Volumetric capnography for the evaluation of pulmonary disease in adult patients with cystic fibrosis and noncystic fibrosis bronchiectasis.

This study was designed to use volumetric capnography to evaluate the breathing pattern and ventilation inhomogeneities in patients with chronic sputum production and bronchiectasis and to correlate the phase 3 slope of the capnographic curve to spirometric measurements. Twenty-four patients with cystic fibrosis (CF) and 21 patients with noncystic fibrosis idiopathic bronchiectasis (BC) were serially enrolled. The diagnosis of cystic fibrosis was based on the finding of at least two abnormal sweat chloride concentrations (iontophoresis sweat test). The diagnosis of bronchiectasis was made when the patient had a complaint of chronic sputum production and compatible findings at high-resolution computed tomography (HRCT) scan of the thorax. Spirometric tests and volumetric capnography were performed. The 114 subjects of the control group for capnographic variables were nonsmoker volunteers, who had no respiratory symptoms whatsoever and no past or present history of lung disease. Compared with controls, patients in CF group had lower SpO(2) (P < 0.0001), higher respiratory rates (RR) (P < 0.0001), smaller expiratory volumes normalized for weight (V(E)/kg) (P < 0.028), smaller expiratory times (Te) (P < 0.0001), and greater phase 3 Slopes normalized for tidal volume (P3Slp/V(E)) (P < 0.0001). Compared with controls, patients in the BC group had lower SpO(2) (P < 0.0001), higher RR (P < 0.004), smaller V(E)/kg (P < 0.04), smaller Te (P < 0.007), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0002). The pooled data from the two patient groups compared with controls showed that the patients had lower SpO(2) (P < 0.0001), higher RR (P < 0.0001), smaller V(E)/kg (P < 0.05), smaller Te (P < 0.0001), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0003). All of the capnographic and spirometric variables evaluated showed no significant differences between CF and BC patients. Spirometric data in this study reveals that the patients had obstructive defects with concomitant low vital capacities and both groups had very similar abnormalities. The capnographic variables in the patient group suggest a restrictive respiratory pattern (greater respiratory rates, smaller expiratory times and expiratory volumes, normal peak expiratory flows). Both groups of patients showed increased phase III slopes compared with controls, which probably indicates the presence of diffuse disease of small airways in both conditions leading to inhomogeneities of ventilation.

Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism.

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 +/- 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 +/- 8.64 to 39.14 +/- 6.77 mmHg) and alveolar air (from 92.97 +/- 2.14 to 63.91 +/- 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 +/- 42.01 to 84.34 +/- 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 +/- 0.34 to 0.33 +/- 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 +/- 1.71 to 60.76 +/- 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 +/- 1.22 to 23.15 +/- 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 +/- 1.36 to 37.61 +/- 12.79 mmHg), as also did the calculated alveolar (from 56.38 +/- 22.47 to 178.09 +/- 37.46 mL) and physiological (from 0.37 +/- 0.05 to 0.75 +/- 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.

Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.

Retrospective analysis of patients who developed pulmonary hypertension during the early postoperative period after liver transplantation.

INTRODUCTION: Pulmonary hypertension (PH) (mean pulmonary arterial pressure [mPAP] > 25 mm Hg) is frequently observed during the postoperative period after liver transplantation (LT). OBJECTIVE: The objective was to compare respiratory function, intensive care unit (ICU) length of stay (LOS), and 30-day survival rates among patients evolving with PH with those who do versus do not develop it during the postoperative period after LT. METHODS: Fifty-seven patients undergoing LT from January 1999 to December 2000 were divided into 2 groups: Group 1 (G1; n = 26), without PH; and Group 2 (G2; n = 31), with moderate PH. Preoperative parameters were Child-Pugh's classification, pulmonary function tests, mPAP, and P(A-a)O(2). During the intraoperative period, warm and cold ischemic times and the amount of blood transfusion were evaluated, whereas mPAP, PaO(2)/FiO(2) ratio, weaning time, ICU LOS, and 30-day survival rates were evaluated postoperatively. RESULTS: mPAP in early postoperative period was 21 +/- 13 mm Hg and 32 +/- 4 mm Hg in G1 and G2, respectively (P <.0001). PaO(2)/FiO(2) was 310 +/- 82 mm Hg in G1 and 272 +/- 84 mm Hg in G2 (P =.48). In G1 and G2, 77% and 74% of patients, respectively, were successfully weaned in the first 24 hours postoperative (P =.10). ICU LOS was 111 hours (range, 45-1098 hours) in G1 and 102 hours (range, 59-284 hours) in G2 (P =.36). The 30-day survival rate was 20 of 26 (77%) in G1 and 26 of 31 (84%) in G2 (P =.44). CONCLUSION: Our data suggest that moderate PH during the early postoperative phases of LT cannot be considered an additional risk factor for pulmonary dysfunction, and for an increased ICU LOS or 30-day mortality rate.

[Technical aspects of intracranial pressure monitoring by subarachnoid method in severe head injury]. / Aspectos técnicos da monitorização da pressão intracraniana pelo método subaracnóideo no traumatismo craniencefálico grave.

Two hundred and six patients with severe head injury (Glasgow Coma Scale of 8 points or less after nonsurgical resuscitation on admission), managed at Intensive Care Unit-Hospital das Clínicas - Universidade Estadual de Campinas were prospectively analysed. All patients were assessed by CT scan and 72 required neurosurgical intervention. All patients were continuously monitored to evaluate intracranial pressure (ICP) levels by a subarachnoid device (11 with subarachnoid metallic bolts and 195 with subarachnoid polyvinyl catheters). The ICP levels were continuously observed in the bedside pressure monitor display and their end-hour values were recorded in a standard chart. The patients were managed according to a standard protocol guided by the ICP levels. There were no intracranial haemorrhagic complications or hematomas due the monitoring method. Sixty six patients were punctured by lateral C1-C2 technique to assess infectious complications and 2 had positive cerebrospinal fluid samples for Acinetobacter sp. The final results measured at hospital discharge showed 75 deaths (36,40%) and 131 (63,60%) survivors. ICP levels had significantly influenced the final results (p<0,001). The subarachnoid method to continuously assess the ICP levels was considered applicable, safe, simple, low cost and useful to advise the management of the patients. The ICP record methodology was practical and useful. Despite the current technical advances the subarachnoid method was considered viable to assess the ICP levels in severe head injury.

Multiple organ failure in septic patients.

Multiple organ failure (MOF) is the main cause of death in ICUs, especially affecting septic patients. It is strongly related to number of systems with failure, type of system involved, risk factors such as age, previous chronic diseases, delayed or inadequate resuscitation, persistent infection, immune suppression, and others. The prognoses is worse for patients rather than in elective or emergency surgical patients. The objective of this article is to provide data from our university teaching hospital ICU related to the incidence of septic patients, the distribution of MOF, and distribution of failure among each of the organs. The mortality rate, relationship between mortality and age, and mortality and types of organs affected were evaluated. The main bacterial causes of sepsis were also identified. A retrospective evaluation was done of 249 patients admitted to the ICU in a 4 month period during 1999. Fifty four patients had sepsis diagnosed by ACCS/SCCM criteria. There were 37 men and 17 women; 24 medical and 30 post-surgical patients (9 after elective surgery and 21 emergency patients). APACHE II score was calculated on admission and MOF, measured for the first five days, was diagnosed using Marshall and Meakins criteria. The statistical method used was non-parametric Mann-Whitney test, p<0.05 was considered significant. The incidence of sepsis was recorded in 54/249 patients (22%). Thirty of these 54 patients (56%) died. Death occurred in 2 of 11 patients with one organ failure (18%), in 14/27 with 2 or 3 organ failures (52%), and 14/16 with 4 or more organ failures (88%). None of the three patients 15 to 20 years old died, 17/32 (55%) patients age 21-60 years, and >61 years 13/19 (68%), died. There were 23 patients with positive bacterial culture. The most frequent bacteria found were: Pseudomonas aeruginosa (5), multiresistant Acinetobacter baumanii (3), Staphylococcus epidermidis (3), Enterobacter aerogenes (3), Klebsiella pneumoniae (2) and multiresistant Staphylococcus aureus (2). The mean value +/- SD of APACHE II (mortality risk) for survivors was 21 +/- 18 and for non-survivors 42 +/- 26 (p<0.001). We conclude that MOF due to sepsis in an ICU is frequent, with high mortality related to the number of failing organs, age and high APACHE II.

Diagnostic investigation of ventilator-associated pneumonia using bronchoalveolar lavage: comparative study with a postmortem lung biopsy

The purpose of the present study was to validate the quantitative culture and cellularity of bronchoalveolar lavage (BAL) for the diagnosis of ventilator-associated pneumonia (VAP). A prospective validation test trial was carried out between 1992 and 1997 in a general adult intensive care unit of a teaching hospital. Thirty-seven patients on mechanical ventilation with suspected VAP who died at most three days after a BAL diagnostic procedure were submitted to a postmortem lung biopsy. BAL effluent was submitted to Gram staining, quantitative culture and cellularity count. Postmortem lung tissue quantitative culture and histopathological findings were considered to be the gold standard exams for VAP diagnosis. According to these criteria, 20 patients (54 percent) were diagnosed as having VAP and 17 (46 percent) as not having the condition. Quantitative culture of BAL effluent showed 90 percent sensitivity (18/20), 94.1 percent specificity (16/17), 94.7 percent positive predictive value and 88.8 percent negative predictive value. Fever and leukocytosis were useless for VAP diagnosis. Gram staining of BAL effluent was negative in 94.1 percent of the patients without VAP (16/17). Regarding the total cellularity of BAL, a cut-off point of 400,000 cells/ml showed a specificity of 94.1 percent (16/17), and a cut-off point of 50 percent of BAL neutrophils showed a sensitivity of 90 percent (19/20). In conclusion, BAL quantitative culture, Gram staining and cellularity might be useful in the diagnostic investigation of VAP

Diagnostic investigation of ventilator-associated pneumonia using bronchoalveolar lavage: comparative study with a postmortem lung biopsy.

The purpose of the present study was to validate the quantitative culture and cellularity of bronchoalveolar lavage (BAL) for the diagnosis of ventilator-associated pneumonia (VAP). A prospective validation test trial was carried out between 1992 and 1997 in a general adult intensive care unit of a teaching hospital. Thirty-seven patients on mechanical ventilation with suspected VAP who died at most three days after a BAL diagnostic procedure were submitted to a postmortem lung biopsy. BAL effluent was submitted to Gram staining, quantitative culture and cellularity count. Postmortem lung tissue quantitative culture and histopathological findings were considered to be the gold standard exams for VAP diagnosis. According to these criteria, 20 patients (54%) were diagnosed as having VAP and 17 (46%) as not having the condition. Quantitative culture of BAL effluent showed 90% sensitivity (18/20), 94.1% specificity (16/17), 94.7% positive predictive value and 88.8% negative predictive value. Fever and leukocytosis were useless for VAP diagnosis. Gram staining of BAL effluent was negative in 94.1% of the patients without VAP (16/17). Regarding the total cellularity of BAL, a cut-off point of 400,000 cells/ml showed a specificity of 94.1% (16/17), and a cut-off point of 50% of BAL neutrophils showed a sensitivity of 90% (19/20). In conclusion, BAL quantitative culture, Gram staining and cellularity might be useful in the diagnostic investigation of VAP.

[Cerebral hemometabolism: variability in the acute phase of traumatic coma]. / Hemometabolismo cerebral: variações na fase aguda do coma traumático.

OBJECTIVE: to evaluate the interrelationships between cerebral and systemic hemometabolic alterations in patients with severe traumatic brain injury managed according to a standardized therapeutic protocol. DESIGN: prospective, interventional study in patients with traumatic coma. SETTING: a general Intensive Care Unit in a teaching hospital. PATIENTS AND METHODS: twenty-seven patients (21M e 6F), aging 14 - 58 years, with severe acute brain trauma, presenting with three to eight points on the Glasgow Coma Scale, were prospectively evaluated according to a cumulative protocol for the management of acute intracranial hypertension, where intracranial pressure (ICP) and cerebral extraction of oxygen (CEO2) were routinely measured. Hemometabolic interrelationships involving mean arterial pressure (MAP), ICP, arterial carbon dioxide tension (PaCO2), CEO2, cerebral perfusion pressure (CPP) and systemic extraction of oxygen (SEO2) were analyzed. INTERVENTIONS: routine therapeutic procedures. RESULTS: no correlation was found between CEO2 and CPP (r = -0.07; p = 0.41). There was a significant negative correlation between PaCO2 and CEO2 (r = -0.24; p = 0.005) and a positive correlation between SEO2 and CEO2 (r = 0.24; p = 0.01). The mortality rate in this group of patients was 25.9% (7/27). CONCLUSION: 1) CPP and CEO2 are unrelated; 2) CEO2 and PaCO2 are closely related; 3) during optimized hyperventilation, CEO2 and SEO2 are coupled.

Invasive hemodynamic monitoring in the postoperative period of cardiac surgery.

OBJECTIVE: To assess the hemodynamic profile of cardiac surgery patients with circulatory instability in the early postoperative period (POP). METHODS: Over a two-year period, 306 patients underwent cardiac surgery. Thirty had hemodynamic instability in the early POP and were monitored with the Swan-Ganz catheter. The following parameters were evaluated: cardiac index (CI), systemic and pulmonary vascular resistance, pulmonary shunt, central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), oxygen delivery and consumption, use of vaso-active drugs and of circulatory support. RESULTS: Twenty patients had low cardiac index (CI), and, 10 had normal or high CI. Systemic vascular resistance was decreased in 11 patients. There was no correlation between oxygen delivery (DO2) and consumption (VO2), p = 0.42, and no correlation between CVP and PCWP, p = 0.065. Pulmonary vascular resistance was decreased in 15 patients and the pulmonary shunt was increased in 19. Two patients with CI < 2 L/min/m2 received circulatory support. CONCLUSION: Patients in the POP of cardiac surgery frequently have a mixed shock due to the systemic inflammatory response syndrome (SIRS). Therefore, invasive hemodynamic monitoring is useful in handling blood volume, choice of vasoactive drugs, and indication for circulatory support.

[Pulse oximetry for the evaluation of oxygen transport in patients in critical condition]. / Oximetria de pulso na avaliação do transporte de oxigênio em pacientes críticos.

In this clinical investigation 35 patients under mechanical ventilation were studied. It was possible to establish the precision of two pulse oximeters of different brands. The performance of these equipments was evaluated by comparing data with the hemo-oximeter and a statistical analysis employed the student t test. Results showed that bias between oximeters reading and hemo-oximeter was similar for both instruments. Eventually critical patients may present conditions that limit the use of this technique. The study showed that the discrepancy in the results observed may be attributed to the presence of the methemoglobin and possible to anaemia associated to hypoxia.

[Neurogenic pulmonary edema. Report of 2 cases]. / Edema pulmonar neurogênico. Relato de dois casos.

Neurogenic pulmonary edema is a rare and serious complication in patients with head injury. It also may develop after a variety of cerebral insults such as subarachnoid hemorrhage, brain tumors and after epileptic seizures. Thirty six patients with severe head injury and four patients with cerebrovascular insults treated in Intensive Care Unit of HC-UNICAMP from January to September 1995 were evaluated. In this period there were two patients with neurogenic pulmonary edema, one with head injury and other with intracerebral hemorrhage. Diagnosis was made by rapid onset of pulmonary edema, severe hypoxemia, decrease of pulmonary complacence and diffuse pulmonary infiltrations, without previous history of tracheal aspiration or any other risk factor for development of adult respiratory distress syndrome. In the first case, with severe head trauma, neurogenic pulmonary edema was diagnosed at admission one hour after trauma, associated with severe systemic inflammatory reaction, and good outcome in three days. The second case, with hemorrhagic vascular insult, developed neurogenic pulmonary edema the fourth day after drainage of intracerebral hematoma and died.

Critical care in South America. The new tradition.

This article offers a brief discussion of some of the aspects of clinical and academic realities of critical and intensive care medicine in South America. Organizational efforts of collaborating physician and nursing intensivists from South American countries, Spain, and Portugal are outlined. Discussion includes the issues of funding and support of health care delivery of the critically ill, and some of the clinical syndromes not commonly seen in North America and Europe, but seen by intensivists in South America.

[From death concepts to brain death diagnostic criteria]. / Dos conceitos de morte aos critérios para o diagnóstico de morte encefálica.

The authors present considerations about death and brain death concepts, as well the legal aspects for its diagnosis in Brazil. They also present the UNICAMP Protocol for the Diagnosis of Brain Death, revised and according with the current law, with standard techniques for the diagnostic exam. They emphasize the importance of a mature ethical position for this frequent and challenging situation.

Highlighting intracranial pressure monitoring in patients with severe acute brain trauma.

Intracranial pressure (ICP) monitoring was carried out in 100 patients with severe acute brain trauma, primarily by means of a subarachnoid catheter. Statistical associations were evaluated between maximum ICP values and: 1) Glasgow Coma Scale (GCS) scores; 2) findings on computed tomography (CT) scans of the head; and 3) mortality. A significant association was found between low GCS scores (3 to 5) and high ICP levels, as well as between focal lesions on CT scans and elevated ICP. Mortality was significantly higher in patients with ICP > 40 mm Hg than in those with ICP < or = 20 mm Hg.

[Streptokinase in severe pulmonary thromboembolism]. / Estreptoquinase no Tromboembolismo Pulmonar Grave.

Severe pulmonary embolism (PE) was treated with streptokinase in four patients, three men and one woman, age 38 to 72 (mean = 53 +/- 14) years. Before the thrombolytic therapy, all patients had pulmonary angiogram and hemodynamic parameters analyzed. The drug was infused through the distal lumen of the Swan-Ganz catheter at the pulmonary artery trunk. The initial dosage was 250,000 units "in bolus" and 100,000 units in 24 to 72 hours. The time interval between the symptoms and treatment had ranged from 2 hours to 5 days. The results are analyzed as follow: reduction on right atrial pressure, mean pulmonary pressure, pulmonary vascular resistance, an increase in the stroke volume and cardiac output. In two cases we observed total lysis, in one partial lysis and one patient died from severe form of PE and late infusion of SK. Reinfusion of the drug was necessary in one patient that had PE recurrence with reliable final result. Finally, no one had severe bleeding despite the use of the intrapulmonary catheter.

Semiquantitative culture in diagnosing venous catheter-related sepsis.

Since Aubaniac (1) described the puncture of the subclavian vein in 1952, and specially after the standardization of parenteral nutrition by Dudrick et al. (11) in 1968, much has been published about complications caused by percutaneous central venous catheterization. Among the various complications provoked by this procedure, a very important one is "primary sepsis" or "catheter-related sepsis", both because of its frequency and because of the morbidity and mortality it causes (18,19). It is, however, difficult to diagnose this complication. The main difficulty lies in differentiating catheters that are really causing sepsis from those that, though showing "positive culture" do not cause bacteremia and are not responsible for the occasional signs of infection that a patient may show (6,7). This difficulty in diagnosing has led to the recommendation that all catheters suspected of causing sepsis be systematically removed. This procedure has the effect of exposing patients in serious condition and with limited venous access to the risks of new punctures. Usually these risks are unnecessary, since 75 to 90% of the catheters removed for this reason are not the real source of infection (3, 17, 19, 21, 22). In 1977, Maki et al. (18) proposed a semiquantitative catheter tip culture that showed considerable correlation with positive hemoculture for the same microorganisms; that is, capable of identifying which "positive catheters" were really causing sepsis. Subsequent research confirmed these results, showing that the semiquantitative catheter tip culture had specificity and sensibility over 80% (10, 15).(ABSTRACT TRUNCATED AT 250 WORDS)

Ultra-estrutura pulmonar e circulacao extracorporea. / Pulmonary ultrastructure and extra-corporal circulation

Com a finalidade de observar o efeito da circulacao extracorporea sobre a ultra-estrutura pulmonar, foram estudados 12 doentes submetidos a cirurgia cardiaca, com um tempo de perfusao de ate 60 minutos. Nao observamos, a microscopia eletronica, as alteracoes degenerativas classicas descritas na literatura