GGC Medicines


Adult Therapeutics Handbook

Management of Infections

Management of Infections

Introduction

Appropriate and prudent use of antimicrobials is important. Antibiotics are overused and not without risk, 1 in 5 courses are associated with adverse events including Clostridium difficile infection, antibiotic resistance (e.g. MRSA, Meticillin Resistant Staphylococcus aureus), drug interactions, drug toxicity, device related infections, Staphylococcus aureus bacteraemia (SAB). Misuse of these agents is also associated with treatment failure and increasing cost to NHSGGC. The following guidelines and policy documents aim to ensure appropriate, prompt and prudent use of antimicrobials within NHSGGC:

  • Infection management guidelines (for empirical antibiotic treatment)
  • Intravenous to Oral Switch Therapy (IVOST) Guideline
  • Gentamicin and Vancomycin dosing guidelines
  • Protected Antimicrobial Policy (previously known as 'Alert Antibiotic Policy'):
    • A list of broad-spectrum agents whose use is limited to specific indications and/or on the advice of a clinical microbiologist or infectious diseases physician.
  • Antibiotic prophylaxis in surgery

These guidelines are reviewed and updated at regular intervals. The most up to date information can be found on the NHSGGC StaffNet, Clinical Guidelines Directory, and search in 'Infections' section (including guideline on Antibiotic Prophylaxis in Surgery; General Principles). There are separate guidelines for infection management in primary care and in paediatrics.

Steps to Prudent Antimicrobial Prescribing

Antibiotics are overused, particularly in elderly patients, those with urinary catheters/bacteria in their urine but no signs or symptoms of urinary tract infection and patients with viral or non-infective exacerbations of COPD.

To ensure appropriate and prudent antimicrobial prescribing follow the steps below:

  • Establish diagnosis and severity of infection. Follow GG&C guidelines and if unsure seek senior clinical advice from within your team.
  • Microbiology sampling - obtain blood (and other) cultures before prescribing antibiotic therapy. Do not routinely swab skin/wounds or culture urine in the absence of infection.
  • Document indication for the antibiotic in the medical notes
  • Document duration of antibiotic therapy in the medical notes and on the drug kardex. On the kardex cross off the day and time when antibiotics should stop, this will avoid unnecessarily long prescriptions of antibiotics.
  • Penicillin allergy - confirm nature with patient / GP. Often patients state they had diarrhoea or nausea and vomiting which is not true allergy. Vancomycin is inferior to beta-lactam therapy in sensitive infections.
  • Review and record therapy daily. Can you simplify (narrower spectrum), switch (IVOST) or stop antibiotic?
  • Before contacting infection specialist:
    • Ensure senior clinical review within your team
    • Confirm adequate empirical prescription (≥48 hours and no missed antibiotic doses)
    • Check microbiology results on portal/Trakcare
    • Source control – drain/aspirate/remove
    • Consider non-infective reasons for poor response.
  • Patient and drug specific factors may affect antibiotic choice and response to therapy, so look at:
    • Previous antimicrobial history
    • Previous infection with multiresistant organisms (check previous culture results)
    • Renal/hepatic function
    • Other medication (see Appendix 1 of the BNF for information on drug interactions)
    • Availability and absorption by the oral route

Sepsis

Early recognition and management is key to improving outcomes for patients. Patients with infection and evidence of organ dysfunction have sepsis which has 10% hospital mortality. These patients are therefore at high risk of acute deterioration and death and consideration should be given to managing these patients in a high dependency / critical care setting. The Quick Sequential Organ Failure Assessment (qSOFA) score (see figure 1 below) is a simple bedside clinical score using 3 criteria to rapidly identify patients with suspected infection who are more likely to have poor outcomes typical of sepsis.

Figure 1 – qSOFA scoring tool

A score of ≥2 of:

  • Confusion (<15 of Glasgow Coma Scale)
  • Respiratory rate ≥22/minute
  • Systolic blood pressure ≤100mmHg

Seymour CW et al. Assessment of Clinical Criteria for Sepsis - For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016; 315(8):762-774. Adapted with permission.

Definition of sepsis

Infection (includes system-related signs or symptoms and/or features of the Systemic Inflammatory Response Syndrome (SIRS*)) with evidence of organ hypoperfusion (see figure 1 above).

Sepsis 6

[Infection] + [either features of SIRS* or signs of systemic infection] +/- [qSOFA ≥2] = Do sepsis 6

Ensure sepsis 6 within one hour:

  1. Blood cultures and any other relevant samples prior to administration of antibiotics. Consider source control.
  2. IV antibiotic administration according to GG&C infection management guidelines. For each hour’s delay in administering antibiotics in septic shock, mortality increases by 7.6%. Communicate with the member of staff who is responsible for administration of the IV antibiotic therapy so it is given promptly. Administer the antibiotic in the clinical area where infection has been recognised and do not delay until arrival at destination ward. Review empirical (best guess) antimicrobial therapy no later than 48 hours after initiation. Simplify and switch to narrow spectrum therapy when microbiology results become available.
  3. Oxygen to maintain target saturation (>94% or 88%-92% in people at risk of hypercapnic respiratory failure)
  4. Measure lactate
  5. Start intravenous fluid resuscitation
  6. Monitor hourly urine output

*SIRS indicated by temperature <36°C or >38°C; tachycardia HR >90 bpm; tachypnoea RR >20 breaths/minute; WCC <4 or >12 x 109/L. SIRS is not specific to bacterial infection. It also arises due to viral and non-infective causes.

HIV Testing

Consider HIV testing in all patients with infection and in higher risk groups:

  • Intravenous Drug Users (IVDU) / People Who Inject Drugs (PWID).
  • Men who have Sex with Men (MSM).
  • From high endemic country or origin of travel.

Indications for IV Antibiotic Therapy

  • Prescribe IV only for those with severe / deep seated infections, sepsis syndrome (see Severe Systemic Infections) or if the oral route is unavailable. Review IV antibiotics daily and switch to oral when appropriate (see IV-Oral Antibiotic Switch Therapy (IVOST)).
  • See figure 2 below for indications for initial IV route of antibiotics.

Figure 2 – Indications for initial IV route of antibiotics

Start IV antibiotic therapy (including gentamicin) within 1 hour of recognition of sepsis or severe infection in the clinical area where the diagnosis has been made. Each hour of delay in administering IV antibiotic therapy is associated with increasing mortality. Indications for IV (within 1 hour) are:

  • Sepsis or deteriorating clinical condition due to bacterial infection irrespective of site
  • Fever and neutropenia / immunosuppression
  • Infection where initial IV therapy is mandatory; endocarditis, CNS infection, S. aureus bacteraemia, vascular graft infection
  • Infection where initial IV therapy is usual; severe pneumonia, bronchiectasis, bone/joint infection, intra-abdominal infection, deep abscess
  • Skin and soft tissue infection; IV therapy if sepsis or ≥2 of heat, erythema, induration/swelling (IV usually for 48-96 hours)
  • Infection requiring antibiotics but oral route compromised (nil by mouth, reduced gastrointestinal absorption, mechanical swallowing disorder, vomiting, unconscious, no oral antibiotic formulation)

Reducing the risk of Clostridium difficile through prudent prescribing

Clostridium difficile infection (CDI) is an important healthcare associated infection in Scottish hospitals. It is life-threatening (reported mortality rate 10-30%) and has the potential for person to person spread within healthcare settings. Particularly at risk are patients who are aged >65 years, frail, immunocompromised or who have chronic obstructive pulmonary disease or cardiovascular disease.

Antibiotic therapy disturbs the normal gastrointestinal flora, depleting organisms which are protective against CDI. Any antibiotic may be associated; those associated most commonly are listed below. Other broad spectrum agents (particularly the carbapenems) are also likely to show an association as prescribing increases. Overall antibiotic exposure, including excessive duration of therapy is also a risk factor for CDI as is surgical prophylaxis (with cephalosporins and quinolones). Proton pump inhibitors and H2 antagonists also increase gastric pH which is associated with an increase in the risk of Clostridium difficile acquisition.

Factors associated with CDI:

  • Increasing age
  • Severe underlying disease
  • Non-surgical gastrointestinal procedures
  • Nasogastric tube
  • Long stay in hospital
  • Stay in intensive care
  • Antibiotic use (clindamycin, cephalosporins, co-amoxiclav, ciprofloxacin (and other quinolones) and piperacillin / tazobactam)
  • Longer duration of antibiotic course
  • Proton pump inhibitors or H2 antagonists

The GG&C antimicrobial guidelines are designed to reduce the risk of CDI by limiting overall antibiotic exposure (reduced prescriptions and duration of therapy) and by limiting those agents which have the strongest association.

 

Content last updated December 2018