Joc Auler

Severe novel influenza A (H1N1) infection in cancer patients

Background: The natural history and consequences of severe H1N1 influenza infection among cancer patients are not yet fully characterized. We describe eight cases of H1N1 infection in cancer patients admitted to the intensive care unit of a referral cancer center. Patients and methods: Clinical data from all patients admitted with acute respiratory failure due to novel viral H1N1 infection were reviewed. Lung tissue was submitted for viral and bacteriological analyses by real-time RT-PCR, and autopsy was conducted on all patients who died. Results: Eight patients were admitted, with ages ranging from 55 to 65 years old. There were five patients with solid organ tumors (62.5%) and three with hematological malignancies (37.5%). Five patients required mechanical ventilation and all died. Four patients had bacterial bronchopneumonia. All deaths occurred due to multiple organ failure. A milder form of lung disease was present in the three cases who survived. Lung tissue analysis was performed in all patients and showed diffuse alveolar damage in most patients. Other lung findings were necrotizing bronchiolitis or extensive hemorrhage. Conclusions: H1N1 viral infection in patients with cancer can cause severe illness, resulting in acute respiratory distress syndrome and death. More data are needed to identify predictors of unfavorable evolution in these patients.

Computed tomography assessment of lung structure in patients undergoing cardiac surgery with cardiopulmonary bypass

Hypoxemia is a frequent complication after coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB), usually attributed to atelectasis. Using computed tomography (CT), we investigated postoperative pulmonary alterations and their impact on blood oxygenation. Eighteen non-hypoxemic patients (15 men and 3 women) with normal cardiac function scheduled for CABG under CPB were studied. Hemodynamic measurements and blood samples were obtained before surgery, after intubation, after CPB, at admission to the intensive care unit, and 12, 24, and 48 h after surgery. Pre- and postoperative volumetric thoracic CT scans were acquired under apnea conditions after a spontaneous expiration. Data were analyzed by the paired Student t-test and one-way repeated measures analysis of variance. Mean age was 63 ± 9 years. The PaO2/FiO2 ratio was significantly reduced after anesthesia induction, reaching its nadir after CPB and partially improving 12 h after surgery. Compared to preoperative CT, there was a 31% postoperative reduction in pulmonary gas volume (P < 0.001) while tissue volume increased by 19% (P < 0.001). Non-aerated lung increased by 253 ± 97 g (P < 0.001), from 3 to 27%, after surgery and poorly aerated lung by 72 ± 68 g (P < 0.001), from 24 to 27%, while normally aerated lung was reduced by 147 ± 119 g (P < 0.001), from 72 to 46%. No correlations (Pearson) were observed between PaO2/FiO2 ratio or shunt fraction at 24 h postoperatively and postoperative lung alterations. The data show that lung structure is profoundly modified after CABG with CPB. Taken together, multiple changes occurring in the lungs contribute to postoperative hypoxemia rather than atelectasis alone.

A micromethod for quantitation of debrisoquine and 4-hydroxydebrisoquine in urine by liquid chromatography

We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred microl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 microg/ml). The 5-microm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lambdaexcitation = 210 nm and lambdaemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2% (D) and 5.3/8.2% (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax(R), po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine, was 6.4% and 31.9%, respectively. The hydroxylation capacity index reported as metabolic ratio was 0.18 (D/4-OHD) for the person investigated and can be compared to reference limits of >12.5 for poor metabolizers (PM) and <12.5 for extensive metabolizers (EM). In parallel, the recovery ratio (RR), another hydroxylation capacity index, was 0.85 (4-OHD: SigmaD + 4-OHD) versus reference limits of RR <0.12 for PM and RR >0. 12 for EM. The healthy volunteer was considered to be an extensive metabolizer on the basis of the debrisoquine test.

Comparative study of pressure-and volume-controlled ventilation on pulse pressure variation in a model of hypovolaemia in rabbits

Background and objective Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume‐controlled ventilation and pressure‐controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Method Thirty‐two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1‐ConPCV was the pressure‐controlled ventilation control group, G2‐HemPCV was associated with haemorrhage, G3‐ConVCV was the volume‐controlled ventilation control group and G4‐HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P < 0.05 was considered to be statistically significant. Results At M0 (baseline), no significant differences were observed among groups. At M1, dynamic parameters differed significantly among the control and hypovolaemic groups (P < 0.05) but not between ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume‐controlled ventilation when compared with those under pressure‐controlled ventilation. Conclusions Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume‐controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure‐controlled ventilation.

Outcomes of 3,400 patients with cancer admitted to intensive care unit: a Brazilian prospective study

ICU admission of critically ill cancer patients was controversial until recently. In the past years, advances in the management of malignancies and organ failures have improved outcomes of patients, resulting in higher rates of survival in the ICU. The aim of this study is to prospectively evaluate the characteristics, short-term and mid-term outcomes of cancer patients requiring intensive care.

Effects of inhaled nitric oxide combined to mechanic ventilation on the patients with acute respiratory dysfunction in postoperative heart surgery: comparative study among pressure controlled ventilation and volume controlled ventilation

Pressure-controlled ventilation (PCV), is related to a better distribution of the inhaling flow and lower pressure peaks, when compared to volume-controlled ventilation (VCV). Nitric oxide (NO) promotes redistribution of blood flow to the ventilated areas and decreases the pulmonary shunt effect improving oxygenation.

0735. Effects of metoprolol in a porcine model of septic shock

The use of cardiovascular drugs increased in recent years [1], including the use of β-blockers, such as metoprolol. And although the β-blockade is still very contradictory in patients with sepsis, both studies in experimental models and in septic patients with previous prescription of β-blockers have shown a potential role of these drugs in patients with sepsis [2, 3].

0731. Effects of sildenafil in a porcine model of endotoxemia

Sepsis-induced lung injury is one of the major causes of morbidity and mortality in intensive care patients [1]. The clinical manifestations include pulmonary hypertension, formation of extravascular lung water (EVLW), and deterioration of pulmonary gas exchange. Administration of sildenafil, a selective inhibitor of isoenzyme phosphodiesterase-5, in patients with pulmonary hypertension improves oxygenation and ameliorates pulmonary hypertension [2].

1071. Impact of volume resuscitation on heart rate variability in a model of hemorrhagic shock in pigs

Hemorrhagic shock is responsible for high mortality rates in civilian injuries and combat casualties. The initial care of these patients comprehends an early assessment of hypovolemia, bleeding management and fluid resuscitation [1], while an adequate autonomic function is essential for maintaining the hemodynamic stability during haemorrhage. The analysis of heart rate variability (HRV) has been shown as a promising noninvasive technique for assessing the cardiac autonomic modulation in trauma, and several recent studies have demonstrated an association between HRV and clinical outcome [2].

Red blood cell transfusion is an independent risk factor for cardiovascular complications in adult patients undergoing cardiac surgery: a propensity score-matched analysis

Red blood cell (RBC) transfusion is associated with a higher occurrence of clinical complications after cardiac surgery. However, the cause-effect relationship is confounded by other risk factors for worse outcomes as advanced age, valve or combined procedure, high EuroSCORE, redo surgery, longer bypass time and previous anemia. The objective of this study was to evaluate the effect of RBC transfusion in a propensity score-matched case-control analysis.