Management of infections in hospital employees

Hospital employees are often exposed to infectious diseases, both within and outside of the hospital. Susceptible personnel are at risk of acquiring infection and are a possible source of infection for patients, other employees and members of their households. In recent years epidemics in hospitals due to rubella, pertussis, hepatitis B and Legionnaires' disease have included infection transmitted to and from personnel. A comprehensive plan for management of hospital personnel exposed to communicable diseases should include the following: (1) protocols for the management of each of the common infectious diseases; (2) protocols for employees who are at special risk (pregnant women) and employees who work in areas of risk for certain infectious diseases (newborn nursery, clinical and pathology laboratories, hemodialysis unit); (3) assessment of infectious disease experience of new employees by history, skin test (tuberculosis) and serology (rubella, hepatitis B), and a plan for subsequent tests during employment; (4) continuous program of education of employees in infection control; and (5) coordination of policies among administration, employee health service and infection control officer and committee.     

Glucose and alanine metabolism during bacterial infections in rats and rhesus monkeys

To investigate the effects of bacterial infection on glucose and alanine metabolism, a variety of studies were carried out in rat and monkey models. These included glucose turnover by a pulse-dose technique in infected rats; alanine and glucose production and utilization in control and septic monkeys; in vivo measurement of gluconeogenesis in rats, with and without an alanine load; the in vitro rate of glucose formation from various substrates by isolated liver perfusion and hepatic cells; and in vivo rates of oxidation of glucose labeled with ¹⁴C at the 1 or 6 carbon position. In rats, glucose turnover was markedly accelerated 24 hr after inoculation of either 10⁴ or 10⁷Streptococcus pneumoniae. Glucose utilization and production were also accelerated during illness and early recovery from a pneumococcal infection in monkeys. The rates of gluconeogenesis as measured by either a pulse technique in rats or continuous infusion of labeled alanine in monkey were significantly elevated during pneumococcal septicemia. During the agonal stages (10⁷) of the pneumococcal infection in rat, an alanine load resulted in a decreased rate of labeled glucose production and an increase in plasma glucose when compared to values of fasted control rats. However, early illness caused similar or increased rates of glucose production from alanine in vivo. Similar reduced rates of glucose formation were observed when the isolated livers or hepatocytes from rats during the agonal stages of infection were perfused with excess quantities of gluconeogenic substrates. Thus, in the rat, gluconeogenic capacity (ability to form glucose from excess substrates) appears to decrease only during the agonal stages of pneumococcal infection. During acute pneumococcal sepsis in the rhesus monkey, alanine production and utilization were significantly elevated and it was estimated that over 90% of the newly produced alanine was utilized for glucose synthesis. When arterial-venous differences were measured across the hindquarters, significantly more alanine was released, presumably from skeletal muscle of the septic monkey, compared to the recovery period or in the control groups. Thus, the increase in glucose synthesis in both rat and monkey appears to be correlated with substrate availability and kinetic rate, rather than gluconeogenic capacity of the liver. The major increase in glucose utilization during both S. pneumoniae and Francisella tularensis live vaccine strain (LVS) infections in rat was a progressive elevation in the rate of oxidation via the pentose phosphate shunt in the rat. Further, the rate of oxidation appeared to be correlated with the magnitude of the bacteremia, which is an indication of the severity of the infection. Therefore, since glucose oxidation is necessary for a number of metabolic processes of various cells (such as phagocytosis and RNA synthesis), the increased glucose production during pneumococcal sepsis in the rat or rhesus monkey may not represent functional wastage to remove the excess alanine produced in skeletal muscle but a necessary process in the host defense mechanism against infectious disease.     

Monoclonal gammopathy of undetermined significance. Natural history in 241 cases

Two hundred forty-one patients with a monoclonal protein in the serum but initially no evidence of multiple myeloma, macroglobulinemia, amyloidosis or lymphoma were followed up for more than five years. At the conclusion of the studies the patients were classified as follows: Group 1, patients without significant increase in monoclonal protein, 57 per cent; group 2, patients with more than 50 per cent increase in monoclonal serum protein or development of monoclonal urine protein, 9 per cent; group 3, patients who died without five-year serum studies, 23 per cent; and group 4, patients in whom myeloma, macroglobulinemia or amyloidosis developed, 11 per cent. Initially, the hemoglobin level, size of serum monoclonal protein peak, number of plasma cells in the bone marrow and levels of normal immunoglobulins were not significantly different among the four groups. The median interval from recognition of the monoclonal protein to diagnosis of multiple myeloma was 64 months, of macroglobulinemia 103 months and of amyloidosis 92 months. A significant increase of the monoclonal protein or development of myeloma, macroglobulinemia or amyloidosis occurred in 18 per cent of the patients with monoclonal immunoglobulin G(IgG), in 28 per cent with immunoglobulin A (IgA) and in 25 per cent with immunoglobulin M (IgM). Retrospective analysis of age, sex, presence of organomegaly, hemoglobin level, size and type of serum monoclonal protein peak, presence of small amounts monoclonal light chain in the urine, serum albumin level, levels of uninvolved immunoglobulins, IgG subclass and level of plasma cells in the bone marrow did not show how to distinguish initially between stable benign disease and progressive disease. Therefore, periodic reexamination of patients with monoclonal gammopathy is essential.     

Familial myeloma. Report of eight families and a study of serum proteins in their relatives

During a 6 year period, eight instances of familial occurrence of myeloma involving siblings (16 cases of myeloma and 3 of probable benign monoclonal gammopathy) were encountered at the Mayo Clinic. No other monoclonal serum protein abnormalities were found in 70 relatives studied. In view of the infrequency of myeloma, the high familial occurrence of this disease suggests the possibility of genetic factors in its etiology. It is most important that a complete family history be obtained from patients with myeloma.     

Total effective compliance of the vascular bed in essential hypertension

Total effective vascular compliance, hemodynamic parameters, cardiopulmonary (CPBV) and total blood volumes (TBV) were determined in 31 men, including nine normotensive controls and 22 permanent essential hypertensive patients. The effective compliance was calculated from the changes in central venous pressure recorded simultaneously with the changes in blood volume obtained after a rapid dextran infusion. In hypertensives, compliance was significantly reduced (1.55 +/- 0.6 vs 2.25 +/- 0.11 ml./mm. Hg/Kg. in controls) (P less than 0.001) and negatively correlated with blood pressure (P less than 0.01), cardiac index (P less than 0.01), and the CPBV/TBV ratio (P less than 0.01). These results suggest that venous compliance contributes to the control of cardiac output in essential hypertension.     

Circulating immune complexes in Hodgkin's disease

Levels of circulating immune complexes (CIC) in the serum of patients with Hodgkin's disease were measured by the Raji cell radioimmunoassay. Elevated levels of immune complexes (mean value of 49 μg/ml ± 21 SE) were detected in 20 of 40 (50 per cent) untreated patients. After treatment, the level of CIC was normal (< 15 μg/ml) in 39 of 41 patients. Recurrent disease developed in two of the 39 patients with normal post-treatment levels of CIC and in one of the two patients with elevated post-treatment levels during the follow-up period of six months to six years. Elevated levels of CIC were detected in patients with Hodgkin's disease in stages I, II and III but not in stage IV. No significant correlations were found in the frequency of elevated levels of CIC or the values observed, and the presence or absence of symptoms (fever, sweats, weight loss) or the histologic subtype of the tumor. Our data indicate that the measurement of CIC by the sensitive and specific Raji cell assay may prove useful in the management of patients with Hodgkin's disease. In particular, serial measurement of the level of CIC could be employed to monitor the response to treatment and to detect recurrent diseases.     

Sequential chemotherapy and late intensification for malignant lymphomas of aggressive histologic type

Fifty-six patients with malignant lymphoma of aggressive histologic type (51 large cell, three diffuse undifferentiated, and two nodular mixed) were treated with three non-cross-resistant combination chemotherapy regimens that were introduced sequentially according to the response to therapy. The objective was to increase the complete remission rate by changing the chemotherapy regimen early if the patient did not attain a complete remission after three courses of treatment. Late intensification was also used with the aim of prolonging the duration of complete remission. The overall complete remission rate obtained with this approach was 82 percent (100 percent in stages I to III and 66 percent in stage IV). The projected survival at four years is 71 percent (93 percent for stages I to III and 55 percent for stage IV). Eighty percent of patients with complete remission are projected to have continued remission at four years. Compared with previous experience with Adriamycin-based combination regimens, these results represent an improvement in remission and survival parameters. The most significant gains occurred in the prolongation of survival of patients with stages I to III disease and in the improved duration of complete remission of patients with stage IV disease. Toxicity included 15 documented infections among 320 courses of therapy, four cases of congestive heart failure, one case of bleomycin lung toxicity, and two cases of liver dysfunction. This multiple combination regimen represents an improvement over previous results utilizing Adriamycin-based combination chemotherapy.     

Decreased contractility and compliance of the left ventricle as complications of thermal trauma

To test the hypothesis that systemic complications of dermal burns encompass dysfunction of myocardial contractile mechanisms, we studied contraction-relaxation properties of isovolumic left ventricular (LV) preparations isolated from guinea pigs 24 hours after full-thickness burn to approximately 47% total body surface area. Compared to control hearts, hearts from burned subjects consistently generated significantly lower values for LV systolic pressure (94 +/- 2 vs 66 +/- 2 mm Hg; p less than 0.001) and maximal rates of LV pressure rise (+ dP/dtmax; 1296 +/-71 vs 1091 +/- 46 mm Hg X sec-1; p less than 0.05) and fall (-dP/dtmax; 1214 +/- 45 vs 856 +/- 34 mm Hg X sec-1; p less than 0.001). The LV contractile deficit of burn hearts was not correlated with changes in tissue water content, and it was not surmountable by excess glucose, insulin, increased coronary flow, or maximal preload elevation. In addition, end-diastolic pressure-volume relationships in burn hearts were shifted upward and to the left of controls in the direction of decreased compliance (p less than 0.05 to p less than 0.01). Thus, LV sequelae of thermal trauma manifest in isolated hearts as decreased contractility, slowed isovolumic relaxation, and decreased diastolic compliance; in the intact animal this combination would reduce ejection and impede filling of the ventricle, with diastolic pressures reflecting changes in compliance as well as in contractile function.     

Significance of early two-dimensional echocardiography after acute myocardial infarction

We performed serial two-dimensional echocardiography (2D echo) in 35 patients with a first transmural myocardial infarction, to correlate initial left ventricular wall motion abnormalities with subsequent in-hospital cardiac complications, peak total creatine kinase level, and haemodynamic alterations, and to observe serial changes in the left ventricular wall motion. A wall motion score was derived by analysing endocardial motion in 15 left ventricular segments. Left ventricular wall motion could be analysed in 30 patients, 14 without (Group 1) and 16 with complications (Group 2). The initial wall motion score in Group 1 patients was 5.2 +/- 0.7 (+/- SEM) compared to 14.2 +/- 1.2 in Group 2 patients (P less than 0.001). A wall motion score of greater than or equal to 10 correlated with the occurrence of complications in 15 of 16 patients (sensitivity 93%, specificity 92%). Initial wall motion score did not correlate significantly with peak total serum creatine kinase and did not change significantly during the first 72 hr in both the groups. In 12 patients who underwent right heart catheterization together with 2D echo, the average wall motion score was 16.4 +/- 2.0 and cardiac index 2.4 +/- 0.3. Wall motion score correlated inversely with the cardiac index in these patients (r = -0.78; P less than 0.01). Thus, 2D echo performed in first transmural myocardial infarction patients soon after admission can identify those likely to have in-hospital complications. 2D echo wall motion score correlated significantly with the cardiac output in this study.     

Tuberculosis in patients undergoing maintenance hemodialysis.

Tuberculosis was diagnosed in eight patients undergoing maintenance hemodialysis and occurred with an incidence 10 times that of the general population. Dialysis-associated tuberculosis is characterized by intermittent fever, anorexia, weight loss and hepatomegaly. Ascites was present in 50 per cent of the patients. A recently converted positive tuberculin skin test was observed in five of eight patients. Tuberculosis was extrapulmonary in seven of eight cases and consequently the diagnosis was frequently delayed. Over-all mortality was 37.5 per cent and correlated with the duration of symptoms prior to initiation of therapy. A trial of antituberculous therapy is warranted in patients undergoing dialysis in whom fever of unknown origin, anorexia, weight loss and/or hepatomegaly develop particularly in areas endemic for tuberculosis.