Hospital-acquired infections in Belgian acute-care hospitals: an estimation of their global impact on mortality, length of stay and healthcare costs.

Assessing the overall burden of disease which can be attributed to hospital-acquired infections (HAIs) remains a challenge. A matched cohort study was performed to estimate excess mortality, length of stay and costs attributable to HAIs in Belgian acute-care hospitals, using six matching factors (hospital, diagnosis-related group, age, ward, Charlson score, estimated length of stay prior to infection). Information was combined from different sources on the epidemiology and burden of HAIs to estimate the impact at national level. The total number of patients affected by a HAI each year was 125 000 (per 10·9 million inhabitants). The excess mortality was 2·8% and excess length of stay was 7·3 days, corresponding to a public healthcare cost of €290 million. A large burden was observed outside the intensive-care unit setting (87% of patients infected and extra costs, 73% of excess deaths).

Hospital-acquired, laboratory-confirmed bloodstream infections: linking national surveillance data to clinical and financial hospital data to estimate increased length of stay and healthcare costs.

This matched cohort study estimates the effect of hospital-acquired bloodstream infection (HA-BSI) on length of stay (LOS) and costs during hospitalisation of 1839 patients (age range <1 to >80 years) gathered from 19 acute hospitals in Belgium. A second objective was to evaluate the impact of the choice of matching criteria. Data from national surveillance of HA-BSI were linked to hospital administrative discharge data, with respect for the patients' right to confidentiality of their health record. Controls were identified based on a set of matching factors: hospital, All-Patient Refined Diagnosis Related Groups, age, principal diagnosis, Charlson Comorbidity Index and time to infection. The results showed that, depending on the choice of matching factors, the estimation of additional LOS decreased from 26 to 10 days, with the most critical factor being the time to infection. The additional LOS attributable to HA-BSI was 9.9 days [95% confidence interval (CI): 7.8, 11.9]. The additional cost per infection was euro4900 [95% CI: euro4035, euro5750]; 58% of those costs were due to LOS, 10% were due to antibiotics, 10% due to other pharmaceutical products and 15% were due to billed medical acts. The main conclusion is that laboratory-confirmed HA-BSIs increase the LOS by 10 days for patients surviving the infection, and that the time to infection plays a crucial role in this estimation.

The 2007 Belgian national prevalence survey for hospital-acquired infections.

Despite ongoing targeted surveillance efforts, no overall in-hospital prevalence data for hospital-acquired infections (HAIs) have been published for Belgium. Sixty-three Belgian acute hospitals participated in a point-prevalence study among either all patients admitted in their institution or 50% of the patients in each ward. HAIs were registered bed-site at a single day per ward during the period October-November 2007. The diagnosis was made according to the Centers for Disease Control and Prevention (CDC) criteria implemented in a custom-made rule-based software expert system available on a portable computer. The total number of patients surveyed nationally was 17 343, from 543 distinct hospital wards. The overall prevalence of HAIs was 7.1% (95% confidence interval: 6.7-7.4%); 6.2% (5.9-6.5%) of the patients suffered from at least one HAI. Prevalence of HAIs on adult intensive care was 31.3%. The major proportion of HAIs was observed among patients admitted on non-intensive care unit (non-ICU) wards, mainly on the wards of internal medicine, surgery, geriatrics and rehabilitation. Urinary tract infections were the most common type of HAI at geriatric and rehabilitation wards. This study demonstrates that the use of a portable computer system with a designated expert system for diagnosing HAIs according to the CDC criteria in a large point prevalence study is feasible and may reduce the within-subject variation. In Belgium, the prevalence of HAIs in acute hospitals thus identified is similar to that of neighbouring countries. As more than 80% of all HAIs occur on non-ICU wards, preventive efforts need to extend beyond the ICU.

Critical conditions for hyperventilation responses. The role of autonomic response propositions during emotional imagery.

Hyperventilation is often conceived of as part of a fight-or-flight response, triggered by situations with high arousal and negative valence. However, a previous study using emotional imagery found hyperventilation responses during imagery of high-arousal scenes regardless of their valence. Those imagery scripts contained suggestions of autonomic activity, which may have partly induced or enhanced the hyperventilatory responsivity. The present study used four emotional scripts--depicting relaxing, fearful, depressive, and pleasant situations--without suggestions of autonomic or respiratory responses. After each imagery trial, participants rated their imagery for valence, arousal, and vividness. Fractional end-tidal carbon dioxide (FetCO2), inspiratory and expiratory time, tidal volume, and pulse rate were measured in a non-intrusive way. Results showed significant FetCO2 drops during the fearful and pleasant scripts. However, this effect was much smaller compared to imagery scripts with autonomic response propositions. Participants imagining scripts without autonomic response information found it harder to imagine the scripts vividly and reported lower levels of subjective arousal.

Hyperventilation beyond fight/flight: respiratory responses during emotional imagery.

Hyperventilation (HV) is often considered part of a defense response, implying an unpleasant emotion (negative valence) combined with a strong action tendency (high arousal). In this study, we investigated the importance of arousal and valence as triggers for HV responses. Forty women imagined eight different scripts varying along the arousal and valence dimensions. The scripts depicted relaxation, fear, depressive, action, and desire situations. After each trial, the imagery was rated for valence, arousal, and vividness. FetCO2, inspiratory and expiratory time, tidal volume, and pulse rate were measured in a nonintrusive way. FetCO2 drops and decreases in inspiratory and expiratory time occurred in all but the depressive and the relaxation scripts, suggesting that a defense conceptualization of hyperventilation is not always appropriate.

Acquiring symptoms in response to odors: a learning perspective on multiple chemical sensitivity.

In this chapter, a learning account is discussed as a potential explanation for the symptoms in multiple chemical sensitivity. Clinical evidence is scarce and anecdotal. A laboratory model provides more convincing results. After a few breathing trials containing CO2-enriched air as an unconditioned stimulus in a compound with harmless odor substances as conditioned stimuli, subjective symptoms are elicited and respiratory behavior is altered by the odors only. Also, mental images can become conditioned stimuli to trigger subjective symptoms. The learning effects cannot be explained by a response bias or by conditioned arousal, and they appear to involve basic associative processes that do not overlap with aware cognition of the relationship between the odors and the CO2 inhalation. Learned symptoms generalize to new odors and they can be eliminated in a Pavlovian extinction procedure. In accordance with clinical findings, neurotic subjects and psychiatric cases are more vulnerable to learning subjective symptoms in response to odors. Consistent with a learning account, cognitive-behavioral treatment techniques appear to produce beneficial results in clinical cases. Several criticisms and unresolved questions regarding the potential role of learning mechanisms are discussed.

Generalization of acquired somatic symptoms in response to odors: a pavlovian perspective on multiple chemical sensitivity.

OBJECTIVE: Somatic symptoms that occur in response to odors can be acquired in a pavlovian conditioning paradigm. The present study investigated 1) whether learned symptoms can generalize to new odors, 2) whether the generalization gradient is linked to the affective or irritant quality of the new odors, and 3) whether the delay between acquisition and testing modulates generalization. METHODS: Conditional odor stimuli (CS) were (diluted) ammonia and niaouli. One odor was mixed with 7.4% CO2-enriched air (unconditional stimulus) during 2-minute breathing trials (CS+ trial), and the other odor was presented with air (CS- trial). Three CS+ and three CS- trials were conducted in a semirandomized order (acquisition phase). The test phase involved one CS+-only (CS+ without CO2) and one CS- test trial, followed by three trials using new odors (butyric acid, acetic acid, and citric aroma). Half of the subjects (N = 28) were tested immediately, and the other half were tested after 1 week. Ventilatory responses were measured during and somatic symptoms were measured after each trial. RESULTS: Participants had more symptoms in response to CS+-only exposures, but only when ammonia was used as the CS+. Also, generalization occurred: More symptoms were reported in response to butyric and acetic acid than to citric aroma and only in participants who had been conditioned. Both the selective conditioning and the generalization effect were mediated by negative affectivity of the participants. The delay between the acquisition and test phases had no effect. CONCLUSIONS: Symptoms that occur in response to odorous substances can be learned and generalize to new substances, especially in persons with high negative affectivity. The findings further support the plausibility of a pavlovian perspective of multiple chemical sensitivity.