Bronchoalveolar lavage in the diagnosis of ventilator-associated pneumonia: to quantitate or not, that is the question.

Quantitative bronchoalveolar lavage (BAL) is used to diagnose ventilator-associated pneumonia (VAP). We prospectively compared semiquantitative (SQ) and quantitative (Qu) culture of BAL for VAP diagnosis. Ventilated patients suspected of VAP underwent bronchoscopic BAL. BAL fluid was examined by both Qu (colony-forming units [CFUs]/mL) and SQ culture (none, sparse, moderate, or heavy) and results were compared. VAP was defined as 105 CFU/mL or greater on Qu culture. Over 36 months, 319 BALs were performed. Sixty-three of 319 (20%) showed diagnostic growth by Qu culture identifying a total of 81 organisms causing VAP. All 63 specimens showed growth of some organism(s) on SQ culture with 79 of 81 causative organisms identified and two (Pseudomonas, one; Corynebacterium, one) not identified. The remaining 256 specimens did not meet the threshold for VAP by the Qu method. Among these, 79 did not show any growth on SQ culture. Among the 240 specimens showing some growth on SQ culture, a total of 384 organisms were identified. VAP rates in relation to strength of growth on SQ culture were: sparse, 10 of 140 (7%); moderate, 24 of 147 (16%); and heavy, 45 of 97 (46%). Sensitivity (Sn), specificity (Sp), positive (PPV), and negative (NPV) predictive values of SQ culture of BAL fluid for the diagnosis of VAP were 97, 21, 21, and 97 per cent, respectively. Nonquantitative culture of BAL fluid is fairly accurate in ruling out VAP (high Sn and NPV). It however has poor Sp and PPV and using this method will lead to unnecessary antimicrobial use with its attendant complications of toxicity, cost, and resistance.

A central venous line protocol decreases bloodstream infections and length of stay in a trauma intensive care unit population.

We evaluated the benefit of a central venous line (CVL) protocol on bloodstream infections (BSIs) and outcome in a trauma intensive care unit (ICU) population. We prospectively compared three groups: Group 1 (January 2003 to June 2004) preprotocol; Group 2 (July 2004 to June 2005) after the start of the protocol that included minimizing CVL use and strict universal precautions; and Group 3 (July 2005 to December 2006) after the addition of a line supply cart and nursing checklist. There were 1622 trauma patients admitted to the trauma ICU during the study period of whom 542 had a CVL. Group 3 had a higher Injury Severity Score (ISS) compared with both Groups 2 and 1 (28.3 +/- 13.0 vs 23.5 +/- 11.7 vs 22.8 +/- 12.0, P = 0.0002) but had a lower BSI rate/1000 line days (Group 1: 16.5; Group 2: 15.0; Group 3: 7.7). Adjusting for ISS group, three had shorter ICU length of stay (LOS) compared with Group 1 (12.11 +/- 1.46 vs 18.16 +/- 1.51, P = 0.01). Logistic regression showed ISS (P = 0.04; OR, 1.025; CI, 1.001-1.050) and a lack of CVL protocol (P = 0.01; OR, 0.31; CI, 0.13-0.76) to be independent predictors of BSI. CVL protocols decrease both BSI and LOS in trauma patients. Strict enforcement by a nurse preserves the integrity of the protocol.

Predictive value of broncho-alveolar lavage fluid Gram's stain in the diagnosis of ventilator-associated pneumonia: a prospective study.

BACKGROUND: Quantitative broncho-alveolar lavage (qBAL) is increasingly being used for diagnosing ventilator-associated pneumonia (VAP). The current study prospectively evaluates the accuracy of broncho-alveolar lavage fluid Gram's stain (GS) in predicting both the presence of VAP and the class of causative microorganism in patients suspected of VAP. METHODS: Patients suspected of VAP in a trauma or surgical intensive care unit underwent bronchoscopic qBAL with GS. Presence and class of organisms seen on GS were correlated respectively with the presence of VAP, as diagnosed by qBAL, and class of causative microorganism. VAP was defined as qBAL >10(5) colony forming units/mL. All data were gathered prospectively. RESULTS: During a 28-month study period, 229 patients underwent 309 qBALs for suspected VAP. Seventy-one (23%) specimens were positive for VAP (qBAL>10(5) CFU/mL). Fifty-four specimens (77%) had one causative microorganism, 13 (18%) had two, 3 (4%) had three, and 1 (1%) demonstrated four microorganisms giving a total of 93 VAPs. Forty-one (62%) of 66 specimens showing moderate or many microorganisms on GS were positive for VAP. However, 7 (4%) of 167 specimens showing none and 23 (30%) of 76 showing few microorganisms on GS were also positive for VAP. Of the 64 qBAL specimens positive for VAP and where the GS showed microorganisms, 6 (23%) of 26 showing only G+ microorganisms on GS had G- VAP (G- alone, 4; G+ and G-, 2), and 1 (8%) of 12 showing G- microorganisms only had G+ and G- VAP. Of the seven qBAL specimens positive for VAP where the GS did not show microorganisms, one had G+ and six had G- VAP. With the threshold of positivity of GS at more than none, the sensitivity, specificity, positive, and negative predictive values of GS for the presence of VAP were 90%, 67%, 45%, and 96% respectively. CONCLUSIONS: Broncho-alveolar lavage fluid GS is poor in predicting the presence of VAP and predicting the class of causative microorganism. Using GS to determine necessity of and to select class of antimicrobial therapy will result in delayed or inappropriate VAP therapy or both.

Prospective evaluation of an extubation protocol in a trauma intensive care unit population.

Little data exists regarding extubation protocols in critically injured trauma patients. The objective of the current study was to prospectively examine the impact of implementing an extubation protocol on the outcomes of ventilated trauma patients in a surgical intensive care unit (STICU). Trauma patients admitted to the STICU over a 15-month period at a Level 1 trauma center were prospectively evaluated. The total period was divided into an education and institution period (April 2002-November 2003) and an evaluation period (December 2003-July 2003). Patient demographics, hospital course, complications, and outcomes from period I were compared with those obtained during period II. From April 8, 2002 through July 5, 2003, 69 patients intubated for greater than 24 hours were included in our analysis. Thirty-three were treated during period I and 36 were treated during period II. Both groups were well matched in terms of age, sex, Injury Severity Score, and chest Abbreviated Injury Score. Ventilation days significantly decreased from a mean of 16.3 to 8.2 days (P = 0.04). ICU length of stay also decreased, nearly meeting significance. A rigorously enforced extubation protocol significantly decreased ventilator days in STICU patients. Continued education of health care providers is key to the success of the protocol.

Actigraphy in the critically ill: correlation with activity, agitation, and sedation.

OBJECTIVES: To determine the feasibility of continuous measurement of limb movement via wrist and ankle actigraphy (an activity measure) in critically ill patients and to compare actigraphy measurements with observed activity, subjective scores on sedation-agitation scales, and heart rate and blood pressure of patients. METHODS: In a prospective, descriptive, correlational study, all activity of 20 adult patients in medical and coronary care units in a university medical center were observed for 2 hours and documented. Wrist and ankle actigraphy, heart rate, and systolic and diastolic blood pressure data were collected every minute. The Comfort Scale and the Richmond Agitation-Sedation Scale were completed at the beginning of the observation period and 1 and 2 hours later. RESULTS: Wrist actigraphy data correlated with scores on the Richmond Agitation-Sedation Scale (r = 0.58) and the Comfort Scale (r = 0.62) and with observed stimulation and activity events of patients (r = 0.45). Correlations with systolic, diastolic, and mean arterial pressures were weaker. Wrist and ankle actigraphy data were significantly correlated (r = 0.69; P < .001); however, their mean values (wrist, 418; ankle, 147) were significantly different (t = 5.77; P < .001). CONCLUSIONS: Actigraphy provides a continuous recording of patients' limb movement. Actigraphy measurements correlate well with patients' observed activity and with subjective scores on agitation and sedation scales. Actigraphy may become particularly important as a continuous measurement of activity for use in behavioral research and may enhance early recognition and management of the excessive activity that characterizes agitation.

Computed tomographic angiography for the diagnosis of blunt carotid/vertebral artery injury: a note of caution.

OBJECTIVE: Computed tomographic angiography (CTA) by 16-channel multidetector scanner is increasingly replacing conventional digital subtraction angiography (DSA) for diagnosing or excluding blunt carotid/vertebral injuries (BCVI). To date there has been only 1 study in which all patients received both examinations. That study reported a high accuracy for 16-detector CTA. The current prospective parallel comparative study aims at validating this high accuracy and examining the rates of evaluability of CTA performed with a 16-detector scanner with image reconstruction by modern imaging software. METHODS: Patients at risk for BCVI (facial/cervical-spinal fractures; unexplained neurologic deficit; anisocoria; lateral neck soft tissue injury; clinical suspicion) underwent both CTA (16-channel multidetector scanner) and DSA. Results of the 2 studies and the clinical course were prospectively recorded. RESULTS: During the 40-month study period ending March 2007, approximately 7000 blunt trauma patients were evaluated and of these 119 (1.7%) consecutive patients meeting inclusion criteria were screened by CTA. Ninety-two patients underwent confirmatory DSA. Twenty-three (22%) DSA identified 26 BCVI (vertebral, 13; carotid, 13). Among these 23 CTAs, 17 identified 19 BCVIs (vertebral, 10; carotid, 9) (true positives), and 6 failed to identify 7 BCVIs (vertebral, 3; carotid, 4) (false negatives). Sixty-nine of the 92 DSA were normal. Of these 69 CTAs, 10 were falsely suspicious for 11 BCVIs (vertebral, 7; carotid, 4) (false positives), and 56 were normal (true negatives). The remaining 3 CTAs were nonevaluable (mistimed contrast, 1; streak artifact, 2). Sixteen of 89 (18%) evaluable CTAs, were suboptimal (mistimed contrast, 9; streak artifacts, 4; motion artifact, 2; body habitus, 1). Excluding the 3 nonevaluable CTAs, the sensitivity, specificity, positive and negative predictive values of CTA for diagnosing or excluding BCVI were 74%, 86%, 65%, and 90% respectively. One patient with grade II carotid artery injuries (by CTA and DSA) on antiplatelet agent developed stroke related to carotid artery injuries. CONCLUSIONS: Current CTA technology cannot reliably diagnose or exclude BCVI. Twenty percent of CTAs are either nonevaluable or suboptimal. Until more data are available and the technique is standardized, the current trend towards using CTA to screen for and/or diagnose these rare but potentially devastating injuries is dangerous.