increases gradually with age. Additionally, left-sided localization and male sex further increased the probability of an anterior position.

INTRODUCCIÓN: La vena yugular interna es anterior o anterolateral a la arteria carótida común en las dos terceras partes de los sujetos estudiados sonográficamente, con la cabeza rotada. OBJETIVO: Se examinó la asociación de diferentes variables con la ubicación anterior de la vena. MÉTODOS: Las ecografías se realizaron en posición supino, con la cabeza rotada hacia el lado contrario al examinado. Se visualizó transversalmente el tercio proximal del cuello, con un transductor de 7.5 mHz. La relación entre los vasos se describió de acuerdo con la proporción de la arteria cubierta por la vena. Se hicieron comparaciones univariadas con la prueba Chi2 de Pearson y un análisis multivariado de las variables candidatas a afectar las relaciones anatómicas estudiadas. RESULTADOS: Se incluyeron 78 individuos, 44 hombres, con edad entre 17-90 años (mediana 64.0, rango= 41-73 años). Se estudió el lado derecho en 75 ocasiones y el izquierdo en 73. La vena se localizó lateral en el 24.3% (IC95% 17.4-32.2) de los vasos estudiados, anterolateral en el 33.8% (IC95%= 26.2-41.4) y anterior en el 41.9% (IC95%= 33.9-49.8). El análisis multivariado identificó: el grupo etáreo (OR= 3.7, IC95%= 2.1-6.4) y sugiere el lado izquierdo (OR= 1.7, IC95%= 0.8-3.5) y el género masculino (OR= 1.2, IC95%= 0.6-2.7), como variables asociadas con la posición anterior de la vena. CONCLUSION: La ubicación anterior de la vena yugular interna respecto a la arteria carótida común aumenta gradualmente con la edad. La localización izquierda y el género masculino pueden aumentar adicionalmente esta probabilidad.

Combination of arterial lactate levels and venous-arterial CO2 to arterial-venous O 2 content difference ratio as markers of resuscitation in patients with septic shock.

PURPOSE: To evaluate the prognostic value of the Cv-aCO2/Da-vO2 ratio combined with lactate levels during the early phases of resuscitation in septic shock. METHODS: Prospective observational study in a 60-bed mixed ICU. One hundred and thirty-five patients with septic shock were included. The resuscitation protocol targeted mean arterial pressure, pulse pressure variations or central venous pressure, mixed venous oxygen saturation, and lactate levels. Patients were classified into four groups according to lactate levels and Cv-aCO2/Da-vO2 ratio at 6 h of resuscitation (T6): group 1, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; group 2, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0; group 3, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; and group 4, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0. RESULTS: Combination of hyperlactatemia and high Cv-aCO2/Da-vO2 ratio was associated with the worst SOFA scores and lower survival rates at day 28 [log rank (Mantel-Cox) = 31.39, p < 0.0001]. Normalization of both variables was associated with the best outcomes. Patients with a high Cv-aCO2/Da-vO2 ratio and lactate <2.0 mmol/L had similar outcomes to hyperlactatemic patients with low Cv-aCO2/Da-vO2 ratio. The multivariate analysis revealed that Cv-aCO2/Da-vO2 ratio at both T0 (RR 3.85; 95 % CI 1.60-9.27) and T6 (RR 3.97; 95 % CI 1.54-10.24) was an independent predictor for mortality at day 28, as well as lactate levels at T6 (RR 1.58; 95 % CI 1.13-2.22). CONCLUSION: Complementing lactate assessment with Cv-aCO2/Da-vO2 ratio during early stages of resuscitation of septic shock can better identify patients at high risk of adverse outcomes. The Cv-aCO2/Da-vO2 ratio may become a potential resuscitation goal in patients with septic shock.

Variations in the anatomical relationship between the common carotid artery and the internal jugular vein:: An ultrasonographic study / Variaciones de la relación anatómica de la arteria carótida común y la vena yugular interna:: Estudio ecográfico

Introduction: The internal jugular vein locates anterior or anterolateral to the common carotid artery in two-thirds of the subjects studied by ultrasound when the head is in a rotated position. Aim:To identify variables associated with the anterior location of the internal jugular vein. Methods: Ultrasound examinations were performed with the patients in the supine position, with the head rotated to the opposite side. The proximal third of the neck was visualized transversely with a 7.5-mHz transducer. The relationship between the vessels was described in accordance with the proportion of the artery overlapped by the vein. Univariate comparisons and a multivariate analysis of potential variables that may affect the anatomic relationships were performed. Results: Seventy-eight patients were included, 44 of whom were men. The patients' ages ranged from 17 to 90 years (median= 64.0, interquartile range 41-73). The right and left sides were studied 75 and 73 times, respectively. The vein was located lateral to the artery in 24.3% (95%CI= 17.4-32.2) of the studies, anterolateral in 33.8% (95%CI= 26.2-41.4) and anterior in 41.9% (95%CI 33.9-49.8). The multivariate analysis identified age group (OR= 3.7, 95%CI= 2.1-6.4) and, less significantly, the left side (OR= 1.7, 95%CI 0.8-3.5) and male gender (OR= 1.2, 95%CI= 0.6-2.7) as variables associated with the anterior position of the vein. Conclusion: The anterior position of the internal jugular vein relative to the common carotid artery increases gradually with age. Additionally, left-sided localization and male sex further increased the probability of an anterior position.

Introducción: La vena yugular interna es anterior o anterolateral a la arteria carótida común en las dos terceras partes de los sujetos estudiados sonográficamente, con la cabeza rotada. Objetivo:Se examinó la asociación de diferentes variables con la ubicación anterior de la vena. Métodos: Las ecografías se realizaron en posición supino, con la cabeza rotada hacia el lado contrario al examinado. Se visualizó transversalmente el tercio proximal del cuello, con un transductor de 7.5 mHz. La relación entre los vasos se describió de acuerdo con la proporción de la arteria cubierta por la vena. Se hicieron comparaciones univariadas con la prueba Chi2 de Pearson y un análisis multivariado de las variables candidatas a afectar las relaciones anatómicas estudiadas Resultados: Se incluyeron 78 individuos, 44 hombres, con edad entre 17-90 años (mediana 64.0, rango= 41-73 años). Se estudió el lado derecho en 75 ocasiones y el izquierdo en 73. La vena se localizó lateral en el 24.3% (IC95%= 17.4-32.2) de los vasos estudiados, anterolateral en el 33.8% (IC95%= 26.2-41.4) y anterior en el 41.9% (IC95%= 33.9-49.8). El análisis multivariado identificó: el grupo etáreo (OR= 3.7, IC95%= 2.1-6.4) y sugiere el lado izquierdo (OR= 1.7, IC95%= 0.8-3.5) y el género masculino (OR= 1.2, IC95%= 0.6-2.7), como variables asociadas con la posición anterior de la vena. Conclusión: La ubicación anterior de la vena yugular interna respecto a la arteria carótida común aumenta gradualmente con la edad. La localización izquierda y el género masculino pueden aumentar adicionalmente esta probabilidad.