Diagnosis Of Nosocomial Pneumonia Research Articles

Antimicrobial treatment failures in patients with community-acquired pneumonia: causes and prognostic implications.

The aim of the study was to determine the causes and prognostic implications of antimicrobial treatment failures in patients with nonresponding and progressive life-threatening, community-acquired pneumonia. Forty-nine patients hospitalized with a presumptive diagnosis of community-acquired pneumonia during a 16-mo period, failure to respond to antimicrobial treatment, and documented repeated microbial investigation >/= 72 h after initiation of in-hospital antimicrobial treatment were recorded. A definite etiology of treatment failure could be established in 32 of 49 (65%) patients, and nine additional patients (18%) had a probable etiology. Treatment failures were mainly infectious in origin and included primary, persistent, and nosocomial infections (n = 10 [19%], 13 [24%], and 11 [20%] of causes, respectively). Definite but not probable persistent infections were mostly due to microbial resistance to the administered initial empiric antimicrobial treatment. Nosocomial infections were particularly frequent in patients with progressive pneumonia. Definite persistent infections and nosocomial infections had the highest associated mortality rates (75 and 88%, respectively). Nosocomial pneumonia was the only cause of treatment failure independently associated with death in multivariate analysis (RR, 16.7; 95% CI, 1.4 to 194.9; p = 0.03). We conclude that the detection of microbial resistance and the diagnosis of nosocomial pneumonia are the two major challenges in hospitalized patients with community-acquired pneumonia who do not respond to initial antimicrobial treatment. In order to establish these potentially life-threatening etiologies, a regular microbial reinvestigation seems mandatory for all patients presenting with antimicrobial treatment failures.

Laboratory diagnosis of nosocomial pneumonia.

The second most common nosocomial infection in the United States is pneumonia, with the highest rates seen in patients requiring mechanical ventilation. Nosocomial pneumonia is a serious disease associated with significant morbidity and mortality; crude mortality rates have been estimated at 20% to 50%. The rapid institution of appropriate antimicrobial therapy has been shown to improve mortality in patients with ventilator associated nosocomial pneumonia. Thus, the identification of nosocomial pneumonia with a timely microbiologic diagnosis is important for the management of these patients. However, the accurate diagnosis of nosocomial pneumonia, along with identification of the responsible organism(s), can be challenging. This task becomes even more difficult in patients who are mechanically ventilated. The presence of new pulmonary infiltrates along with clinical criteria including fever, cough, and purulent secretions are neither sensitive nor specific for the diagnosis of nosocomial pneumonia. The laboratory can enhance the accuracy of pneumonia diagnosis, as well as provide the identification of an etiologic organism(s). There are, however, many challenges which confront the laboratory including: the ability to identify organisms from an extensive microbiologic spectrum; distinguishing colonization from infection of predominately gram-negative oropharyngeal flora; and providing timely results. This article reviews the various diagnostic tests available for nosocomial lung infections, and in particular, ventilator associated pneumonia including: blood cultures; pleural fluid; expectorated sputum; endotracheal aspirates; and respiratory specimens obtained by more invasive techniques using bronchoscopy and transthoracic needle aspiration. Emphasis is placed on optimal specimen collection, the processing of samples in the laboratory, and on the evaluation of potential risks and benefits associated with the varying techniques.

Effects of fiberoptic bronchoscopy on intracranial pressure in patients with brain injury: a prospective clinical study.

Fiberoptic bronchoscopy (FB) plays an important role in making the diagnosis of nosocomial pneumonia and resolving lobar atelectasis in critically injured trauma patients. It has been shown to be a safe procedure with only occasional complications. However, in patients with head injuries, FB can lead to intracranial hypertension. Sustained increases in intracranial pressure (ICP) leads to poor outcome in these patients. Because of this, a prospective study was done not only to assess the effect of FB on ICP and cerebral perfusion pressure (CPP) in patients with brain injuries, but also to identify a regimen of sedation and anesthesia that could prevent significant increases in ICP during FB. Twenty-six FB were performed in 23 patients with ICP monitors or ICP monitors and ventriculostomy drains in place for Glasgow Coma Scale score < 8 or management of postcraniotomy trauma. FB was performed to aid in the diagnosis of nosocomial pneumonia or to aid in resolving lobar atelectasis. Before FB, all patients received a standard anesthetic regimen consisting of vecuronium (10 mg), morphine sulfate (4 mg), and midazolam (2.5 mg). Patients with diminished cranial compliance, defined as ICP > 10 mm Hg, also received a nebulizer treatment of 3 mL of 4% lidocaine before FB. All patients were preoxygenated with FIO2 = 1.0 for 10 minutes. Intracranial pressure, mean arterial pressure, and CPP were monitored continuously throughout the procedure. These same variables were also recorded at baseline and at 2-minute intervals during the procedure. The time to return to baseline ICP was also recorded. The mean ICP at baseline (immediately before FB) was 12.6 mm Hg. After introduction of the bronchoscope, the ICP rapidly increased in 21 procedures (81%) and the mean highest ICP was 38.0 mm Hg. There was also a concomitant increase in mean arterial pressure such that there was no substantial change in CPP. The mean lowest CPP was 73.1 mm Hg. The average time for return of ICP to baseline was 13.9 minutes. In the subgroup of patients with ICP > 10, attempting to blunt the tracheal stimulation by anesthetizing the trachea with 4% nebulized lidocaine did not seem to be successful. The mean highest ICP in this subgroup was 41.8 mm Hg. The CPP changed in a similar manner, as the mean lowest CPP was 74.0 mm Hg. The mean time to return to baseline was 12.5 minutes. No patient had acute neurologic deterioration secondary to FB. Although FB is an important procedure in the pulmonary care of head injured patients, it produces substantial, but transient, increases in ICP and should be used with caution in patients with diminished cranial compliance. Sedation, analgesia, paralysis, and topical tracheal anesthesia did not completely prevent the rise in ICP. Although no acute deterioration in condition occurred, secondary brain injury caused by localized cerebral ischemia is certainly possible. Because of the substantial increases in ICP, herniation may be precipitated in an occasional patient. Further study is needed to identify a regimen that will confer protection.

Diagnosis of Nosocomial Pneumonia in Cancer Patients Undergoing Mechanical Ventilation: A Prospective Comparison of the Plugged Telescoping Catheter With the Protected Specimen Brush

Quantitative culture of protected samples of lower respiratory tract secretions obtained by a fiberoptic protected specimen brush (PSB) is widely accepted for the diagnosis of ventilator-associated pneumonia (VAP), but this diagnostic procedure is time consuming, expensive, and may give rise to iatrogenic complications, especially in cancer patients who often present with thrombocytopenia. The plugged telescoping catheter (PTC) could be a satisfactory alternative to the PSB in this setting. The aim of the present study was to evaluate the interest of the PTC to diagnose VAP in ventilated cancer patients. A prospective observational study. A 15-bed medical-surgical ICU in a comprehensive cancer center. Over a 9-month period, 42 patients suspected of having bacterial VAP during mechanical ventilation underwent 69 bronchial samplings: a blinded PTC and a fiberoptic PSB were performed successively in each case. A positive culture for both sampling procedures was defined as the recovery of > or = 10(3) cfu/mL of at least one potential pathogen. The PSB result was taken as the reference standard. The overall agreement between the techniques was 87% (60/69). PTC had a sensitivity of 67%, a specificity of 93%, a positive predictive value of 71%, and a negative predictive value of 91%. We conclude that the accuracy of the blinded PTC compares well with that of the PSB for the diagnosis of VAP in cancer patients. The sensitivity of the PTC observed herein, which is slightly lower than that described in previous studies, may be due to the blinded nature of the method: the indications for initial or secondary coupling with a directed sampling method in patients with suspicion of localized pneumonia remain to be determined.

A Prospective Study of Non-bronchoscopic Bronchoalveolar Lavage (nbBAL) Compared to Protected Specimen Brush (PSB) in the Diagnosis of Nosocomial Pneumonia in the Ventilated ICU Patient

A Prospective Study of Non-bronchoscopic Bronchoalveolar Lavage (nbBAL) Compared to Protected Specimen Brush (PSB) in the Diagnosis of Nosocomial Pneumonia in the Ventilated ICU Patient

Effectiveness of selective digestive tract decontamination to control an outbreak of nosocomial pneumonia caused by Pseudomonas aeruginosa in mechanically ventilated patients

The use of selective digestive tract decontamination (SDD) to reduce the endemic nosocomial pneumonia (NP) rate in intensive care unit (ICU) patients is well established although it has still not been widely endorsed. In addition, SDD appears to be effective in controlling outbreaks of nosocomial infection (NI), although this warrants further evaluation. This study was thus designed to evaluate the potential role of SDD in controlling an outbreak of NP due to Pseudomonas aeruginosa occurring in mechanically ventilated patients. In an initial four-month period, there was an abnormally high incidence (56%: 14 of 25 mechanically ventilated patients) of NP due to P. aeruginosa. A diagnosis of NP was based on the association of clinical criteria with a positive quantitative culture of a protected distal bronchoalveolar sample yielding a bacterial concentration ≥10 3 CFU/ml. In the subsequent four-month period, there was a systematic daily administration of an SDD regimen based upon neomycin, colistin and oropharyngeal application of povidone-iodine to all patients receiving mechanical ventilation (MV) for more than 48 hours throughout their ICU stay (Group 2, n=20). Demographic and baseline characteristics of patients in both groups were comparable. The groups were also similar with respect to the severity of acute illness and medical condition. Only one episode (5%) of NP due to P. aeruginosa occurred in Group 2 (p&lt;0.02). The rate of NP due to other microorganisms was similar in the two groups (24% in Group 1 versus 25% in Group 2). The mean duration of MV was shorter in Group 2, as was stay in the ICU: 7.8±4 versus 17±12 days, p=0.03, and 12.7±6 versus 25.4±20 days, p=0.02, respectively. Mortality rates were similar in both groups (40%). We conclude that SDD devoted to control an abnormally high rate of NP due to P. aeruginosa in mechanically ventilated patients was effective. Accordingly, a short-term trial of SDD could be recommended when traditional infection control measures have failed.

Effectiveness of selective digestive tract decontamination to control an outbreak of nosocomial pneumonia caused byPseudomonas aeruginosain mechanically ventilated patients

The use of selective digestive tract decontamination (SDD) to reduce the endemic nosocomial pneumonia (NP) rate in intensive care unit (ICU) patients is well established although it has still not been widely endorsed. In addition, SDD appears to be effective in controlling outbreaks of nosocomial infection (NI), although this warrants further evaluation. This study was thus designed to evaluate the potential role of SDD in controlling an outbreak of NP due to Pseudomonas aeruginosa occurring in mechanically ventilated patients. In an initial four-month period, there was an abnormally high incidence (56%: 14 of 25 mechanically ventilated patients) of NP due to P. aeruginosa. A diagnosis of NP was based on the association of clinical criteria with a positive quantitative culture of a protected distal bronchoalveolar sample yielding a bacterial concentration ≥10 3 CFU/ml. In the subsequent four-month period, there was a systematic daily administration of an SDD regimen based upon neomycin, colistin and oroph...

Hospital-acquired pneumonia: methicillin resistance and intensive care unit admission

Although epidemiologic investigations of hospital-acquired pneumonia have certain intrinsic limitations because of the heterogeneity of the study populations, the difficulties in making a clinical diagnosis of nosocomial pneumonia, and the need for better microbiologic assays, recent studies have provided new and important data concerning the role of Staphylococcus aureus in this disease. This pathogen has now been identified as the most frequent cause of nosocomial pneumonia in hospitals in both Europe and the United States among patients in general hospital units as well as in the intensive care unit (ICU). Patients who have been treated with mechanical ventilation are at especially high risk for S. aureus pneumonia. The incidence of nosocomial pneumonia related to methicillin-resistant S. aureus (MRSA) has increased in recent years in many countries, especially among patients in the ICU. Because hospitalized patients with suspected nosocomial pneumonia often have many risk factors for MRSA infection, it seems advisable to include coverage of MRSA in the initial therapeutic regimen for these patients until MRSA infection is excluded.

Quality assessment of protected specimen brush samples by microscopic cell count.

Protected specimen brushing (PSB), combined with quantitative culture, is now recognized as one of the reference methods for diagnosis of nosocomial pneumonia. However, no criteria exist with which to assess the quality of the PSB sample. We studied numbers of inflammatory cells and bronchial cells per microscopic field (magnification: x500, objective x50) in cytospin preparations of PSB samples. Results of cell count and quantitative culture in a first study period were compared with those in a second study period, following adaptation of the PSB technique and collection of samples from more peripheral sites. The cellular content of samples from patients and controls was investigated. We examined 86 samples from patients with suspected nosocomial pneumonia and 15 samples from uninfected controls. The number of samples with a high cellular content was considerably greater in the second study period. No positive cultures were obtained from samples containing < 10 cells per field. The numbers of cells in samples from uninfected controls were comparable to the numbers in samples from patients. Our results indicate that absence of cells probably represents inadequate sampling. Negative PSB cultures with cytospin preparations containing < 10 cells per microscopic field should therefore be considered with caution, and resampling considered.

Diagnosis of nosocomial pneumonia in mechanically ventilated patients: repeatability of the bronchoalveolar lavage.

The repeatability of the bronchoalveolar lavage (BAL) was assessed prospectively in 44 mechanically ventilated patients with suspected nosocomial pneumonia. Two BAL were performed in the same lung area (contiguous segment) during two fibroscopic procedures performed with a thirty minute interval. All the bronchoscopies were performed by the same operator. The statistical analysis looked out for bias (MacNemar test), agreement, and repeatability (kappa test). In the 44 patients studied, the qualitative repeatability (i.e., presence or absence of bacteria) was excellent (95.4%). However, in the 16 patients having at least one positive culture, these results were more controversial. The quantitative repeatability for bacteria (same log10 for both BAL of the same patient) was the lowest of all the results (26.7%). The distinction between presence and absence of bacterial pneumonia (based on the 10[4] cfu/ml threshold) showed a repeatability of 75% with no bias, an agreement of 47% and a just-significant kappa test (test = 1.97; p = 1.96 for a 5% risk error). BAL seems to have excellent repeatability when sterile. Its repeatability when positive needs further studies to be assessed.

Prevention of nosocomial infection in mechanically ventilated patients: selective digestive decontamination versus sucralfate

Objective: To evaluate the efficacy of two regimens, selective digestive decontamination (SDD) and sucralfate, in the prophylaxis of nosocomial infection in critically ill patients requiring prolonged mechanical ventilation. Design: Prospective, randomised, multi-centre trial. Setting: Medical and surgical intensive care units in 10 hospitals in Catalonia, Spain. Subjects: A total of 129 patients requiring mechanical ventilation for at least four days participated in the study. The absence of infection and use of systemic or topical antibiotic therapy prior to the diagnosis of nosocomial pneumonia was also required. Interventions: Patients were randomly assigned to the control group (n=42) in which histamine H2-receptor antagonists were given; the SDD group (n=41) using topical polymyxin E, tobramycin, and amphotericin B in the pharynx and stomach; and the sucralfate group (n=46). Patients in both regimens received intravenous cefotaxime for four days. Endpoints: The follow-up period was limited to ICU stay and included from the patient's entry into the study until extubation with a cutoff limit of 40 days, or until exclusion from the study due to development of nosocomial infection and/or administration of antibiotics for any reason. Mortality attributable to nosocomial pneumonia or another infection was defined as death with progressive respiratory failure and/or septic shock during the course of infection. Measurements and main results: SDD patients showed a lower incidence of nosocomial infection (36.6%) than sucralfate-treated patients (54.3%) and controls (71.4%) (p=0.006). Nosocomial pneumonia was more frequent among controls (50%) than in SDD (17%) and sucralfate (30%) groups (p=0.005). Early-onset pneumonia (within the four days of ICU stay) was less common in either SDD-or sucralfate-treated patients (28.6% and 14.3%) than in controls (61.9%) (p=0.015). A statistically significant difference (p=0.037) in late-onset pneumonia was found between SDD and sucralfate using Kaplan-Meier estimates. The development of infection other than nosocomial pneumonia was also significantly different between the SDD group and controls and between SDD and sucralfate. Conclusions: Both SDD and sucralfate regimens reduced the occurrence of nosocomial infection in mechanically ventilated patients, particularly in the occurrence of nosocomial pneumonia. Selective decontamination was more effective than sucralfate in preventing 'late-onset' pneumonia and nosocomial infection other than pneumonia.

Prevention of nosocomial infection in mechanically ventilated patients: selective digestive decontamination versus sucralfate

Objective: To evaluate the efficacy of two regimens, selective digestive decontamination (SDD) and sucralfate, in the prophylaxis of nosocomial infection in critically ill patients requiring prolonged mechanical ventilation. Design: Prospective, randomised, multi-centre trial. Setting: Medical and surgical intensive care units in 10 hospitals in Catalonia, Spain. Subjects: A total of 129 patients requiring mechanical ventilation for at least four days participated in the study. The absence of infection and use of systemic or topical antibiotic therapy prior to the diagnosis of nosocomial pneumonia was also required. Interventions: Patients were randomly assigned to the control group (n=42) in which histamine H2-receptor antagonists were given; the SDD group (n=41) using topical polymyxin E, tobramycin, and amphotericin B in the pharynx and stomach; and the sucralfate group (n=46). Patients in both regimens received intravenous cefotaxime for four days. Endpoints: The follow-up period was limited to ICU st...

“Blind” Protected Specimen Brushing vs Bronchoscopic Techniques in the Aetiological Diagnosis of Ventilator-associated Pneumonia

The aetiological diagnosis of nosocomial pneumonia in intensive care unit (ICU) patients requires a valid, cheap and safe method. This method should be suitable for all mechanically-ventilated patients and all ICUs. The aim of this study was to assess the diagnostic yields of three methods: “blind” bronchial brushing (Accu-Cath) (protective specimen brush-nonbronchofibroscopic (PSB-non BF)); bronchofibroscopic protected specimen brushing (PSB-BF) and bronchoalveolar lavage (BAL). We prospectively studied the diagnostic values of the three methods as well as the agreement between microbiological results in 74 patients with 88 episodes of clinically suspected ventilator-associated pneumonia (VAP) and 22 control subjects. VAP episodes were also divided into those with (n=24) and without antibiotic pretreatment (n=64), and into those with (n=78) and without (n=10) right lower lobe infiltrates on chest radiography. No differences were found as regards the bacteriological yield of the three techniques. Furthermore, the rate of concordant results was high; 92% for PSB-BF and BAL; 84% for PSB-nonBF and BAL; 85% for PSB-nonBF and PSB-BF; and 85% for PSB-nonBF combined with both bronchoscopic techniques. The diagnostic yields in suspected VAP were 66, 59 and 56% for PSB-nonBF, PSB-BF and BAL, respectively. We conclude that “blind” bronchial brushing has similar accuracy to bronchoscopic techniques commonly used in the diagnosis of ventilator-associated pneumonia, constituting an interesting alternative in hospitals where fibreoptic bronchoscopy is not available.

New perspectives in the diagnosis of nosocomial pneumonia.

In the past decade, much has been learned about the diagnosis of nosocomial pneumonia. Most of these reports focused on evaluating the diagnostic reliability of different techniques and identifying an adequate gold standard. In the past year, the most outstanding studies focused on practical issues such as developing more rapid and less invasive diagnostic techniques and tools, simplifying previously standardized techniques, and searching for safer and more cost-effective procedures. Following the current trend, in the next few years we should spend more time learning about the impact of current techniques on outcome and less time looking for "El Dorado."

Diagnostic Testing of ICU-Acquired Pneumonia-To the Editor

In his letter, Dr. Cykert proposes to use the results of distal samplings in the diagnosis of nosocomial pneumonia using the overall information obtained by quantitative tests following the Bayesian approach rather than cutoff points. We absolutely agree that, for any threshold, a quantitative test adds information for medical decision making. Diagnostic Testing of ICU-Acquired PneumoniaCHESTVol. 110Issue 1PreviewTo the Editor: Full-Text PDF

Usefulness of Airway Visualization in the Diagnosis of Nosocomial Pneumonia in Ventilated Patients

Clinical diagnosis of nosocomial pneumonia in ventilated patients remains a challenge in the ICU as none of the clinical biological and radiologic parameters can predict its diagnosis. To our knowledge, however, the accuracy of direct visualization of the bronchial tree has never been investigated. To evaluate the interest of airway visualization and to select independent parameters that predict nosocomial pneumonia in ventilated patients. A ten-bed medical-surgical ICU. All consecutive patients suspected of having nosocomial pneumonia who underwent bronchoscopy with protected specimen brush, culture examination of BAL, and direct examination of BAL were studied. Clinical and biological data and airways findings were recorded prospectively. Patients were classified as having pneumonia or not according to the results of distal bacteriologic samples, follow-up, and histologic study. Respective accuracies of each variable were calculated using univariate analysis and stepwise logistic regression. Ninety-one patients with suspected nosocomial pneumonia were studied. Patients were randomly assigned to a construction group (n = 46) and a validation group (n = 45). Using multivariate analysis, 3 factors were associated with pneumonia (a decrease in PaO2/fraction of inspired oxygen ratio > or = 50 mm Hg, odds ratio [OR] = 9.97, p = 0.026; the presence of distal purulent secretions, OR = 7.46, p = 0.044; the persistence of distal secretions surging from distal bronchi during exhalation, OR = 12.25, p = 0.013). These three factors remained associated with pneumonia in the validation group. Interobserver repeatability of the bronchoscopic parameters was good. Having 2 or more of these 3 independent factors was able to predict pneumonia with a 94% sensitivity and a 89% specificity in the construction group and with a 78% sensitivity and a 89% specificity in the validation group. We conclude that direct visualization of the bronchial tree can immediately and accurately predict nosocomial pneumonia in ventilated patients before obtaining definite results of protected samples.

The value of clinical judgment in the diagnosis of nosocomial pneumonia

Nosocomial pneumonia presents a diagnostic and therapeutic challenge in the care of critically ill patients. The present study was designed to determine as closely as possible the occurrence of nosocomial pneumonia in surgical intensive care unit (ICU) patients using clinical, radiographic, and bacteriological parameters in a prospective concurrent fashion. This clinical study enrolled all surgical, trauma, and neurosurgical patients admitted to a surgical ICU over a 13-month period. Routine surveillance was used to identify those patients suspected of developing nosocomial pneumonia. Numerous clinical parameters concerning ventilatory support, acute lung injury, organ dysfunction, nutrition, and length of stays were used to identify factors disposing to development of pneumonia. Univariate and multivariate analyses were used for this purpose. Patients thought to have pneumonia were then followed concurrently to determine, as closely as possible, whether pneumonia was present by serial examination of clinical, bacteriologic, and radiographic data. Those "validated" by this process were then compared to those "nonvalidated" to see if any distinction could be made. Of the 352 patients enrolled, 46 (13%) were initially labeled as having developed nosocomial pneumonia when compared to the 306 patients without pneumonia. Univariate analysis demonstrated a greater need for intubation and mechanical ventilation, longer mechanical ventilation, more acute lung injury, longer ICU and hospital stays, poorer nutrition, and higher mortality (17% versus 5%, P < 0.01). Multivariate analysis demonstrated only length of ICU stay and length of intubation/mechanical ventilation as longer in the pneumonia group. On further concurrent review, 23 of 46 patients were validated as having pneumonia while the rest were felt not to have pneumonia. When the two groups were compared, only asymmetric and segmental radiographic infiltrates distinguished validated from nonvalidated pneumonia patients and all other clinical parameters, including mortality and length of stay, were similar. Nosocomial pneumonia was initially suspected in 13% of this ICU population. Numerous clinical parameters clearly distinguished these pneumonia patients from others and they suffered a substantially higher mortality. However, within this pneumonia group, only half of the patients could be validated as truly having pneumonia using available clinical parameters. Nevertheless, those validated were indistinguishable in their clinical behavior from those who were not. This calls into question the need for elaborate and sometimes expensive investigations for diagnosis of nosocomial pneumonia.

The Effect of Fiberoptic Bronchoscopy on Cerebral Hemodynamics in Patients With Severe Head Injury

Concerns exist about the effect of flexible fiberoptic bronchoscopy (FFB) on intracranial pressure (ICP). We studied the effect of FFB on cerebral hemodynamics in patients with severe head injury. Prior to FFB, patients were anesthetized and muscle relaxants were given as necessary to eliminate coughing. Comparisons were made of mean arterial pressure (MAP), ICP, and cerebral perfusion pressure (CPP) prior to, during, and after FFB, as well as comparisons of mean cerebral hemodynamic values in an 8-hour period before and after FFB. Observations were made of changes in neurologic status post-FFB. Surgical intensive care unit of Level 1 Trauma Center. Fifteen patients with severe head injury in whom ICP was monitored and who required FFB for diagnosis of nosocomial pneumonia or treatment of lobar collapse. Pre-FFB ICP averaged 14.3 mm Hg (range, 6 to 26 mm Hg). During FFB, patients experienced a mean increase in ICP of 13.5 mm Hg above basal values (p = 0.0001). At peak ICP, MAP increased from a baseline of 92.3 mm Hg (SD +/- 16.1) to 111.5 mm Hg (+/- 13.9). Mean CPP was 83.7 mm Hg at peak ICP (range, 52 to 121 mm Hg), a 14.0% increase over baseline. The ICP and MAP returned to basal levels following bronchoscopy. No patient had a clinically significant increase in ICP or demonstrated any deterioration in Glasgow Coma Scale score or neurologic examination findings post-FFB. Although FFB causes an increase in ICP in patients with severe head injury, MAP also rises, and an adequate CPP is maintained. The ICP returns to basal levels after the procedure. When properly performed, FFB does not adversely affect neurologic status in patients with severe head injury.

Reproducibility of Protected Brush Catheter Specimen Cultures in Critically Ill Patients with Suspected Nosocomial Pneumonia

OBJECTIVE: To determine the reproducibility of two protected brush catheter (PBC) specimens obtained during the same bronchoscopy in critically ill patients with suspected ventilator associated pneumonia.DESIGN: Prospective, observational study.SETTING: Two university-affiliated multidisciplinary intensive care un its with a combined total of 50 beds.PATIENTS: A total of 75 (50 male. 25 female) patients with 84 episodes of suspected ventilator associated pneumonia were studied be tween January 1, 1991 and June 30, 1992. Age was 60.7±1.9 (mean ± SEM) years, and mean APACHE II score was 22.4±2.0. Twenty-four patients were admitted from various medical services, 19 from surgical services including the operating room, 16 with central nervous system disease and 16 following multiple trauma. Twenty patients were transferred directly to the intensive care unit from peripheral hospitals.INTERVENTIONS: All patients had lower respiratory tract secretions obtained for culture by both aspiration through the endotracheal n1be (tracheal aspirates) and flexible bronchoscopy, with separate samples obtained by two PBCs (PBC-A and PBC-8).MAIN RESULTS: The overall proportion of agreement between the results of t he two PBC specimens was 0.928, with a calculated kappa statistic (κ) = 0.853 (P&lt;0.01 versus κ=0.4, 95% CL 0.692, 1.014) indicating excellent agreement between the two specimens. Both PBC specimens had significant (ie, more than 103colony-forming units/mL) growth (positive/positive) in 33 cases, nonsignificant growth in 45 cases (negative/negative) and discordant results in six (positive/negative, n=3 or negative/positive, n=3 ). There was a significant relationship (P&lt;0.05) between the concurrent use of antibiotics and a negative PBC result. However, after exclusion of patients on antibiotics, the overall proportion of agreement between the two PBCs was 0.94 with κ=0.875 (P&lt;0.01 versus κ=0.4, 95% CL 0.721, 1.029), which also indicates excellent agreement between the two tests.CONCLUSIONS: Although discordant results were observed in 7.2% cases, the overall reproducibility of the PBC results appears to be high. The significant relationship between concurrent antibiotic use and a negative PBC result is of concern clinically since many patients arc being treated with antibiotics al the time of bronchoscopy. Therefore, when the diagnosis of nosocomial pneumonia in critically ill patients is established, the PBC result should be considered only in association with all the other clinical data, particularly in patients receiving concurrent antibiotics.

ANALYSIS OF CHARGES ASSOCIATED WITH DIAGNOSIS OF NOSOCOMIAL PNEUMONIA

Many ventilated trauma patients thought to have nosocomial pneumonia have pulmonary contusion or systemic inflammatory response syndrome with tracheobronchial colonization. Fiberoptic bronchoscopy with quantitative culture techniques of protected specimen brush (PSB; threshold 10(3) cfu/mL) or bronchoalveolar lavage (BAL; threshold 10(5) cfu/mL) can potentially eliminate the false positive cultures of the upper airway seen with routine sputum aspirates (RS). However, bronchoscopy is expensive, and routine use may not be cost effective. This prospective study evaluated the patient charges associated with bronchoscopy and quantitative cultures compared with RS for the diagnosis of nosocomial pneumonia. Specimens were obtained by RS, PSB, and BAL from the lower airway in 107 trauma patients (136 sets of triplicate cultures). All patients had clinical evidence suggestive of pneumonia (fever, leukocytosis, purulent sputum, abnormal roentgenographic findings). Typical oral flora were considered contaminants; no gram-negative specimens were excluded. Mean age was 40 years and mean ISS was 29. Seventy-eight percent had blunt injuries, 22% penetrating, and 42% had chest injuries. The incidence of nosocomial pneumonia according to each method was: RS-73%; PSB-34%; BAL-25%. Considering all charges involved (bronchoscopy, equipment, microbiologic analysis, and antibiotics), and based on a 14-day course of ceftazidime and vancomycin, the charges for PSB were 58% of RS, and charges for BAL were 43% of RS. We conclude that the charges associated with bronchoscopy are high, but can be offset by antibiotic savings. Side effects of unnecessary antibiotic therapy would be avoided. Further study is needed to determine the efficacy of PSB or BAL in trauma patients.