Infection Prevention and Control in the Critical Care Setting

Patients in the critical care setting are more susceptible to Health Care Associated Infections (HCAIs), making infection prevention and control even more crucial within this setting. Some of the most common infection manifestations in the critically ill patient include pneumonia following intubation, bloodstream infections following IV catheterisation, and UTIs following urinary catheterisation.

Susceptibility to HCAIs within the critically ill population can be due to:

  • altered immunity – due to steroid use, surgery, anaesthesia and age
  • invasive lines – provide direct entry of bacteria into the patient’s bloodstream
  • underlying illnesses or conditions
  • broad spectrum antibiotics
  • mechanical ventilation

These risks cause an increased morbidity and mortality rate, a longer hospitalisation stay, and subsequently, higher treatment costs.

Antibiotic Use

We are currently witnessing a dramatic increase in infections by multi-drug resistant pathogens, leading to difficult infection management due to the scarcity of available antibiotics. Even more so, within the critical care setting there is an increased risk of patient-to-patient transmission, increased antibiotic use, and critically sick patients.

Multi Drug Resistant organisms (MDRO)

GRAM POSITIVES

  • VRE – Vancomycin-resistant Enterococci
  • MRSA – Methicillin-resistant Staphylococcus aureus

GRAM NEGATIVES

  • CRE – Carbapenem-resistant Enterobacterales
  • Pseudomonas aeruginosa CRE
  • ESBL-positive bacteria

OTHERS

  • Clostridium difficile
  • Neisseria meningitidis
  • Mycobacteria tuberculosis
Retrieved from https://slideplayer.com/slide/13193459/ on 28th January 2023

Infection Prevention and Control in the ICU Setting

General Preventive Techniques

  • follow the 5 moments of hand hygiene
  • alcohol hand rub should be the first hand hygiene choice – unless hands are visibly soiled
  • nails should be kept well trimmed with no gels
  • reduce jewellery use to just one plain wedding band if necessary
  • keep patients with MDRO in isolation rooms if possible
  • allocate equipment to one patient without sharing
  • screen patients for MDRO, specifically for MRSA, CRE and VRE on admission and at least weekly thereon
  • promote awareness on ANTT (aseptic non-touch technique) amongst colleagues
  • ensure disinfection of shared equipment such as monitoring lines, saturation probes, ECG leads, and blood pressure cuffs
  • promote education on infection prevention and control for staff and cleaners
  • educate patients’ relatives on infection prevention and control measures
  • ensure appropriate antibiotic use
  • ensure terminal cleaning of bed area upon patient discharge
infection prevention and control
Retrieved from https://surewash.com/news/moments-hand-hygiene/ on 28th January 2023

Glove Use

  • change gloves between procedures on the same patient when performing dirty vs aseptic tasks
  • change gloves between patients
  • don gloves immediately before contact with patient body fluid, mucous membranes, or non-intact skin
  • remove and discard immediately after a procedure and perform hand hygiene so that contamination is not transferred to another patient

Rectal screening for CRE and VRE

  • insert a charcoal swab approximately 2cn inside the rectum and rotate gently
  • ensure swab is brown-stained with faeces to ensure a good sample has been taken, as inadequate samples are not processed by the lab

Bathing Patients in Critical Care Setting

  • as previously mentioned, there is a high prevalence of MDROs in the critical care setting
  • daily chlorhexidine bathing of patients in the critical care setting is encouraged since chlorhexidine helps reduce the risk of acquiring MDROs
  • washing the patient’s body with chlorhexidine has been showing effectiveness in the prevention of carriage and possibly bloodstream infections with Gram-positive MDROs (MRSA and VRE)
  • chlorhexidine washes have shown possible eradication of carriage and infection prevention of Gram-negative MDROs, however, more evidence is required in this regard

Disinfecting Isolation Rooms

  • isolation rooms should be disinfected on a daily basis
  • isolation rooms should be cleaned last using yellow cloths, disposable gloves, and chlorine-based disinfectant
  • terminal cleaning and disinfection of isolation rooms should be done following patient discharge; all surfaces need to be cleaned with detergent; mattresses and pillows should be cleaned with environmental disinfectant wipes; UV-C disinfection should be performed, by which more than 99.9% of C. difficile spores and MRSA are killed in minutes

ADVANTAGES OF USING CHLORINE-BASED DISINFECTANT:

  • inexpensive
  • low toxicity
  • rapid effect
  • broad spectrum disinfectant – bacteriocidal, tuberculocidal, fungicidal, virucidal

DISADVANTAGES OF USING CHLORINE-BASED DISINFECTANT:

  • corrosive
  • long contact time
  • employee complaints

The Nurse’s Role in Proper Antibiotic Management

  • knowledge on antibiotic resistance
  • knowledge on the most frequently used antibiotics within the critical care setting
  • knowledge on the disadvantages of using broad spectrum antibiotics – prolonged use increases risk of C. difficile
  • administer antibiotics at the recommended dosage intervals for optimal effectiveness
    • administer IV antibiotics safely and effectively, with diligence to dosage, dilution, timing and calculations
  • administer IV antibiotics to patients with sepsis within 1 hour following diagnosis to increase risk of survival
  • list reminders for antibiotic review eg. stop date, reason for prescription, change of route, etc
  • therapeutic monitoring of antibiotic levels eg. Gentamicin, Amikacin and Vancomycin require serum blood level checking for safe and effective treatment; ensure samples are taken at the appropriate time for best results
  • understand when to withold an antibiotic dose until results are available eg. in the case of Gentamicin
  • serum blood level samplings should be properly documented in both the patient’s notes and on the lab request form
  • proper handover on transfer from ICU to another ward

Ventilator Associated Pneumonia (VAP)

Pneumonia is an infection in the lung parenchyma, particularly in the bronchioles and alveoli, which is caused by pathogens such as bacteria, fungi and viruses.

Ventilated Associated Pneumonia (VAP) is pneumonia which develops 48 hours following intubation and initiation of mechanical ventilation. VAP is considered to be the 2nd most common HCAIs but the most serious one, with 25% of these patients with VAP ending up dead.

VAP happens because intubation bypasses all natural defense mechanisms within the tracheo-bronchial tree that protect the lower respiratory tract from infections.

Causative organisms, some of which are often present in the oropharyngeal cavity and the gastrointestinal system, are:

  • Gram-negative aerobes – Pseudonomas aeruginosa, Klebsiella pneumonia, Acinetobacter, Enterobacter
  • Gram-positive aerobes – Staphylococcus aureus/MRSA

There are 5 defense mechanisms which are bypassed during ventilation:

  • The Larynx and the Glottis – prevent aspiration of oral content
  • The Coughing Reflex – helps in the expelling of secretions and aspirated matter from the larger airways
  • Mucous – helps trap small particles
  • Cilia – hair-like structures which help move mucous up from the lower respiratory tract towards the larynx to be expelled
  • Phagocytic Cells – engulf bacteria if or when they manage to reach the alveoli

Aspiration of contaminated fluids and secretions into the lungs can happen in various ways:

  • colonisation of pathogenic bacteria within the oropharynx or tracheo-bronchial tree
  • the stomach, through enteral feeding, certain drugs (eg. stress ulcer prophylaxis), and supine patient positioning, may act as a source of pathogens for VAP
  • inhalation of aerosols through contaminated intubation or nebulisation equipment

Pathological development of pneumonia

  1. aspiration of contaminated fluids or secretions into the lungs
  2. initiation of the inflammatory response
  3. swelling of the mucous membranes of the alveoli and bronchi
  4. pus collects within the alveoli
  5. interference of pus with the gas exchange process
  6. development of pneumonia
infection prevention and control
Retrieved from https://www.uptodate.com/contents/pneumonia-in-adults-beyond-the-basics/print on 28th January 2023

Signs & Symptoms of VAP Pneumonia

  • temperature of >38°C
  • tachypnoea and/or dyspnoea
  • purulent sputum (off-white, yellow or green, and opaque)
  • worsening ABGs – poor SaO2 and increased ventilatory demands
  • positive sputum and/or blood cultures
  • leukocytosis >12,000 WBC/mm2
  • chest x-ray or CT scan with evidence of pneumonia

NOTE: Diagnosing VAP can be difficult!

infection prevention and control
Chest X-rays and CT-scan of a 65-year-old man who developed ventilator-associated pneumonia. Chest X-ray performed the day VAP was suspected seems normal (a), whereas the CT-scan performed the same day showed consolidation of the left inferior lobe (b, d). Bronchoalveolar lavage yielded 105Enterobacter aerogenes. The next day, chest X-ray showed progression of pulmonary infiltrates (c). VAP diagnosis based on chest X-ray would have been delayed – Retrieved from https://link.springer.com/article/10.1007/s00134-020-05980-0 on 28th January 2023

VAP Risk Factors

  • length of time in which the patient is exposed to the healthcare environment
  • predisposing host-related factors such as age, malnutrition etc
  • treatment factors eg. endotracheal intubation, prolonged exposure to antibiotics

VAP Consequences

  • increased mortality
  • prolonged mechanical ventilation
  • increased antibiotic use
  • prolonged stay at the ITU and hospital
  • increased medical cost

VAP Infection Prevention and Control

  • do not intubate patient unless necessary
  • choose non-invasive ventilation over invasive ventilation where possible
  • elevate head of bed 30-45° especially for patients receiving enteral feeding
  • minimise aspiration of contaminated oropharyngeal and tracheal secretions
  • suction subglottic secretions
  • avoid gastric over distention
  • avoid unplanned extubation
  • maintain correct ETT cuff pressure (20cm H2O)
  • provide frequent oral hygiene – suctioning, toothbrushing, and using chlorhexidine mouthwashes
  • use HME filters rather than heated humidifiers
  • remove condensate from ventilatory circuits periodically
  • extubate as soon as possible

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Infection Prevention and Control

Infection prevention and control (IPC) is a practical, evidence-based approach which prevents patients and health workers from being harmed by avoidable infection and as a result of antimicrobial resistance.

No one should catch an infection while receiving health care, yet, these infections can spread through outbreaks and many regular care practices, affecting hundreds of millions of people across the world every year.

World Health Organisation

The Chain of Infection

infection prevention and control
Retrieved from https://activesocialcare.com/handbook/infection-prevention-and-control/the-chain-of-infection on 12th January 2022

A HAI (hospital acquired infection) occurs:

  • up to 48 hours after hospital admission
  • up to 3 days after discharge
  • up to 30 days after an operation

RESERVOIR:

A microorganism lives and multiplies in what we call ‘reservoirs’: humans (eg. chickenpox, hepatitis B, and HIV), animals (eg. rabies, and salmonella), or inanimate objects (eg. tetanus).

INFECTION SOURCE:

This is the source of infection – a specific infection outbreak or an individual infection. An endogenous infection refers to an infection caused by the patient’s own microflora, while an exogenous infection refers to an infection caused through an environmental source. Zoonosis refers to an infection originating from an animal source.

ENTRY PORTALS:

  • respiratory tract eg. pneumonia
  • GI tract eg. Clostridioides difficile or C. difficile
  • genito-urinary tract eg. CAUTI (catheter acquired urinary tract infection)
  • skin breaks (including traumatic and surgical wounds)
  • blood (through needles and catheters)

All patients are at risk of acquiring a MDRO (multi-drug resistant organism)!

TRANSMISSION ROUTES

  • direct and indirect contact
  • air
  • food
  • drink
  • water
  • insects

Direct or indirect contact include transmission via hands, transmission by inanimate objects, transmission by contact with blood, and transmission through sex…

Transmission via Hands:

  • Staphylococcus aureus can be spread by staff, either through spreading their own nasal staph to their patients, or spreading staph from one patient to another.
  • Gram-negative bacteria can be found colonising a patient’s skin, and then transmitted onto staff hands.
  • Enteric Infections such as shigella and rotavirus (commonly found in children) are faecal-oral spreads transmitted via hands in the community and hospital setting.

Transmission via Inanimate Objects a.k.a. Fomites:

This type of transmission happens passively from one inanimate object to another. Objects include surgical instruments as well as more common objects such as pens, stethoscopes, books, suction catheters, bedpans etc.

Transmission via Sexual Contact:

Sexually transmitted diseases (STDs) are considered to be very fragile and so, they do not usually survive on inanimate objects. STDs include syphilis gonorrhoea, chlamydia, HIV, herpes, etc.

Transmission via Blood:

Transmission by contact with infected blood happens through wounds, menses, human bites, blood products, specimens, contaminated needles (including needle-stick injuries), and during traumatic sexual intercourse.

Endemic Hepatitis B is transmitted during birth from the mother to her baby. Other infections which can pass to the foetus during pregnancy includes rubella, cytomegalovirus and syphilis.

Transmission via Air a.k.a. Airborne Transmission

Transmission via air happens through sneezing, coughing and speaking. Small droplets (<0.1mm) evaporate; Solid droplet nuclei may remain airborne…these may be eventually inhaled. Measles, chickenpox and tuberculosis are spread in this way. Large droplets fall to the ground.

Transmission via Food, Drink, and Water:

Transmission of infection via food, drink and water usually happens in enteric infections via faecal-oral spread.

In food poisoning, bacteria multiply in food prior to ingestion, producing enteric toxin (eg. in staph aureus) or multiply and produce toxin in bowel lumen (eg. in cholera and E.coli). Salmonella happens through infection following ingestion of poorly-cooked food. Brucellosis is an infection resulting from drinking unpasteurised contaminated milk. In water-borne cholera, faecal excretion by-carriers contaminate river water which is then consumed downstream.

Transmission via Insects a.k.a Anthropod-borne Infections:

Anthropod-borne infections are transmitted by blood-sucking insects such as mosquitos (malaria). These parasites have the ability to multiply in their hosts.

The Infection Spectrum

Contamination => Colonisation => Critical Colonisation => Infection

Colonisation is the presence of multiplying bacteria with no reaction or symptoms.

Infection is the presence of multiplying bacteria which affects the host’s defenses, causing clinical symptoms.

Bacteria can be transmitted even if no infection is present. This explains why Staphylococcus aureus, which is endemic, can be found outside the hospital, within the community, undetected.

MRSA – Methicillin Resistant Staphylococcus Aureus

MRSA is resistant to common antibiotics such as penicillins and cephalosporins. MRSA can be carried around by healthy individuals without any symptoms for weeks to years.

MRSA in a patient with a low colonisation level may not be detected by culture. Anterior nares specimen testing result in the highest identification rate for MRSA. Gloves should be worn when caring for infected wounds of patients with MRSA.

Patients are screened for MRSA on admission and more importantly before important procedures.

Treatment for MRSA decolonisation:

  • 2% Mupirocin (Bactroban) nasal ointment 3 times per day for 5 days (apply small amount to inner nostrils using tube, press nostrils together and massage for about 1 minute).
  • Daily full body and hair washes with 4% chlorhexidine gluconate.

Isolation and Contact Precautions for Infection Prevention and Control

Isolation and contact precautions should be put in place in the case of current or previous 6 months colonisation or infection with MDRO. Contact precautions notice should be put up on the patient’s door, and related information should be provided for both the patient and relatives.

Contact precautions can be stopped:

  • if the organism is not cultured again
  • in case of 3 consecutive negative MRSA screen cultures

Terminal cleaning of patient’s room must be performed!

Infection Prevention and Control

5 Moments for Hand Hygiene

  1. BEFORE patient contact
  2. BEFORE aseptic task
  3. AFTER body fluid exposure
  4. AFTER patient contact
  5. AFTER leaving patient surrounding
  • Soap & Water mechanically remove microorganisms and soil but DO NOT kill microorganisms; remove transient skin flora, but only limited resident flora.
  • Alcohol Rub DOES NOT mechanically remove microorganisms or soil, but kills microorganisms; kills transient skin flora, but only limited resident flora.
  • Aqueous Antiseptic Solutions mechanically remove and kill microorganisms and soil; remove and kill transient and some resident skin flora.

Standard Precautions for Infection Prevention and Control

Standard precautions should be applied by all staff in all healthcare settings to all patients regardless of diagnosis and infection status all the time.

  1. Good hand hygiene practice
  2. Use waterproof dressings to cover wounds or skin lesions
  3. Use cough etiquette
  4. Do not touch your eyes, nose, mouth or face, or adjust PPEs with contaminated hands or gloves
  5. Limit contact with patient’s items in immediate surrounding area to the minimum
  6. Use recommended PPEs for required tasks anticipating possible risks

Donning PPEs Sequence:

  1. Gown
  2. Mask
  3. Visor
  4. Gloves

Doffing PPEs Sequence:

  1. Gloves
  2. Visor
  3. Gown
  4. Mask

Swabbing Methods

Staphylococcus aureus produces a higher cultivation of bacteria in the nose and throat, thus swabbing methods used for MRSA are the nasal swab or the throat swab. Note however, that MRSA can also be found in other locations within the body, such as in wounds.

Nasal Swab

Throat Swab

Wound Swab

Urine Sampling

Sputum Sampling

Stool Sampling

Blood Cultures

Retrieved from https://studylib.net/doc/8188811/bd-vacutainer%C2%AE-system—st-vincent-s-university-hospital on 13th January 2022

Peripheral Vascular Catheter Care

Retrieved from https://www.facebook.com/641909052635080/photos/visual-infusion-phlebitis-score-detail-has-been-attached-hereindetail-topic-will/1149380728554574/ on 13th January 2022

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