Usefulness of transesophageal echocardiography in the treatment of critically ill patients

To evaluate the usefulness of transesophageal echocardiography (TEE) in the treatment of critically ill patients, 80 patients (51 male and 29 female; mean age, 53 years) undergoing both transthoracic echocardiography (TTE) and TEE were studied in a 2-year period. Of these, 48 patients were studied in the ICU, while the other 32 patients were directly referred from the emergency departments. Indications for the study included suspected aortic dissection (34 patients), hemodynamic instability (22 patients), suspected cardiac source of embolism (11 patients), evaluation of the severity of mitral regurgitation (7 patients), and suspected infective endocarditis (6 patients). The probe was passed successfully in 78 of 80 attempts (98 percent). No significant complications were recorded during the transesophageal echocardiographic study. Transesophageal echocardiography provided critical information that was not obtained by TTE in 39 of 78 studies (50 percent, p < 0.005). Cardiac surgery was prompted by TEE findings in 14 patients (18 percent) and these findings were all confirmed at operation. Transesophageal echocardiography was a safe, well-tolerated, and valuable diagnostic approach for the rapid detection of specific cardiac abnormalities in patients with critical illness; TEE should be considered in the treatment of critically ill patients especially when TTE provided inadequate information.     

Comparison of gastric mucosal pH and clinical judgement in critically ill patients

OBJECTIVES: To compare gastric tonometry (pHi) with estimates of pHi in ill injured patients, and to correlate pHi with haemodynamic variables. DESIGN: Prospective, non-interventional study. SETTING: ICU of Level I trauma centre, USA. MAIN OUTCOME MEASURES: 154 gastric tonometry measurements were compared with physicians' estimates of adequacy of resuscitation. Resuscitation was categorised as inadequate (pHi < 7.35) or adequate (pHi> or = 7.35). Measured and estimated pHi were also compared with oxygen delivery, oxygen consumption, cardiac index, mixed venous O2 saturation, and critical illness scores. RESULTS: Estimated pHi was often higher than measured pHi in the judgement of all four surgical intensive care physicians. Measured pHi correlated positively with mixed venous O2 tension (r = 0.21). There were significant negative correlations between measured pHi and both oxygen delivery (r = -0.25) and oxygen consumption (r = 0.28). Estimated pHi correlated positively with mean arterial pressure (r = 0.21) and hospital day (r = 0.26); it correlated negatively with pulmonary arterial elastance (r = -0.35). CONCLUSION: Experienced intensive care physicians tended to overestimate visceral perfusion, which suggests that gastric tonometry adds useful information over and above routine haemodynamic indices. Arterial blood pressure and mixed venous oxygen saturation correlated better with measured pHi than with other indices of perfusion.     

Prediction of response to treatment in a randomized clinical trial of marital therapy.

This study investigated demographic, intrapersonal, and interpersonal predictors of treatment response in a randomized clinical trial of 134 distressed married couples, which examined traditional (N. S. Jacobson & G. Margolin, 1979) and integrative (N. S. Jacobson & A. Christensen, 1996) behavioral couple therapy. Results based on hierarchical linear modeling revealed that interpersonal variables were the strongest predictors, but their effects were largely limited to predicting initial marital dissatisfaction; greater individual mental health was also associated with less distress initially. Couples who were married longer demonstrated stronger treatment gains, and exploratory analyses suggested that sexually dissatisfied couples showed slower initial, but overall more consistent, gains in the integrative versus the traditional approach. Findings are considered in light of the previous literature on predicting response to marital therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficient allocation of patients to treatment cells in clinical trials with more than two treatment conditions

OBJECTIVE: Clinical trials generally allocate patients to equal-sized treatment groups. The authors propose that it may be more efficient to allocate unequal proportions of the total sample size to treatments when more than two treatments are being compared. METHOD: This proposal is illustrated with two examples. One involved a comparison of three treatments and used a dichotomous categorical outcome. The other involved comparison of three treatments and used a continuous measure. RESULTS: In both examples, a considerable increase in efficiency was realized by reducing the number of patients assigned to the placebo cell. CONCLUSIONS: Unequal allocation of patients to treatments should be considered when more than two groups are compared.     

Use of 2% propofol to produce diurnal sedation in critically ill patients

OBJECTIVE: The assessment of propofol to produce diurnal sedation in critically ill patients. DESIGN: Prospective clinical study. SETTING: Intensive Care Unit, University Hospital. PATIENTS AND PARTICIPANTS: Thirty consecutive patients admitted to the Intensive Care Unit older than 18 years who were expected to be sedated for more than 50 h. INTERVENTIONS: The patients were randomised into two groups. All received sedation with a constant background infusion of morphine and a variable infusion rate of propofol, which was altered hourly to maintain the intended sedation score. The first group received constant light sedation (CLS) over 50 h aiming for a Ramsay score of 2-3. The second group received CLS between 0600 h and 2200 h and additional night sedation (ANS) with propofol between 2200 h and 0600 h, aiming for a sedation score of 4-5. MEASUREMENTS AND RESULTS: Patients were studied for 50 h from 1800 h on the first day of admission. Recordings of heart rate, blood pressure, sedation scores and propofol and morphine infusion rates were made hourly. An APACHE II score was recorded for each patient. Sedation scores were analysed by blind visual assessment and cosinor analysis, which is used in chronobiology to examine the correlation of data with a cosine curve. Patients in the ANS group had significantly better rhythmicity of sedation levels using cosinor analysis (r = 26% v 8%) p < 0.01. There was no difference between the CLS and ANS groups with respect to age, sex or APACHE II scores. Nine out of 15 patients in the ANS group achieved diurnal sedation. Three patients in the CLS group showed diurnal rhythmicity of sedation, which can be attributed to natural sleep, and had a median APACHE II score of 12. Five patients in the CLS group and three in the ANS group showed a deep constant sedation pattern. They had high APACHE II scores (median 21.5) and an obtunded conscious level on admission due to severe sepsis. CONCLUSION: Propofol can safely provide diurnal sedation in the critically ill when titrated against the Ramsay score. Sedation levels cannot be manipulated in some severely ill patients.     

Myocardial performance in critically ill patients: response to whole blood transfusion as a prognostic measure

The standardized stroke work, which is derived from the left ventricular stroke work (LVSW) and the pulmonary capillary wedge pressure (WP), is presented as a convenient index for tracking changes in the overall cardiac function and relating these changes to other cardiorespiratory variables. This index and its response to whole blood transfusion were used to assess cardiac function in 102 critically ill patients with hemorrhagic or traumatic shock. Survivors had greater mean values of the standardized stroke work before, during, and after transfusion than did the nonsurvivors (p < 0.05). Moreover, the maximal change in standardized stroke work in response to transfusion was greater in survivors than in nonsurvivors (p < 0.05): this response was found to be dependent on the stage of shock. The experience of the authors with this index suggests that it is a useful way to follow changes in myocardial performance in critically ill patients over time, and in quantitating changes in myocardial function after whole blood transfusion or other forms of volume therapy.     

Clinical evaluation of a continuous intra-arterial blood gas system in critically ill patients

OBJECTIVE: To evaluate the clinical performance of a new, continuous intra-arterial blood gas monitoring system (CIABG) in abnormal ranges of blood gases, and during episodes of low blood pressure, in critically ill patients. DESIGN: Prospective study. SETTINGS: Medical ICU, University Hospital. METHODS: The CIABG system, based on fluorescent dyes, consists of a fiber-optic sensor introduced through an arterial catheter. Twenty-one sensors were evaluated in 15 acutely ill patients. A high failure rate (6/21) was found, due to the brittleness of the fibers. The bias, between CIABG and standard method, and precision were determined for each fiber and for the overall values. Analysis focused on the data collected in patients with arterial oxygen tension (PaO2) values below 75 mmHg, pH lower than 7.35 and arterial carbon dioxide partial pressure (PaCO2) values exceeding 50 mmHg and during episodes of low blood pressure. The accuracy of the CIABG to follow sequential changes in blood gases was studied among the abnormal values. RESULTS: Measurements with CIABG among the abnormal values showed biases of +2mmHg, +0.1mmHg and +0.005 for PaO2, PaCO2 and pH, respectively, and precisions of 9.0mmHg, 3.5mmHg and 0.027, respectively. Bias and precision were not influenced by hemodynamic instability. A substantial difference in the performance of individual CIABG was observed for PaO2 analysis, with 30% of the fibers having a much poorer performance than the others. The sensors were kept in place for 5 +/- 2 days and the drift rate per day was 0.005 for pH, 0.6mmHg for PaCO2 and -1.2mmHg for PaO2. CONCLUSION: In situations of severe hypoxemia, hypercapnia and acidosis, the agreement between CIABG and arterial blood sampling (ABS) is better for PaCO2 and pH than for PaO2, and is not influenced by episodes of low blood pressure.     

Application of a new method for analysis of exhaled gas in critically ill patients

OBJECTIVE: Application of a new method for analysis of exhaled gas in critically ill patients. DESIGN: Open study. SETTING: Surgical intensive care unit of an university hospital. PATIENTS: Thirty-seven consecutive, critically ill, mechanically ventilated patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Chemical analysis of the patient's exhaled gas was based upon substance adsorption and concentration onto activated charcoal, microwave desorption and gas chromatographic separation. Patients with acute respiratory distress syndrome (ARDS) exhaled less isoprene than those without ARDS [9.8 (8.2-21.6) vs 21.8 (13.9-41.4) nmol/m2 per min [median (95% confidence interval)], p = 0.04]. In patients who developed pulmonary infection, pentane elimination increased from 0.4 (0.0-5.4) to 2.7 (0.6-6.1, p = 0.05) nmol/m2 per min and isoprene elimination decreased from 5.2 (0-33) to 5.0 (0-17, p = 0.05) nmol/m2 per min, resulting in a significant increase in pentane/isoprene ratio from 0.1 (0-0.3) to 0.4 (0-15, p = 0.007) when compared to patients without pulmonary infection. CONCLUSIONS: The new method allows quantitative analysis of human gas samples with low substance concentrations and is well suited for clinical studies which involve the investigation of metabolic processes in the lung and the body.     

Evaluation of oxygen uptake and delivery in critically ill patients: a statistical reappraisal

Computer simulation of pulsatile non-Newtonian blood flow has been carried out in different human carotid artery bifurcation models. In the first part of the investigation, two rigid walled models are analysed, differing in the bifurcation angle (wide angle and acute angle bifurcation) and in the shape of both the sinus (narrow and larger sinus width) and the bifurcation region (small and larger rounding of the flow divider), in order to contribute to the study of the geometric factor in atherosclerosis. The results show a significant difference in the wall shear stress and in the flow separation. Flow recirculation in the sinus is much more pronounced in the acute angle carotid. An important factor in flow separation is the sinus width. In the second part of the study, flow velocity and wall shear stress distribution have been analysed in a compliant carotid artery bifurcation model. In the mathematical model, the non-Newtonian flow field and the idealized elastic wall displacement are coupled and calculated iteratively at each time step. Maximum displacement of approximately 6% of the diastolic vessel diameter occurs at the side wall of the bifurcation region. The investigation demonstrates that the wall distensibility alters the flow field and the wall shear stress during the systolic phase. Comparison with corresponding rigid wall results shows that flow separation and wall shear stress are reduced in the distensible wall model.     

Continuous infusion of loop diuretics in the critically ill: a review of the literature

OBJECTIVES: a) To present the pharmacodynamic concepts behind the administration of loop diuretics via continuous infusion; b) to review the clinical trials and reports in critically ill patients that have described this method of drug delivery; and c) to discuss the data. DATA SOURCES: Review of MEDLINE and International Pharmaceutical Abstracts from 1966 to the present. STUDY SELECTION: Study design was not a factor in selecting literature for this review. All studies, case reports, and case series describing infusion of a loop diuretic are included. DATA EXTRACTION: Cited literature was found in peer-reviewed clinical or basic science journals. DATA SYNTHESIS: There is a pharmacodynamic basis for the use of a controlled infusion of the loop diuretics in critically ill patients requiring extensive diuresis. Animal and human volunteer studies have demonstrated a clear improvement in efficiency of diuresis by controlled infusion Clinical studies in critically ill patients have demonstrated an improved diuretic response with a controlled infusion. Adverse effects appear to be minimal, and the amount of drug required for effect is less than the required amount for bolus administration. CONCLUSION: Administration of loop diuretics by continuous intravenous infusion may improve diuresis in critically ill patients who require prompt, controllable diuresis, or who demonstrate "diuretic tolerance" to conventional administration regimens. Despite few, well-designed studies using this method of administration in clinical practice, pharmacodynamic concepts support continuous infusion over bolus administration, including decreased dosage requirements, improved diuretic response and few adverse effects.     

Sedation of adult critically ill ventilated patients in intensive care units: a national survey

Pain management presents exciting opportunities for nurse anesthetists. Today there are thousands of pain clinics and pain services dedicated to the diagnosis and treatment of chronic and acute pain. By becoming familiar with the principles involved in the management of chronic and acute pain, the different treatment modalities available, and the organization of pain clinics and pain services, nurse anesthetists will be able to take advantage of the opportunities they provide.     

"Making two responses to a single object: Implications for the central attentional bottleneck": Correction.

Reports an error in the original article by C. Fagot and H. Pashler (Journal of Experimental Psychology: Human Perception and Performance, 1992[Nov], Vol 18[4], 1058–2079). Figures 3 and 7 are in error. The corrected figures are presented. (The following abstract of this article originally appeared in record 1993-12299-001.) Experiments with 2 stimuli and 2 responses have revealed a central attentional bottleneck and pointed to response selection as its primary locus; however, little has been said about the underlying reasons for this bottleneck. These reasons are explored. In the 1st 3 experiments, Ss made 2 separate responses to different aspects of the same object. Interference between selection of the responses persisted, ruling out the possibility that the dual-task bottleneck is caused by the input to the response-selection mechanisms being limited to one object at a time. The next 4 experiments examined what happens when 2 responses are made to the same attribute of a single object. These experiments show that only one response selection occurred. Hence, the central mechanism is not limited to picking one motor action at a time. Several possible theories about the nature of the bottleneck are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of various estimators of a treatment difference for a multi-centre clinical trial

When a clinical trial is conducted at more than one centre it is likely that the true treatment effect will not be identical at each centre. In other words there will be some degree of treatment-by-centre interaction. A number of alternative approaches for dealing with this have been suggested in the literature. These include frequentist approaches with a fixed or random effects model for the observed data and Bayesian approaches. In the fixed effects model, there are two common competing estimators of the treatment difference, based on weighted or unweighted estimates from individual centres. Which one of these should be used is the subject of some controversy and we do not intend to take a particular methodological position in this paper. Our intention is to provide some insight into the relative merits of the indicated range of possible estimators of the treatment effect. For the fixed effects model, we also look at the merits of using a preliminary test for interaction assuming a 10 per cent significance level for the test. In order to make comparisons we have simulated a 'typical' trial which compares an active drug with a placebo in the treatment of hypertension, using systolic blood pressure as the primary variable. As well as allowing the treatment effect to vary between centres, we have concentrated on the particular case where one centre is out of line with the others in terms of its true treatment difference. The various estimators that result from the different approaches are compared in terms of mean squared error and power to reject the null hypothesis of no treatment difference. Overall, the approach that uses the fixed effects weighted estimator of overall treatment difference is recommended as one that has much to offer.     

Prediction of response to treatment in a randomized clinical trial of couple therapy: A 2-year follow-up.

Many studies have examined pretreatment predictors of immediate posttreatment outcome, but few studies have examined prediction of long-term treatment response to couple therapies. Four groups of predictors (demographic, intrapersonal, communication, and other interpersonal) and 2 moderators (pretreatment severity and type of therapy) were explored as predictors of clinically significant change measured 2 years after treatment termination. Results demonstrated that power processes and expressed emotional arousal were the strongest predictors of 2-year response to treatment. Moderation analyses showed that these variables predicted differential treatment response to traditional versus integrative behavioral couple therapy and that more variables predicted 2-year response for couples who were less distressed when beginning treatment. Findings are discussed with regard to existing work on prediction of treatment response, and directions for further study are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of treatment efficacy in a clinical trial of three psychosocial treatments for adolescent depression

OBJECTIVE: To assess the predictors of treatment outcome across treatments, as well as those associated with differential treatment response. METHOD: One hundred seven adolescent outpatients, aged 13 to 18 years, with DSM-III-R major depression were randomly assigned to one of three manual-based, brief (12 to 16 sessions) psychosocial treatments: cognitive-behavioral therapy (CBT), systemic-behavioral family therapy, or nondirective supportive therapy. Those with good and poor outcomes were compared. RESULTS: Continued depression was predicted by clinical referral (versus via advertisement) and was in part mediated by hopelessness. Other predictors of depression were comorbid anxiety disorder and higher levels of cognitive distortion and hopelessness at intake. Achievement of clinical remission was predicted by a higher level of self-reported depression. Poorer functional status was predicted by a higher level of initial interviewer-rated depression. Comorbid anxiety and maternal depressive symptoms predicted differential treatment efficacy. CBT's performance continued to be robust with respect to nondirective supportive therapy, even in the presence of the above-noted adverse predictors. CONCLUSION: Predictors of poor outcome may give clues as to how to boost treatment response. Subjects who come to treatment for clinical trials via advertisement (versus clinical referral) may show more favorable treatment responses. CBT is likely to be a robust intervention even in more complex and difficult-to-treat patients.     

Family-focused treatment versus individual treatment for bipolar disorder: Results of a randomized clinical trial.

Recently hospitalized bipolar, manic patients (N=53) were randomly assigned to a 9-month, manual-based, family-focused psychoeducational therapy (n=28) or to an individually focused patient treatment (n=25). All patients received concurrent treatment with mood-stabilizing medications. Structured follow-up assessments were conducted at 3-month intervals for a 1-year period of active treatment and a 1-year period of posttreatment follow-up. Compared with patients in individual therapy, those in family-focused treatment were less likely to be rehospitalized during the 2-year study period. Patients in family treatment also experienced fewer mood disorder relapses over the 2 years, although they did not differ from patients in individual treatment in their likelihood of a first relapse. Results suggest that family psychoeducational treatment is a useful adjunct to pharmacotherapy in decreasing the risk of relapse and hospitalization frequently associated with bipolar disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)