Cyrus C. Hopkins

Catheter complications in total parenteral nutrition. A prospective study of 200 consecutive patients.

Abstract The complications related to central venous catheters for total parenteral nutrition were prospectively evaluated in 200 patients. Catheter sepsis was defined as an episode of sepsis, for which no anatomic locus could be identified, that resolved on removal of the catheter. The insertion of 355 catheters for 4492 days led to complications involving 4 per cent of the catheters and 6 per cent of the patients. Catheter sepsis was associated with 7 per cent of catheters and occurred in 11 per cent of patients. Eight cases of superior-vena-cava thrombosis and three of pulmonary embolism were found in 34 autopsied patients. Catheters used with strict aseptic technic were complicated by a sepsis rate of 3 per cent as compared to one of 20 per cent when breaks in the protocol were observed (p = 0.01). Thus, total parenteral nutrition can be employed with an acceptable risk, provided catheter care is according to protocol. (N Engl J Med 290:757–761, 1974)

Perioperative antibiotic prophylaxis for herniorrhaphy and breast surgery

We assessed the efficacy of perioperative antibiotic prophylaxis for surgery in a randomized, double-blind trial of 1218 patients undergoing herniorrhaphy or surgery involving the breast, including excision of a breast mass, mastectomy, reduction mammoplasty, and axillary-node dissection. The prophylactic regimen was a single dose of cefonicid (1 g intravenously) administered approximately half an hour before surgery. The patients were followed up for four to six weeks after surgery. Blinding was maintained until the last patient completed the follow-up and all diagnoses of infection had been made. The patients who received prophylaxis had 48 percent fewer probable or definite infections than those who did not (Mantel-Haenszel risk ratio, 0.52; 95 percent confidence interval, 0.32 to 0.84; P = 0.01). For patients undergoing a procedure involving the breast, infection occurred in 6.6 percent of the cefonicid recipients (20 of 303) and 12.2 percent of the placebo recipients (37 of 303); for those undergoing herniorrhaphy, infection occurred in 2.3 percent of the cefonicid recipients (7 of 301) and 4.2 percent of the placebo recipients (13 of 311). There were comparable reductions in the numbers of definite wound infections (Mantel-Haenszel risk ratio, 0.49), wounds that drained pus (risk ratio, 0.43), Staphylococcus aureus wound isolates (risk ratio, 0.49), and urinary tract infections (risk ratio, 0.40). There were also comparable reductions in the need for postoperative antibiotic therapy, non-routine visits to a physician for problems involving wound healing, incision and drainage procedures, and readmission because of problems with wound healing. We conclude that perioperative antibiotic prophylaxis with cefonicid is useful for herniorrhaphy and certain types of breast surgery.

Cryptosporidiosis in Immunocompetent Patients

The intestinal protozoan cryptosporidium is known to cause diarrhea in immunocompromised patients, but few cases have been reported in detail in immunocompetent persons. During a 12-month period, we identified cryptosporidium in the stools of 43 immunocompetent patients. The numbers of cases were increased in those under 4 years old and in those from 30 to 39 years old. Of 30 index cases, 23 (77 per cent) were diagnosed in the late summer or the fall. Fifteen of the 43 patients (35 per cent) had other gastrointestinal pathogens, of which only Giardia lamblia was statistically associated with cryptosporidium. In the 28 patients in whom other gastrointestinal pathogens were not identified, the clinical manifestations were predominantly watery, nonbloody diarrhea and, less commonly, abdominal discomfort, anorexia, fever, nausea, and weight loss. The infection was self-limited in all 43 patients. Clustering of cases occurred in a day-care center and in two families. These clinical observations confirm worldwide findings and suggest that cryptosporidium is a relatively common nonviral cause of self-limited diarrhea in immunocompetent persons in the northeastern United States.

Rapid diagnosis of intravascular catheter-associated infection by direct gram staining of catheter segments

We conducted a study to determine the usefulness of the Gram stain in the detection of intravascular catheter-associated infection. A total of 330 intravascular catheters were prospectively collected from adults and children suspected of having such an infection. Semiquantitative solid-agar cultures of the distal catheter tip were correlated with blood cultures. Catheter-associated bacteremia occurred in 34 per cent of cases in which catheter tips were colonized (greater than or equal to 15 colonies per agar plate). There were no cases of catheter-associated bacteremia in patients with uncolonized catheters. Immediately after culture, whole catheter segments were stained by the Gram technique. Gram-negative and gram-positive bacteria and yeast were easily identifiable under oil immersion (X 1000), located predominantly on external catheter surfaces. Any catheter with at least one organism per 20 oil-immersion fields was designated as positive by Gram stain, but the majority of the 41 positive catheters had much larger numbers of organisms. The Gram stain of the catheter tip was 100 per cent sensitive and 96.9 per cent specific for the detection of catheter-tip colonization, with positive and negative predictive values of 83.9 and 100 per cent, respectively. We conclude that a Gram stain of the distal catheter tip is a simple, inexpensive, and accurate test for the rapid diagnosis of intravascular catheter-associated infection.

The efficacy of postoperative autotransfusion in patients undergoing cardiac operations.

The efficacy of postoperative autotransfusion in lowering the requirement for banked-blood transfusion was studied in two groups, each having 168 patients, who underwent cardiac operations between April, 1979, and May, 1980. A Sorenson autotransfusion system was available for use in the autotransfusion group, whereas the control group received routine closed mediastinal drainage. Of the autotransfusion group, 81% met the criterion for autotransfusion (mediastinal losses of 450 ml or more during 4 hours), but only 61% of the autotransfusion group actually received autologous blood (mean autotransfusion volume, 399 +/- 25 ml). The patients receiving autologous blood required significantly less banked blood than their matched controls (447 +/- 60 ml and 744 +/- 83 ml, respectively; p less than 0.001). In the subgroup of patients with large mediastinal losses (more than 1,250 ml), this difference was even greater (autotransfusion, 642 ml compared with control, 1,145 ml; p less than 0.01). Postoperative autotransfusion is a simple, safe, and cost-effective method to reduce dependence on banked blood, especially when mediastinal losses are large. Obtaining maximum benefit requires familiarity of staff with the system and use of a consistent protocol.

Invasive aspergillus infection: possible non-ward common source within the hospital environment☆

Six immunocompromised patients housed in widely separated portions of a hospital campus developed invasive aspergillosis during a single month. This represented a significant increase (P less than .001) in the number of cases observed over the 3 years which included this event (19 cases in 36 months). Epidemiological investigation suggested that this cluster of cases was due to a common source outbreak related to construction activity in a central radiology suite serving the hospital. Such non-ward exposures to nosocomial hazards are becoming increasingly important for immunosuppressed hosts.

Simplified surveillance for nosocomial bloodstream infections

OBJECTIVE To compare a surveillance definition of noso comial bloodstream infections requiring only microbiology data to the Centers for Disease Control and Preventions (CDC) current definition. SETTING Six teaching hospitals. METHODS We classified a representative sample of 73 positive blood cultures from six hospitals growing common skin contaminant isolates using a definition for bacteremia requiring only microbiology data and the CDC definition for primary bloodstream infection (National Nosocomial Infections Surveillance [NNIS] System review method). The classifications assigned during routine prospective surveillance also were noted, and the time required to classify isolates by the two methods was compared. RESULTS Among 65 blood cultures growing common skin contaminant isolates obtained from adults, the agreement rate between the microbiology data method and the NNIS review method was 91%. Agreement was significantly poorer for the eight blood cultures growing common skin contaminant isolates obtained from pediatric patients. The microbiology data method requires approximately 20 minutes less time per isolate than does routine surveillance. CONCLUSIONS A definition based on microbiology data alone yields the same result as the CDCs definition in the large majority of instances. It is more resource-efficient than the CDCs current definition.

Implementation and evaluation of an algorithm for isolation of patients with suspected pulmonary tuberculosis.

OBJECTIVE To implement and evaluate an algorithm designed to assist in the consistent placement of patients with suspected pulmonary tuberculosis into negative-pressure isolation rooms (NPIRs). DESIGN A standard algorithm was designed for the appropriate room placement of patients with suspected pulmonary tuberculosis using clinical, radiographic, and laboratory criteria and reported risk factors. A case-patient was defined as an inpatient who had at least one Mycobacterium tuberculosis culture-positive respiratory specimen from January 1, 1993, through December 31, 1994. Demographic, clinical, laboratory, case contact, and isolation and room placement data were collected prospectively on all case patients. SETTING A 900-bed university teaching and referral center. RESULTS During 1993 and 1994, 69 patients were evaluated for possible pulmonary tuberculosis, and 31 case-patients were identified. Of the 31 case-patients, 26 (84%) were placed on respiratory isolation in NPIRs, including 19 (61%) who were isolated within 24 hours of admission (1993, 14 of 20 [70%]; 1994, 5 of 11 [45%]). Seven case-patients (23%) were isolated in NPIRs following delays that ranged from 2 to 31 days (median, 9 days), and five case-patients (16%) never were isolated during admissions of from 3 to 28 days (median, 4 days). These 12 case-patients contributed a total of 136 patient-exposure days during their hospitalizations. Misclassification of patient risk status by user error delayed isolation of five (42%) of the 12 improperly isolated case-patients. CONCLUSIONS The use of an algorithm incorporating radiographic, laboratory, and clinical criteria and reported risk factors may assist in the rapid isolation of patients with suspected pulmonary tuberculosis.

Rapid Diagnosis of Intravascular Catheter-Associated Infection by Direct Gram Staining of Catheter Segments

Abstract We conducted a study to determine the usefulness of the Gram stain in the detection of intravascular catheter-associated infection. A total of 330 intravascular catheters were prospectively collected from adults and children suspected of having such an infection. Semiquantitative solid-agar cultures of the distal catheter tip were correlated with blood cultures. Catheter-associated bacteremia occurred in 34 per cent of cases in which catheter tips were colonized (≥15 colonies per agar plate). There were no cases of catheter-associated bacteremia in patients with uncolonized catheters. Immediately after culture, whole catheter segments were stained by the Gram technique. Gram-negative and gram-positive bacteria and yeast were easily identifiable under oil immersion (X1000), located predominantly on external catheter surfaces. Any catheter with at least one organism per 20 oil-immersion fields was designated as positive by Gram stain, but the majority of the 41 positive catheters had much larger nu...

Microbial Examination of Kidney Lithotripter Tub Water and Epidural Anesthesia Catheters

Kidney lithotripsy patients frequently receive epidural anesthesia via indwelling epidural catheters. In our hospital, patients are immersed in a tub of warm, continuously-flowing tap water. The epidural catheter-entry site is covered by a transparent occlusive dressing. To determine the risk of microbial colonization of the epidural catheter during lithotripsy, we performed quantitative cultures of tub water and semiquantitative cultures of catheters in 63 lithotripsy procedures. Most of the tub water organisms were typical tap water and skin flora isolates. Total colony counts were generally low with no significant progression during the course of serial procedures. Forty-two epidural catheters were cultured; 34 (81%) were sterile, 8 (19%) were colonized with small numbers of flavobacteria or coagulase-negative staphylococci. Only four catheters had organisms present on catheter segments covered by the transparent occlusive dressing (in each case there was a single colony forming unit per semiquantitative plate) and these organisms were probable contaminants. We conclude that with our current lithotripsy procedures, the risk for the development of epidural catheter-associated infection seems to be low.