Guilherme Penna

Treatment of essential hypertension does not normalize capillary rarefaction

OBJECTIVES To determine if capillary rarefaction persists when hypertension is treated with angiotensin converting enzyme inhibitor, thiazidic diuretic and/or beta-blocker, and to identify which microcirculatory alterations (structural and functional) persist after anti-hypertensive treatment. METHODS We evaluated 28 well-controlled essential hypertensive patients and 19 normotensive subjects. Nailfold videocapillaroscopy examination of the fourth finger of the left hand was used to determine the functional capillary densities at baseline, during post-occlusive hyperemia, and after venous congestion. Capillary loop diameters (afferent, apical and efferent) and red blood cell velocity were also quantified. RESULTS Compared with normotensive subjects, hypertensive patients showed lower mean functional capillary density at baseline (25.1±1.4 vs. 33.9±1.9 cap/mm2, p<0.01), during post-occlusive reactive hyperemia (29.3±1.9 vs. 38.2±2.2 cap/mm2, p<0.01) and during venous congestion responses (31.4±1.9 vs. 41.1±2.3 cap/mm2, p<0.01). Based on the density during venous congestion, the estimated structural capillary deficit was 25.1%. Mean capillary diameters were not different at the three local points, but red blood cell velocity at baseline was significantly lower in the hypertensive group (0.98±0.05 vs. 1.17±0.04 mm/s, p<0.05). CONCLUSIONS Patients treated for essential hypertension showed microvascular rarefaction, regardless of the type of therapy used. In addition, the reduced red blood cell velocity associated with capillary rarefaction might reflect the increased systemic vascular resistance, which is a hallmark of hypertension.

Changing sedative infusion from propofol to midazolam improves sublingual microcirculatory perfusion in patients with septic shock

PURPOSE The goal of this study was to explore possible microcirculatory alterations by changing sedative infusion from propofol to midazolam in patients with septic shock. MATERIALS AND METHODS Patients (n=16) were sedated with propofol during the first 24 hours after intubation, then with midazolam, following a predefined algorithm. Systemic hemodynamics, perfusion parameters, and microcirculation were assessed at 2 time points: just before stopping propofol and 30 minutes after the start of midazolam infusion. Sublingual microcirculation was evaluated by sidestream dark-field imaging. RESULTS The microvascular flow index and the proportion of perfused small vessels were greater when patients were on midazolam than when on propofol infusion (2.8 [2.4-2.9] vs 2.3 [1.9-2.6] and 96.4% [93.7%-97.6%] vs 92.7% [88.3%-94.7%], respectively; P<.005), and the flow heterogeneity index was greater with propofol than with midazolam use (0.49 [0.2-0.8] vs 0.19 [0.1-0.4], P<.05). There were no significant changes in systemic hemodynamics and perfusion parameters either during propofol use or during midazolam infusions. Data are presented as median (25th-75th percentiles). CONCLUSIONS In this study, sublingual microcirculatory perfusion improved when the infusion was changed from propofol to midazolam in patients with septic shock. This observation could not be explained by changes in systemic hemodynamics.

Complicações após cirurgia de revascularização miocárdica em pacientes idosos

PURPOSE: Due to the increasing longevity of the and high prevalence of coronary heart disease in the aged , coronary artery bypass graft surgery has become frequent in older patients. The purpose of this study is to describe operative features, length of stay, complications and short term outcomes after coronary artery bypass graft in such patients. METHODS: From February 2005 to October 2007, 269 patients underwent coronary artery bypass graft. Demographic data, comorbidities, prognostic scores, coronary artery bypass graft elective versus urgent indication, intensive care unit length of stay, postoperative complications and intensive care unit mortality were recorded. Intra-operative characteristics, such as total surgery time, use of bypass device, on-pump time, urine output, fluid balance, use of blood products and number of grafts, were analyzed. Patients were divided in four age groups: group I (< 60 n = 68), II (60 to 69 n = 86), III (70 to 79 n = 93) IV and older than 80 years (n = 22). RESULTS: Group IV patients were more frequently submitted to coronary artery bypass graft combined with valve replacement, emergency surgery, and had longer stay in the intensive care unit (p < 0.01). The incidence of at least one postoperative complication was also higher among patients older than 80 (p < 0.001). Multivariate analysis identified age and on-pump time as independent risk factors for development of complications. Mortality increased in patients older than 70 years (p = 0.03). CONCLUSIONS: Octogenarian patients undergoing coronary artery bypass graft have longer intensive care unit length of stay, incidence of complications and mortality. Age and on-pump time were independent risk factors associated with the incidence of postoperative complications.

Fatores preditores precoces de reinternação em unidade de terapia intensiva

OBJECTIVE: To predict readmission in intensive care unit analyzing the first 24 hours data after intensive care unit admission. METHODS: The first intensive care unit admission of patients was analyzed from January to May 2009 in a mixed unit. Readmission to the unit was considered those during the same hospital stay or within 3 months after intensive care unit discharge. Deaths during the first admission were excluded. Demographic data, use of mechanical ventilation, and report of stay longer than 3 days were submitted to uni and multivariate analysis for readmission. RESULTS: Five hundred seventy-seven patients were included (33 excluded deaths). The readmission group had 59 patients, while 518 patients were not readmitted. The lead time between the index admission and readmission was 9 (3-28) days (18 were readmitted in less than 3 days), and 10 died. Patients readmitted at least once to the intensive care unit had the differences below in comparison to the control group: older age: 75 (67-81) versus 67 (56-78) years, P<0.01; admission for respiratory insufficiency or sepsis: 33 versus 13%, P<0.01; medical admission: 49 versus 32%, P<0.05; higher SAPS II score: 27 (21-35) versus 23 (18-29) points, P<0.01; Charlson index: 2 (1-2) versus 1 (0-2) points, P<0.01; first ICU stay longer than 3 days: 35 versus 23%, P<0.01. After logistic regression, higher age, Charlson index and admission for respiratory and sepsis were independently associated to readmissions in intensive care unit. CONCLUSION: Age, comorbidities and respiratory- and/or sepsis-related admission are associated with increased readmission risk in the studied sample.

Avaliação da microcirculação: uma nova arma no manejo da sepse?

The progression into multi-organ failure continues to be a common feature of sepsis and is directly related to microcirculatory dysfunction. Based on a PubMed database search using the key words microcirculation and sepsis, twenty-six articles were selected for this review. The relevant references from these articles were also selected and included in this analysis. Orthogonal polarization spectral imaging allows for the bedside assessment of the microcirculation of critically ill patients. Such imaging has established a correlation between microvascular dysfunction and patient outcomes, which allows practitioners to directly assess the effects of therapeutic interventions. However, the causal relationships between microcirculatory dysfunction, adverse outcomes, and the effects of therapies aimed at these microcirculatory changes in sepsis, are not clear.The progression into multi-organ failure continues to be a common feature of sepsis and is directly related to microcirculatory dysfunction. Based on a PubMed database search using the key words microcirculation and sepsis, twenty-six articles were selected for this review. The relevant references from these articles were also selected and included in this analysis. Orthogonal polarization spectral imaging allows for the bedside assessment of the microcirculation of critically ill patients. Such imaging has established a correlation between microvascular dysfunction and patient outcomes, which allows practitioners to directly assess the effects of therapeutic interventions. However, the causal relationships between microcirculatory dysfunction, adverse outcomes, and the effects of therapies aimed at these microcirculatory changes in sepsis, are not clear.

Complicações pós-operatórias de pacientes com dissecção de aorta ascendente tratados cirurgicamente

OBJECTIVES: Ascending aortic dissection has a poor prognosis if it is not promptly corrected surgically. Even with surgical correction, postoperative management is feared because of its complicated course. Our aim was to describe the incidence of postoperative complications and identify the 1 and 6-month mortality rate of our ascending aortic dissection surgical cohort. Secondarily, a comparison was made between ascending aortic dissection patients and paired-matched patients who received urgent coronary artery bypass graft surgery. METHODS: A retrospective analysis of a prospectively-collected database from February 2005 through June 2008 revealed 12 ascending aortic dissection and 10 elective ascending aortic aneurysm repair patients. These patients were analyzed for demographic and perioperative characteristics. Ascending aortic dissection patients were compared to paired-matched coronary artery bypass graft surgery patients according to age (± 3 years), gender, elective/urgent procedure and surgical team. The main outcome was in-hospital morbidity, defined by postoperative complications, intensive care unit admission and hospital length of stay. RESULTS: Twenty-two patients received operations to correct ascending aortic dissections and ascending aortic aneurysms, while 246 patients received coronary artery bypass graft surgeries. Ascending aortic dissection patients were notably similar to ascending aortic aneurysm brackets, except for longer mechanical ventilation times and lengths of stay in the hospital. After matching coronary artery bypass graft surgery patients to an ascending aortic dissection group, the following significantly worse results were found for the Aorta group: higher incidence of postoperative complications (91% vs. 45%, p=0.03), and longer hospital length of stay (19 [11-41] vs. 12.5 [8.5-13] days, p=0.05). No difference in mortality was found at the 1-month (8.3%) or 6-month (16.6%) postoperative care date. CONCLUSION: Ascending aortic dissection correction is associated with an increased incidence of postoperative complications and an increased hospital length of stay, but 1 and 6-month mortality is similar to that of paired-matched coronary artery bypass graft surgery patients.

Cateter venoso profundo recoberto com antibiótico para reduzir infecção: estudo piloto

BACKGROUND AND OBJECTIVES Nosocomial catheter related bloodstream infections (CR-BSI) increase morbidity and mortality in critically ill patients. Central venous catheters (CVC) coated with rifampin and minocycline (RM) decrease rates of colonization and CR-BSI. However, recent trials challenged the clinical impact of such catheters. We designed this trial to compare rates of colonization and CR-BSI in RM catheters and controls in a cohort of critically ill patients in Brazil. METHODS Prospective, controlled trial conducted in one medico-surgical ICU. Patients were assigned to receive a control or RM CVC. After removal, tips were cultured in association with blood cultures. Rates of colonization and CR-BSI were recorded. RESULTS Among 120 catheters inserted, 100 could be evaluated, 49 in the uncoated and 51 in the coated group. Clinical characteristics of patients were similar in the two groups. Two cases of CR-BSI (3.9%) occurred in patients who received RM catheters compared with 5 (10.2%) in the uncoated group (p = 0.26). Six RM catheters (11.8%) were colonized compared with 14 (28.6%) control catheters (p = 0.036). Kaplan-Meier analysis showed no significant differences in the risk of colonization or CR-BSI. Rates of CR-BSI were 4.7 per 1000 catheter-days in the RM coated group compared to 11.4 per 1000 catheter days in the uncoated group (p = 0.45). CONCLUSIONS In this pilot study, we showed lower rates of colonization in RM coated when compared with uncoated catheters. Incidence and rates of CR-BSI were similar in the two groups.

Comparação entre as variações respiratórias da amplitude de onda pletismográfica da oximetria de pulso e do pulso arterial em pacientes com e sem uso de norepinefrina

OBJECTIVES: Arterial pulse pressure respiratory variation is a good predictor of fluid response in ventilated patients. Recently, it was shown that respiratory variation in arterial pulse pressure correlates with variation in pulse oximetry plethysmographic waveform amplitude. We wanted to evaluate the correlation between respiratory variation in arterial pulse pressure and respiratory variation in pulse oximetry plethysmographic waveform amplitude, and to determine whether this correlation was influenced by norepinephrine administration. METHODS: Prospective study of sixty patients with normal sinus rhythm on mechanical ventilation, profoundly sedated and with stable hemodynamics. Oxygenation index and invasive arterial pressure were monitored. Respiratory variation in arterial pulse pressure and respiratory variation in pulse oximetry plethysmographic waveform amplitude were recorded simultaneously in a beat-to-beat evaluation, and were compared using the Pearson coefficient of agreement and linear regression. RESULTS: Thirty patients (50%) required norepinephrine. There was a significant correlation (K = 0.66; p < 0.001) between respiratory variation in arterial pulse pressure and respiratory variation in pulse oximetry plethysmographic waveform amplitude. Area under the ROC curve was 0.88 (range, 0.79 - 0.97), with a best cutoff value of 14% to predict a respiratory variation in arterial pulse pressure of 13. The use of norepinephrine did not influence the correlation (K = 0.63, p = 0.001, respectively). CONCLUSIONS: Respiratory variation in arterial pulse pressure above 13% can be accurately predicted by a respiratory variation in pulse oximetry plethysmographic waveform amplitude of 14%. The use of norepinephrine does not alter this relationship.

Complicações após cirurgia de revascularização miocárdica em pacientes idosos: resposta da carta ao editor

1-9 Physicians from the Intensive Care Unit of Casa de Saude Sao Jose, Rio de Janeiro (RJ), Brazil. 10 – Physician from the Intensive Care Unit of Casa de Saude Sao Jose, Rio de Janeiro (RJ), Brazil and Institute for Clinical Research Evandro Chagas FIOCRUZ, Rio de Janeiro (RJ), Brazil. We wish to thank Dr. Helcio Griffhorn for his interest in our work. We have shown that octogenarians present a longer stay, higher incidence of complications and higher mortality, with worse peri-operative severity of illness. However, nonelderly and sexagenarian patients had similar performance, disclosing increased life expectancy and quality in Brazilian population.(1) Septuagenarian were characterized by hybrid results, showing increased severity of disease, higher incidence of postoperative atrial fibrillation and reoperation, however ICU length of stay and mortality were similar to those of younger groups. Worse performance of elderly can result from need for urgent surgery, efforts to prolong treatment with drugs and coronary angioplasty procedures. Blood transfusion was more often used at preoperative of septuagenarians and octogenarians (critical levels of anemia with advanced age or greater use of blood products may significantly influence outcomes).(2,3) The study included only patients submitted to coronary artery bypass graft (CABG) as the main surgery although a significant number also had an indication for valve replacement, secondarily. As commented, mortality of CABG patients who needed valve replacement is higher (15.5%). There were 61 orovalvular surgeries during the study’s period, with 6 deaths, but they were excluded because we wanted to specifically analyze a homogeneous group of CABG. Presence of aortic valve disease may increase surgical and extracorporeal circulation (ECC) duration, however there was no impact on the incidence of complications, perhaps due to exclusion of most orovalvular surgeries. Of the 343 cardiac surgeries in this time period, 11(3%) were performed without ECC. Duration of surgery and morbidity may be less frequent with this approach,(4) but could increase heterogeneity of the study group. Decision of the operation technique always rested upon the surgical team before admission. If the complications most often found in elderly (atrial fibrillation, left ventricle failure, significant thoracic bleeding, acute renal dysfunction and nosocomial sepsis) were added to high frequency of urgent surgeries and longer time of ECC, there are reasons for higher morbidity and mortality of elderly patients. Finally, postoperative transient inflammatory reaction that comes together with ECC was analyzed in some studies. Cytokines, as macrophage migration inhibitor factor, interleukin 6 and monocyte chemoattractant protein, undergo a significant early increase after induction of anesthesia and return to baseline levels after 24 hours, and(5) correlate with levels of organ dysfunctions. Researchers are looking for predictive biomarkers of postoperative morbidity, mainly in the elderly. Received from the Intensive Care Unit of the Casa de Saude Sao Jose, Rio de Janeiro (RJ), Brazil. Submitted on January 16, 2009 Accepted on January 31, 2009