Early- and Late-Onset Pneumonia: Is This Still a Useful Classification?

The choice of empirical treatment of nosocomial pneumonia in the intensive-care unit (ICU) used to rely on the interval after the start of mechanical ventilation. Nowadays, however, the question of whether in fact there is a difference in the distribution of causative pathogens is under debate. Data from 308 ICUs from the German National Nosocomial Infection Surveillance System, including information on relevant pathogens isolated in 11,285 cases of nosocomial pneumonia from 1997 to 2004, were used for our evaluation. Each individual pneumonia case was allocated either to early- or to late-onset pneumonia, with three differentiation criteria: onset on the 4th day, the 5th day, or the 7th day in the ICU. The frequency of pathogens was evaluated according to these categories. A total of 5,066 additional cases of pneumonia were reported from 2005 to 2006, after the CDC criteria had been modified. From 1997 to 2004, the most frequent microorganisms were Staphylococcus aureus (2,718 cases, including 720 with methicillin [meticillin]-resistant S. aureus), followed by Pseudomonas aeruginosa (1,837 cases), Klebsiella pneumoniae (1,305 cases), Escherichia coli (1,137 cases), Enterobacter spp. (937 cases), streptococci (671 cases), Haemophilus influenzae (509 cases), Acinetobacter spp. (493 cases), and Stenotrophomonas maltophilia (308 cases). The order of the four most frequent pathogens (accounting for 53.7% of all pathogens) was the same in both groups and was independent of the cutoff categories applied: S. aureus was first, followed by P. aeruginosa, K. pneumoniae, and E. coli. Thus, the predictabilities of the occurrence of pathogens were similar for the earlier (1997-to-2004) and later (2005-to-2006) time frames. This classification is no longer helpful for empirical antibiotic therapy, since the pathogens are the same for both groups.For a long time it was common to distinguish between an early onset (the first 4 days) and a late onset (after the 4th day) of ventilator-associated pneumonia (VAP) (18). Early-onset nosocomial pneumonia was believed to be due primarily to gram-negative bacteria, such as Haemophilus influenzae, and methicillin (meticillin)-sensitive Staphylococcus aureus (MSSA) and Streptococcus pneumoniae. For late-onset nosocomial pneumonia, the most commonly encountered causative pathogens reported were higher-level antibiotic-resistant gram-negative bacteria, such as Pseudomonas aeruginosa, Acinetobacter spp., or methicillin-resistant S. aureus (MRSA). This classification leads to different strategies for empirical antimicrobial treatment: monotherapy with narrow-spectrum antibiotics for the treatment of early-onset pneumonia but broad-spectrum therapy for Pseudomonas spp. or MRSA with late-onset infection (2).Meanwhile, guidelines and articles that discuss this classification are using different criteria for distinguishing between early- and late-onset nosocomial pneumonia. Some authors regard the 4th day in the intensive-care unit (ICU) as the last day of an early onset (4, 6, 16, 20, 22), while others set the 5th (23) or even the 7th (11, 14, 24) day as the limit. Furthermore, it still remains uncertain from the relevant literature whether the given threshold refers to the number of days in the hospital or the number of days following intubation (23). The concept itself, though, still remains accepted in general (3, 23).During our surveillance activities in several ICUs, however, we got the impression that this widely used classification may no longer be appropriate for determining the antimicrobial therapy required. We have therefore used data from the German National Nosocomial Infection Surveillance System, KISS (Krankenhaus-Infektions-Surveillance-System), to investigate this question, drawing on a huge database provided by German ICUs (10).     

E‐learning: Is This Teaching at Students or Teaching With Students?

The development of e-learning as a teaching strategy in higher education has implications relating to student learning, the role of the teacher, and the institution of higher education. This paper debates the andragogical and pedagogical theories that support the development of e-learning to date. Leading to a discussion on how the process of e-learning may be contributing to the "stamp-me-smart" culture and restricting the development of critical thinking within student nurses. Concluding that e-learning has a top-down institution-led development that is contrary to the student-led development espoused by universities.     

Ventricular Tachycardia in Non‐Compaction of Left Ventricle: Is This a Frequent Complication?

BACKGROUND: Isolated left ventricular non-compaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is recognized by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favorable substrate for ventricular arrhythmias is unclear. Some reports have found that the fatal ventricular arrhythmias may occur in approximately half of the patients. In this report we investigated about this association. METHODS AND RESULTS: In total we evaluated a continuous series of 238 patients affected by non-compaction. Periodic Holter monitoring was performed every 6 months for 4 years. Only 11 patients had documented ventricular tachycardia, which was sustained in two cases and non-sustained in nine. In no cases we observed ventricular fibrillation. CONCLUSIONS: Non-compaction alone does not seem to be a risk factor for malignant ventricular arrhythmias.     

Does This Bite Need an Antibiotic?

Nurse practitioners (NPs) who work in acute care settings can evaluate challenging dermatologic cases. It is vital for NPs to be able to understand the differences between cellulitis and inflammatory reactions. Often, large local reactions to bites/stings are frequently misdiagnosed as bacterial cellulitis. Pressure from patients and demand for unnecessary antibiotics can impact the goals of astute antibiotic stewardship. This case report reinforces the differences between cellulitis and inflammatory reactions and how NPs can approach these challenging visits.     

‘… and in This Corner,the Patient’

Readers are invited to submit questions relating to problem cases. Inquiries will be answered by qualified consultants and replies forwarded by mail promptly. Selected problems and solutions are published every month in this section.