Factors Associated With Prolonged Mechanical Ventilation and Reventilation in Acute Cervical Spinal Cord Injury Patients

MINI: In this study, respiratory function at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical spinal cord injury. Serum thiobarbituric acid-reactive substances level at admission can be a useful predictor for severity in acute cervical patients with spinal cord injury.

STUDY DESIGN

Patients who had suffered from acute blunt cervical spinal cord injury (SCI) and admitted our hospital within 24 hours after injury were included in the study.

OBJECTIVE

We compared the respiratory function and serum reactive oxidative stress (ROS) after acute cervical SCI, and tried to find out the valuable predictors of weaning in patients with acute cervical SCI.

SUMMARY OF BACKGROUND DATA

Ventilation impairment is a major complication of acute cervical SCI. Evidence of oxygen radical formation in secondary injury from animal SCI models demonstrates an immediate postinjury increase in ROS production after SCI. We hypothesize that the serum ROS is associated with the severity of patients with acute cervical SCI.

METHODS

Thirty-eight adult patients who had acute cervical SCI and 58 healthy volunteers were enrolled. Respiratory function at admission, at the time of extubation and at 48 hours after extubation, serum oxidative stress, Injury Severity Score and Japanese Orthopaedic Association score at admission were compared.

RESULTS

The most notable predictor of mechanical ventilation more than 48 hours was serum thiobarbituric acid-reactive substances (TBARS) level at admission (P = 0.027), and the cut-off value of serum TBARS level was 731.7 μmol/L (sensitivity 87.5% and specificity 78.9%). For the reventilation ≤5 days, the notable predictors were respiratory function at the time of extubation (maximal inspiratory pressure, P = 0.040; maximal expiratory pressure, P = 0.020; and tidal volume, P = 0.036) and serum TBARS level at admission (P = 0.013), the cut-off value of serum TBARS level at admission was 762.3 μmol/L (sensitivity 100% and specificity 90.0%).

CONCLUSION

In this study, respiratory function (maximal inspiratory pressure, maximal expiratory pressure, and tidal volume) at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical SCI. Serum TBARS level at admission can be a useful predictor for severity in acute cervical SCI patients.

LEVEL OF EVIDENCE

3.

Semi-recumbent position versus supine position for the prevention of ventilator-associated pneumonia in adults requiring mechanical ventilation

BACKGROUND

Ventilator-associated pneumonia (VAP) is associated with increased mortality, prolonged length of hospital stay and increased healthcare costs in critically ill patients. Guidelines recommend a semi-recumbent position (30º to 45º) for preventing VAP among patients requiring mechanical ventilation. However, due to methodological limitations in existing systematic reviews, uncertainty remains regarding the benefits and harms of the semi-recumbent position for preventing VAP.

OBJECTIVES

To assess the effectiveness and safety of semi-recumbent positioning versus supine positioning to prevent ventilator-associated pneumonia (VAP) in adults requiring mechanical ventilation.

SEARCH METHODS

We searched CENTRAL (2015, Issue 10), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1946 to October 2015), EMBASE (2010 to October 2015), CINAHL (1981 to October 2015) and the Chinese Biomedical Literature Database (CBM) (1978 to October 2015).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing semi-recumbent versus supine positioning (0º to 10º), or RCTs comparing alternative degrees of positioning in mechanically ventilated patients. Our outcomes included clinically suspected VAP, microbiologically confirmed VAP, intensive care unit (ICU) mortality, hospital mortality, length of ICU stay, length of hospital stay, duration of ventilation, antibiotic use and any adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently and in duplicate screened titles, abstracts and full texts, assessed risk of bias and extracted data using standardised forms. We calculated the mean difference (MD) and 95% confidence interval (95% CI) for continuous data and the risk ratio (RR) and 95% CI for binary data. We performed meta-analysis using the random-effects model. We used the grading of recommendations, assessment, development and evaluation (GRADE) approach to grade the quality of evidence.

MAIN RESULTS

We included 10 trials involving 878 participants, among which 28 participants in two trials did not provide complete data due to loss to follow-up. We judged all trials to be at high risk of bias. Semi-recumbent position (30º to 60º) versus supine position (0° to 10°) A semi-recumbent position (30º to 60º) significantly reduced the risk of clinically suspected VAP compared to a 0º to 10º supine position (eight trials, 759 participants, 14.3% versus 40.2%, RR 0.36; 95% CI 0.25 to 0.50; risk difference (RD) 25.7%; 95% CI 20.1% to 30.1%; GRADE: moderate quality evidence).There was no significant difference between the two positions in the following outcomes: microbiologically confirmed VAP (three trials, 419 participants, 12.6% versus 31.6%, RR 0.44; 95% CI 0.11 to 1.77; GRADE: very low quality evidence), ICU mortality (two trials, 307 participants, 29.8% versus 34.3%, RR 0.87; 95% CI 0.59 to 1.27; GRADE: low quality evidence), hospital mortality (three trials, 346 participants, 23.8% versus 27.6%, RR 0.84; 95% CI 0.59 to 1.20; GRADE: low quality evidence), length of ICU stay (three trials, 346 participants, MD -1.64 days; 95% CI -4.41 to 1.14 days; GRADE moderate quality evidence), length of hospital stay (two trials, 260 participants, MD -9.47 days; 95% CI -34.21 to 15.27 days; GRADE: very low quality evidence), duration of ventilation (four trials, 458 participants, MD -3.35 days; 95% CI -7.80 to 1.09 days), antibiotic use (three trials, 284 participants, 84.8% versus 84.2%, RR 1.00; 95% CI 0.97 to 1.03) and pressure ulcers (one trial, 221 participants, 28% versus 30%, RR 0.91; 95% CI 0.60 to 1.38; GRADE: low quality evidence). No other adverse events were reported. Semi-recumbent position (45°) versus 25° to 30° We found no statistically significant differences in the following prespecified outcomes: clinically suspected VAP (two trials, 91 participants, RR 0.74; 95% CI 0.35 to 1.56; GRADE: very low quality evidence), microbiologically confirmed VAP (one trial, 30 participants, RR 0.61; 95% CI 0.20 to 1.84: GRADE: very low quality evidence), ICU mortality (one trial, 30 participants, RR 0.57; 95% CI 0.15 to 2.13; GRADE: very low quality evidence), hospital mortality (two trials, 91 participants, RR 1.00; 95% CI 0.38 to 2.65; GRADE: very low quality evidence), length of ICU stay (one trial, 30 participants, MD 1.6 days; 95% CI -0.88 to 4.08 days; GRADE: very low quality evidence) and antibiotic use (two trials, 91 participants, RR 1.11; 95% CI 0.84 to 1.47). No adverse events were reported.

AUTHORS' CONCLUSIONS

A semi-recumbent position (≧ 30º) may reduce clinically suspected VAP compared to a 0° to 10° supine position. However, the evidence is seriously limited with a high risk of bias. No adequate evidence is available to draw any definitive conclusion on other outcomes and the comparison of alternative semi-recumbent positions. Adverse events, particularly venous thromboembolism, were under-reported.

Screening for Ventilator-Associated Pneumonia in the Surgical Intensive Care Unit: A Single-Institution Analysis of 1,013 Lower Respiratory Tract Cultures

BACKGROUND

Refinement of criteria for both screening and initiation of empiric therapy in ventilator-associated pneumonia (VAP) will minimize antibiotic overuse. We hypothesized that variables within the commonly used Clinical Pulmonary Infection Score (CPIS) have unfavorable test performance characteristics.

METHODS

Consecutive bronchoalveolar lavage (BAL) cultures obtained from surgical intensive care unit patients were abstracted (2009-2012). Ventilator-associated pneumonia was defined as ≥10(5) cfu/mL. The CPIS both without (CPISclinical) and with (CPISclinical+GS) the result of gram stain (GS) was calculated. Test performance characteristics for the sample, as well as several subgroups, were compared.

RESULTS

One thousand thirteen lower respiratory tract cultures from 492 patients were analyzed; 438 (43.2%) of cultures were classified as VAP, and 310 of 492 patients (62.4%) had ≥1 episode of VAP. Both CPISclinical and CPISclinical+GS had poor discrimination for VAP (Receiver-operating characteristic area under the curve=0.55 and 0.66, respectively). Sensitivity of CPISclinical using a threshold of >6 was 21%; the lowest threshold for CPISclinical for which the sensitivity was at least 85% was 3. The highest sensitivity among the individual CPIS components was new CXR infiltrate (91.1%). Among the subset of cultures sent during the early VAP window (days intubated 2-5), organisms on GS had a sensitivity of 93.3%. The CPISclinical, CPISclinical+GS, organisms, and neutrophils on GS parameters all became less accurate in both the late VAP window and when screening for recurrent VAP. Every case of VAP had at least one of the following: 1) fever; 2) new CXR infiltrate, or 3) organisms on GS.

CONCLUSION

In this series of BALs, traditional screening tools for VAP missed the majority of microbiological confirmed cases. Screening based on either new CXR infiltrate or fever yielded an acceptably high sensitivity. The only scenario identified in which empiric antibiotics could be withheld safely was the absence of organisms on GS in the early VAP window.

Bacteremia and empyema caused by Shewanella algae in a trauma patient

OBJECTIVE

To describe the first reported case of bacteremia and empyema caused by Shewanella algae and summarize the existing literature on Shewanella human infection.

CASE SUMMARY

A 25-year-old healthy male was shot through the chest into the abdomen and fled into an adjacent body of seawater. He underwent surgical repair of his injuries, including pleural decortication. Leukocytosis, bandemia, and copious yellow bronchorrhea led to cultures; piperacillin/tazobactam and vancomycin were started for broad-spectrum empiric management based on the local intensive care unit antibiogram. Blood and pleural fluid cultures revealed S algae. Sputum cultures grew methicillin-sensitive Staphylococcus aureus and Haemophilus influenzae. He was successfully managed with an empiric and then tailored antibiotic regimen.

DISCUSSION

Shewanella algae is a rare Gram-negative bacillus that has infrequently been reported to cause infection. It is found predominantly in men. Shewanella algae infections span bacteremia to necrotizing soft tissue infection and are associated with injury and seawater exposure. Shewanella is susceptible to the majority of third- and fourth-generation cephalosporins, aminoglycosides, chloramphenicol, erythromycin, aztreonam, and fluoroquinolones, but are less predictably susceptible to tetracycline and trimethoprim/sulfamethoxazole and carbapenem agents. Shewanella infection is associated with medical comorbidities, in particular, renal failure and cardiovascular disease.

CONCLUSIONS

To our knowledge, this is the first case report of bacteremia and empyema caused by S algae. Such a case involving a young healthy individual should encourage health care providers to be aware of the potential infections caused by unusual pathogens, and to employ appropriate empiric antibiotic therapy based on reported sensitivity profiles. Based on available susceptibilities, we recommend using a third or fourth-generation cephalosporin as first-line pharmacologic management with regimen de-escalation based on culture-derived data.

Factors predicting ventilator dependence in patients with ventilator-associated pneumonia

Objectives. To determine risk factors associated with ventilator dependence in patients with ventilator-associated pneumonia (VAP). Study Design. A retrospective study was conducted at Chang Gung Memorial Hospital, Kaohsiung, from January 1, 2007 to January 31, 2008. Methods. This study evaluated 163 adult patients (aged ≥18 years). Eligibility was evaluated according to the criterion for VAP, Sequential Organ Failure Assessment (SOFA) score, Acute Physiological Assessment and Chronic Health Evaluation II (APACHE II) score. Oxygenation index, underlying comorbidities, septic shock status, previous tracheostomy status, and factors related to pneumonia were collected for analysis. Results. Of the 163 VAP patients in the study, 90 patients survived, yielding a mortality rate of 44.8%. Among the 90 surviving patients, only 36 (40%) had been weaned off ventilators at the time of discharge. Multivariate logistic regression analysis was used to identify underlying factors such as congestive cardiac failure (P = 0.009), initial high oxygenation index value (P = 0.04), increased SOFA scores (P = 0.01), and increased APACHE II scores (P = 0.02) as independent predictors of ventilator dependence. Results from the Kaplan-Meier method indicate that initial therapy with antibiotics could increase the ventilator weaning rate (log Rank test, P < 0.001). Conclusions. Preexisting cardiopulmonary function, high APACHE II and SOFA scores, and high oxygenation index were the strongest predictors of ventilator dependence. Initial empiric antibiotic treatment can improve ventilator weaning rates at the time of discharge.

Neurocritical care nursing research priorities

The science of nursing has long been discussed as a blending of the art and science of caring, and nursing research builds the evidence of support for nursing practice. Nurses and nursing care are key to successful neurocritical care research endeavors. Ideally nursing care should be evidence based and supported by solid research. The goal of nursing research is to expand the knowledge of caring for patients. Within the scope of nursing research, the priorities for research in neurocritical care should support this goal. In this manuscript, we discuss what we believe are the priorities of neurocritical care nursing research, the obstacles, and some possible solutions.

Reducing VAP by instituting a care bundle using improvement methodology in a UK paediatric intensive care unit

Preventing ventilator-associated pneumonia (VAP) is one of the Department of Health Saving Lives initiatives. We describe the institution of a purpose-designed bundle of care in a tertiary paediatric ICU based on the available literature as part of our hospital's transformation project into reducing health-care-associated infection. A nurse-led VAP surveillance programme is in place, and we used this to compare VAP incidence before and after commencing a series of care measures aimed at reducing VAP as part of an overall drive for patient safety. The diagnostic criteria, surveillance methods and rates of VAP (5.6 per 1,000 ventilator days) have been previously reported. Nurse educators were added to the original core group, as a key feature is buy in from nursing staff. All nursing staff had multiple training opportunities, and VAP project education became a routine part of staff induction. The major features of the bundle of care were (1) elevation of bed to maximum (target, 45°; however, no beds currently permit this so achieved 20-30°), (2) mouth care using chlorhexidine or tooth brushing, (3) clean suctioning practice, (4) all patients not on full feeds commenced on ranitidine and (5) 4-hourly documentation. Compliance with these aspects was monitored. After the institution of the bundle, no paediatric case of VAP was recorded over a 12-month period, according to a priori definitions. One adult patient had a confirmed VAP over the same time interval. A paediatric VAP bundle was associated with reduced VAP on a UK PICU.

The pathogen of ventilator-associated pneumonia does not influence the mortality rate of surgical intensive care unit patients treated with a rotational antibiotic system

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the leading causes of morbidity in critically ill surgical patients. Certain pathogens (e.g., methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa) have been associated with an excess mortality rate from sepsis in several studies, but not in the surgical setting specifically or when protocol-driven antibiotic therapy is administered.

PURPOSE

We sought to determine which factors and, in particular, whether the individual pathogen affected the mortality rate in our surgical intensive care unit (ICU), where a rotational antibiotic system has been employed continuously since 1997. We hypothesized that the type of pathogen and illness severity were the primary influences on the mortality rate of patients with VAP.

METHODS

A total of 198 consecutive patients from a university surgical ICU, with clinical signs of VAP confirmed by quantified isolation of significant numbers of a pathogen (> or =10(4) colony-forming units [cfu]/mL) from bronchoalveolar (BAL) fluid obtained by fiberoptic bronchoscopy, were identified prospectively from January 2001 to November 2004. The data collected were age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) III score, multiple organ dysfunction score, unit day of diagnosis, time (h) to antibiotic administration (TTA), appropriateness of initial therapy (AIT), unit and hospital length of stay, and mortality rate. Pathogens were classified as non-lactose-fermenting gram-negative bacilli (NGNB), lactose-fermenting gram-negative bacilli (LGNB), methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, yeast, community-acquired pneumonia (e.g., Streptococcus pneumoniae), or other pathogens. Patients with a polymicrobial isolate were placed in the "other" category.

RESULTS

The overall mortality rate was 32.3% vs. 55% as predicted by APACHE III normative data. The overall AIT was 92%. The mortality rate for NGNB infections was 35.6% vs. 29.4% for LGNB infections (p = NS). By logistic regression, neither TTA, AIT, nor pathogen influenced the mortality rate.

CONCLUSIONS

The type of pathogen does not influence death in surgical ICU patients with VAP diagnosed rigorously and treated by a rotational antibiotic system. The high proportion of AIT as a result of the rotational antibiotic administration system optimizes bacterial killing and negates the impact of bacterial resistance, contributing to better outcomes.

Hospital-acquired pneumonia: pathophysiology, diagnosis, and treatment

Hospital-acquired pneumonia (HAP) is one of the most common causes of nosocomial infection, morbidity, and mortality in hospitalized patients. Many patient- and disease-specific factors contribute to the pathophysiology of HAP, particularly in the surgical population. Risk-factor modification and inpatient prevention strategies can have a significant impact on the incidence of HAP. While the best diagnostic strategy remains a subject of some debate, prompt and appropriate antimicrobial therapy in patients suspected of having HAP has been shown to significantly decrease mortality. Because the pathogens responsible for HAP are frequently more virulent and have greater resistance to commonly used antimicrobials than other pathogens, clinicians must have knowledge of the resistance patterns at their institutions to choose appropriate therapy.

Does de-escalation of antibiotic therapy for ventilator-associated pneumonia affect the likelihood of recurrent pneumonia or mortality in critically ill surgical patients?

BACKGROUND

Ventilator-associated pneumonia (VAP) is a leading cause of mortality in critically ill patients. Although previous studies have shown that de-escalation therapy (DT) of antibiotics may decrease costs and the development of resistant pathogens, minimal data have shown its effect in surgical patients or in any patients with septic shock. We hypothesized that DT for VAP was not associated with an increased rate of recurrent pneumonia (RP) or mortality in a high acuity cohort of critically ill surgical patients.

METHODS

All surgical intensive care unit (SICU) patients from January 2005 to May 2007 with VAP diagnosed by quantitative bronchoalveolar lavage with a positive threshold of 10,000 CFU/mL were identified. Data collected included age, gender, Acute Physiologic and Chronic Health Evaluation Score III (A3), type of bacterial or other pathogen, antibiotics used for initial and final therapy, mortality, RP, and appropriateness of initial therapy (AIT). Patients were designated as receiving AIT, DT, or escalation of antibiotic therapy based on microbiology for their VAP.

RESULTS

One hundred thirty-eight of 1,596 SICU patients developed VAP during the study period (8.7%). For VAP patients, the mean Acute Physiologic and Chronic Health Evaluation III score was 82.7 points with a mean age of 63.8 years. The RP rate was 30% and did not differ between patients receiving DT (27.3%) and those who did not receive DT (35.1%). Overall mortality was 37% (55% predicted by A3 norms) and did not differ between those receiving DT (33.8%) or not (42.1%). The most common pathogens for primary VAP were methicillin-resistant Staphylococcus aureus (14%), Escherichia coli (11%), and Pseudomonas aeruginosa (9%) whereas P. aeruginosa was the most common pathogen in RP. The AIT for all VAP was 93%. De-escalation of therapy occurred in 55% of patients with AIT whereas 8% of VAP patients required escalation of antibiotic therapy. The most commonly used initial antibiotic choice was vancomycin/piperacillin-tazobactam (16%) and the final choice was piperacillin-tazobactam (20%). Logistic regression demonstrated no specific parameter correlated with development of RP. Higher A3 (Odds ratio, 1.03; 95% confidence interval, 1.01-1.05) was associated with mortality whereas lack of RP (odds ratio, 0.31; 95% confidence interval, 0.12-0.80), and AIT reduced mortality (odds ratio, 0.024; 95% confidence interval, 0.007-0.221). Age, gender, individual pathogen, individual antibiotic regimen, and the use of DT had no effect on mortality.

CONCLUSION

De-escalation therapy did not lead to RP or increased mortality in critically ill surgical patients with VAP. De-escalation therapy was also shown to be safe in patients with septic shock. Because of its acknowledged benefits and lack of demonstrable risks, de-escalation therapy should be used whenever possible in critically ill patients with VAP.

Volatile compounds characteristic of sinus-related bacteria and infected sinus mucus: analysis by solid-phase microextraction and gas chromatography-mass spectrometry

Volatile compounds from human breath are a potential source of information for disease diagnosis. Breath may include volatile organic compounds (VOCs) originating in the nasal sinuses. If the sinuses are infected, disease-specific volatiles may enter exhaled air. Sinus infections are commonly caused by several known bacteria. We examined the volatiles characteristic of infectious bacteria in culture using solid-phase microextraction to collect and gas chromatography-mass spectrometry as well as gas chromatography with flame photometric detection to separate and analyze the resulting VOCs. Infected sinus mucus samples were also collected and their VOCs examined. Similar characteristic volatiles were seen from both cultures of individual "pure" bacteria and several mucus samples. However, the relative amounts of characteristic VOCs from individual bacteria differ greatly between cultures and sinus mucus. New compounds, not seen in culture were also seen in some mucus samples. Our results suggest an important role for growth substrate and environment. Our data further suggests that in some sinus mucus samples identification of bacteria-specific volatiles is possible and can suggest the identity of an infecting organism to physicians. Knowledge of these bacteria-related volatiles is necessary to create electronic nose-based, volatile-specific sensors for non-invasive examination for suspected sinus infection.

Ventilator-associated pneumonia in a paediatric intensive care unit in a developing country with high HIV prevalence

AIM

To obtain preliminary prevalence, aetiological and outcome data on South African paediatric patients with ventilator-associated pneumonia (VAP).

METHODS

Non-bronchoscopic bronchoalveolar lavage (BAL) specimens taken between January 2004 and September 2005 were prospectively recorded and related clinical data were retrospectively reviewed. VAP was defined as a new isolate on BAL and a modified Clinical Pulmonary Infection Score > or =5.

RESULTS

A total of 230 patients aged 3.9 (2.2-9.1) months (median interquartile range (IQR) ) underwent 309 BALs during 244 paediatric intensive care unit (PICU) admissions. Most patients (84%) were admitted with acute infectious diseases, with a 70% incidence of comorbidity. Thirty-three patients (14.3%) were HIV-exposed but uninfected and 58 (25.2%) were HIV-infected. Of 172 BALs taken > or =48 h after intubation, 63 specimens from 55 patients fulfilled VAP criteria. Acinetobacter baumannii was the most common VAP pathogen, followed by Klebsiella pneumoniae, viruses, yeasts and Staphylococcus aureus. Patients who developed VAP had a higher proportion of comorbid conditions (76% vs. 55%, P= 0.01) and reintubations (39% vs. 12%, P < 0.0001) when compared with non-VAP patients. Median (IQR) length of PICU stay was 12.5 (5-21) days versus 8 (5-14) days (P= 0.03); and the risk adjusted PICU mortality was 1.38 versus 0.79 (P= 0.002) in VAP versus non-VAP patients, respectively.

CONCLUSIONS

VAP is associated with significant morbidity and mortality and may relate to the high incidence of comorbid conditions in this population. Primary VAP pathogens differ from developed countries.

Treatment of severe sepsis secondary to mycobacterium avium-intracellulare with recombinant human activated protein C

BACKGROUND

Mycobacterium avium-intracellulare (MAI) is a well-described pathogen in patients with acquired immune deficiency syndrome (AIDS). However, peritonitis and severe sepsis as a complication of disseminated MAI is rare. We report a case that represents the first successful use of recombinant human activated protein C (rhAPC) in the treatment of severe sepsis secondary to mycobacterial infection and only the second reported case of MAI peritonitis with no known predisposing factor other than AIDS.

METHODS

Case report and review of the pertinent literature.

RESULTS

A 36-year-old man with AIDS presented to the emergency department with acute-onset right-sided abdominal pain, fever, and chills. Abdominal computed tomography revealed multiple rim-enhancing fluid collections. Despite immediate surgical drainage and debridement and appropriate antimicrobial therapy targeting the non-tuberculous acid-fast bacilli found in intraperitoneal fluid, the patient developed severe sepsis and septic shock. Clinical improvement occurred after infusion of recombinant human activated protein C (rhAPC) and specific antimicrobial chemotherapy directed against MAI.

CONCLUSIONS

Treatment with rhAPC decreases the mortality rate of bacterial sepsis of abdominal origin and may confer a similar benefit in the treatment of abdominal mycobacterial sepsis.