Accuracy of precordial percussion in detecting cardiomegaly.

STUDY OBJECTIVE: To assess the value of precordial percussion in detecting cardiomegaly, and to compare it with palpation of the apical impulse. DESIGN: Descriptive study. SETTING: Hospitals and clinics of a university medical center. PATIENTS: Light indirect percussion of the precordium was performed on 72 inpatients and 28 outpatients. All patients had a posteroanterior radiograph of the chest. Percussors were unaware of the clinical history and of chest roentgenogram results. MEASUREMENTS AND MAIN RESULTS: Thirty-six patients (36%) had cardiomegaly, defined as a cardiothoracic ratio of greater than 0.5 on chest roentgenogram. The cardiothoracic ratio was significantly correlated with percussion distance from the midsternal line in the left fourth (r = 0.35, p less than 0.0006), fifth (r = 0.65, p less than 0.00001), and sixth (r = 0.40, p less than 0.0001) intercostal spaces. After adjustment for clinical symptoms and systolic and diastolic blood pressures, percussion distance in the left fifth intercostal space remained a significant independent predictor of the cardiothoracic ratio. Percussion distance in the left fifth interspace discriminated cardiomegaly with a receiver-operating characteristic (ROC) area of 0.95. Percussion dullness more than 10.5 cm from the midsternal line in the left fifth interspace had a sensitivity of 94.4% (95% confidence interval [CI], 79.9% to 99.0%) and a specificity of 67.2% (CI, 54.2% to 78.1%). Distance of the apical impulse from the midsternal line discriminated with an ROC area of 0.95, but an impulse was palpated in only 40% of cases. CONCLUSIONS: Percussion in the left fifth intercostal space accurately discriminates patients with and without cardiomegaly, and adds information beyond that obtainable from the history and other parts of the physical examination.

The effect on grades of the timing and site of third-year internal medicine clerkships.

Two important factors affecting the performances of third-year medical students on their basic internal medicine clerkships were investigated: (1) the effect on their grades of when in the academic year they took the internal medicine clerkship, and (2) the effect on their grades of the site of the clerkship. During the academic years 1983-84, 1984-85, and 1985-86, the Department of Internal Medicine of the University of Illinois College of Medicine at Chicago conducted 12-week junior clerkships at six hospital sites. The study analyzed the 535 students' subjective grades, clerkship examination scores, final grades, and National Board of Medical Examiners Part I (NBME-I) scores. Although students' performances as characterized by subjective evaluations did not improve as the academic year progressed, mean scores on clerkship examinations improved steadily during the same period. The site of the clerkship, whether a community-affiliated hospital or a medical center hospital, affected neither subjective nor objective grades.

Selective effect of cefoxitin prophylaxis on post-cesarean-section microbial flora.

A double-blind study was done to test the efficacy of cefoxitin in the prevention of post-cesarean-section infection. The antibiotic was given in three 2-g doses; the initial dose was given immediately after the cord was clamped, and subsequent doses were given four and eight hours later. Cefoxitin prophylaxis significantly reduced morbidity serious enough to require therapeutic antibiotics or to prolong the hospital stay and led to an overall reduction in the anaerobic microbial flora of the endocervix. However, the antibiotic was selective for the overgrowth of enterococci, which were present in nearly half the postoperative cultures of patients who had received the drug. Enterococcal sepsis occurred in one patient, and three other patients had significant bacteriuria and/or urinary tract infections from enterococci. No cefoxitin-resistant strains of Enterobacteriaceae, among species normally sensitive to the drug, were isolated from the stool samples after prophylaxis. The risk of enterococcal colonization and superinfection must be weighted against the benefits of reduction of the infection risk when deciding upon routine antibiotic prophylaxis for cesarean section.

Sickled erythrocytes, hyphema, and secondary glaucoma: VI. The relationship between intracameral blood cells and aqueous humor pH, PO2, and PCO2.

Injection of Hgb SC blood into rabbit anterior chambers resulted in lowering of aqueous humor pH and PO2 and elevation of aqueous humor PCO2. These effects appear to contribute to the sickling of erythrocytes that occurs in aqueous humor.

The sudden infant death syndrome and epidemic viral disease.

A study was done to investigate the relationship between the sudden infant death syndrome (SIDS) and epidemic respiratory viral disease among hospitalized children under 18 months of age. During the 42 month-period of this study, there were 778 sudden infant deaths in Chicago and 3244 hospital admissions of children under 18 months for respiratory disease. Four outbreaks of respiratory syncytial (RS) virus infections, three outbreaks of influenza A virus infections, and several small clusters of parainfluenza virus infections occurred during the course of this study. Influenza A was the only virus infection found to have a statistically significant association with SIDS. Although environmental temperature was also significantly correlated with SIDS, the association with influenza A virus infection was independent of this temperature effect and neither association was strong.

Community-acquired purulent meningitis: a review of 1,316 cases during the antibiotic era, 1954-1976.

This review of 1,316 cases of purulent meningitis assessed changes in the etiology, clinical features, and fatality rate during the antibiotic era. Hemophilus influenzae was the most frequent cause of purulent meningitis (458 cases), Neisseria meningitidis the second most frequent (396 cases), and Streptococcus pneumoniae the third most frequent (178 cases). No bacterial etiology was found for 148 patients with purulent meningitis, the fourth major category of meningitis throughout the 23 years surveyed. Few patients had notable underlying diseases or predisposing conditions; 77.4% were less than 10 years old, but only 13 patients were less than one month old. Patients with meningitis caused by Staphylococcus aureus or various streptococci commonly had associated suppurative foci and the highest fatality rate. There were 103 deaths, of which 70.8% occurred during the first 48 hr of hospitalization. Antibiotics had been given to 54.6% of patients before admission to the hospital. Bacteriologic and cerebrospinal fluid (CSF) findings for patients who received antibiotics prior to admission ("pretreated") were compared with these findings for those who had not had antibiotics in 1,032 cases of meningitis caused by H. influenzae, N. meningitidis, or S. pneumoniae. No significant differences in white blood cell counts or in glucose or protein concentrations in CSF were noted among patients infected with any of the three organisms; positive cultures of blood and CSF were significantly less frequent in "pretreated" patients whose disease was caused by any of the three organisms, and particularly in those with meningitis due to N. meningitidis. Nasopharyngeal, throat, and rectal swabs and CSF specimens from 141 patients were cultured for virus. Enteroviruses were isolated from rectal swabs of two patients with bacterial meningitis and from the CSF of two patients (in mixed culture with Salmonella enteritidis in one case).

Tuberculosis in physicians: a continuing problem.

We evaluated the occurrence of active tuberculosis in 4,575 physicians who graduated between 1938 and 1981 from the same medical school. There were 66 cases. Fifteen (23%) cases were detected after 1970 including 4 diagnosed in 1981. For most years, the incidence of tuberculosis was higher in physicians than in the general population. Forty-eight (73%) patients were between 25 and 34 yr of age at the time of diagnosis. Two thirds of all cases occurred within 6 yr of graduation, even in graduates since 1970. The risk of tuberculosis was 140 per 100,000 persons-years within 6 yr of graduation. Sixty-three percent of initially tuberculin-negative medical students who subsequently had active tuberculosis converted their tuberculin reaction during medical school or clinical training. Recipients of BCG vaccine had 40% less tuberculosis than unimmunized, initially tuberculin-negative, physicians. Health authorities should be cognizant of the continuing risk of tuberculosis in medical students and physicians.

The epidemiology and natural history of streptococcal pyoderma: an endemic disease of the rural southern United States.

In order to study the natural history of endemic pyoderma, the host and environmental risk factors to infection, the immunologic response and the risk of acute glomerulonephritis (AGN) a prospective study was done between June 29 and December 13, 1970 in 444 black children aged 2-6 years attending project Headstart centers in Holmes County, Mississippi. The weekly prevalence of pyoderma was about 40-50% during July and August but decreased to 4% during the last week of the study. "Pyoderma-type" serotypes of group A streptococci were isolated from about 70% of the skin lesions and similar serotypes were also commonly isolated from the pharynx. The seasonal prevalence and T and M typing pattern of most of the pharyngeal isolates mirrored the skin isolates. Many of the streptococci appear to belong to previously unrecognized M-types and one strain has been designated provisional M type 67 by the International Subcommittee on Pneumococci and Streptococci. Staphylococci were also isolated commonly from the skin lesions, especially late in their evolution. Despite an 80% incidence of streptococcal pyoderma during the summer months, only 3 children (0.67%) developed AGN; all of these children had clinically mild disease. The risk of a major outbreak of AGN in populations like these is substantial. Surveillance for clusters of AGN is indicated and widespread benzathine penicillin prophylaxis should be used in the event of an outbreak. Also, further research to determine the long term prognosis of clinically mild AGN and to detect useful laboratory markers of nephritogenicity are indicated.