Simulation as a set-up for technical proficiency: can a virtual warm-up improve live fibre-optic intubation?

BACKGROUND: Fibre-optic intubation (FOI) is an advanced technical skill, which anaesthesia residents must frequently perform under pressure. In surgical subspecialties, a virtual 'warm-up' has been used to prime a practitioner's skill set immediately before performance of challenging procedures. This study examined whether a virtual warm-up improved the performance of elective live patient FOI by anaesthesia residents. METHODS: Clinical anaesthesia yr 1 and 2 (CA1 and CA2) residents were recruited to perform elective asleep oral FOI. Residents either underwent a 5 min, guided warm-up (using a bronchoscopy simulator) immediately before live FOI on patients with predicted normal airways or performed live FOI on similar patients without the warm-up. Subjects were timed performing FOI (from scope passing teeth to viewing the carina) and were graded on a 45-point skill scale by attending anaesthetists. After a washout period, all subjects were resampled as members of the opposite cohort. Multivariate analysis was performed to control for variations in previous FOI experience of the residents. RESULTS: Thirty-three anaesthesia residents were recruited, of whom 22 were CA1 and 11 were CA2. Virtual warm-up conferred a 37% reduction in time for CA1s (mean 35.8 (SD 3.2) s vs. 57 (SD 3.2) s, P<0.0002) and a 26% decrease for CA2s (mean 23 (SD 1.7) s vs. 31 (SD 1.7) s, P=0.0118). Global skill score increased with warm-up by 4.8 points for CA1s (mean 32.8 (SD 1.2) vs. 37.6 (SD 1.2), P=0.0079) and 5.1 points for CA2s (37.7 (SD 1.1) vs. 42.8 (SD 1.1), P=0.0125). Crossover period and sequence did not show a statistically significant association with performance. CONCLUSIONS: Virtual warm-up significantly improved performance by residents of FOI in live patients with normal airway anatomy, as measured both by speed and by a scaled evaluation of skills.

Selective depletion of myelin-reactive T cells with the anti-OX-40 antibody ameliorates autoimmune encephalomyelitis.

The OX-40 protein was selectively upregulated on encephalitogenic myelin basic protein (MBP)-specific T cells at the site of inflammation during the onset of experimental autoimmune encephalomyelitis (EAE). An OX-40 immunotoxin was used to target and eliminate MBP-specific T cells within the central nervous system without affecting peripheral T cells. When injected in vivo, the OX-40 immunotoxin bound exclusively to myelin-reactive T cells isolated from the CNS, which resulted in amelioration of EAE. Expression of the human OX-40 antigen was also found in peripheral blood of patients with acute graft-versus-host disease and the synovia of patients with rheumatoid arthritis during active disease. The unique expression of the OX-40 molecule may provide a novel therapeutic strategy for eliminating autoreactive CD4+T cells that does not require prior knowledge of the pathogenic autoantigen.

Factors affecting long-term survival (>10 years) after cardiac transplantation in the cyclosporine era.

OBJECTIVES: The aim of this study was to determine long-term survival (>10 years) after cardiac transplantation in the cyclosporine era and identify risk factors influencing long-term survival. BACKGROUND: Despite the availability of newer modalities for heart failure, cardiac transplantation remains the treatment of choice for end-stage heart disease. METHODS: Between 1983 and 1988, 195 patients underwent heart transplantation at a single center for the treatment of end-stage heart disease. Multivariable logistic regression analysis of pretransplant risk factors affecting long-term survival after cardiac transplantation included various recipient and donor demographic, immunologic and peritransplant variables. RESULTS: Among the group of 195 cardiac transplant recipients, actuarial survival was 72%, 58% and 39% at 1, 5 and 10 years respectively. In the 65 patients who survived >10 years, mean cardiac index was 2.91/m2 and mean ejection fraction was 58%. Transplant-related coronary artery disease (TRCAD) was detected in only 14 of the 65 patients (22%). By multivariable analysis, the only risk factor found to adversely affect long-term survival was a pretransplant diagnosis of ischemic cardiomyopathy (p = 0.04). CONCLUSIONS: Long-term survivors maintain normal hemodynamic function of their allografts with a low prevalence of TRCAD. It is possible that similar risk factors that lead to coronary artery disease in native vessels continue to operate in the post-transplant period, thereby contributing to adverse outcomes after cardiac transplantation. Aggressive preventive and therapeutic measures are essential to limit the risk factors for development of coronary atherosclerosis and enable long-term survival after cardiac transplantation.

De novo immunosuppression with sirolimus and tacrolimus in heart transplant recipients compared with cyclosporine and mycophenolate mofetil: a one-year follow-up analysis.

BACKGROUND: Limited data exist regarding the safety and efficacy of sirolimus in combination with a calcineurin inhibitor in heart transplant recipients. METHODS: From January 2001 to June 2002, 31 de novo heart transplant recipients (treatment group) received a combination of sirolimus, tacrolimus, low-dose rabbit antithymocyte globulin, and glucocorticoids. Outcomes, such as actuarial survival, rate of rejection, incidence of infection, probability of developing diabetes mellitus, renal function, platelet and white blood cell counts, and incidence of coronary artery disease at 1 year, were compared with a cohort of 25 patients (control group) who underwent transplantation primarily in 2000 and in early 2002 treated with cyclosporine, mycophenolate mofetil, and glucocorticoids. All patients were followed up for at least 12 months. RESULTS: Kaplan-Meier actuarial 1-year survival rates were equivalent between groups (97% for the treatment group and 88% for the control group), as was freedom from allograft rejection (48% and 42% for treatment and control groups, respectively). No cases of transplant arteriopathy were noted within the first posttransplantation year. Renal function was not significantly affected in either group. There was a striking increased incidence of mediastinitis in the treatment group (19%) versus 0% in the control group (P = .02). Tacrolimus-sirolimus therapy was associated with a nearly 11-fold increased incidence of new-onset diabetes mellitus as well (P = .004). CONCLUSION: Tacrolimus, sirolimus, and steroids (following low-dose rabbit antithymocyte globulin) were associated with an increased incidence of mediastinitis and posttransplantation diabetes mellitus. No obvious long-term benefit on survival, arteriopathy, or renal function was noted.

Outcome of anesthesia and surgery in hypothyroid patients.

We retrospectively examined the outcome of anesthesia and surgery in 59 hypothyroid patients and in 59 paired euthyroid matched controls. Hypothyroid patients had more preoperative risk factors but did not differ as a group from controls with regard to duration of surgery or anesthesia, lowest temperature and BP recorded during surgery, need for vasopressors, time to extubation, fluid and electrolyte imbalances, incidence of arrhythmias, pulmonary and myocardial infarction, sepsis, need for postoperative respiratory assistance, bleeding complications, or time to hospital dismissal. Analysis of subsets of hypothyroidism (thyroxine level, less than 1.0, less than 3.0, and greater than or equal to 3.0 micrograms/dL) also failed to disclose any significant differences compared with matched controls. Among patients with mild or moderate hypothyroidism, we found no evidence to justify deferring needed surgery until the hypothyroidism has been corrected.

The effect of TCR V beta 8 peptide protection and therapy on T cell populations isolated from the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis.

Vaccination or treatment of Lewis rats with TCR V beta 8 peptides can prevent or reverse the clinical signs of experimental autoimmune encephalomyelitis (EAE) which is mediated predominantly by V beta 8.2+ CD4+/CD45R lo T cells. However, rats protected or treated with V beta 8 peptides still developed histological lesions in the spinal cord (SC), even though they remained clinically well. We sought to discern phenotypic changes characteristic of these SC infiltrating lymphocytes. In particular, we focused on whether the immunoregulatory mechanism induced by TCR peptides caused a reduction of V beta 8.2+ T cells, or induced changes in CD45R lo or hi/CD4+ subpopulations that have been associated respectively with EAE induction or recovery. In the V beta 8 peptide vaccinated rats there was a dramatic decrease in the number of V beta 8.2+ T cells isolated from the SC early in disease. During the recovery phase, however, the number of V beta 8.2+ SC T cells was similar in protected and control groups; in contrast, there was striking reduction in the number and size of CD45R hi/CD4+ T cells in the protected animals. In rats treated with V beta 8.2 peptide, no changes were observed in the number of SC V beta 8.2+ T cells or expression of V beta 8.2 message, but similar to vaccinated rats, there was a marked decrease in the number of CD45R hi/CD4+ T cells. These data suggest that vaccination with TCR peptides prevented the initial influx of encephalitogenic V beta 8.2+ T cells into the central nervous system (CNS), whereas treatment appeared to inactivate V beta 8.2+ T cells already present in the CNS. In both cases, TCR peptide-induced inhibition of the encephalitogenic T cells apparently preempted the need for CD45R hi/CD4+ T cells that may normally be necessary to resolve the disease.

Cyclosporine-associated end-stage nephropathy after cardiac transplantation: incidence and progression.

BACKGROUND: The salutary immunosuppressive effects of cyclosporine in extending cardiac allograft survival may be curtailed by its nephrotoxic effects. We reviewed our first 9 years of experience with cyclosporine after cardiac transplantation, to evaluate the incidence and progression of cyclosporine-associated end-stage renal failure necessitating chronic hemodialysis. METHODS: Retrospective computer-based file review and personal interview when possible. RESULTS: The population at risk was comprised of all adult cardiac recipients surviving at least 3 years (n=293). Of these, 19 (6.5%) developed end-stage renal failure requiring chronic hemodialysis. There were 17 men and 2 women (mean age of 45 +/- 11 years). The mean creatinine clearance for the study group decreased by 38% (P<0.001 vs. before transplant) by 6 months after transplantation and by 48% by 3 years postoperatively (P<0.001 vs. before transplant). The mean serum creatinine rose by 80% (P< 0.001 vs. before transplant) by 6 months after transplantation and by 125% by 3 years postoperatively (P<0.001 vs. before transplant). Time elapsed from transplantation to hemodialysis ranged from 3.7 to 9.5 years (mean 6.4 +/- 2). Actuarial 1- year survival after onset of hemodialysis was 75%. CONCLUSIONS: Although cyclosporine remains the central immunosuppressive agent for cardiac allograft recipients, its use leads to a greater than one-third decrease in creatinine clearance by 6 months after transplantation and progression to end-stage renal failure, requiring hemodialysis in 6.5% of cardiac transplant recipients. Moreover, these patients are at increased risk of death compared with other cardiac allograft recipients. This data warrants the search of alternative or adjunctive agents that would allow decreased dosing or reduced nephrotoxicity of cyclosporine, while maintaining equivalent survival.

Lymphokine mRNA expression in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis is associated with a host recruited CD45R hi/CD4+ population during recovery.

To evaluate CD4+ T cell subpopulations involved in the induction and recovery from experimental autoimmune encephalomyelitis (EAE), the CD45R phenotype and lymphokine mRNA profile was evaluated for encephalitogenic CD4+ T cell lines in vitro and compared to CD4+ T cells isolated from the spinal cord of Lewis rats with EAE. All of the myelin basic protein (MBP)-specific T cell lines and clones that adoptively transferred EAE were > 90% CD4+ and > 90% CD45R lo. A time course of EAE disease progression was monitored as a function of the percentage of CD45R hi/CD4+ T cells isolated from the spinal cords of diseased animals. The majority of CD4+ T cells found in the central nervous system during the early phase of passive EAE were CD45R lo (the same as the encephalitogenic lines/clones). A large increase of the CD45R hi/CD4+ T cells (up to 45%) was observed during the peak and recovery phases of EAE. Lymphokine mRNA production was analyzed from antigen-stimulated MBP-specific lines, and from spinal cord lymphocytes isolated from rats with EAE. The BP-specific lines produced Th1 lymphokines (IL-2, IFN-gamma, and TNF-alpha), while the spinal cord lymphocytes produced the same Th1 lymphokines as well as IL-4 and IL-10. The CD45R hi/CD4+ T cells isolated from the spinal cords were larger and expressed more lymphokine RNA per cell than the CD45R lo/CD4+ T cells. The encephalitogenic cells (CD45R lo) were detected in the spinal cords of rats with a fluorescent dye and by allelic transfers and all of the CD45R hi/CD4+ T cells were found to be host recruited. Thus, it appears that the CD45R hi/CD4+ lymphocytes found in the spinal cord represent a host-recruited, activated cellular infiltrate that increased in number in the recovery phase of EAE and synthesized both Th1 and Th2 lymphokines.

Outcomes in seriously ill neonates with coarctation of the aorta. A multiinstitutional study.

Among 326 severely symptomatic neonates with coarctation with or without ventricular septal defect, four died before an initial procedure was performed. Among the 322 undergoing an initial procedure, survival for at least 24 months was 84%; the hazard function for death was lower initially but more prolonged in patients without than in those with ventricular septal defect. Important mitral valve anomalies coexisted in 5% of patients, left ventricular hypoplasia in 5% (more commonly in patients without ventricular septal defect), narrowing of the left ventricular outflow tract in 9% (more common in patients without ventricular septal defect), and narrowing of the proximal arch in 1%; one or more of these anomalies was present in most patients without ventricular septal defect who died. Five percent of the 322 patients had more than one of these coexisting anomalies, and 8% had just one. The most commonly used technique of repair of the coarctation was resection and end-to-end anastomosis, but no technique was a risk factor for death by multivariable analysis. Extension of the area of resection so that the end-to-end anastomosis was proximal to the left subclavian artery but distal to the left common carotid artery did not increase risk; extensions beyond this, and in the case of patch graft repair, extensions proximal to the left subclavian artery, did increase risk. Patch graft repair was associated with the highest prevalence (21%) of reintervention to the coarctation repair. Among patients with coexisting moderate-sized or large ventricular septal defects, repair of the coarctation, pulmonary trunk banding, and subsequent repair of the defect were associated with the highest 2-year survival, 97% in those with single ventricular septal defect. The risk-adjusted outcomes in two institutions were less good than in all others.

Hypoplastic left heart syndrome: valuing the survival.

OBJECTIVE: To examine the survival, developmental status, quality of life, and direct medical costs of children with hypoplastic left heart syndrome who have undergone stage I, II, and III reconstructive surgery. METHODS: A total of 106 children underwent staged repair for classic hypoplastic left heart syndrome between February 1990 and March 1999 (stage I: 106; stage II: 49; stage III: 25; 4 converted to heart transplantation). Survival was analyzed by the Kaplan-Meier method. In a cross-sectional study, parents assessed quality of life by completing the Infant/Toddler Child Health Questionnaire or Child Health Questionnaire Parent Format-28; they assessed developmental progress by completing the Ages and Stages Questionnaire. The ratio-of-costs-to-charges method was used to derive hospital costs, and payments were used to capture physician time and wholesale pricing for outpatient medications. RESULTS: Institutional 1-year and 5-year actuarial survivals were 58% and 54%. Birth weight, the need for preoperative inotropic drugs, and surgical experience were predictors of survival. Norwood I patients achieved fewer developmental benchmarks than those who survived to subsequent stages. Child Health Questionnaire Parent Format-28 mean summary scores for physical and psychosocial health were 48.5 +/- 6.3 and 42.8 +/- 9.9. The median inpatient costs for stage I, II, and III repairs were $51,000, $33,892, and $52,183, respectively. Monthly outpatient and readmission costs were less than 10% of total costs. CONCLUSION: A prospective, large-scale study of the comprehensive outcomes of staged repair and transplantation is needed. This study will need to address the longer-term developmental and quality-of-life outcomes, as well as the long-term cost effectiveness of these procedures.

Safety and efficacy of aprotinin under conditions of deep hypothermia and circulatory arrest.

Aprotinin has been successfully used to reduce blood loss and blood product requirements in patients undergoing primary and reoperative cardiac operations. Its safety and efficacy during profound hypothermia and circulatory arrest have been questioned, however. A retrospective review compared 24 patients who received aprotinin during complex aortic procedures under profound hypothermia and circulatory arrest with 24 age-matched patients undergoing similar procedures without aprotinin. Activated clotting time was maintained at longer than 500 seconds (kaolin activating agent) or longer than 750 seconds (celite). We observed no statistically significant difference in the incidence of neurologic events (p not significant) or myocardial infarctions (p not significant), and there was a trend toward reduced in-hospital mortality rate in aprotinin-treated patients. A higher incidence of postoperative renal dysfunction was encountered in aprotinin-treated patients. Aprotinin recipients had a significant reduction in requirements for postoperative homologous erythrocytes (p = 0.01). We conclude that aprotinin may be safely and effectively used in patients undergoing deep hypothermia and circulatory arrest.

Development of an intraluminal device for the treatment of aortic regurgitation: prototype and in vitro testing system.

OBJECTIVES: Development of an intraluminal device to reduce aortic regurgitation could provide a strategy intermediate between medical treatment and aortic valve replacement. An initial prototype and a testing system have been designed. METHODS: Aortic valves obtained from heart transplant recipients were explanted and assessed in a mock circulatory loop with resistive and capacitive elements, including pressure-flow characteristics, similar to those of a normal arterial system. Normal heart function was simulated by a pulsatile ventricular-assist device. Pressure on each side of the valve and flow through the valve were recorded, allowing the calculation of regurgitant fractions and transvalvular gradients. Six solid geometrically differing obturators were tested. RESULTS: All six designs resulted in significant reduction in aortic regurgitation (p < 0.0001), ranging from 15% to 38% improvement compared with control values. Small increases in transvalvular gradients (from 0 to 7 mm Hg) were also noted. DISCUSSION: Initial results suggest that an intraluminally placed obturator can reduce aortic regurgitation without creating clinically significant transvalvular gradients. These initial in vitro experiments demonstrate the feasibility of an intraluminal device for the treatment of aortic valve disease, and further investigation is warranted.

A randomized double-blind study of the effect of triiodothyronine on cardiac function and morbidity after coronary bypass surgery.

BACKGROUND: Although triiodothyronine deficiency has been described after cardiopulmonary bypass, data supporting its use have been conflicting. A double-blind, randomized, placebo-controlled study was undertaken to further define the effect of triiodothyronine on hemodynamics and outcome after coronary artery bypass grafting. METHODS: A total of 170 patients undergoing elective coronary artery bypass grafting were enrolled and completed the study from November 1996 through March 1998. On removal of the aortic crossclamp, patients were randomized to receive either intravenous triiodothyronine (0.4 microgram/kg bolus plus 0.1 microgram/kg infusion administered over a 6-hour period, n = 81) or placebo (n = 89). Outcome variables included hemodynamic profile and inotropic drug/pressor requirements at several time points (mean +/- standard error of the mean), perioperative morbidity (arrhythmia/ischemia/infarction), and mortality. RESULTS: Despite similar baseline characteristics, patients randomized to triiodothyronine had a higher cardiac index and lower inotropic requirements after the operation. Subjects receiving triiodothyronine demonstrated a significantly lower incidence of postoperative myocardial ischemia (4% vs 18%, P =.007) and pacemaker dependence (14% vs 25%, P =.013). Seven patients in the placebo group required postoperative mechanical assistance (intra-aortic balloon pump, n = 4; left ventricular assist device, n = 3), compared with none in the triiodothyronine group (P =.01). There were 2 deaths in the placebo group and no deaths in the triiodothyronine group. CONCLUSIONS: Parenteral triiodothyronine given after crossclamp removal during elective coronary artery bypass grafting significantly improved postoperative ventricular function, reduced the need for treatment with inotropic agents and mechanical devices, and decreased the incidence of myocardial ischemia. The incidence of atrial fibrillation was slightly decreased, and the need for postoperative pacemaker support was reduced.

Management of vasodilatory shock after cardiac surgery: identification of predisposing factors and use of a novel pressor agent.

BACKGROUND: Cardiopulmonary bypass can be associated with vasodilatory hypotension requiring pressor support. We have previously found arginine vasopressin to be a remarkably effective pressor in a variety of vasodilatory shock states. We investigated the incidence and clinical predictors of vasodilatory shock in a general population of cardiac surgical patients and the effects of low-dose arginine vasopressin as treatment of this syndrome in patients with heart failure. METHODS: Patients undergoing cardiopulmonary bypass (n = 145) were studied prospectively. Preoperative ejection fraction, medications, and perioperative hemodynamics were recorded, and postbypass serum arginine vasopressin levels were measured. Vasodilatory shock was defined as a mean arterial pressure lower than 70 mm Hg, a cardiac index greater than 2.5 L/min/m2, and norepinephrine dependence. Predictors of vasodilatory shock were investigated by logistic regression analysis. The hemodynamic responses of patients who received arginine vasopressin infusions for vasodilatory shock after cardiopulmonary bypass for left ventricular assist device placement or heart transplantation were analyzed retrospectively. RESULTS: Eleven of 145 general cardiac surgery patients (8%) met criteria for postbypass vasodilatory shock. By multivariate analysis, an ejection fraction lower than 0.35 and angiotensin-converting enzyme inhibitor use were independent predictors of postbypass vasodilatory shock (relative risks of 9.1 and 11.9, respectively). Vasodilatory shock was associated with inappropriately low serum arginine vasopressin concentrations (12.0 +/- 6.6 pg/mL). Retrospective analysis found 40 patients with postbypass vasodilatory shock who received low-dose arginine vasopressin infusions, resulting in increased mean arterial pressure and decreased norepinephrine requirements. CONCLUSIONS: Low ejection fraction and angiotensin-converting enzyme inhibitor use are risk factors for postbypass vasodilatory shock, and this syndrome is associated with vasopressin deficiency. In patients exhibiting this syndrome after high-risk cardiac operations, replacement of arginine vasopressin increases blood pressure and reduces catecholamine pressor requirements.

Duration of left ventricular assist device support affects transplant survival.

BACKGROUND: Left ventricular assist devices have become an important tool in the successful treatment of heart failure as bridges to transplantation. The optimal duration of device support before heart transplantation is debated. We report the effect of left ventricular device support duration on survival after heart transplantation. METHODS: All patients bridged to heart transplantation with the ThermoCardiosystems Heartmate 1,000 IP left ventricular assist device between January 1, 1986, and October 15, 1994, were included in our study. Parameters studied included duration of support, measures of end-organ function, and complications while supported with the device. Patients supported < 30 days were compared with patients supported > 30 days before undergoing transplantation. RESULTS: Patients supported for < 30 days had a threefold increased perioperative mortality compared with patients supported > 30 days (p = 0.031). Laboratory values of end-organ function were similar before left ventricular device insertion in both groups, although at the time of transplantation patients supported < 30 days had a significantly elevated bilirubin level compared with patients supported > 30 days (p < 0.001). Patients supported > 30 days had significantly more infections than the < 30 days group (p = 0.0345). CONCLUSIONS: Patients supported for > 30 days with left ventricular assist devices have improved post-transplant perioperative survival because of normalization of end-organ function and improved physiologic status secondary to aggressive physical rehabilitation. Patients should be supported for > 30 days in combination with physical rehabilitation, to improve early survival after heart transplantation.

The influence of infection on survival and successful transplantation in patients with left ventricular assist devices.

BACKGROUND: Mechanical cardiac assistance has recently emerged as a tenable option in the treatment of end-stage heart failure. In spite of recent technical improvements that have reduced the incidence of life-threatening complications, the reported frequency of infections in these patients has remained high. METHODS: Over a 5-year period, 60 patients underwent insertion of a left ventricular assist device (LVAD) at our institution. Detailed medical records were kept prospectively for all patients, and a variety of endpoints were analyzed, including the incidence, nature, and sequelae of infections before and after LVAD implantation and after transplantation. RESULTS: Twenty-nine of 60 patients (48%) undergoing LVAD insertion subsequently had development of infections. The most frequent sites of infection were blood, LVAD drivelines, and central venous catheters, representing 61% of all infections. At the time of LVAD implantation, 13 of 60 patients (22%) had culture-proven infections. In spite of an increased incidence of subsequent infection (77% vs 40%), there were no differences in rates of mortality (31% vs 26%), LVAD endocarditis, (23% vs 11%) and eventual transplantation (62% vs 57%) between these patients and those without periimplantation infections. Although the overall mortality rate was not influenced by infections during LVAD support (28% vs 26%), the development of LVAD endocarditis was associated with a high mortality rate. Finally, although patients with infections during LVAD support had significantly longer median support times than those who remained infection free (101 vs 49 days, respectively), there was no difference in the rate of successful transplantation (59% vs 58%) or in the rate of infection after transplantation (35% vs 28%). CONCLUSIONS: Infections are common in patients undergoing LVAD support, but they do not adversely affect survival, the rate of successful transplantation, or the incidence of posttransplantation infection. Periimplantation infections may increase the risk of subsequent infections, but they also do not influence survival or transplantability. Patients with development of LVAD endocarditis are at increased risk for morbidity and death and require early and aggressive therapy, potentially including device explantation.

Indices of dehydration among frail nursing home patients: highly variable but stable over time.

OBJECTIVE: To determine changes in standard laboratory measures of dehydration among residents of a nursing home care unit (NHCU) over a 6-month period. DESIGN: A prospective cohort analytic study. SETTING: A 130-bed NHCU in a Department of Veterans Affairs Hospital. PATIENTS: Fifteen infirm but stable male residents (mean age 77 years; range (R) 62-93) on one ward of the NHCU. MAIN OUTCOME MEASURES: We studied prospectively for 6 months the serum osmolality (osm), serum sodium (Na), blood urea nitrogen/creatinine (BUN/Cr) ratios and weight (wt) for 15 patients of the NHCU. None of the patients was acutely ill during the study period or exhibited clinical signs of dehydration. RESULTS: Mean serum osm at baseline: 291.6 mOsm/kg (R 278 to 300); 3 months: 291.5 mOsm/kg (R 276 to 301); 6 months: 291.3 mOsm/kg (R 283-300) were all similar. Forty percent (6/15) of patients had at least one high normal/elevated reading (> or = 295 mOsm/kg) during the study. Three patients (20%) had readings of > or = 300 mOsm/kg, but none of these patients had either concurrent increased serum Na (> or = 146 mmole/L) or BUN/Cr ratios (> or = 25). Mean serum Na at baseline: 143.0 mmole/L (R 139-148); 3 months: 142.1 mmole/L (R 138-149); 6 months: 142.9 mmole/L (R 137-150) were all similar. Sixty percent (9/15) of the patients maintained normal (nl) serum Na levels throughout the study. The relationship between the change in serum Na and serum osm levels from baseline to 6 months was not significant (r = 0.242). BUN/Cr ratios ranged from 12-34 over the study period with 3 of 15 patients (20%) demonstrating elevated ratios consistently throughout the study without clinical evidence of dehydration. Only two patients had both high nl/elevated serum osm and elevated serum Na, although both had nl BUN/Cr ratios. Neither of these patients was thought by staff to be clinically dehydrated. Analysis of variance (ANOVA) indicated none of the laboratory measures changed significantly over time (serum osm: F(2,28) < 1; Na: F(2,28) < 1; BUN/Cr: F(2,28) < 1). There was no significant change in weight between the baseline and six month readings. CONCLUSIONS: These data suggest that in the presence of clinical stability, long-term care residents may have a serum osm in the high normal/elevated range without overt clinical evidence of dehydration, an accompanying elevated Na, or BUN/Cr ratio. This may indicate a different central osm setting for these residents as the serum osm appeared to be stable for each resident over time. These data also suggest that measures of serum osm, Na, and BUN/Cr in the long-term care setting may accurately predict future laboratory values in an individual patient if baseline values are drawn when the patient is not acutely ill.

Dehydration and death during febrile episodes in the nursing home.

OBJECTIVE: To determine the incidence of early hypernatremic dehydration among residents of a nursing home care unit (NHCU) presenting with significant febrile episodes (FE). DESIGN: Prospective cohort analytic study. FE were defined as temperature (T) > 100 degrees F oral (o) or 101 degrees F rectal (r) for > or = 24 hours. SETTING: NHCU in a Veterans Administration hospital. PATIENTS: A total of 130 residents of the NHCU were monitored for FE during a 4-month study period. MAIN OUTCOME MEASURES: Blood urea nitrogen (BUN)/creatinine (Cr) (abnormal > or = 25) and serum sodium (Na)(abnormal > or = 146 mmol/L) were drawn within 24-48 hours of the onset of all FE; documentation of impaired oral intake (OI) by staff; necessity of transfer to acute medical wards and mortality were recorded. RESULTS: There were 48 FE among 42 residents (39 M, 3 F; mean age 75 +/- 11.3). Maximum recorded T during the FE ranged from 100.1 degrees F-102.2 degrees F o and 101.2 degrees F-105.3 degrees F r. Laboratory values were available for 40/48 FE. Twenty-three percent (9/40) had elevated BUN/Cr ratios, 25% (10/40) had elevated serum Na, and 12.5% (5/40) had both. In patients noted to have impaired OI (n = 11) as documented by staff, increased serum Na or BUN/Cr ratio was observed in 82% (9/11). A random control group of 37 nonacutely ill, nonfebrile NHCU residents (33 M, 4 F; mean age 75 +/- 10.1) having routine annual laboratory tests revealed only 1 resident (age 95) with an elevated Na of 146 and BUN/Cr ratio of 26 and 1 resident with an increased BUN/Cr ratio of 28. None of the controls had any staff documentation of impaired OI. Of the 5 deaths in the febrile group with laboratory data (total deaths = 6; 14%), 100% had either elevated serum Na and/or elevated BUN/Cr ratios, and 80% (4/5) had both. Comparing the febrile group with controls, BUN/Cr ratios were found to be significantly elevated in the febrile group (P < 0.05). Serum sodium values were also significantly elevated in the febrile group (P < 0.01). CONCLUSIONS: Staff documentation of impaired OI was highly associated with either elevated serum Na or increased BUN/Cr ratios. These data show that many older NHCU patients with significant fevers often have early impaired OI and laboratory evidence of dehydration. These data indicate that staff should institute appropriate monitoring for dehydration at the time of earliest detection of fever in this population.

Optimal timing of revascularization: transmural versus nontransmural acute myocardial infarction.

BACKGROUND: Higher mortality for emergency coronary artery bypass grafting (CABG) after an acute myocardial infarction (AMI) is well established. Whether it applies to both transmural and nontransmural AMI is unclear. This information may have different therapeutic implications for each cohort of patients. METHODS: A retrospective multicenter analysis of 44,365 patients who underwent CABG after myocardial infarction between 1993 and 1996 by 179 surgeons at 32 hospitals in New York State was performed. RESULTS: Overall hospital mortality for all patients with or without AMI was 2.5% versus 3.1% for patients who underwent CABG with history of myocardial infarction. Hospital mortality decreased with increasing time interval between CABG and AMI; 11.8%, 9.5%, and 2.8% (p < 0.001 for all values) for less than 6 hours, 6 hours to 1 day, and greater than 1 day, respectively. Patients with transmural and nontransmural AMI had identical mortality of 3.1%. However, different patterns emerged when comparing these two groups of patients with respect to time of operation. Mortality was higher in the transmural group if CABG was performed within 7 days after AMI. Multivariate analysis confirmed that CABG within 1 day and 6 hours of AMI are independent risk factors for mortality in the transmural and nontransmural groups, respectively. CONCLUSIONS: Early operation after transmural AMI has a significantly higher risk, and surgeons should be prepared to provide aggressive cardiac support including left ventricular assist devices in this ailing population. Waiting in some may be warranted.

Quality of life with an implanted left ventricular assist device.

BACKGROUND: With the increasing use of left ventricular assist devices (LVADs) for longer-term support of patients awaiting cardiac transplantation, we must now consider whether to use these devices as alternatives to medical therapy when biologic hearts are needed but not forthcoming. This expansion of use depends as much on quality of life as it does on survival. To draw an inference about long-term quality of life with implanted LVADs, we studied "bridged" patients at our institution. METHODS: We elicited, by standard gamble, the utilities (preferences) of bridged patients at three points in their care: before LVAD implantation, during LVAD support, and after cardiac transplantation. RESULTS: Utility was 0.548 (+/-0.276) before implantation, 0.809 (+/-0.136) during LVAD support, and 0.964 (+/-0.089) after transplantation. For patients interviewed during all three states of health, the utilities were significantly different (p = 0.0009 by analysis of variance). CONCLUSIONS: The quality of life with an LVAD was substantially better than with medical therapy, on par with renal transplantation (as established by others), and not as good as after cardiac transplantation. These results portend an acceptable quality of life for long-term use of LVADs for patients with end-stage heart failure and contribute to the growing body of evidence supporting a clinical trial to test this new use.