Richard H. Parker

Diagnostic Usefulness and Safety of Transtracheal Aspiration

ACCURATE interpretation of the significance of the isolation of potentially pathogenic microorganisms by culture of expectorated respiratory-tract secretions is frequently impossible. Often, such m...

Bacteremia due to gram-positive cocci in patients with neoplastic disease

Abstract Fifty-seven bacteremias caused by gram-positive cocci were observed over a four and a half year period in patients with a wide variety of malignant diseases. All patients had two or more positive antemortem blood cultures with the same microorganism. The number of bacteremic episodes were divided between Streptococcus pneumoniae (14), other streptococci (17) and Staphylococcus aureus (26). Seventy per cent, including 50 per cent of the pneumococcal bacteremias, were nosocomial. An identifiable portal of bacterial entry in the skin or the gastrointestinal or respiratory tract mucosa was present in 95 per cent, fever in 81 per cent and a prebacteremic performance status of less than 2 in 53 per cent. Granulocytopenia was present in only 18 per cent of the cases at the onset of the bacteremia. These bacteremias appeared to be responsive to antimicrobial therapy with an over-all immediate mortality rate of 23 per cent; 16 per cent in adequately treated patients. Poor outcome was associated with a prebacteremic performance status of 3 or 4, other than optimal antimicrobial therapy, a neutrophil count of less than 1,000/mm 3 at the onset of the infection, and bacteremia due to Strep, pneumoniae. Hospitalized cancer patients, especially those with a poor performance status, should be monitored closely for breaks in the mucocutaneous host defense barriers and, if these are present in the face of suspected systemic infection, initial antimicrobial therapy should include drugs appropriate for the treatment of gram-positive coccal microorganisms.

Intravenous Followed by Oral Antimicrobial Therapy for Staphylococcal Endocarditis

We have treated 35 cases of staphylococcal endocarditis in 33 patients with intravenous followed by oral antimicrobial therapy. All patients had three or more blood cultures positive for Staphylococcus aureus, and all had cardiac murmurs characteristic of valvular insufficiency. The mean total duration of antimicrobial therapy was 42.4 d, consisting of a mean of 16.4 d of intravenous therapy followed by a mean of 26 d of oral therapy. Intravenous antimicrobial therapy included sodium nafcillin (32 cases; mean dose 9.2 g daily) and clindamycin (three cases). Oral therapy included dicloxacillin or oxacillin (30 cases; mean dose 4.5 g daily), clindamycin (four cases), and potassium penicillin V (one case). Serum bactericidal titers using the blood culture isolates showed similar activity with both intravenous and oral drugs. All patients treated with this sequential intravenous and oral regimen were cured. A regimen of initial intravenous followed by oral antimicrobial therapy, monitored with serum antibacterial activity studies, is a safe, effective, well-tolerated, and economical treatment for staphylococcal endocarditis.

Neurotoxicity during intravenous infusion of penicillin. A review.

Early in its clinical use and again in recent years, reports appeared stressing the direct neurotoxic potential of this agent. Neurotoxic manifestations in both man and animals have been observed after direct application to the cerebral cortex,2 following injection intracerebrally,3-6 after installation into the frontal sinuses,7 and where high cerebrospinal fluid concentrations have been achieved by inj ection intraventricularly,8 intracisternally,940 or into the lumbar subarachnoid space.11-’4 During the past decade, similar toxic effects have been observed in many clinical settings with intravenous administration of varying doses to patients with impairment of renal function7’15-27 and those undergoing cardiopulmonary bypass.23’28-31

Bacterial Safety of Reconstituted Continuous Drip Tube Feeding

Chemically defined diets require reconstitution and transfer to a delivery system. When reconstituted High Vivonex was noted in our Medical Center to be bacteriologically contaminated, we instituted a series of control procedures. We then reevaluated bacterial growth in reconstituted High Nitrogen Vivonex and diluted Isocal under ward conditions. The mixtures were prepared with sterile water versus tap water, using a hand washed blender versus a machine washed blender. We also investigated the bacteriological effect of blast freezing reconstituted High Nitrogen Vivonex. All preparations of the nonfrozen High Nitrogen Vivonex showed occasional low level contamination, although quantitative cultures did not show logarithmic growth over eight hours of observation. No growth occurred in the blast frozen High Nitrogen Vivonex or in the Isocal. We conclude that reconstituted High Nitrogen Vivonex and diluted Isocal may be prepared and hung safely for eight hours, and that blast freezing of High Nitrogen Vivonex is bacteriologically safe. As a result of our initial findings of bacteriologic contamination, we believe a program for bacterial monitoring of the tube feeding is desirable.

Nocardial Brain Abscess Cured with Cycloserine and Sulfonamides

Antimicrobic therapy is as important as surgical drainage in the treatment of cerebral nocardial abscess. On the bases of high probability of effectiveness, assured central nervous system penetration, practicality for long-term peroral administration, and the favorable result herein reported, combined antimicrobic therapy using cycloserine and sulfonamides is recommended for cerebral nocardiosis.

Characteristics of Ascitic Fluid in the Alcoholic Cirrhotic

A prospective study was conducted to define the characteristics of ascitic fluid in alcoholic cirrhotics with and without spontaneous bacterial peritonitis (SBP); to correlate these with findings in the peripheral blood; and to determine whether the use of counterimmunoelectrophoresis (CIE) for bacterial antigens will aid in the early diagnosis of SBP. Fifty-one alcoholic cirrhotics had simultaneous determination of their blood or serum and ascitic fluid for the following: WBC and differential count, RBC, LDH, amylase, glucose, total protein, and protein electrophoresis, CIE for pneumococcal andKlebsiella antigens, culture for aerobic and anaerobic bacteria and mycobacteria, and cytology. Of the 51 patients, 2 had SBP (4%). In the other 49 patients (54 sera and ascitic fluids), CIE was positive for pneumococcal antigen in 4/54 sera and in 3/54 ascitic fluids. The mean WBC count in the ascitic fluid was 349. In 4% the count was above 1000, in 18% between 501–1000, and in 32% between 301–500; polymorphs were >30% in 19/54 (32%). Specific gravity was >1.020 in 10/54 (22%), and ascitic fluid total protein of 3.0g/100 ml or above was noted in 24% (12/54). Mean ascitic fluid/serum ratios of total protein, albumin, and globulin were 0.31, 0.33, and 0.30 respectively, and mean ascitic fluid/serum ratios of LDH, amylase, and glucose were 0.54, 0.79, and 1.04. All cultures (except those with SBP) and cytology were negative. Our study confirmed the observation of others, that a significant number of noninfected cirrhotics have increased ascitic fluid WBC, % polymorphs, specific gravity, and total protein concentration. CIE was not helpful in the early diagnosis of SBP.

Pharmacokinetics of Nafcillin in Patients with Renal Failure

Nafcillin, a pencillinase-resistant penicillin, is frequently used for treatment of staphylococcal infections in hemodialysis patients. Despite its widespread use, there is a paucity of available data regarding the pharmacokinetics of nafcillin in hemodialysis patients. Therefore, sodium nafcillin, 25 mg/kg, was given intravenously over a 5- to 15-min period to 12 hemodialysis patients. Eleven patients were studied during dialysis, and eight of these were studied again during the interdialysis period. The initial serum half-life for nafcillin was 0.208 h during dialyses and 0.278 h between dialyses. The terminal half-life was 1.48 h during dialyses and 1.89 h between dialyses. There was no statistically significant difference between these values. These data indicate that renal failure does not appreciably affect the serum half-life of nafcillin, and hemodialysis does not accelerate the rate of clearance of nafcillin from the blood. Therefore, no modification of the usual nafcillin dosage is necessary when using this drug in hemodialysis patients.

Nafcillin Entry into Human Cerebrospinal Fluid

The entry of nafcillin into the cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twenty studies were performed in 18 patients receiving 40 mg of sodium nafcillin per kg intravenously over 30 min. The CSF specimens were obtained at 1, 2, 3, and 4 h postinfusion, and sera were obtained at 5 min and 1, 2, 3, and 4 h. Nafcillin was uniformly detected in the lumbar CSF at 1 h, peaked at 2 h postinfusion, and was still detectable in the CSF of three of four patients studied at 4 h.

Nafcillin concentration in cerebrospinal fluid during treatment of staphylococcal infections.

The nafcillin concentration of simultaneous cerebrospinal fluid (CSF) and serum specimens from nine patients being treated with parenteral nafcillin for staphylococcal infection were measured. Marked variations in the ratio of CSF/serum nafcillin concentration were observed. However, the concentration of nafcillin in the CSF was greater than the minimum lethal concentration (MLC) for Staphylococcus aureus in eight of the nine patients. In five patients with CSF pleocytosis, the nafcillin concentration was three to 100 times the MLC. These results support the recommendation to use nafcillin in doses of at least 100 to 200 mg/kg body weight-day for treatment of meningitis caused by S. aureus.