Antimicrobial therapy for intra-abdominal infections: guidelines from the Infectious Disease Advisory Board (IDAB).

Intra-abdominal infection is a common cause of severe sepsis in a hospital setting and remains associated with a significant morbidity, mortality and resource use. Early adequate surgery or drainage remain the cornerstones of intra-abdominal infection management and impact on patients outcome. Concomitant early and adequate empiric antimicrobial therapy further influences patients morbidity and mortality. Multiple empirical regimens have been proposed in this setting, but rarely supported by well designed, randomized-controlled studies. The current manuscript summarizes the recommendations of the Infection Disease Advisory Board on the management of intra-abdominal infections. Empiric antimicrobial therapy for the most common causes of abdominal infections is proposed. In addition, particular attention has been paid on antibiotic treatment duration.

Temporal scanner thermometry: a new method of core temperature estimation in ICU patients.

BACKGROUND AND AIMS: Temperature measurement is a routine task of patient care, with considerable clinical impact, especially in the ICU. This study was conducted to evaluate the accuracy and variability of the Temporal Artery Thermometer (TAT) in ICU-patients. Therefore, a convenience sample of 57 adult patients, with indwelling pulmonary artery catheters (PAC) in a 40-bed intensive care unit in a university teaching hospital was used. METHODS: The study design was a prospective, descriptive comparative analysis. Body temperature was thereby measured simultaneously with the TAT and the Axillary Thermometer (AT), and was compared with the temperature recording of the PAC. The use of vasoactive medication was recorded. RESULTS AND CONCLUSIONS: Mean temperature of all measurements was: PAC: 37.1 degrees C (SD: 0.87), TAT 37.0 degrees C (SD: 0.68) and axillary thermometer: 36.6 degrees C (SD: 0.94). The measurements of the TAT and the PAC were not significantly different (man differnce: 0.14 degrees C; SD: 0.51; p = 0.33); whereas the measurements of the PAC and the AT differed significantly (mean difference: 0.46 degerees C; SD: 0.39; p < 0.001). Mean diference in PAC versus TAT analyses, between patients with vasopressor therapy (0.12 degrees C; SD: 0.55), and without vasopressor therapy (0.19 degrees C; SD: 0.48) was not statistically significant (p = 0.47). CONCLUSION: We can conclude that the temporal scanner has a relatively good reliability with an acceptable accuracy and variability in patients with normothermia. The results are comparable to those of the AT, but they do not seem to be sufficient to prove any substantial benefit compared to rectal, oral or bladder thermometry.

Fungal infections in patients with severe acute pancreatitis and the use of prophylactic therapy.

Data from an 8-year period for 46 patients with severe acute pancreatitis and infected pancreatic necrosis were analyzed to determine the incidence of fungal infection, to identify risk factors for the development of fungal infection, and to assess the use of early fluconazole treatment. Intraabdominal fungal infection was found in 17 (37%) of 46 patients. Candida albicans was isolated most frequently (15 patients); Candida tropicalis and Candida krusei were found in 1 patient each. Characteristics of patients with fungal infection were not different from patients without fungal infection. The difference in mortality was not statistically significant between patients with fungal infection and patients without fungal infection. Early antifungal therapy (prophylactic or preemptive antifungal therapy) was administered to 18 patients, and only 3 of them developed fungal infection. In this cohort of critically ill patients, no risk factors for fungal infection could be demonstrated, and mortality among patients who received early antifungal therapy was not different. Early treatment with fluconazole seems to prevent fungal infection in these high-risk patients.

Diquat intoxication: report of two cases and review of the literature.

Animal experiments have suggested that diquat is less toxic than the more widely used paraquat. In this paper, nine previously reported cases of diquat intoxication are reviewed, together with the description of our personal observations in two additional patients. These two patients, like four other patients described in the literature, died from complications involving the gastrointestinal tract, brain and kidneys. Thus, diquat intoxication is apparently not as innocent as was originally thought. In this paper, special attention has been given to the major clinical differences between diquat and paraquat intoxication. In contrast with the latter, severe diquat intoxication induces gastrointestinal fluid sequestration and is associated with cerebral hemorrhagic lesions and a higher incidence of severe acute renal failure. Despite an asymptomatic clinical interval of up to 48 hours after ingestion, hemoperfusion should be started as soon as possible to prevent toxic levels of diquat in tissue.

Use of dopexamine hydrochloride in intensive care patients with low-output left ventricular heart failure.

The short- and long-term hemodynamic effects of intravenous dopexamine hydrochloride (Dopacard) were studied in 12 patients with low cardiac output left ventricular heart failure. In the short-term study, a dose of 4 micrograms/kg/min produced a 60% increase in cardiac output (p less than 0.001), a 30% increase in stroke volume (p less than 0.01), a 23% increase in heart rate (p less than 0.01) and a 39% decrease in systemic vascular resistance (p less than 0.001). In the long-term study, there was a sustained hemodynamic benefit after 8 hours of dopexamine hydrochloride infusion (mean dose 3.5 micrograms/kg/min). There was a 32% increase in cardiac output (p less than 0.001), an 18% increase in stroke volume (p less than 0.05), a 12% increase in heart rate (p less than 0.001) and a 30% decrease in systemic vascular resistance (p less than 0.01). After 48 hours of dopexamine hydrochloride infusion (mean dose 3.8 micrograms/kg/min), the hemodynamic effect was significant only for cardiac output (+20%, p less than 0.05) and for systemic vascular resistance (-26%, p less than 0.01). Thus, dopexamine hydrochloride has beneficial short-term hemodynamic effects in patients with low-output left ventricular heart failure and the benefit appears to diminish with long-term infusion.

Evaluation of the hemodynamic and respiratory effects of inverse ratio ventilation with a right ventricular ejection fraction catheter.

Pc-IRV has been shown to have respiratory advantages, compared with CPPV. However, the hemodynamic effects of this ventilation mode have not yet been fully elucidated. We used a REF catheter to monitor the hemodynamic changes in the RV. Fifteen ARDS patients were included in the study. The respiratory data showed a 35 percent decrease of PIP and a 32 percent decrease of VTi and VTe with Pc-IRV 4:1 compared with CPPV. Hemodynamic parameters showed a significant incrase in CI (17 percent) in Pc-IRV 4:1, without change in REF. Observing in retrospect the pressure-volume relationship of the RV, we could differentiate a preload (group 1) and an afterload dependent group of patients (group 2), CI was significantly different in the two groups as it rose only in the preload-dependent patients. RVEDVI showed a significant change in group 1, whereas this was absent in the second group. REF was maintained in switching ventilation from CPPV to Pc-IRV with increasing I:E ratio. Pc-IRV appears to be a good alternative ventilatory mode in comparison with CPPV in a selected group of patients with preload dependency (responders); in these patients with respiratory insufficiency, close hemodynamic monitoring is required to optimize ventilation, especially in relation to the hemodynamic effects.

Evaluation of transesophageal echocardiography as a diagnostic and therapeutic aid in a critical care setting.

OBJECTIVES: To assess the impact of transesophageal echocardiography (TEE) on therapeutic management in relation to pulmonary artery catheterization (PAC) in the ICU. DESIGN: Retrospective analysis of 108 consecutive TEE video and related patient files during a 7-month period. SETTING: A 33-bed medical and surgical ICU. METHODS: All critically ill patients with or without PAC in whom a TEE was performed, excluding postoperative cardiac surgical patients. Patients were divided in a cardiac and a septic group depending on the primary disease on admission to the ICU. The impact of TEE in relation to PAC on ICU management was evaluated in whether therapy changes were performed strictly on the basis of the TEE findings. MAIN RESULTS: Of 64% of patients with a PAC, 44% underwent therapy changes after TEE: 41% in the cardiac and 54% in the septic subgroup. In 41% of patients without a PAC, TEE led to a change in therapy. CONCLUSIONS: TEE results in altered therapeutic management in at least one third of our (noncardiac surgery) ICU patient population independent of the presence of a PAC.

Penetration of netilmicin in the lower respiratory tract after once-daily dosing.

A major criticism of the use of aminoglycosides for the treatment of pneumonia is the poor penetration in infected airways. Once-daily dosing of aminoglycosides results in higher peak plasma concentrations without increasing toxic reactions and with optimization of pharmacodynamic properties. To predict intrapulmonary antimicrobial activity after once-daily dosing of aminoglycosides, it is necessary to determine the respective bronchial and alveolar disposition. We prospectively conducted a pharmacokinetic study of netilmicin following the first intravenous administration of a once-daily dosing schedule in 20 ventilated patients with pneumonia. A bronchoscopic sampling of bronchial secretions and a subsegmental bronchoalveolar lavage (BAL) were performed 60, 90, 120, and 180 min (five patients at each time point) on the first treatment day after intravenous administration over 30 min of 450 mg of netilmicin. The netilmicin concentrations in the alveolar lining fluid (ALF) were calculated using urea as an endogenous marker of dilution. In bronchial secretions, a peak concentration of 2.00 (SEM: 0.26) mg/L or 6 percent of the 30-min plasma concentration was reached at 120 min. In ALF, much higher levels were found. At 120 min, a peak ALF concentration of 14.7 (SEM: 2.22) mg/L or 41 percent of the 30-min plasma concentration was reached. Spearman's rank correlation testing failed to show a correlation between bronchial and ALF concentrations. Higher plasma concentrations of netilmicin after once-daily dosing give rise to ALF concentrations exceeding the minimum inhibitory concentration of susceptible respiratory pathogens involved in nosocomial pneumonia, while bronchial concentrations remain low. Aminoglycoside concentrations in bronchial secretions cannot be used to predict alveolar concentrations. Low diffusibility can no longer be considered as a disadvantage of aminoglycosides for treating pneumonias.

Acute hemodynamic changes of pressure-controlled inverse ratio ventilation in the adult respiratory distress syndrome. A transesophageal echocardiographic and Doppler study.

Twelve patients with the adult respiratory distress syndrome were included in this study and evaluated by transesophageal echocardiography and Doppler, assessing right and left ventricular intracardiac blood flow alterations with progressive increase of inspiration-to-expiration (I-E) ratios. Whereas midpulmonary artery flow parameters did not show any change, early left ventricular filling demonstrated a significant increase after switching the ventilatory mode from volume to pressure-controlled ventilation with 2:1 I-E ratio (end-inspiration: 39 +/- 26 cm with positive end-expiratory pressure [PEEP]-ventilation to 68 +/- 56 cm with pressure-controlled inverse-ratio ventilation, 2:1; p < 0.01; at end-expiration, from 67 +/- 21 cm with PEEP-ventilation to 83 +/- 36 cm with pressure-controlled ventilation 1:1; p < or = 0.05), resulting probably from different ventilatory flow and pressure curves. In the meanwhile, cardiac index demonstrated a significant augmentation (from 4.73 +/- 1.71 L/min.m2 to 5.56 +/- 1.66 L/min.m2; p < 0.05). Pressure-controlled inverse ratio ventilation results in both respiratory and hemodynamic advantages as is demonstrated by this study.

Early predictors of mortality and morbidity after severe closed head injury.

Mortality and morbidity of 158 patients with severe head injury were studied in relation to age, and early (24-h) clinical and computed tomography data. For comparison of outcome data in survivors, a group of 32 patients with traumatic injuries to parts of the body other than the head was used as controls. Within the head-injured group, the mortality rate was 51%. Logistic regression analyses combined 13 out of 16 predictors into a model with an accuracy of 93%, a sensitivity of 90%, and a specificity of 95%. These include age, Glasgow Coma Scale (GCS) score, pupillary reactivity, blood pressure, intracranial pressure, blood glucose, platelet count, body temperature, cerebral lactate, and subdural, intracranial, subarachnoid, and ventricular hemorrhage. At 6 months postinjury, head-injury survivors and trauma controls were evaluated with the Glasgow Outcome Scale (GOS), a neuropsychological test battery and the Sickness Impact Profile (SIP). Head-injury survivors had a higher proportion of disabilities and neuropsychological dysfunctions than trauma controls. They also report more quality of life-related functional limitations on the SIP scales for mobility, intellectual behavior, communication, home management, eating, and work. Linear regression analysis resulted in age being the only important predictor of outcome on the GOS, the GCS score being the best predictor of neuropsychological functioning, and pupillary reactivity being the most predictive for self-reported quality of life as measured by SIP. Those factors important for predicting mortality (clinical variables such as ICP or blood glucose level, and CT observations) failed to show any significant relationship with morbidity.

Pressure measurement evaluation and accuracy validation: the Gabarith test.

OBJECTIVE: The dynamic distortion introduced by manometric systems has been known for many years, with several methods developed to describe and quantify the degree of distortion. We developed the Gabarith as a technique to describe more accurately, and yet more simply, the dynamic accuracy of the chain of monitoring. SETTING: A pressure monitoring system transforms some input signal, i.e. the actual pressure waveform present in the artery, into some other shape of waveform, i.e. the waveform displayed on the patient monitor. This transformation is characterized by the transfer function of the total system. A complete technique to define the transfer function is to measure the response directly at many different frequencies and combine them to produce the dynamic response plot. METHOD: We described the dynamic response of a monitoring chain and we simplified the communication of this dynamic response to users by developing the Gabarith, as a tolerance envelope based on the frequency content of typical pressure waveforms. If a given monitoring chain's dynamic response (including a catheter, a pressure kit and a monitor) can be shown to fall within that tolerance envelope, the chain will provide adequate dynamic accuracy. CONCLUSION: "Gabarith tested" means that a pressure kit, in combination with a catheter and a monitor, has had its frequency response function measured and that the function falls within a tolerance band for dynamic accuracy. Passing a Gabarith means that a given level of accuracy will be reached when using the sets which have passed the corresponding test.

Left ventricular systolic and diastolic function in septic shock.

OBJECTIVE: The identification of myocardial dysfunction in septic shock has not yet been fully elucidated. We therefore studied patients with persistently vasopressor-dependent septic shock, both with invasive haemodynamic monitoring and transoesophageal two-dimensional and Doppler echocardiography (TEE). DESIGN: Prospective study. SETTING: General ICU in University Hospital. PATIENTS AND METHODS: All patients were monitored with arterial and pulmonary artery catheters. Haemodynamics were obtained concomitantly with TEE measurements. TEE was performed at three levels: a) a midpapillary short axis view of the left ventricle (LV) in order to measure end-systolic and end-diastolic areas; b) at the level of both the mitral valve for early (E) and late (A) filling parameters and c) the level of the right upper pulmonary vein for systolic (S) and diastolic (D) filling characteristics. Each parameter was characterised by maximal flow velocity and time velocity integral. RESULTS: Although the measurements of cardiac index demonstrated a wide range, three subsets of patients were identified post hoc after analysis on the basis of different Doppler patterns: first, patients with a LV without regional wall motion abnormalities and both E/A and S/D greater than 1 (group 1); second, patients with a comparable haemodynamic condition, apparently normal LV systolic function but with altered Doppler patterns: S/D less than 1 in conjunction with E/A more than 1 (group 2); finally, patients with compromised global LV systolic function, E/A less than 1 and S/D less than (group 3). CONCLUSIONS: Notwithstanding the known various interfering factors which limit the broad applicability of TEE to determine LV function in septic shock, our data suggest that cardiac dysfunction in septic shock shows a continuum from isolated diastolic dysfunction to both diastolic and systolic ventricular failure. These data strengthen the need of including the evaluation of pulmonary venous Doppler parameters in each investigation in order to obtain supplementary information to interpret diastolic function of the LV in septic shock patients.

Use of continuous bispectral EEG monitoring to assess depth of sedation in ICU patients.

Monitoring the depth of sedation in patients under intensive care is difficult. Clinical assessment by the different scoring systems produces insufficient information, especially once deeply sedated patients become unresponsive to any external stimulation. Recently, the bispectral index (BIS), the result of computerized bispectral electroencephalographic monitoring, was found to be the best predictor of depth of anaesthesia during surgical intervention. This report concerns BIS monitoring in 18 randomly selected, deeply sedated, surgical patients in the intensive care unit, who were unresponsive to standard clinical stimulation (Ramsay sedation score). A wide range of BIS was observed, with 15 of the patients having a BIS below 60, indicating a state of deep sedation (or possibly over-sedation). Therefore, further studies using BIS monitoring in patients under intensive care are needed to determine if this method can guide sedation and prevent oversedation in this context and, most importantly, to analyse its final cost-benefit ratio.

Cerebral perfusion pressure and intracranial pressure in relation to neuropsychological outcome.

OBJECTIVE: The study attempted to examine the relationship between neuropsychological functioning and reduced cerebral perfusion pressure (CPP), raised intracranial pressure (ICP), and reduced mean arterial pressure (MAP), monitored during intensive care treatment. DESIGN: This prospective follow-up study included consecutive patients and evaluated outcome at 6 months postinjury by the administration of a neuropsychological test battery. SETTING: The study was conducted at the University Hospital of Gent, Belgium. PATIENTS AND PARTICIPANTS: Over a 30-month period, 43 patients were included. Inclusion criteria were the following: hospital admission following closed head injury. ICP monitoring, no medical history of central nervous system disease or mental retardation, survival for at least 6 months, and informed consent for participation. INTERVENTIONS: All patients received the hospital's standard treatment for head injury, which remained unchanged during the study period. MEASUREMENTS AND RESULTS: Reduced CPP was analyzed using the number of observed values below 70 mmhg, raised ICP using the number of values above 20 mmHg, and MAP using the number of values below 80 mmHg. The neuropsychological test battery included 11 measures of attention, information processing, motor reaction time, memory, learning, visuoconstruction, verbal fluency, and mental flexibility. No linear relationships were found between overall neuropsychological impairment and episodes of reduced CPP, raised ICP, or reduced MAP. CONCLUSIONS: Although reduced CPP and raised ICP are frequent, often fatal, complications of head injury, in survivors they do not seem to be related to later neuropsychological functioning.

Reappraisal of attributable mortality in critically ill patients with nosocomial bacteraemia involving Pseudomonas aeruginosa.

In a retrospective study, population characteristics and outcome were investigated in intensive care unit (ICU) patients with hospital-acquired Pseudomonas aeruginosa bacteraemia admitted over a seven-year period (January 1992 through December 1998). A matched cohort study was performed in which all ICU patients with P. aeruginosa bacteraemia were defined as cases (N=53). Matching (1:2 ratio) of the controls (N=106) was based on the APACHE II classification: an equal APACHE II score (+/-1 point) and an equal diagnostic category. Patients with P. aeruginosa bacteraemia had a higher incidence of acute respiratory failure, haemodynamic instability, a longer ICU stay and length of ventilator dependence (P<0.05). In-hospital mortalities for cases and controls were 62.3 vs. 47.2% respectively (P=0.073). Thus, the attributable mortality was 15.1% (95% confidence intervals: -1.0-31.2). In a multivariate survival analysis the APACHE II score was the only variable independently associated with mortality. In conclusion, P. aeruginosa bacteraemia is associated with a clinically relevant attributable mortality (15%). However, we could not find statistical evidence of P. aeruginosa being an independent predictor of mortality.

Outcome in critically ill patients with candidal fungaemia: Candida albicans vs. Candida glabrata.

In a retrospective study (1 January 1992-12 December 1998), we investigated population characteristics and outcome in critically ill patients with fungaemia involving C. albicans (n=41) and C. glabrata (n=15). Patients with C. glabrata fungaemia were significantly older compared with patients in the C. albicans group (P=0.024). There were no other differences in population characteristics or severity of illness. Logistic regression analysis showed age (P=0.021), the presence of a polymicrobial blood stream infection (P=0.039), and renal failure (P=0.044) to be independent predictors of mortality. There was no significant difference in in-hospital mortality between the C. glabrata and C. albicans groups (60.0% vs. 41.5%; P=0.24). Since age was an independent predictor of mortality, the trend towards a higher mortality in patients with C. glabrata can be explained by this population being significantly older. In conclusion, we found no difference in mortality between patients with fungaemia involving C. albicans and C. glabrata.

Invasive aspergillosis in critically ill patients: attributable mortality and excesses in length of ICU stay and ventilator dependence.

Invasive aspergillosis is a rare disease in intensive care unit (ICU) patients and carries a poor prognosis. The aim of the present study was to determine the attributable mortality due to invasive aspergillosis in critically ill patients. In a retrospective, matched cohort study (July 1997-December 1999), 37 ICU patients with invasive aspergillosis were identified together with 74 control patients. Matching of control (1:2) patients was based on the acute physiology and chronic health evaluation (APACHE) II classification: an equal APACHE II score (+/-1 point) and diagnostic category. This matching procedure results in an equal expected in-hospital mortality for cases and controls. Additionally, control patients were required to have an ICU stay equivalent to or longer than the case before the first culture positive for Aspergillus spp. Patients with invasive aspergillosis were more likely to experience acute renal failure (43.2% versus 20.5%; P = 0.020). They also had a longer ICU stay (median: 13 days versus seven days; P < 0.001) as well as a more extended period of mechanical ventilator dependency (median: 13 days versus four days; P < 0.001). Hospital mortalities for cases and controls were 75.7% versus 56.8%, respectively (P=0.051). The attributable mortality was 18.9% (95% CI: 1.1-36.7). A multivariate survival analysis showed invasive aspergillosis [hazard ratio (HR): 1.9, 95% CI: 1.2-3.0; P = 0.004] and acute respiratory failure (HR: 6.5, 95%: 1.4-29.3; P < 0.016) to be independently associated with in-hospital mortality. In conclusion, it was found that invasive aspergillosis in ICU patients carries a significant attributable mortality of 18.9%. In a multivariate analysis, adjusting for other co-morbidity factors, invasive aspergillosis was recognized as an independent predictor of mortality.

Successful treatment of aortic rupture presenting as a syncope: the role of echocardiography in diagnosis.

A syncope was the first symptom of aortic rupture in a patient with chronic arterial hypertension. This syncope was the consequence of an acute haemopericardium which resulted in a sudden drop of the cardiac output. Urgent echocardiographic examination in the emergency room made early diagnosis and life-saving pericardiocentesis possible.

Personality change following head injury: assessment with the NEO Five-Factor Inventory.

We evaluated personality change following head injury in 68 patients at 6 months postinjury using the NEO Five-Factor Inventory to assess the five personality dimensions of the Five-Factor Model of Personality. All items had to be rated twice, once for the preinjury and once for the current status. Twenty-eight trauma patients with injuries to other parts of the body than the head were used as controls. For the head-injured group, 63 relatives also completed the questionnaire. The results showed no differences between the ratings of head-injured patients and the ratings of trauma control patients. Both groups showed significant change in the personality dimensions Neuroticism, Extraversion, and Conscientiousness. Compared to their relatives, head-injured patients report a smaller change in Extraversion and Conscientiousness. Changes were not reported on the Openness and Agreeableness scales, by neither the head-injured or their relatives, nor by the trauma controls.

Cardiac output-changes during hemodialysis with ultrafiltration.

Cardiovascular hemodynamics were studied noninvasively before, during and after hemodialysis with ultrafiltration in 18 patients on chronic hemodialysis. The cardiac output (CO) was determined by a continuous wave Doppler method. Overall, no major CO changes were seen (7.8 +/- 0.6 l/min post- versus 7.4 +/- 0.5 l/min pre-dialysis). Mean blood pressure rose slightly but significantly from 103 +/- 4 mmHg before to 113 +/- 3 mmHg after hemodialysis (p less than 0.01). Important interindividual differences in the intradialytic evolution of CO were observed. In patients with previous myocardial infarction or dilated cardiomyopathy (n = 12), CO rose significantly from 7.3 +/- 0.7 l/min before to 8.4 +/- 0.6 l/min after hemodialysis (p less than 0.05), while in patients without manifest myocardial disease (n = 6) CO decreased from 7.5 +/- 0.7 l/min to 6.6 +/- 0.9 l/min (NS). Comparison of the evolution of CO in both groups by variance analysis revealed a significant difference (p less than 0.01). It is concluded that, in response to hemodialysis with ultrafiltration, CO probably will increase in patients with myocardial infarction or congestive cardiomyopathy, but probably will decrease in patients without.