Postcardiac Surgery Intensive Care Unit Research Articles

Auditing plasma transfusion in intensive care: Use of decision time interval analysis.

To present a new method for displaying blood utilization data based on analysis of decision time intervals (DTIs). Retrospective study of patients treated in a medical intensive care unit (ICU), surgical ICU, or postcardiac surgery ICU at an academic hospital between January 2018 and June 2023. Each patient's episode of care was divided into a series of DTIs. Transfusions during each time interval were recorded. In total, 16,562 patients received 6980 units of plasma and 21,034 units of red blood cells during 111,557 time intervals of care. Patients had international normalized ratio (INR) values ranging from less than 1.0 to more than 4.0. Data on plasma transfusion at different INR values were displayed as the number of transfusion episodes, number of units given, or the proportion of DTIs with transfusion. Clinicians transfused plasma on 1.5% of occasions when the INR was 1.5 or less and on 2.2% of occasions when the INR was less than 2.0. Plasma was transfused without red blood cells in only 0.75% of DTIs. Transfusion practice was statistically different among the 3 ICUs. Compared with traditional methods of displaying the results of blood audits, DTI analysis displays information regarding the decision both to transfuse and to not transfuse. Utilization reviews that display data based on decision time analysis reveal clinical practice patterns very different from those suggested by traditional displays of plasma audit data.

A comparative study between serum lactate level versus change in end tidal carbon dioxide level regarding assessment of hemodynamic instability in intensive care unit patients after cardiac surgeries

ABSTRACT Background After cardiac surgeries, elevated lactate level is used as a marker of tissue hypoperfusion. Still, there is a search for other helpful markers of hemodynamic instability. Exhaled carbon dioxide has been recently studied as marker of cardiac output and tissue perfusion and may be considered a reliable alternative which is more convenient and real time. Objectives The main aim is to correlate between end tidal carbon dioxide (ETCO2) and serum lactate level as indicators of hemodynamic instability in intensive care unit (ICU) patients after cardiac surgeries. The secondary objective is to correlate the measured parameters to the changes in the vital data and the resuscitation efforts. Methods A prospective cohort study that enrolled 51 adult patients admitted to ICU after cardiac surgeries. The serum lactate and ETCO2 values as well as vital data and vasopressor doses were recorded on admission to ICU, after 2 hours and after 6 hours. Results The study shows insignificant weak positive correlation between Lactate and ETCO2 levels at admission (r = 0.172, p value = 0.229), and insignificant negative weak correlation after 2 hours (r = -0.148, p value = 0.300) and after 6 hours (r = -0.235, p value = 0.096). Moreover, lactate level showed significant direct relation with the doses of vasopressors at admission, after 2 hours and after 6 hours postoperative (p value < 0.001 at all intervals). Whereas there was insignificant relation between ETCO2 and doses of vasopressors at all intervals (p value = 0.23, 0.4 and 0.18 respectively). Conclusion In post-cardiac surgery ICU patients we detected no statistically significant relation between serum lactate and ETCO2 as indicators of hemodynamic instability. The change in ETCO2 over a period of time has failed so far to be of a beneficial value as a non-invasive real-time cardiac output monitoring parameter. In addition, serum lactate had strong correlation with changes in vital signs and resuscitation efforts.

Utility of Transfontanelle Ultrasound in Predicting the Fluid Responsiveness in Children After Repair of Congenital Heart Diseases: A Prospective Observational Study

Postoperative fluid management in children undergoing cardiac surgery requires a balanced optimization. The blood flow velocity variation in the internal carotid artery (ΔICA) measured through transfontanelle ultrasound has been shown to predict fluid responsiveness during cardiac surgery. It may provide an excellent window to study fluid responsiveness in infants during the postoperative period when the intensivist is faced with the challenges of poor echocardiographic window. The authors aimed to observe the correlation between ΔICA measured on transfontanelle ultrasound with the respiratory variability of peak aortic blood flow velocity (ΔVpeak) on transthoracic echocardiography as a marker of fluid responsiveness in infants on mechanical ventilation during the postoperative period after cardiac surgery. A prospective observational study. The postcardiac surgery intensive care unit (ICU) of a tertiary care hospital. Thirty infants undergoing congenital cardiac surgery. A fluid bolus of 10 mL/kg administered over 10 minutes at 1 and 6 hours after ICU admission. Patients were categorized into fluid responders and nonresponders based on >15% increase in the indexed stroke volume. A total of 50 fluid boluses were administered in 30 patients. Among these, 22 (73.33%) were responders and 8 (26.67%) were nonresponders. There was moderate correlation between ΔICA and peak aortic blood flow velocity variation (ΔVpeak) (r=0.59, p ≤ 0.001). The ΔVpeak >14.74% had 68% sensitivity and 75% specificity to predict fluid responsiveness (area under the receiver operating characteristic [AUROC], 0.749; p=0.001; positive likelihood ratio, 2.71; negative likelihood ratio, 0.43). The ΔICA >9.85% could predict fluid responsiveness in infants (AUROC, 0.728; p=0.003; 75% sensitivity; 60% specificity; positive likelihood ratio, 1.85; negative likelihood ratio, 0.42). Among children younger than 6 months, ΔICA >9.85% was a better predictor of fluid responsiveness (AUROC, 0.889; p=0.009) than ΔVpeak >15% (AUROC, 0.778; p=0.061). The ICA variability >9.85% measured via transfontanelle ultrasound is a good predictor of fluid responsiveness in infants, especially those younger than 6 months on mechanical ventilation after cardiac surgery.

Cardiac Safety of Clonidine and Quetiapine in Post-Cardiac Surgery Intensive Care Unit Patients

Background: Clonidine and quetiapine are frequently used medications in the cardiac surgery intensive care unit (ICU). Objective: The purpose of this study is to assess the impact of clonidine compared to quetiapine on cardiac safety outcomes in adult cardiac surgery ICU patients. Methods: This was a single-center, retrospective observational analysis at a tertiary care, academic medical center. Results: One hundred and sixty-one cardiac surgery patients who were administered clonidine or quetiapine during their ICU stay were included between June 2015 and May 2017. The major endpoint of this study was a cardiac safety composite of bradycardia, hypotension, and QTc prolongation. Minor endpoints included ICU and hospital length of stay, and in-hospital mortality. There were 115 patients included in the clonidine arm and 46 patients in the quetiapine arm. There was no difference between groups with regard to the major endpoint (30.43% vs 33.15%; P < .8). There was a shorter ICU and hospital length of stay in the clonidine arm compared to quetiapine P < .0001. All other endpoints were not statistically significant. Conclusion: Patients who received clonidine tended to have undergone less complex procedures, be younger, and have a lower APACHE II score than patients who received quetiapine. The incidence of composite cardiac safety outcomes was not different in clonidine compared to quetiapine in cardiac surgery ICU patients.

Effect of High-Flow Nasal Oxygen on Respiratory Parameters and Pulmonary Complications After Early Extubation Following Pediatric Heart Surgery

Objectives: The aim of this study was to evaluate the effect of high-flow nasal cannula (HFNC) after early extubation on children undergoing cardiac surgery. Methods: This randomized controlled clinical trial was performed among 92 children aged 1 to 24 months undergoing cardiac surgery from March 5 to August 30, 2020, in a pediatric post-cardiac surgery intensive care unit (ICU). The patients were randomized to receive either HFNC or conventional oxygen therapy after extubation. Arterial blood samples were collected after anesthesia induction, after the end of the surgery, at the time of entering the ICU while they were intubated, 6 hours after entering the ICU, before removing the endotracheal tube, immediately after extubation, as well as 1, 6, 12, 24, and 36 hours after extubation. The patients were compared regarding PaCO2, PaO2/FiO2 ratios, respiratory failure, need for reintubation, development of atelectasis, pneumothorax, pleural effusion, and length of ICU stay. Results: The patients were similar regarding demographic characteristics, the duration of surgery, and mechanical ventilation (P &gt; 0.05). On the first and second days after the surgery, the mean modified radiologic atelectasis score (m-RAS) was lower in the HFNC group compared to the conventional oxygen therapy group (P &lt; 0.05). The frequency of respiratory failure did not differ in the groups before and after the surgery (P &gt; 0.05). PaCO2 was lower in the HFNC group than in the control group after extubation (P &lt; 0.001). PaO2/FIO2 ratio was significantly higher in the HFNC group one hour after extubation and afterward in comparison to the control group (P &lt; 0.001). The need for re-intubation (P &lt; 0.013) and the length of ICU stay (P &lt; 0.001) were significantly lower in the HFNC group compared to the control group. Conclusions: It was found that HFNC could improve the respiratory parameters and reduce postoperative pulmonary complications in infants following a congenital heart surgery.

Role of oral nystatin prophylaxis in cardiac surgery with prolongedextracorporeal circulation.

Duration >120minutes of extracorporeal circulation (ECC) during cardiopulmonary bypass procedure was associated to an increased risk of candidemia in the intensive care unit (ICU). To evaluate oral nystatin prophylaxis in cardiac surgery considering its exclusive effect on Candida, in the absence of systemic effects and selection of resistant strains to polyene. We conducted an observational study in the postcardiac surgery ICU of Policlinico "Umberto I" of Rome. From January 2014, all patients with a prolonged ECC >120minutes were systematically treated with oral nystatin (Prophylaxis group). This group was compared with all patients hospitalised in the same ICU, who have not received oral nystatin after ECC >120minutes (No prophylaxis group). Overall, 672 consecutive patients were analyzed: 318 (47.3%) patients belonged to the no prophylaxis group, and 354 (52.7%) patients to the prophylaxis group. Diagnosis of candidemia was confirmed in 7 (2.2%) patients, all belonged to the no prophylaxis group. At multivariate analysis, oral nystatin prophylaxis showed a protective effect for development of candidemia after cardiac surgery. Oral nystatin prophylaxis, in patients who underwent a ECC >120minutes, seems to reduce development of candidemia; however, the real efficacy of such prophylaxis approach requires further investigation.

A post cardiac surgery intervention to manage delirium involving families: a randomized pilot study.

As many delirium manifestations (e.g., hallucinations or fears) are linked to patients' experiences and personality traits, it is suggested that interventions should be tailored to optimize its management. The inclusion of family members, as part of an intervention, has recently emerged as a solution to developing individualised patient care, but has never been assessed in post-cardiac surgery intensive care unit where almost half of patients will present with delirium. To assess the feasibility, acceptability and preliminary efficacy of an nursing intervention involving family caregivers (FC) in delirium management following cardiac surgery. A randomized pilot study. A total of 30 patient/FC dyads were recruited and randomized to usual care (n = 14) or intervention (n = 16). The intervention was based on the Human Caring Theory, a mentoring model, and sources informing self-efficacy. It comprised seven planned encounters spread over 3 days between an intervention nurse and the FC, each including a 30-min visit at the patient's bedside. During this bedside visit, the FC used delirium management strategies, e.g. reorient the person with delirium. The primary indicator of acceptability was to obtain consent from 75% of approached FCs. The preliminary effect of the intervention on patient outcomes was assessed on (1) delirium severity using the Delirium Index, (2) occurrence of complications, such as falls, (3) length of postoperative hospital stay and (4) psycho-functional recovery using the Sickness Impact Profile. The preliminary effect on FC outcomes was assessed on FC anxiety and self-efficacy. Data were analysed using descriptive statistics, ANCOVAs and logistic regressions. The primary indicator of obtaining consent from FC was achieved (77%). Of the 14 dyads, thirteen (93%) dyads received all seven encounters planned in the experimental intervention. Intervention group patients presented better psycho-functional recovery scores when compared with control group patients (p = 0·01). Mean delirium severity scores showed similar trajectories on days 1, 2 and 3 in both groups. The mentoring intervention was acceptable and feasible and shows promising results in improving patients and FC outcomes. Nurses should involve, if willing, FC to participate in activities that optimise patient well-being FC to use recognized delirium management strategies like reorientation and reassurance.

Assessment of limited chest x-ray technique in postcardiac surgery management

Objectives:The objective of this study is to investigate the safety of elimination of chest radiography in the postcardiac surgery Intensive Care Unit (ICU).Methods and Design:We compared patients in two different groups of routine CXR (RCXR) and limited CXR (LCXR) and their diagnostic and therapeutic outcome in a University hospital-based single center from 2014 to 2016. 3 CXR in the RCXR group and 1 CXR in the limited group was performed, in addition to on-demand criteria.Measurement and Main Results:A total of 978 samples were acceptable for analysis which 55.21% of RCXR and 59.50% of LCXR were male patients. In total, 523 abnormalities in RCXR group and 154 occasions in LCXR group resulted in 26.73% diagnostic efficacy for RCXRs and 28.57% for LCXR. From 1956 CXR that was taken in RCXR group, 72 occasions required intervention (3.68%) and 84 cases out of 539 (15.58%) LCXR needed an action to therapy. This means a 14.40% in RCXRs’ abnormalities and 56.00% of LCXRs’ abnormalities were accompanied with some interventions.Conclusions:Abolishing routine CXR in the ICUs would not be harmful for the patients, and it can be managed based on their clinical status and other safer imaging techniques.

Validation of the Critical-Care Pain Observation Tool and Vital Signs in Relation to the Sensory and Affective Components of Pain During Mediastinal Tube Removal in Postoperative Cardiac Surgery Intensive Care Unit Adults.

The Critical-Care Pain Observation Tool (CPOT) is a behavioral scale recommended in clinical practice guidelines for the assessment of pain in nonverbal intensive care unit (ICU) adults. Although the CPOT has been validated in various ICU patient groups, its association with the affective component of pain has not yet been explored, and in most studies, turning was the used nociceptive procedure. In this study, we aim to validate the use of the CPOT and vital signs in association with the sensory and affective components of pain during mediastinal tube removal (MTR) in postoperative cardiac surgery ICU adults. A sample of 125 patients participated in this prospective repeated-measures, within-subject study. A total of 6 assessments of the main study variables (CPOT scores and patients' self-reports of pain intensity and unpleasantness) were completed by trained research assistants while patients were in the ICU. Assessments were done before, during, and 15 minutes after the nonnociceptive procedure (ie, noninvasive blood pressure taking [NIBP]) and nociceptive procedure (ie, MTR). Discriminant validation of the scale use was supported as higher CPOT scores were obtained during MTR (mean [SD], 2.74 [1.61]) compared with NIBP (mean [SD], 0.50 [0.747]) (t124 = 14.33, P < .001). Similarly, higher values were recorded for mean arterial pressure and heart and respiratory rates during MTR compared with NIBP (P < .01). During MTR, CPOT scores correlated significantly with self-report of pain intensity (r = 0.419, P < .01) and unpleasantness (r = 0.313, P < .01), supporting criterion and convergent validation. Conversely, vital signs did not correlate with either self-report. Study findings confirmed the validity of the CPOT for the assessment of the sensory and affective components of pain in the postcardiac surgery ICU adults. Vital signs were not specific to pain and should be used only as cues to begin further assessment of pain using validated instruments for this purpose.

Impact of vitamin C supplementation on post-cardiac surgery ICU and hospital length of stay.

Background:Prolonged intensive care unit (ICU) and hospital stay after cardiac surgery is vitally important and is influenced by both intraoperative and postoperative factors.Objectives:This randomized clinical trial study was designed to assess whether vitamin C supplementation could reduce the length of ICU and hospital stay in post-cardiac surgery patients.Patients and Methods:Two hundred and ninety patients scheduled for adult cardiac surgery including coronary, valve and congenital operations were randomized into two groups: an intervention group, who received 2 g of vitamin C (ascorbic acid) intravenously, immediately before surgery in the operating theatre, followed by 1 g daily oral doses for the first 4 postoperative days; and a placebo group, who received an equal number of identical tablets in the same shape and size.Results:Hospital length of stay was significantly different between the two groups (10.17 ± 4.63 days in the intervention group vs. 12 ± 4.51 days in the placebo group; P = 0.01), while there was no significant difference in the ICU stay between the groups (3.42 ± 1.06 days in intervention group vs. 3.43 ± 1.09 days in the placebo group; P = 0.88). There were significant differences in the intubation time and the drainage volume in the ICU and the first 24 postoperative hours between the two groups (P for both = 0.003).Conclusions:Vitamin C can decrease the length of hospital stay, drainage volume in the ICU and in the first 24 postoperative hours, intubation time and some complications in patients after cardiac surgery; perhaps by decreasing inflammatory factors.

Fatal adenoviral necrotizing bronchiolitis case in a post-cardiac surgery intensive care unit

Fatal adenoviral necrotizing bronchiolitis case in a post-cardiac surgery intensive care unit

Flow-Regulated Extracorporeal Arteriovenous Tubing Loop for Cardiac Output Measurements by Ultrasound Velocity Dilution: Validation in Post-Cardiac Surgery Intensive Care Unit Patients

Assessment of cardiac output (CO) is crucial in the management of the critically ill, especially in post cardiac surgery intensive care unit (ICU) patients. In this study, we validated CO measured by the novel ultrasound dilution (COUD) with those measured by pulmonary artery (PA) thermodilution (COTD) in 26 adult post cardiac surgery patients. For COUD, blood was circulated through an extracorporeal arteriovenous (AV) loop from the radial artery catheter to the introducer of PA catheter for 5-8 minutes. Three to four injections of 25 ml body temperature isotonic saline were performed into the venous limb of the AV loop. For COTD, five injections of 10 ml ice cold saline were performed. A total of 77 COUD and COTD measurement sets were compared. Cardiac output measured by thermodilution ranged from 3.28 to 9.4 L/min, whereas COUD ranged from 2.85 to 10.1 L/min. The correlation between the methods was found to be r = 0.91, COUD = 0.93(COTD) + 0.42 L/min. Bias and precision (mean difference ± 2SDs) was -0.004 ± 1.34 L/min between the two methods. The percentage error (2SD/mean) was 22.2%, which is below the clinically acceptable limit (<30%). Cardiac output measured by ultrasound dilution and thermodilution methods agreed well in post cardiac surgery ICU patients and hence can be interchangeably used.

Estimation of Hemodynamic Parameters by Arterial Waveform: Available Technologies

To the Editor: Funk et al.1 present an interesting review concerning new minimally invasive technologies and devices available for measurement of cardiac output. In their review, Funk et al. did not consider 2 systems: the first is the Modelflow by Wesseling and co-workers2 installed on the Finometer® (Finapres Medical Systems, Amsterdam, The Netherlands); the second is the Pressure Recording Analytical Method (PRAM; used by MostCare®, Vytech Health, Padova, Italy) by Romano et al.3,4 “Pulse contour methods” (PCMs) can be divided into 3 categories: PCMs requiring an indicator dilution cardiac output measurement to calibrate the pulse contour; PCMs requiring patient demographic and physical characteristics for arterial impedance estimation; PCMs that work without any kind of calibration or preloaded data. The PRAM is the only methodology belonging to category 3 because neither calibration nor adjustments based on experimental data are required.3–5 Therefore, PRAM is different than all the other PCMs including the more recent Flo Trac Vigileo® (Edwards LifeSciences, Irvine, CA) and LiDCOrapid™ (LiDCO Ltd, London, UK), which require preloaded patient's demographic and physical characteristics (age, height, gender, and weight), similar to Modelflow6,7 (category 2). For PRAM, the area under the systolic portion of the arterial wave is computed by considering both pulsatile and continuous contributions (Acp). Stroke volume derives from the ratio between Acp and the arterial impedance Z(t) that is directly determined from the detailed analysis of the arterial wave sampled at high frequency (1000 Hz).3 Stefano Romagnoli, MD Heart and Vessels Department Cardiac and Vascular Anesthesia and Post-Cardiac Surgery Intensive Care Unit Careggi Hospital Florence, Italy [email protected] Salvatore Mario Romano, PhD Heart and Vessels Department Critical Care Medicine and Surgery University of Florence Careggi Hospital Florence, Italy

EComment: Brain natriuretic peptide is removed by continuous veno-venous hemofiltration in pediatric patients

We wanted to evaluate if brain natriuretic peptide (BNP) is cleared during continuous veno-venous hemofiltration (CVVH) sessions in children with congenital heart disease. A prospective observational single-center study was conducted in a post-cardiac surgery intensive care unit of the city children's hospital. Ten children requiring CVVH for acute kidney injury following cardiac surgery were enrolled. Seven of them were undergoing postoperative extracorporeal membrane oxygenation. BNP clearance was evaluated by the difference between pre-filter and post-filter BNP blood amount indexed to pre-filter BNP concentration. All CVVH treatments were performed with 0.6 m2 polyacrylonitrile filter, in predilution setting, at a dose of 80 ml/kg/h. Troponin I and myoglobin levels were also measured and CVVH clearances of these markers calculated for comparison with BNP. A significant decrease in post-filter compared with pre-filter levels of BNP was shown in all 10 cases (P 0.05) and their clearance was significantly lower than BNP (P: 0.0004). A daily analysis of BNP levels showed a significant decrease of its blood concentration. BNP levels were significantly reduced after three and four days from CVVH start (P<0.05). During 80 ml/kg/h CVVH, utilizing polyacrylonitrile membranes, BNP is efficiently cleared from blood in a small cohort of pediatric post-cardiosurgical patients. In this situation, BNP absolute blood levels may be unpredictable.

Brain natriuretic peptide is removed by continuous veno-venous hemofiltration in pediatric patients

We wanted to evaluate if brain natriuretic peptide (BNP) is cleared during continuous veno-venous hemofiltration (CVVH) sessions in children with congenital heart disease. A prospective observational single-center study was conducted in a post-cardiac surgery intensive care unit of the city children's hospital. Ten children requiring CVVH for acute kidney injury following cardiac surgery were enrolled. Seven of them were undergoing postoperative extracorporeal membrane oxygenation. BNP clearance was evaluated by the difference between pre-filter and post-filter BNP blood amount indexed to pre-filter BNP concentration. All CVVH treatments were performed with 0.6 m2 polyacrylonitrile filter, in predilution setting, at a dose of 80 ml/kg/h. Troponin I and myoglobin levels were also measured and CVVH clearances of these markers calculated for comparison with BNP. A significant decrease in post-filter compared with pre-filter levels of BNP was shown in all 10 cases (P<0.01). Median BNP clearance was 35.6 (29-39.3) ml/min. Troponin I and myoglobin levels did not show any significant drop between pre- and post-filter values (P>0.05) and their clearance was significantly lower than BNP (P: 0.0004). A daily analysis of BNP levels showed a significant decrease of its blood concentration. BNP levels were significantly reduced after three and four days from CVVH start (P<0.05). During 80 ml/kg/h CVVH, utilizing polyacrylonitrile membranes, BNP is efficiently cleared from blood in a small cohort of pediatric post-cardiosurgical patients. In this situation, BNP absolute blood levels may be unpredictable.

Beliefs and attitudes of intensive care nurses toward visits and open visiting policy

To describe the beliefs and attitudes of intensive care unit (ICU) nurses toward visiting, visiting hours, and open visiting policies in critical care settings. A descriptive, cross-sectional, multicenter survey. Seventeen hospitals in Flanders (Dutch-speaking Belgium), including 30 ICUs. Sixteen mixed adult medical/surgical ICUs, three medical ICUs, five surgical ICUs, three coronary care units, two post-cardiac surgery ICUs, and one burn unit. A total of 531 intensive care nurses. We devised a questionnaire comprising 20 items assessing beliefs and 14 items assessing attitudes. Nurses indicated their level of agreement for each statement on a five-point rating scale. Nurses believed that open visiting hampers planning of adequate nursing care (75.2%), interferes with direct nursing care (73.8%), and causes nurses to spend more time in providing information to the patients' families (82.3%). The presumed effects of visits on the patients and families were contradictory. Most nurses (75.3%) did not want to liberalize the visiting policy of their unit. ICU nurses have rather skeptical beliefs and attitudes toward visiting and open visiting policy. This suggests that the culture at Flemish ICUs is not ready for a drastic liberalization of the visiting policy.

Positive end-expiratory pressure increases pulmonary venous vascular resistance in patients after coronary artery surgery.

To investigate the effect of positive and-expiratory pressure (PEEP) on the longitudinal distribution of pulmonary vascular resistance in patients immediately after coronary artery bypass grafting. Prospective, intervention study. Postcardiac surgery intensive care unit in a teaching institution. Twenty patients after elective coronary artery bypass grafting. The effect of PEEP on pulmonary circulation, at four different levels (0, 5, 10, and 15 cm H2O), was analyzed in 20 patients. Mean pulmonary arterial pressure, left atrial pressure, pulmonary artery occlusion pressure, and pulmonary capillary pressure were measured at each PEEP level. A model consisting of two resistances in series was used to analyze the effect of PEEP on the pulmonary circulation. The pulmonary vascular resistance for each area (arterial and venous) of the circulation was calculated. Pulmonary vascular resistance increased from 216 +/- 70 dyne.sec/cm5 at a PEEP of 0 cm H2O to 308 +/- 125 dyne.sec/cm5 at a PEEP of 15 cm H2O (p < .001). This increase, however, resulted solely from an increase in the resistance of the venous part of the pulmonary circulation from 66 +/- 29 to 134 +/- 69 dyne.sec/cm5 (p < .001), without any change in pulmonary arterial resistance. PEEP increases pulmonary vascular resistance solely by increasing pulmonary venous resistance. When applying PEEP, changes in pulmonary vascular resistance may impede the resorption of pulmonary edema fluid.

Incidence, Risk, and Prognosis Factors of Nosocomial Pneumonia in Mechanically Ventilated Patients

Seventy-eight (24%) episodes of nosocomial pneumonia (NP) were detected in 322 consecutive mechanically ventilated patients admitted to a 1,000-bed teaching hospital from April 1987 through May 1988 to assess the incidence, risk, and prognosis factors of NP acquired during mechanical ventilation (MV). The risk and prognosis factors for developing NP during MV were studied using both univariate and multivariate statistical techniques. Multivariate analysis selected the following variables significantly associated with a higher risk for developing ventilator-associated pneumonia: more than one intubation during MV (p = 0.000012), a prior episode of aspiration of gastric content (p = 0.00018), a MV period longer than 3 days (p = 0.015), the presence of chronic obstructive pulmonary disease (COPD) (p = 0.048), and the use of positive end-expiratory pressure (PEEP) during MV (p = 0.092). The presence of an ultimately or rapidly fatal underlying disease (p = 0.0018), worsening of acute respiratory failure caused by pneumonia (p = 0.0096), the presence of septic shock (p = 0.016), an inappropriate antibiotic treatment (p = 0.02), and the type of intensive care unit (ICU) hospitalization (noncardiac surgery and nonsurgical ICU compared with post-cardiac surgery ICU) (p = 0.08) were those factors selected by a stepwise logistic regression analysis as independently worsening the prognosis. The overall fatality rate was 23% (73 of 322). The mortality of patients with NP was higher (33%; 26 of 78; p less than 0.01) when compared with fatality rates of patients without NP (19%; 47 of 244).(ABSTRACT TRUNCATED AT 250 WORDS)