Haemophilus pneumonia is a common cause of early pulmonary dysfunction following trauma

Analysis of Hypoxemia in Early Ventilator-Associated Pneumonia Secondary to Haemophilus in Trauma Patients

BACKGROUND

Haemophilus species bacteria (HSB) are known pathogens responsible for early pneumonia in intubated trauma patients. The primary goal of this study was to examine the incidence and extent of hypoxemia in intubated trauma patients who develop early ventilator-associated pneumonia (VAP) secondary to HSB. On the basis of our clinical experiences, we hypothesized that patients with Haemophilus species bacteria pneumonia (HSBP) would have a high rate of hypoxemia but that the effect would be transient.

METHODS

Retrospective review of intubated trauma patients from an urban level I trauma center with HSBP diagnosed by deep tracheal aspirate or bronchoalveolar lavage from April 2007 to November 2012. Collected variables included day of HSBP diagnosis; PaO2 to FIO2 ratio (P:F) at HSBP diagnosis as well as HSBP day three and HSBP day seven; injury severity score (ISS) and its component parts; admission Glasgow Coma Scale (GCS) score; and mortality. Hypoxemia was defined as P:F <200. χ(2) Tests were utilized to assess factors that differed between hypoxemic and non-hypoxemic patients; data are presented as median (interquartile range, IQR).

RESULTS

Sixty-nine patients were identified (80% male; age, 35 y [range, 24-49]; ISS 27 [9-59]). Diagnosis of HSBP occurred early (hospital day 4 [range, 3-5]). Forty-three percent of patients had acute respiratory distress syndrome (ARDS) on HSBP day 1; this decreased to 26% on day three and to 30% on day seven. Forty patients (77%) had a tracheostomy performed. Patients with hypoxemia were significantly less likely to have a severe head injury (GCS<9), p<0.05. Patients with hypoxemia had similar hospital length of stay and mortality to patients who did not develop hypoxemia.

CONCLUSION

Haemophilus species bacteria pneumonia in trauma patients is associated with high rates of transient hypoxemia and a high tracheostomy rate, although subsequent outcomes are not affected. Patients with head injuries had a lower incidence of hypoxemia from pneumonia.

A Retrospective Study of Nosocomial Pneumonia in Postoperative Patients Shows a Higher Mortality Rate in Patients Receiving Nasogastric Tube Feeding

Pneumonia remains a significant cause of morbidity and mortality in surgical patients. Though most studies have focused on pneumonia in trauma or special respiratory intensive care units (ICU), we examine postoperative ventilator-associated pneumonia in patients undergoing elective operations. We hypothesized that a study of multiple clinical variables would disclose factors influencing morbidity and mortality in these patients. We conducted a retrospective review of 1969 patients who underwent elective general, cardiac, and general thoracic procedures during a 6-month period in a private teaching hospital. A total of 77 patients (3.9%) developed postoperative ventilator-associated pneumonia. Thirty-eight (49%) patients had a history of smoking and 27 (35%) had chronic obstructive pulmonary disease (COPD). Among these 77 patients, 20 (26%) experienced recurrent pneumonia. The overall mortality rate for patients developing pneumonia was 34 per cent. At diagnosis of pneumonia, 33 patients were receiving enteral nutrition through nasogastric feeding tubes, whereas 41 received no enteral feeding. The method of nutritional intake was not known in 3 patients. The feeding/nonfeeding groups were similar in age and underlying disease, differing significantly only in the higher number of smokers in the patients not receiving enteral nutrition ( P = 0.03). To our surprise, the mortality rate from all causes was higher ( P = 0.018) in the patients who received tube feedings through soft, nasogastric feedings (33%) than in those not enterally fed (17%). Parenteral nutrition, COPD, number of ventilator days, and the location of the tip of the feeding tube did not correlate with mortality. The mortality rate from all causes was higher in patients with postoperative pneumonia who received tube feedings, despite similar underlying medical illnesses. Enteral feeding of postoperative surgical patients has many desirable effects, but prospective studies should address harmful effects, such as presumed aspiration and related pneumonia.

A time-dependent analysis of intensive care unit pneumonia in trauma patients

BACKGROUND

Appropriate and timely antibiotic therapy to treat pneumonia in trauma patients is extremely important. We evaluated the incidence and microbiology of pneumonia stratified by days postadmission and risk factors.

METHODS

Prospective data were collected on 714 trauma patients admitted to the intensive care unit over a 1-year period. Pneumonia was classified as community acquired (CAP) (< or = 3 days), early nosocomial (ENP) (4-6 days), or late nosocomial (LNP) (> or = 7 days). In addition, pneumonia was classified as CAP only, nosocomial only (NI), or combination (CAP and NI, or ENP and LNP) pneumonia. Strict institutional guidelines were followed for diagnosis.

RESULTS

One hundred eighty-two patients (25%) were diagnosed with 204 pneumonias over the study period. One hundred twenty-five (61%) of these pneumonias were ventilator associated. Staphylococcus aureus and Haemophilus influenzae were the most common pathogens isolated. Twenty-one percent of patients with CAP acquired an LNP (p < 0.025), in which Pseudomonas was the most common organism. Haemophilus caused LNP in 12% of patients. Cancer (p < 0.01), liver failure (p < 0.05), and age (p < 0.01) were predictive of nontypical pathogens in patients with CAP and ENP (p < 0.05). Obesity was most predictive of increased ventilator days (p < 0.001) and intensive care unit length of stay (p < 0.001). Increased age, alcohol abuse, and field airway were most predictive of mortality.

CONCLUSION

Unanticipated pathogens were isolated in each class of pneumonia. The clinician must be aware of significant risk factors that may predispose patients to pathogens that are not ordinarily covered with standard antibiotic therapy.

Emergence of resistant microbes in critical care units is transient, despite an unrestricted formulary and multiple antibiotic trials

BACKGROUND

Antimicrobial resistance is a growing problem in the intensive care setting. This study was designed to evaluate the trends in bacterial prevalence and changes in antibiotic resistance at a large university hospital over the past decade. Antimicrobial resistance data were compared among the surgical intensive care unit (SICU), medical intensive care unit (MICU), and burn unit (BNU).

MATERIALS AND METHODS

A large database was created using hospital-wide data from 1989 to 2000. A retrospective analysis of the evolution of organism prevalence, antibiotic resistance, and response to study protocols was evaluated. The formulary was relatively unrestricted. All positive cultures were examined, focusing on wound, blood, and sputum cultures. Six primary antibiotics were targeted specifically to follow resistance patterns.

RESULTS

There were 847 identified positive wound cultures, 2,862 positive sputum cultures, and 2,252 positive blood cultures. The incidence of gram-positive and gram-negative organisms changed little in the SICU and BNU; however, there was a large increase in gram-positive organisms and yeast in the MICU over the past 5 years. Anaerobic bacteria and yeast were nearly nonexistent pathogens in the SICU and BNU. The resistance pattern of most organisms changed little following the introduction of a new antibiotic. However, the effectiveness of study antibiotics after formal clinical study periods decreased dramatically, albeit transiently.

CONCLUSION

Hospital-wide antibiotic resistance data may be misleading and may not reflect individual critical care units throughout the hospital. Bacterial flora, including resistant organisms, changed little over 10 years, despite an unrestricted formulary. The emergence of resistant and opportunistic organisms is related to antibiotic usage and can vary significantly over time. This suggests that a policy of administering limited duration, narrow spectrum antibiotics may reduce drug resistance.

Nosocomial pneumonia in the pediatric trauma patient: a single center's experience

OBJECTIVES

To evaluate a single center's experience with the frequency rate, patterns of occurrence, and impact on outcome of nosocomial pneumonia in the critically injured child.

DESIGN

Retrospective review of prospectively collected data.

SETTING

Level I university trauma center with a pediatric trauma intensive care unit.

PATIENTS

A total of 523 consecutive critically injured children admitted to the pediatric intensive care unit during an 80-month interval.

MEASUREMENTS AND RESULTS

Thirty-five episodes of nosocomial pneumonia were identified in 29 children (frequency rate of 5.5%). The mean age of the children was 9.2 yrs, and the mean Injury Severity Score was 27 +/- 9. In 91% of patients (26 children), nosocomial pneumonia was associated with mechanical ventilation. This represented a 13% frequency rate in injured children who were ventilated during the study period. The most common organisms recovered were Staphylococcus aureus (21%), Haemophilus influenzae (19%), Pseudomonas (11%), and Enterobacter (11%). Early pneumonia (diagnosed < or = 7 days after injury) was predominantly caused by Haemophilus species. In contrast, Enterobacter and/or Pseudomonas were isolated primarily in late pneumonia (diagnosed >7 days after injury). Staphylococcus was prominent throughout the hospitalization. Overall, children with nosocomial pneumonia were more severely injured (Injury Severity Score 27 vs. 17, p < .001) and had a longer hospital stay (26 vs. 7 days, p < .001). Despite this, mortality (6.9% vs. 7.9%, p = NS) was not significantly different from injured children without pneumonia.

CONCLUSIONS

In this study of a single pediatric trauma center, nosocomial pneumonia occurred in a small but significant percentage of injured children. The frequency rate increased two- to three-fold with mechanical ventilation. Microbiology varied with day of onset. In contrast to the adult, mortality did not seem to be significantly altered by this complication. Analysis of additional pediatric trauma centers is encouraged to confirm these characteristics of nosocomial pneumonia in the injured child.

Infectious complications in critically injured children

PURPOSE

Infection will complicate the care of a significant number of injured adults. Trauma is the leading cause of mortality in the pediatric population, yet little information is available regarding the incidence of infection in this group. This study evaluates infectious complications in the critically injured child.

METHODS

All children admitted to the pediatric intensive care unit from an urban level-1 trauma center during an 80-consecutive-month period were studied. Infection was defined by Centers for Disease Control criteria and was identified by a retrospective review of the medical records. Demographic and clinical information, including microbiologic data, were compiled for all study patients. Data were analyzed using Student's (t)test or chi2 analysis where appropriate.

RESULTS

Five hundred twenty-three children were at risk for infection during the study period. Seventy-eight infections were documented in 53 children (incidence, 10.1%). Nosocomial infections accounted for 78% of these with a majority (85%) being device associated. Common infections in this group included lower respiratory (n = 35), primary bloodstream (n = 10), and urinary tract (n = 7). Trauma-related infections were primarily wound (n = 9), intraabdominal (n = 3), or central nervous system (n = 3). Bacterial pathogens predominated, and the most frequent microorganisms recovered were Staphylococcus aureus, Pseudomonas sp, and Haemophilus sp. Children with infectious complications were more severely injured (injury severity score [ISS] 24 versus 17, P < .001) and had a longer hospital stay (21 days v 6 days, P < .001) compared with children without infection during the same period. Overall mortality rate for the study group was 5.7% and was not significantly different from children without infection.

CONCLUSIONS

Infection is a significant source of morbidity in the critically injured child. Nosocomial infections predominate, and a majority of these are device related, emphasizing the need for continued vigilance toward prevention in this high-risk group.

Management of infections in the trauma patient

Infections play a leading role in the morbidity and mortality of injured patients. This article discusses risk factors that can increase the chances of a nosocomial infection. It also discusses common types of infection, causative organisms, and the approach to the febrile trauma patient.

Utility of Gram's stain and efficacy of quantitative cultures for posttraumatic pneumonia: a prospective study

OBJECTIVE

This prospective trial examined the efficacy of using bronchoalveolar lavage (BAL) for the diagnosis of pneumonia (PN) and the utility of Gram's stain (GS) for dictating empiric therapy.

SUMMARY BACKGROUND DATA

Posttraumatic nosocomial PN remains a significant cause of morbidity and mortality. However, its diagnosis is elusive, especially in multiply injured patients. The systemic inflammatory response syndrome of fever, leukocytosis, and a hyperdynamic state is common in trauma patients, especially patients with pulmonary contusion. Bronchoscopy with BAL with quantitative cultures of the lavage effluent may distinguish between PN and systemic inflammatory response syndrome, and GS of the lavage effluent may guide empiric therapy before quantitative culture results.

METHODS

Mechanically ventilated trauma patients with a clinical diagnosis of PN (fever, leukocytosis, purulent sputum, and new or changing infiltrate on chest radiograph) underwent bronchoscopy with BAL. Effluent was sent for GS and quantitative cultures. The diagnostic threshold for PN was > or =10(5) colony-forming units (CFU)/mL, and antibiotics were continued. Antibiotics were stopped for < 10(5) CFU/mL and the diagnosis of systemic inflammatory response syndrome was made. Causative organisms for PN were compared to GS.

RESULTS

Over a 2-year period, 232 patients underwent 443 bronchoscopies with BAL (71% men, 29% women; mean age, 41). The mean injury severity score was 30. Sixty percent of the patients had pulmonary contusion, and 59% were cigarette smokers. The overall incidence of PN was 39% and was no different regardless of the number of BALs a patient had. The false-negative rate of BAL was 7%. GS identified gram-positive organisms in 80% of patients with gram-positive PN and 40% of patients with gram-negative PN. GS identified gram-negative organisms in 52% of patients with gram-positive PN and 77% with gram-negative PN. The duration of the intensive care unit stay relative to the timing of BAL was beneficial for guiding empiric therapy. BAL in week 1 primarily identified Haemophilus influenzae and gram-positive organisms; Acinetobacter sp. and Pseudomonas sp. were more common after week 1.

CONCLUSIONS

Bronchoscopy with BAL is an effective method to diagnose PN and avoids prolonged, unnecessary antibiotic therapy. Empiric therapy should be adjusted to the duration of the intensive care unit stay because the causative bacteria flora changes over time. GS of BAL effluent correlates poorly with quantitative cultures and is not reliable for dictating empiric therapy.