Performance of a minimally invasive uncalibrated cardiac output monitoring system (Flotrac/Vigileo) in haemodynamically unstable patients.

BACKGROUND: Early haemodynamic assessment is of particular importance in the evaluation of haemodynamically compromised patients, but is often precluded by the invasiveness and complexity of the established cardiac output (CO) monitoring techniques. The FloTrac/Vigileo system allows minimally invasive CO determination based on the arterial pressure waveform derived from any standard arterial catheter, and the algorithm underlying CO calculation was recently modified to allow a more precise estimate of aortic compliance. METHODS: Using the new software, we studied 25 haemodynamically unstable patients who had a radial artery catheter and underwent invasive haemodynamic monitoring with the PiCCO system. PiCCO-derived transpulmonary thermodilution and pulse contour CO (reference-CO) were compared with the CO values obtained with the FloTrac/Vigileo system (AP-CO). Reported CO values are indexed to body surface area. Agreement between reference-CO and AP-CO recorded during routine clinical care was assessed using Bland-Altman statistics. RESULTS: Overall bias between the reference-CO and the AP-CO (n=324) was 0.68 litre min(-1) m(-2) with a high percentage error of +/- 58.8% (95% limits of agreement +/- 1.94 l min(-1) m(-2)). There was a significant difference (P<0.001) between the radial and the femoral mean arterial pressures, and bias was significantly larger for a mean pressure difference of >5 mm Hg (0.93 vs 0.57 litre min(-1) m(-2), P=0.032). No connection was found between the norepinephrine dose and the CO agreement. CONCLUSIONS: Despite the updated algorithm, AP-CO still showed a limited agreement with the reference-CO and systematically underestimated the CO so that the method is not suitable to replace invasive CO monitoring at present.

Different dosages of dobutamine in septic shock patients: determining oxygen consumption with a metabolic monitor integrated in a ventilator.

OBJECTIVE: Oxygen consumption (VO2) obtained from respiratory gases by indirect calorimetry (VO2,IC) with a metabolic monitor integrated in a ventilator were to be compared to VO2 obtained by the Fick principle (VO2,Fick) in septic patients following an increase in oxygen delivery (DO2) induced by positive inotropic support. DESIGN: Prospective clinical study. SETTING: University Hospital, Surgical Intensive Care Unit (ICU). PATIENTS: Thirty patients suffering from sepsis. INTERVENTIONS: DO2 was increased by dobutamine infusion, starting with an initial dosage of 5 microg x kg x min, increased to a maximum of 10 microg x kg x min. MEASUREMENTS AND MAIN RESULTS: Dobutamine infusion induced a dosage-related increase in DO2 (from 577 +/- 192 to 752 +/- 202 ml x min x m2, p < 0.01), which was associated with a statistically significant increase in VO2,IC (from 173 +/- 30 to 188 +/- 28 ml x min x m2, p < 0.01) and in VO2,Fick (from 140 +/- 25 to 156 +/- 24 ml x min x m2, p < 0.01). The comparison between VO2,IC and VO2,Fick revealed differences (bias and precision--33 +/- 32 ml x min x m2). CONCLUSIONS: With a metabolic monitor integrated in a ventilator it was possible to carry out continuous monitoring of calorimetric data under clinical conditions. In contrast to previous studies using indirect calorimetry, this study showed a moderate correlation between VO2 and DO2 in septic patients using either method. The clinical relevance of this finding requires further investigation. Different factors (e. g. injectant temperature, pulmonary VO2) produced substantial differences between VO2,IC and VO2,Fick as previously shown.

The relationship of HIV status, type of coagulation disorder, and school absenteeism to cognition, educational performance, mood, and behavior of boys with hemophilia.

Psychological and educational data were analyzed for all school-aged males with hemophilia at the Hemophilia Center of Central Pennsylvania (N = 66). Mean IQ (113.5) was higher than normal, and 2.4 times as many boys with hemophilia were enrolled in gifted programming than is the state average for boys. However, there was a disproportionately high prevalence of attention-deficit/hyperactivity disorder (ADHD; 28.3%), learning disability (LD; 15.8%), and graphomotor weakness. These were not significantly associated with HIV status or type and severity of coagulation disorder. School absenteeism was high but was not significantly related to academic achievement, IQ/achievement discrepancy, need for educational intervention, or diagnosis of ADHD or LD.

Blood product use by hemophiliacs in relation to AIDS risk awareness and patient variables.

Although some hemophiliacs in other studies have reported restricting blood product use because of fear of possible transmission of the human immunodeficiency virus (HIV), no overall change in the quantity of blood products infused between January 1981 through December 1985 was found in a sample of 40 hemophiliacs before or after they became aware of the risk of contracting the acquired immunodeficiency syndrome (AIDS). However, there was a significant linear increase in blood product use with time during the period of AIDS risk awareness. This may be a nonspecific, chance finding; or it may reflect an increase in spontaneous bleeds secondary to AIDS-related stress. The implications of these findings are discussed, and specific areas for future research are recommended.

Sexual practices and AIDS knowledge among women partners of HIV-infected hemophiliacs.

About 12 percent of the women sex partners of hemophilic men who are seropositive for the human immunodeficiency virus (HIV) have themselves become seropositive. Questionnaires were completed in January 1988 by 15 women who were in long-term, monogamous relationships with HIV-positive hemophiliacs; 11 of the women were not HIV seropositive and 4 were. None of the couples was abstaining from sexual intercourse, and during the 4 weeks prior to responding, the couples had intercourse a mean of 6.2 times. Sixty percent always used condoms, 13 percent did so most of the time, and the remaining 27 percent did sometimes. Condom use was not significantly related to either frequency of intercourse, the women's knowledge of acquired immunodeficiency syndrome (AIDS) and AIDS-risk reduction, the actual HIV status of both partners and the women's perceived status of both, the extent of the women's worry about contracting AIDS, their reported degree of negative impact from AIDS, or to their mood, age, or education. All women who reported not always using condoms had been informed of their own and their partner's HIV status; were counseled repeatedly regarding risk reduction; acknowledged the possibility of heterosexual HIV transmission; said they knew of recommendations for the use of condoms; recognized their risk of HIV infection; claimed some degree of worry about acquiring HIV through sexual activity; had children at home; and were not, with one exception, trying to become pregnant. There were several possible factors influencing the decision by women at high risk for acquiring HIV not to use condoms. Among them were complaints that the women found condoms unpleasant or an unwanted reminder of AIDS, a sense of obligation or a drive to continue unaltered sexual relations, the false reassurance of HIV-negative test results for some of the women who did not always use condoms, a willingness to sacrifice and to share their partner's fate, a desire to avoid communicating rejection and adding to their partner's burdens, and difficulty changing long-standing behavior patterns despite logical understanding of the risks involved.

Outcome prediction of acute renal failure in medical intensive care.

Data acquired prospectively from 134 patients with acute renal failure requiring dialysis in a medical intensive care unit (ICU) were analysed in order to derive indicators predicting ICU-survival. Mortality in the ICU was 56.7%. Linear discriminant analysis correctly predicted outcome in 79.9% at the start of dialysis, and 84.7% at 48 h after the first dialysis. The most important predictive variables were mechanical ventilation and low blood pressure. On the other hand, the total correct classification rates achieved by a standardised system for scoring ICU-patients (APACHE II) did not exceed 58.2%. It is concluded that outcome prediction by APACHE II and even by the discriminant functions is too inaccurate to become the basis for clinical decisions either concerning the initiation or the continuation of dialysis treatment in ARF.

Parent attitudes and child personality traits in hemophilia: a six-year longitudinal study.

Using standardized instruments, personality traits of twenty-two hemophilic boys and child-rearing attitudes and practices of their parents were evaluated at the beginning and end of a six-year period, during which psychosocial services were provided in a comprehensive care hemophilia program. The children changed significantly in a positive direction on two traits, enthusiasm and self-reliance. No significant negative personality trait changes were found. Scores remained within the normal range on the remaining traits, with the exception of a significant positive elevation on the intelligence dimension at both pre- and posttest. Mothers and fathers scored positively compared with parental attitude norms during both the initial and follow-up evaluations, without significant changes in overall mean scores. Strong relationships were revealed between individual changes in child personality and parent attitude scores. Despite the fact that between pre- and posttest boys with hemophilia and their parents became aware of the risk of contracting AIDS from blood product use, personality traits and parent child-rearing attitudes remained positive.