A novel method of continuous measurement of head of bed elevation in ventilated patients

Objective We developed a novel pressure transducer-based method of continuous measurement of head of bed elevation. Following validation of the method we hypothesized that head of bed angles would be at or above 30 ° among mechanically ventilated patients throughout the day due to a hospital-wide initiative on ventilator-associated pneumonia prevention and standardized electronic order entry system to keep head of bed at an angle of 30 ° or greater. Design and setting Prospective observational study in university hospital intensive care units. Patients and participants Twenty-nine consecutive mechanically ventilated patients with no contraindications for semirecumbency. Measurements and results We acquired 113 pairs of measurements on unused beds for validation of the method at angles between 3 ° and 70 °. Correlation between transducer and protractor was fitted into a linear regression model (R ² = 0.98) with minimal variation of data along the line of equality. Bland–Altman analysis showed a mean difference of 1.6 ° ± 1.6 °. Ninety-six percent of differences were within 2 SD from the mean. This method was then used among 29 intubated patients to collect head of bed data over a 24-h period for 3 consecutive days. Contrary to our hypothesis, all patients had head of bed angles less than 30 °. Conclusions Our results suggest that this method could be used with high reliability and patients in our institution were not kept even at 30 °. The results are in accord with those of a recent study which found that continued maintenance of previously suggested head of bed angles was difficult to attain clinically. This may lead us to reevaluate methods studying the impact of head of bed elevation in VAP prevention.     

The value of lumbar puncture in the evaluation of critically ill, non-immunosuppressed, surgical patients: a retrospective analysis of 70 cases

Objective: To evaluate the diagnostic value of lumbar puncture (LP) in surgical intensive care unit (SICU) patients. Design: Retrospective chart review. Setting: Surgical intensive care unit at a major tertiary care medical center. Patients: All patients admitted to the SICU during the period 1987–1995 who had a lumbar puncture, excluding those with a history of recent head trauma or a neurosurgical procedure. Measurements: Cerebral spinal fluid (CSF) results, indication for lumbar puncture, admitting service, length of ICU stay, presence of fever and use of antibiotics. Results: Of 7,555 admissions to the SICU over the period 1987–1995, 204 patients underwent LP during the hospital admission. Four charts could not be located and 75 patients underwent LP in locations other than the SICU. Of the remaining 125 cases, 55 carried a neurosurgical diagnosis and 70 had non-neurosurgical problems. Fifty-three (75 %) of the patients had received antibiotics prior to the procedure. Among the 70 cases without a primary neurosurgical diagnosis, LP was performed to rule out infective meningitis suggested by fever and mental status changes (30 patients), mental status changes alone (7 patients), systemic illness with fever and/or mental status changes (10 patients), seizures (10 patients), meningismus (+/− fever, 4 patients), or a combination of neurological findings (8 patients). There were no cases in which meningitis was positively diagnosed. Medical management was altered in only two patients based upon the results obtained by LP. Conclusions: We conclude that LP in SICU patients without a recent history of head trauma or a neurosurgical operation is a low yield procedure, especially for the diagnosis of bacterial meningitis. Received: 10 September 1996 Accepted: 6 May 1997     

Esophageal and transpulmonary pressures in acute respiratory failure

OBJECTIVE: Pressure inflating the lung during mechanical ventilation is the difference between pressure applied at the airway opening (Pao) and pleural pressure (Ppl). Depending on the chest wall's contribution to respiratory mechanics, a given positive end-expiratory and/or end-inspiratory plateau pressure may be appropriate for one patient but inadequate or potentially injurious for another. Thus, failure to account for chest wall mechanics may affect results in clinical trials of mechanical ventilation strategies in acute respiratory distress syndrome. By measuring esophageal pressure (Pes), we sought to characterize influence of the chest wall on Ppl and transpulmonary pressure (PL) in patients with acute respiratory failure. DESIGN: Prospective observational study. SETTING: Medical and surgical intensive care units at Beth Israel Deaconess Medical Center. PATIENTS: Seventy patients with acute respiratory failure. INTERVENTIONS: Placement of esophageal balloon-catheters. MEASUREMENTS AND MAIN RESULTS: Airway, esophageal, and gastric pressures recorded at end-exhalation and end-inflation Pes averaged 17.5 +/- 5.7 cm H2O at end-expiration and 21.2 +/- 7.7 cm H2O at end-inflation and were not significantly correlated with body mass index or chest wall elastance. Estimated PL was 1.5 +/- 6.3 cm H2O at end-expiration, 21.4 +/- 9.3 cm H2O at end-inflation, and 18.4 +/- 10.2 cm H2O (n = 40) during an end-inspiratory hold (plateau). Although PL at end-expiration was significantly correlated with positive end-expiratory pressure (p < .0001), only 24% of the variance in PL was explained by Pao (R = .243), and 52% was due to variation in Pes. CONCLUSIONS: In patients in acute respiratory failure, elevated esophageal pressures suggest that chest wall mechanical properties often contribute substantially and unpredictably to total respiratory impedance, and therefore Pao may not adequately predict PL or lung distention. Systematic use of esophageal manometry has the potential to improve ventilator management in acute respiratory failure by providing more direct assessment of lung distending pressure.     

Implementation and outcomes of the Multiple Urgent Sepsis Therapies (MUST) protocol

OBJECTIVES: To describe the effectiveness of a comprehensive, interdisciplinary sepsis treatment protocol with regard to both implementation and outcomes and to compare the mortality rates and therapies of patients with septic shock with similar historical controls. DESIGN: Prospective, interventional cohort study with a historical control comparison group. SETTING: Urban, tertiary care, university hospital with 46,000 emergency department visits and 4,100 intensive care unit admissions annually. PATIENTS: Inclusion criteria were a) emergency department patients aged > or =18 yrs, b) suspected infection, and c) lactate of >4 mmol/L or septic shock. Exclusion criteria were a) emergent operation, b) prehospital cardiac arrest, and c) comfort measures only. Time period: protocol, November 10, 2003, through November 9, 2004; historical controls, February 1, 2000, through January 31, 2001. INTERVENTION: A sepsis treatment pathway incorporating empirical antibiotics, early goal-directed therapy, drotrecogin alfa, steroids, intensive insulin therapy, and lung-protective ventilation. MEASUREMENTS AND MAIN RESULTS: There were 116 protocol patients, with a mortality rate of 18% (11-25%), of which 79 patients had septic shock. Comparing these patients with 51 historical controls, protocol patients received more fluid (4.0 vs. 2.5 L crystalloid, p < .001), earlier antibiotics (90 vs. 120 mins, p < .013), more appropriate empirical coverage (97% vs. 88%, p < .05), more vasopressors in the first 6 hrs (80% vs. 45%, p < .001), tighter glucose control (mean morning glucose, 123 vs. 140, p < .001), and more frequent assessment of adrenal function (82% vs. 10%, p < .001), with a nonstatistically significant increase in dobutamine use (14% vs. 4%, p = .06) and red blood cell transfusions (30% vs. 18%, p = .07) in the first 24 hrs. For protocol patients with septic shock, 28-day in-hospital mortality was 20.3% compared with 29.4% for historical controls (p = .3). CONCLUSIONS: Clinical implementation of a comprehensive sepsis treatment protocol is feasible and is associated with changes in therapies such as time to antibiotics, intravenous fluid delivery, and vasopressor use in the first 6 hrs. No statistically significant decrease in mortality was demonstrated, as this trial was not sufficiently powered to assess mortality benefits.     

Low-dose dopamine in the intensive care unit

For much of the last four decades, low-dose dopamine has been considered the drug of choice to treat and prevent renal failure in the intensive care unit (ICU). The multifactorial etiology of renal failure in the ICU and the presence of coexisting multisystem organ dysfunction make the design and execution of clinical trials to study this problem difficult. However, in the last decade, several meta-analyses and one large randomized trial have all shown a lack of benefit of low-dose dopamine in improving renal function. There are multiple reasons for this lack of efficacy. While dopamine does cause a diuretic effect, it does very little to improve mortality, creatinine clearance, or the incidence of dialysis. Evidence is also growing of its adverse effects on the immune, endocrine, and respiratory systems. It may also potentially increase mortality in sepsis. It is the opinion of the authors that the practice of using low-dose dopamine should be abandoned. Other drugs and treatment modalities need to be explored to address the serious issue of renal failure in the ICU.     

Bedside ultrasonography in the differential diagnosis of pulmonary pathologies in the intensive care unit

Among critically ill patients, opacification of a part or whole lung field on chest radiography may pose a challenge in the differential diagnosis of acute pulmonary pathologies (eg, pneumothorax, hemothorax, pleural effusion, atelectasis, and solid organ in thoracic cavity) and selection of treatment modalities. In cases in which clinical findings, history, and imaging studies are not conclusive, bedside ultrasonography may be invaluable in achieving a diagnosis. We present two cases in which portable ultrasonography at the bedside was critical to the diagnosis and subsequent management of the patient.     

Using the theory of reasoned action to explain physician intention to prescribe emergency contraception

CONTEXT: Although research has examined providers' knowledge, attitudes and prescribing behaviors with regard to emergency contraception, none has used a theory-based approach to understanding the interplay of these factors. METHODS: A cross-sectional survey of 96 faculty physicians from one Southern and three Midwestern universities was conducted in 2004 to assess factors associated with intention to prescribe emergency contraception. The theory of reasoned action guided the study hypotheses and survey design. Correlation and regression analyses were used to examine the data. RESULTS:Only 42% of respondents strongly intended to prescribe emergency contraception for teenagers, but 65-77% intended to do so for all other specified groups (women who ask for the method, who have had a method problem, who have experienced rape or incest, and who have had unprotected sex). Consistent with the theory of reasoned action, high intention to prescribe emergency contraception was associated with positive attitudes toward doing so and with the perception that specific colleagues or professional groups support prescribing it; however, the perception of support by colleagues or professional groups in general did not predict intention. Also consistent with the theory, physicians' knowledge about emergency contraception and their demographic characteristics were not significant. CONCLUSIONS: Interventions to encourage physicians to provide emergency contraception should take into account their attitudes toward the method and the components of those attitudes.