A summary of the initial management of patients admitted to hospital with suspected community acquired pneumonia (CAP) is presented in fig 8. Tables 4 and 5, respectively, summarise (1) the relevant microbiological investigations and (2) empirical antibiotic choices recommended in patients with CAP.



Figure 8 
Hospital management of community acquired pneumonia (CAP) in the first 4 h. CXR, chest x ray; DBP, diastolic blood pressure; SBP, systolic blood pressure.



View this table:

Table 4 
Recommendations for the microbiological investigation of community acquired pneumonia (CAP)



View this table:

Table 5 
Initial empirical treatment regimens for community acquired pneumonia (CAP) in adults



### Investigations ( Section 5 )

#### When should a chest radiograph be performed in the community?

1. It is not necessary to perform a chest radiograph in patients with suspected CAP unless:

2. 

#### When should a chest radiograph be performed in hospital?

1. All patients admitted to hospital with suspected CAP should have a chest radiograph performed as soon as possible to confirm or refute the diagnosis. [D] The objective of any service should be for the chest radiograph to be performed in time for antibiotics to be administered within 4 h of presentation to hospital should the diagnosis of CAP be confirmed.

#### When should the chest radiograph be repeated during recovery?

1. The chest radiograph need not be repeated prior to hospital discharge in those who have made a satisfactory clinical recovery from CAP. [D]

2. A chest radiograph should be arranged after about 6 weeks for all those patients who have persistence of symptoms or physical signs or who are at higher risk of underlying malignancy (especially smokers and those aged >50 years) whether or not they have been admitted to hospital. [D]

3. Further investigations which may include bronchoscopy should be considered in patients with persisting signs, symptoms …

https://thorax.bmj.com/content/thoraxjnl/64/Suppl_3/iii1.full.pdf

BTS guidelines for the management of community acquired pneumonia in adults: update 2009.

T F Torrence (ed) 1982 Edinburgh: Scottish Academic Press xiii + 103 pp price £7.50 In 1865 James Clerk Maxwell published in the Philosophical Transactions a long paper entitled 'A dynamical theory of the electromagnetic field'. In this work, about which he wrote to a relative, 'I have a paper afloat, with an electromagnetic theory of light, which, till I am convinced of the contrary, Ihold to be great guns', he set up the electromagnetic field equations unifying electricity and magnetism, and identified light as 'an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws'.

A Dynamical Theory of the Electromagnetic Field

C-Reactive Protein Is an Independent Predictor of Severity in Community-acquired Pneumonia

Contribution of C-Reactive Protein to the Diagnosis and Assessment of Severity of Community-Acquired Pneumonia

Objectives To evaluate the diagnostic accuracy of C reactive protein in detecting radiologically proved pneumonia and to evaluate how well it can discriminate between bacterial and viral infections of the lower respiratory tract.

Data sources Medline and Embase (January 1966 to April 2004), with reference checking.

Study selection We included articles comparing C reactive protein with a chest radiograph or with microbiological work-up as a reference test. Two authors independently assessed methodological items.

Results None of the studies met all validity criteria. Six studies used an infiltrate on chest radiograph as reference test. Sensitivities ranged from 10% to 98%, specificities from 44% to 99%. For adults, the relation of C reactive protein with an infiltrate (in a subgroup analysis of five studies) showed an area under the curve of 0.80 (95% confidence interval 0.75 to 0.85). In 12 studies, the relation of C reactive protein with a bacterial aetiology of infection of the lower respiratory tract was studied. Sensitivities ranged from 8% to 99%, specificities from 27% to 95%. These data were epidemiologically and statistically heterogeneous, so overall outcomes could not be calculated.

Conclusion Testing for C reactive protein is neither sufficiently sensitive to rule out nor sufficiently specific to rule in an infiltrate on chest radiograph and bacterial aetiology of lower respiratory tract infection. The methodological quality of the diagnostic studies is generally poor. The evidence not consistently and sufficiently supports a wide introduction of C reactive protein as a rapid test to guide antibiotics prescription.

https://www.bmj.com/content/bmj/331/7507/26.full.pdf

Diagnostic value of C reactive protein in infections of the lower respiratory tract: systematic review

The diagnostic value of C-reactive protein (CRP) admission serum levels as an indicator of the aetiology of community-acquired pneumonia (CAP) was evaluated. A cohort of 1,222 patients with CAP was assessed. CRP levels were analysed in 258 patients with a single aetiological diagnosis. The mean CRP values in patients with pyogenic, atypical, viral and Legionella pneumophila pneumonia were: 16 mg x dL(-1), 13 mg x dL(-1), 14 mg x dL(-1) and 25 mg x dL(-1), respectively. CRP levels were not significantly different among patients outcome research team (PORT) groups (19 mg x dL(-1) in groups I-II, 16 mg x dL(-1) in group III and 16 mg x dL(-1) in groups IV-V). A cut-off point of 25 mg x dL(-1) had a sensibility, specificity, positive predictive value and negative predictive value of 0.6, 0.83, 0.3, and 0.94, respectively. After controlling for age and PORT score, the odds of having a CRP level >25 mg x dL(-1) was 6.9 times higher in patients with L. pneumophila pneumonia than in those with non-L. pneumophila pneumonia. Patients with Legionella pneumophila pneumonia had higher C-reactive protein levels than those with pneumonia of any other aetiology, independently of severity of infection. Being a cheap and readily available test, C-reactive protein may be a useful adjunctive procedure in the diagnosis of community-acquired pneumonia.

https://erj.ersjournals.com/content/erj/21/4/702.full.pdf

C-reactive protein levels in community-acquired pneumonia.

The increased adoption of renewable energy generation is reducing the inertial response of the Great Britain (GB) power system, which translates into larger frequency variations in both transient and pseudo-steady-state operation. To help mitigate this, National Grid, the transmission system operator in GB, has designed a control scheme called enhanced frequency response (EFR) specifically aimed at energy storage systems (ESSs). This study proposes a control system that enables the provision of EFR services from a multi-electrical ESS and at the same time allows the management of the state of charge (SOC) of each ESS. The proposed control system uses a Fuzzy Logic Controller to maintain the SOC as near as possible to the desired SOC of each ESS while providing EFR. The performance of the proposed controller is validated in transient and steady-state domains. Simulation results highlight the benefits of managing the SOC of the energy storage assets with the proposed controller. These benefits include a reduced rate of change of frequency and frequency nadir following a loss of generation as well as an increase in the service performance measure which renders into increased economic benefits for the service provider.

/pdf/controller-to-enable-the-enhanced-frequency-response-541mnrrsqy.pdf

Controller to enable the enhanced frequency response services from a multi-electrical energy storage system

Looking to the future, there are several challenges that the electricity networks will face: prosperity, sustainable growth, global, and security. The electricity industry situation is complex beca ...

Transmission system-friendly microgrids: an option to provide ancillary services

Looking to the future, there are several challenges that electricity networks will face: prosperity, global sustainable growth and security. The electricity industry situation is complex because resources worldwide are becoming scarce and the need for sustainable growth is important. Dealing with this challenge led to the foundation of micro-grids. The classical “micro-grid” defines a mix of distributed energy resources (DER) capable of providing sufficient and continuous energy to a significant portion of the internal demand. Transmission system friendly micro-grids is a novel concept to encourage the power electronic converters to provide grid services and functionalities in line with new standards such as IEEE 1547- 2018. This paper presents a method for reducing losses by injecting reactive power from the grid-connected DER. The methodology is developed in Python and the system is modelled in DIgSILENT PowerFactory. The paper includes numerical results of the proposed methodology to show the suitability of the proposed concept.

A Transmission System Friendly Micro-grid: Optimising Active Power Losses

The system frequency is a very complex electromechanical variable in a power system. The complexity comes from an appropriate understanding of the phenomena related to the frequency creation and its measurement and estimation. The objective of this paper is to present a comprehensive explanation of the concept of frequency and its potential character in the operation and control of power systems. The significant contribution of this paper is an explanation of the electro-mechanical nature of the frequency, and the introduction of the non-pure frequency concept related to need to measure the frequency from the voltage signal at any bus and the pure-frequency coming from the electro-mechanical character of the frequency generated at the synchronous generators. An illustrative simulation example is used to demonstrate the two characters of the frequency proposed in this paper.

Francisco Sanchez

Papers

C-reactive protein levels in community-acquired pneumonia.

Controller to enable the enhanced frequency response services from a multi-electrical energy storage system

Transmission system-friendly microgrids: an option to provide ancillary services

A Transmission System Friendly Micro-grid: Optimising Active Power Losses

Unveiling the Character of the Frequency in Power Systems