Coma Prevalence in Critical Care Units in Chile: Results of a Cross-Sectional Survey on World Coma Day.

BACKGROUND: The purpose of this study was to assess the prevalence of coma among patients in critical care units in Chile. We also aimed to provide insight into the demographic characteristics, etiologies, and complications associated with coma. METHODS: A single day cross-sectional study was conducted through a national survey of public and private hospitals with critical and intensive cardiac care units across Chile. Data were collected using an online questionnaire that contained questions regarding critically ill patients' information, demographic characteristics, etiology and duration of coma, medical complications, and support requirements. RESULTS: A total of 84% of all health facilities answered, accounting for a total of 2,708 patients. The overall coma prevalence was 2.9%. The median age of the comatose patients was 61 years (interquartile range 50-72) and 66.2% were male. The median coma duration was five days (interquartile range 2-9). Cerebral hemorrhage was the most common etiology, followed by severe hypoxic-ischemic encephalopathy, acute ischemic stroke, and traumatic brain injury. A total of 48.1% of coma patients experienced acute and ongoing treatment complications, with pneumonia being the most common complication, and 97.4% required support during comatose management. CONCLUSIONS: This study provides an overview of the prevalence of coma in Chilean critical and cardiac care units. Coma is a common condition. Comatose patients frequently experience medical complications during their hospitalization.

[Septic shock originating from a pulmonary focus caused by Pasteurella multocida. Report of one case]. / Shock séptico de foco respiratorio por Pasteurella multocida en un paciente inmunocompetente. Caso Clínico.

Pasteurella multocida is a gram-negative coccobacillus bacterium found as a commensal in the oropharynx of domestic animals such as cats and dogs and some farm animals. Soft tissue infections and occasionally bacteremia in immunocompromised patients with direct contact with animals are described. We report a 61 year old male with a history of scratches and close contact with domestic cats, with a septic shock originating from a pulmonary focus, requiring mechanical ventilation and vasopressors. Blood cultures disclosed the presence of Pasteurella multocida. He responded successfully to antimicrobials.

Vitamin E Blocks Connexin Hemichannels and Prevents Deleterious Effects of Glucocorticoid Treatment on Skeletal Muscles.

Glucocorticoids are frequently used as anti-inflammatory and immunosuppressive agents. However, high doses and/or prolonged use induce undesired secondary effects such as muscular atrophy. Recently, de novo expression of connexin43 and connexin45 hemichannels (Cx43 HCs and Cx45 HCs, respectively) has been proposed to play a critical role in the mechanism underlying myofiber atrophy induced by dexamethasone (Dex: a synthetic glucocorticoid), but their involvement in specific muscle changes promoted by Dex remains poorly understood. Moreover, treatments that could prevent the undesired effects of glucocorticoids on skeletal muscles remain unknown. In the present work, a 7-day Dex treatment in adult mice was found to induce weight loss and skeletal muscle changes including expression of functional Cx43/Cx45 HCs, elevated atrogin immunoreactivity, atrophy, oxidative stress and mitochondrial dysfunction. All these undesired effects were absent in muscles of mice simultaneously treated with Dex and vitamin E (VitE). Moreover, VitE was found to rapidly inhibit the activity of Cx HCs in freshly isolated myofibers of Dex treated mice. Exposure to alkaline pH induced free radical generation only in HeLa cells expressing Cx43 or Cx45 where Ca2+ was present in the extracellular milieu, response that was prevented by VitE. Besides, VitE and two other anti-oxidant compounds, Tempol and Resveratrol, were found to inhibit Cx43 HCs in HeLa cells transfectants. Thus, we propose that in addition to their intrinsic anti-oxidant potency, some antioxidants could be used to reduce expression and/or opening of Cx HCs and consequently reduce the undesired effect of glucocorticoids on skeletal muscles.

[Continuous intra arterial nimodipine for vasospasm secondary to subarachnoid hemorrhage. Report of one case]. / Terapia continua intra-arterial selectiva con nimodipino para el tratamiento del vasoespasmo refractario en hemorragia subaracnoidea aneurismática. Caso clínico.

We report a 39-year-old male with an aneurysmal subarachnoid hemorrhage without hydrocephalus, in whom a right choroidal aneurysm was early excluded by endovascular coil insertion. Intracranial pressure (PIC) and cerebral oxygenation (PtiO2) sensors for neuromonitoring were installed due to a persistent comatose state. From the 3rd day, neuromonitoring became altered. CT angiography and cerebral angiography showed severe proximal and distal vasospasm (VE) of the middle (ACM) and anterior (ACA) right cerebral arteries. VE was treated with angioplasty and intravenous nimodipine. Forty eight hours later, despite hemodynamic maximization, neuromonitoring became altered again, mainly explained by a decrease in PtiO2 below 15 mmHg. A severe VE in ACM and right ACA was confirmed by angiography. Given the presence of an early and recurrent VE, which was associated with a decrease in cerebral oxygenation, internal carotid micro-catheters for continuous nimodipine infusion were installed. This therapy maintained a normal neuromonitoring for 15 days. During this period, attempts were done to decrease or discontinue the infusion, but the patient presented parallel falls of cerebral oxygenation or decreased cerebral perfusion observed with perfusion CT, interpreted as persistent VE. Finally, the infusion was stopped at day 15 without significant complication. We conclude that intra-arterial nimodipine continuous infusion in refractory VE can be useful and safe in selected patients. Multimodal neuromonitoring is essential.

[Acute pulmonary fibrosis associated with Paraquat poisoning. Report of one case]. / Fibrosis pulmonar aguda asociada a intoxicación por Paraquat: caso clínico.

Paraquat, a non-selective bipyridyl pesticide, is one of the leading causes of death from intoxication in many parts of Asia and America. It is the second most sold herbicide worldwide, being widely used in Chile. Its ingestion generates toxicity due to the release of superoxide radicals, mainly affecting kidneys, lungs and liver. There is no antidote available. We report a 31 years old male who ingested Paraquat for suicidal purposes. He developed an acute renal and hepatic failure and a rapidly progressive severe respiratory failure with images compatible with acute pulmonary fibrosis. No response to immunosuppressive treatment was observed. He died eight days after admission. The use of cyclophosphamide associated with glucocorticoids could lower risk of death the in these patients, although the pathophysiology of respiratory failure is still under study.

Dexamethasone-induced muscular atrophy is mediated by functional expression of connexin-based hemichannels.

Long-term treatment with high glucocorticoid doses induces skeletal muscle atrophy. However, the molecular mechanism of such atrophy remains unclear. We evaluated the possible involvement of connexin-based hemichannels (Cx HCs) in muscle atrophy induced by dexamethasone (DEX), a synthetic glucocorticoid, on control (Cx43(fl/fl)Cx45(fl/fl)) and Cx43/Cx45 expression-deficient (Cx43(fl/fl)Cx45(fl/fl):Myo-Cre) skeletal myofibers. Myofibers of Cx43(fl/fl)Cx45(fl/fl) mice treated with DEX (5h) expressed several proteins that form non-selective membrane channels (Cx39, Cx43, Cx45, Panx1, P2X7 receptor and TRPV2). After 5h DEX treatment in vivo, myofibers of Cx43(fl/fl)Cx45(fl/fl) mice showed Evans blue uptake, which was absent in myofibers of Cx43(fl/fl)Cx45(fl/fl):Myo-Cre mice. Similar results were obtained in vitro using ethidium as an HC permeability probe, and DEX-induced dye uptake in control myofibers was blocked by P2X7 receptor inhibitors. DEX also induced a significant increase in basal intracellular Ca(2+) signal and a reduction in resting membrane potential in Cx43(fl/fl)Cx45(fl/fl) myofibers, changes that were not elicited by myofibers deficient in Cx43/Cx45 expression. Moreover, treatment with DEX induced NFκB activation and increased mRNA levels of TNF-α in control but not in Cx43/Cx45 expression-deficient myofibers. Finally, a prolonged DEX treatment (7days) increased atrogin-1 and Murf-1 and reduced the cross sectional area of Cx43(fl/fl)Cx45(fl/fl) myofibers, but these parameters remained unaffected in Cx43(fl/fl)Cx45(fl/fl):Myo-Cre myofibers. Therefore, DEX-induced expression of Cx43 and Cx45 plays a critical role in early sarcolemma changes that lead to atrophy. Consequently, this side effect of chronic glucocorticoid treatment might be avoided by co-administration with a Cx HC blocker.

Leptospirosis-associated catastrophic respiratory failure supported by extracorporeal membrane oxygenation.

A previously healthy, 39-year-old obese farmer, arrived hypotensive and tachycardic, with fever, myalgia, headache, abdominal pain, diarrhea, and progressive dyspnea. Ten days before symptoms onset, he was in direct contact with mice and working in a contaminated drain. Patient laboratory showed acute kidney injury and thrombocytopenia. Chest X-ray exhibited bilateral diffuse interstitial infiltrates. First-line empirical antibiotics were started and influenza discarded. Patient evolved with severe respiratory failure, associated with hemoptysis, and rapidly severe hemodynamic compromise. Despite neuromuscular blockade and prone positioning, respiratory failure increased. Accordingly, veno-venous ECMO was initiated, with bilateral femoral extraction and jugular return. After ECMO connection, there was no significant improvement in oxygenation, and low pre-membrane saturations and low arterial PaO2 of the membrane showed that we were out of the limits of the rated flow. Thus, a second membrane oxygenator was installed in parallel. Afterward, oxygenation improved, with subsequent perfusion enhancement. Regarding etiology, due to high suspicion index, Leptospira serology was performed, coming back positive and meropenem was maintained. The patient ultimately recovered and experience excellent outcome. The clinical relevance of the case is the scared evidence of leptospirosis-associated severe respiratory failure treated with ECMO. This experience emphasizes the importance of an optimal support, which requires enough membrane surface and flow for an obese, highly hyperdynamic patient, during this reversible disease. A high index of suspicion is needed for an adequate diagnosis of leptospirosis to implement the correct treatment, particularly in the association of respiratory failure, pulmonary hemorrhage, and an epidemiological-related context.

[Metformin-associated lactic acidosis. Report of one case]. / Acidosis láctica asociada a metformina. Caso clínico.

Metformin-associated lactic acidosis is a severe and infrequent adverse event. Early diagnosis is essential to start an early treatment, which often has favorable results. We report a 56 years old non-insulin-requiring type 2 diabetic female who developed a severe metabolic acidosis associated with metformin in relation to an acute renal failure secondary to infectious diarrhea. Early treatment with bicarbonate and continuous hemofiltration allowed a quick improvement of the patient. Metformin-associated lactic acidosis has an elevated mortality (50-80%) and has a specific and effective treatment. Therefore, the condition must be born in mind.

[Acute small bowel diverticulitis in a patient with crohn’s disease]. / Diverticulitis aguda de intestino delgado en un paciente con enfermedad de Crohn: Report of one case.

Diverticular disease of the small intestine is rare, especially when it is located in the jejunum. It is generally asymptomatic, but in some patients it may have complications such as acute diverticulitis with peritonitis, gastrointestinal bleeding or obstruction. In such cases, the recommended treatment is surgery. We report a 77-year-old patient with ileal Crohn’s disease with a long-standing inflammatory phenotype, who developed acute diverticulitis of the jejunum presenting a severe septic shock and secondary multiple-organ failure. It resolved with medical treatment and prolonged antibiotic therapy.

Impairment of exogenous lactate clearance in experimental hyperdynamic septic shock is not related to total liver hypoperfusion.

INTRODUCTION: Although the prognostic value of persistent hyperlactatemia in septic shock is unequivocal, its physiological determinants are controversial. Particularly, the role of impaired hepatic clearance has been underestimated and is only considered relevant in patients with liver ischemia or cirrhosis. Our objectives were to establish whether endotoxemia impairs whole body net lactate clearance, and to explore a potential role for total liver hypoperfusion during the early phase of septic shock. METHODS: After anesthesia, 12 sheep were subjected to hemodynamic/perfusion monitoring including hepatic and portal catheterization, and a hepatic ultrasound flow probe. After stabilization (point A), sheep were alternatively assigned to lipopolysaccharide (LPS) (5 mcg/kg bolus followed by 4 mcg/kg/h) or sham for a three-hour study period. After 60 minutes of shock, animals were fluid resuscitated to normalize mean arterial pressure. Repeated series of measurements were performed immediately after fluid resuscitation (point B), and one (point C) and two hours later (point D). Monitoring included systemic and regional hemodynamics, blood gases and lactate measurements, and ex-vivo hepatic mitochondrial respiration at point D. Parallel exogenous lactate and sorbitol clearances were performed at points B and D. Both groups included an intravenous bolus followed by serial blood sampling to draw a curve using the least squares method. RESULTS: Significant hyperlactatemia was already present in LPS as compared to sham animals at point B (4.7 (3.1 to 6.7) versus 1.8 (1.5 to 3.7) mmol/L), increasing to 10.2 (7.8 to 12.3) mmol/L at point D. A significant increase in portal and hepatic lactate levels in LPS animals was also observed. No within-group difference in hepatic DO2, VO2 or O2 extraction, total hepatic blood flow (point D: 915 (773 to 1,046) versus 655 (593 to 1,175) ml/min), mitochondrial respiration, liver enzymes or sorbitol clearance was found. However, there was a highly significant decrease in lactate clearance in LPS animals (point B: 46 (30 to 180) versus 1,212 (743 to 2,116) ml/min, P < 0.01; point D: 113 (65 to 322) versus 944 (363 to 1,235) ml/min, P < 0.01). CONCLUSIONS: Endotoxemia induces an early and severe impairment in lactate clearance that is not related to total liver hypoperfusion.

[Early determinants of acute kidney injury during experimental intra-abdominal sepsis]. / Determinantes precoces en el desarrollo de injuria renal aguda durante la sepsis abdominal experimental.

BACKGROUND: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. AIM: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. MATERIAL AND METHODS: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. RESULTS: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. CONCLUSIONS: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.

Effects of changes in trunk inclination on ventilatory efficiency in ARDS patients: quasi-experimental study.

BACKGROUND: Trunk inclination from semirecumbent head-upright to supine-flat positioning reduces driving pressure and increases respiratory system compliance in patients with acute respiratory distress syndrome (ARDS). These effects are associated with an improved ventilatory ratio and reduction in the partial pressure of carbon dioxide (PaCO2). However, these physiological effects have not been completely studied, and their mechanisms have not yet been elucidated. Therefore, this study aimed to evaluate the effects of a change in trunk inclination from semirecumbent (45°) to supine-flat (10°) on physiological dead space and ventilation distribution in different lung regions. RESULTS: Twenty-two ARDS patients on pressure-controlled ventilation underwent three 60-min steps in which trunk inclination was changed from 45° (baseline) to 10° (intervention) and back to 45° (control) in the last step. Tunk inclination from a semirecumbent (45°) to a supine-flat (10°) position resulted in a higher tidal volume [371 (± 76) vs. 433 (± 84) mL (P < 0.001)] and respiratory system compliance [34 (± 10) to 41 (± 12) mL/cmH2O (P < 0.001)]. The CO2 exhaled per minute improved from 191 mL/min (± 34) to 227 mL/min (± 38) (P < 0.001). Accordingly, Bohr's dead space ratio decreased from 0.49 (± 0.07) to 0.41 (± 0.06) (p < 0.001), and PaCO2 decreased from 43 (± 5) to 36 (± 4) mmHg (p < 0.001). In addition, the impedance ratio, which divides the ventilation activity of the ventral region by the dorsal region ventilation activity in tidal images, dropped from 1.27 (0.83-1.78) to 0.86 (0.51-1.33) (p < 0.001). These results, calculated from functional EIT images, indicated further ventilation activity in the dorsal lung regions. These effects rapidly reversed once the patient was repositioned at 45°. CONCLUSIONS: A change in trunk inclination from a semirecumbent (45 degrees) to a supine-flat position (10 degrees) improved Bohr's dead space ratio and reduced PaCO2 in patients with ARDS. This effect is associated with an increase in tidal volume and respiratory system compliance, along with further favourable impedance ventilation distribution toward the dorsal lung regions. This study highlights the importance of considering trunk inclination as a modifiable determinant of physiological parameters. The angle of trunk inclination is essential information that must be reported in ARDS patients.

The holistic view on perfusion monitoring in septic shock.

PURPOSE OF REVIEW: To review recent evidence concerning the interactions between hemodynamic and perfusion parameters during septic shock resuscitation, and to propose some basic foundations for a more comprehensive perfusion assessment. RECENT FINDINGS: Several recent studies have expanded our knowledge about the physiologic determinants and limitations of currently used perfusion parameters such as central venous oxygen saturation and lactate. Macrohemodynamic, metabolic, peripheral and microcirculatory parameters tend to change in parallel in response to fluid loading during initial resuscitation. In contrast, perfusion markers are poorly correlated in patients who evolve with a persistent circulatory dysfunction. Therefore, assessment of perfusion status based solely on a single parameter can lead to inaccurate or misleading conclusions. SUMMARY: All individual perfusion parameters have extensive limitations to adequately reflect tissue perfusion during persistent sepsis-related circulatory dysfunction. A multimodal approach integrating macrohemodynamic, metabolic, peripheral and eventually microcirculatory perfusion parameters may overcome those limitations. This approach may also provide a thorough understanding on the predominant driving forces of hypoperfusion, and lead to physiologically oriented interventions.

Intestinal perforation secondary to blunt inguinal trauma in a soccer player: a case report.

BACKGROUND: Intestinal perforation caused by blunt trauma to an inguinal hernia is a very uncommon event. CASE REPORT: We present the case of a 55-year old man who suffered trauma to the inguinal area while playing soccer and later developed intense abdominal pain with no categorical signs of peritoneal irritation. Computed tomography scan at arrival showed a right inguinal hernia, with partial protrusion of the ileum, inflammatory changes of the mesenteric fat tissue inside the hernial sac, and free intraperitoneal fluid. Several hours later he developed hypotension and fever. An emergency laparotomy was performed, revealing ileum perforation with peritonitis. Intestinal perforation was repaired without intestinal resection. After surgery, the patient developed severe septic shock with multiple organ failure. He recovered without sequelae and was discharged 3 weeks later. CONCLUSION: This case emphasizes the potential clinical complications associated with this condition.

[Pharmacokinetic considerations in critically ill patients]. / Consideraciones farmacocinéticas en el paciente crítico.

Critically ill patients in Intensive Care Units (ICUs) are exposed to multiple procedures and usually require complex treatment regimens. Many of them suffer from comorbidities and different complications such as organ failure, drug-drug interactions, and unusual therapeutic interventions that can produce significant pathophysiologic changes. For that reason, pharmacokinetics for several substances is different to what is described for healthy patients, complicating drug selection and drug dosage to achieve appropriate effects. Low doses may determine a reduction of drug effectiveness and overdoses leading to toxicity. The aim of this paper is to review the pharmacokinetic considerations that must be considered when treating acute ICU patients.

[Mini bronchoalveolar lavage in patients with severe respiratory failure]. / Resultados preliminares y factibilidad del mini lavado bronco-alveolar en pacientes cursando falla respiratoria severa.

BACKGROUND: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronchoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). AIM: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. MATERIAL AND METHODS: Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distress syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. RESULTS: At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty five percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no significant differences between hemodynamic and respiratory variables before and after the procedure. CONCLUSIONS: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.

[Evaluation of competencies for tracheal intubation among medical students]. / Evaluación de competencias de intubación traqueal mediante un escenario simulado en internos de medicina.

BACKGROUND: Chilean medical schools curricula are focused on the acquisition of competencies. Tracheal intubation is considered a terminal competence. AIM: To evaluate the competencies related to airway management including tracheal intubation in undergraduate medical students. MATERIAL AND METHODS: Prospective observational study. Thirty medical students in the sixth year of a seven years undergraduate program (25.2% of the cohort) were randomly chosen and invited to participate in a simulated environment of elective tracheal intubation using a manikin. The students were assessed according to a checklist validated with the Delphi technique and a written self-assessment questionnaire. RESULTS: Seventeen students (57%) accepted to participate, corresponding to 14.3% of the cohort. Tracheal intubation was achieved by 64%, with 60 seconds as the mean time of apnea. Less than half of the students checked the instruments, performed pre-oxygenation or evaluated the airway. Eighty-seven percent of the students said that the current curriculum offers them minimal competencies for airway management in a real clinical situation and all prefer simulated scenarios for the acquisition of clinical skills. CONCLUSIONS: The methodology currently used to teach tracheal intubation is not assuring the acquisition of the competencies to the students in this curriculum stage. More effective teaching methods are required, and the use of simulated scenarios can be a useful tool.