Infective Endocarditis (IE) is a microbial infection of the endocardial surface of the heart, most commonly the heart valves. The pathogenic sequence is:
GCC Context: Rheumatic heart disease (RHD) remains prevalent among South Asian, Egyptian, and East African expats in the Gulf — particularly in construction workers and domestic staff. RHD significantly elevates IE risk.
Painful subcutaneous nodules on finger/toe pads. Immune complex deposition. Last 1–2 days. Classic but uncommon.
Painless erythematous/haemorrhagic macules on palms & soles. Septic emboli. More common in acute Staph IE.
Subungual linear dark streaks. Non-specific (also seen in trauma). More proximal = more suspicious for IE.
Retinal haemorrhages with white/pale centres (Litten sign). Seen on fundoscopy. Immune complex microinfarcts of retinal vessels.
Never start antibiotics before collecting blood cultures. Empirical antibiotics given before cultures significantly reduce diagnostic yield and may result in culture-negative IE — making organism identification and targeted therapy impossible.
Echo is the cornerstone of IE diagnosis. Perform echocardiography in all patients with suspected IE within 24 hours. Negative echo does NOT exclude IE if clinical suspicion is high — repeat at 5–7 days.
Limitations: poor acoustic window in obese/COPD patients, limited views of prosthetic valves (shadowing). If TTE inconclusive and suspicion high, proceed to TOE.
Preferred in prosthetic valve IE, periannular abscess detection, and pre-surgical planning. Repeat every 5–7 days if initial negative but suspicion persists.
Start empirical antibiotics only AFTER 3 sets of blood cultures are drawn. Every hour of delay after cultures are collected risks deterioration — but antibiotics before cultures destroy diagnostic accuracy.
Covers streptococci and enterococci. Add flucloxacillin or oxacillin if Staph aureus suspected (acute presentation, IV drug use, skin source).
Vancomycin covers MRSA and coagulase-negative Staph. Rifampicin added for prosthetic valve IE (biofilm penetration). Confirm organism and sensitivities urgently.
| Organism | Native Valve (NVE) | Prosthetic Valve (PVE) | Duration |
|---|---|---|---|
| Strep. viridans / Strep. gallolyticus (MIC ≤0.125) | Penicillin G or Amoxicillin | Penicillin/Amoxicillin + Gentamicin | 4 weeks (NVE uncomplicated 2 weeks) |
| Staph. aureus (MSSA) | Flucloxacillin (cloxacillin) IV | Flucloxacillin + Rifampicin + Gentamicin (first 2 weeks) | 4–6 weeks NVE; ≥6 weeks PVE |
| Staph. aureus (MRSA) | Vancomycin or Daptomycin | Vancomycin + Rifampicin + Gentamicin | 6 weeks PVE minimum |
| Enterococcus spp. | Ampicillin + Ceftriaxone (preferred) or + Gentamicin | Ampicillin + Ceftriaxone or + Gentamicin | 6 weeks (NVE); ≥6 weeks (PVE) |
| Coagulase-negative Staphylococci (PVE) | — | Vancomycin + Rifampicin + Gentamicin | ≥6 weeks |
| HACEK group | Ceftriaxone 2g daily IV | Ceftriaxone 2g daily IV | 4 weeks NVE; 6 weeks PVE |
| Fungal (Candida, Aspergillus) | Amphotericin B ± flucytosine (Candida: liposomal AmB or micafungin) | Same + early surgery usually required | Indefinite suppression often needed |
Peripherally Inserted Central Catheter (PICC) is the preferred IV access for 4–6 week antibiotic therapy. Inserted under ultrasound guidance, confirmed by X-ray tip position at SVC/right atrial junction.
Available in UAE (DHA), Saudi Arabia (SCFHS-supervised), and Qatar (Hamad Medical). Patient selection criteria: haemodynamically stable, no surgical indication, no active embolic complications, reliable IV access, supervised home environment.
OPAT patients must have a clear escalation plan: any fever, new symptoms, or IV access problems = attend emergency immediately. Do not self-adjust antibiotic doses.
Acute heart failure secondary to valvular destruction is the most common cause of death in IE and the most common indication for urgent surgery. Recognise early — do not delay surgical referral.
Vegetation erodes valve leaflets → acute severe regurgitation → acute volume overload → LV/RV cannot compensate (no time for adaptive hypertrophy) → acute pulmonary oedema (mitral/aortic IE) or acute right heart failure (tricuspid/pulmonary IE).
Embolism is the most common complication of IE, occurring in 20–50% of cases. Risk highest with large vegetations (>10mm), Staph aureus, mitral valve involvement.
Neuro obs hourly: GCS, pupils, focal neurology, speech.
Monitor urine output, daily dipstick, renal function.
SpO₂ monitoring, respiratory rate, sputum culture.
Anticoagulation in IE: Anticoagulation does NOT prevent emboli in IE and increases haemorrhagic stroke risk — do NOT add anticoagulation for embolic prevention. Review pre-existing anticoagulation (prosthetic valve patients) with cardiology team.
Emergency surgery (<24h): Acute severe regurgitation + refractory pulmonary oedema or cardiogenic shock.
Right-sided IE is predominantly associated with IV drug use (IVDU) and affects the tricuspid valve in 90% of cases. Pulmonary valve involvement is rare.
IVDU is less prevalent in GCC nationals but exists among expat populations and is culturally highly stigmatised. Non-judgmental approach, addiction referral, and harm reduction counselling are essential nursing competencies regardless of cultural setting.
RHD remains prevalent among South Asian (Pakistani, Indian, Bangladeshi), Egyptian, and East African expat communities in the Gulf. Rheumatic mitral and aortic valve disease significantly elevate IE risk. These populations frequently work in construction, hospitality, and domestic service — with limited healthcare access and delayed dental care.
IE antibiotic prophylaxis is only recommended for the highest-risk patients undergoing the highest-risk dental procedures. Routine prophylaxis for all cardiac patients is no longer recommended (ESC 2023, AHA 2021, NICE 2016).
Mitral valve prolapse, bicuspid aortic valve, repaired VSD/ASD (without residual defect) — do NOT qualify for prophylaxis per current guidelines.
Dental services in GCC are predominantly private and expensive for low-income expat workers. Many unskilled workers (construction, domestic) have poor baseline dental health and avoid dental care due to:
Nurses should: provide dental referral letters in the patient's first language where possible, link with hospital-based dental services, and document dental history as part of IE nursing assessment.
For patients with IVDU-related IE, non-judgmental harm reduction education significantly reduces recurrence risk. Recurrent IE in IVDU carries very high mortality.
GCC Note: Drug use is criminalised in most GCC states. Nurses must maintain patient confidentiality and non-judgmental care. Harm reduction services may be limited — escalate to social work and pastoral care teams.
| Category | Criterion | Key Detail |
|---|---|---|
| MAJOR | Positive Blood Cultures | Typical organism x2 separate cultures; or persistently positive x2 (>12h apart); or single Coxiella/high IgG titre |
| Endocardial Involvement | Vegetation / abscess / pseudoaneurysm / new valvular regurgitation / prosthetic dehiscence / abnormal PET/CT activity around prosthesis | |
| MINOR | Predisposing condition | High-risk cardiac lesion OR IV drug use |
| Fever | Temperature >38°C | |
| Vascular phenomena | Arterial emboli, septic pulmonary infarcts, mycotic aneurysm, ICH, conjunctival haemorrhages, Janeway lesions | |
| Immunological phenomena | Glomerulonephritis, Osler nodes, Roth spots, RF positive | |
| Microbiological evidence | Positive cultures not meeting major criteria; excludes single CoNS | |
| Definite IE | 2 Major OR 1 Major + 3 Minor OR 5 Minor | |
| Possible IE | 1 Major + 1 Minor OR 3 Minor | |
| Rejected | Alternative diagnosis / resolves <4 days abx / no pathological evidence | |
Mnemonic: Osler = Ouch (painful), on the Outer surface of digits
Mnemonic: Janeway = Just doesn't hurt, on the Junction of palm/sole
Linear dark-red streaks in subungual region. Lie parallel to long axis of nail. Non-specific — also in trauma, vasculitis. Proximal splinters more suspicious for IE than distal. Minor criterion.
Retinal haemorrhages with pale/white centre on fundoscopy. Caused by immune complex microinfarcts. Also seen in anaemia, leukaemia, diabetes. Fundoscopy essential in any suspected IE.
| Organism | First-line Antibiotic | Penicillin Allergy Alternative | Duration |
|---|---|---|---|
| Strep viridans/gallolyticus (sens) | Amoxicillin/Penicillin G IV | Vancomycin | 4 wks NVE; 6 wks PVE |
| Staph aureus (MSSA) | Flucloxacillin/Cloxacillin IV | Vancomycin | 4–6 wks NVE; 6+ wks PVE |
| Staph aureus (MRSA) | Vancomycin IV (AUC-guided) | Daptomycin | 6 wks |
| Enterococcus faecalis | Ampicillin + Ceftriaxone IV | Vancomycin + Gentamicin | 6 wks |
| HACEK | Ceftriaxone 2g/day IV | Fluoroquinolone | 4 wks NVE; 6 wks PVE |
| Candida | Liposomal Amphotericin B or Micafungin | Fluconazole (step down) | Indefinite (often lifelong suppression) |
Definite IE. 2 Major criteria = Definite. Also Definite: 1 Major + 3 Minor, or 5 Minor criteria.
Osler nodes are PAINFUL (tender, finger/toe pads, immune complex). Janeway lesions are PAINLESS (palms/soles, septic emboli). This is a classic exam trap.
3 sets from 3 different peripheral sites. Each set = 1 aerobic + 1 anaerobic bottle. 10 mL per bottle. Volume is critical for diagnostic yield.
Trough <1 mg/L (synergy dosing for IE uses low-dose gentamicin to minimise nephrotoxicity/ototoxicity). Check after 3rd dose, twice weekly thereafter.
Staphylococcus aureus (most common). Affects tricuspid valve. Presents with septic pulmonary emboli. Managed medically first (surgery rarely needed for isolated tricuspid IE).
AUC/MIC ratio 400–600 mg·h/L (ASHP/IDSA 2020). Trough-only monitoring (15–20 mg/L) is the older method still used in some centres. Check trough 30 min before 4th dose.
Periannular abscess with conduction system involvement. This is an urgent surgical indication. Also monitor for complete AV block. Continuous telemetry essential in aortic valve IE.
Amoxicillin 2g PO, 30–60 minutes before procedure. If penicillin allergic: clindamycin 600mg (or azithromycin 500mg). IV ampicillin 2g if cannot take oral medication.
~90–96% for TOE. TTE sensitivity is ~75%. TOE preferred in prosthetic valve IE, poor TTE acoustic window, negative TTE with high suspicion.
Prosthetic valve IE where standard echo is inconclusive. ¹⁸F-FDG PET/CT demonstrating abnormal activity around prosthetic valve is now a Major Duke Criterion (ESC 2015 modification).