POST-OPERATIVE FEVER

DR. BOLARINWA A.K.

HOUSE SURGEON
(GIT SURGERY)
OUTLINE

 Case scenario
 Introduction
 Pathophysiology
 Predisposing factors
 Differentials
 Evaluation
 Treatment
 Conclusion
CASE SCENARIO

 A 66year old woman underwent hemi-colectomy after a perforation

due to diverticulitis.
 1st Day post-op, the patient complains of cough and is noted to
have a Numerous Temperature spike
 She was intubated for the procedure with a laryngeal mask airway.
 Vitals on examination: BP:130/80mmHg; HR:102/min; RR:12/min;
T:39.3°C
 O/E: chest; Dull on percussion over LLLZ; Breath sounds
diminished
 What is your diagnosis?
INTRODUCTION

 The postoperative period begins immediately after surgery and

ends with the first follow up visit.
 It can also be said to terminate with the resolution of the surgical
sequelae.
 The length of the post operative period is variable.
 Complications can occur in this period, one of such is post
operative pyrexia (fever).
 Fever is an elevation of body temperature that
exceeds the normal daily variation and occurs in
conjunction with an increase in the hypothalamic set
point.
 Normal body temperature range: 36.9°C-37.4°C
 Types:

• Continuous (sustained)
• Intermittent
• Remittent
• Relapsing.
TYPES OF FEVER

 Continuous fever-fever occur all over 24 hours with difference between max and min
<1°C.
• E.g. 1st week of typhoid fever
 Intermittent fever -occur daily but touches to normal limit once during 24 hours.
 According to pattern they can be:
• Quatidian – fever every 24 hour (P.Falciparum, TB, UTI)
• Tertian – fever every 48 hour (P. Vivax)
• Quartan – fever every 72 hour (P. Malaria).
 Remittent fever -occur all over 24 hour with difference between
max and min is more than 1 degree Celsius and never touches to
normal limit.
• E.g. 2nd week of typhoid fever
 Relapsing – period of fever followed by period of normal
temperature.
• Eg. Pel-ebstein fever – hodgkins
• Cyclic netropenia.
What is Post-op fever?

 Post operative fever can be defined as a core temperature (aural/

rectal) >38°C on two consecutive post operative days or >39°C on
any one post operative day
• Axillary temperature < 0.5°C core temperature
 Post operative fever can be distressing to the patient & importantly
a cause of great concern to the surgeon
 It may also be an indicator of a severe and life-threatening
underlying pathology.
 The reported incidence varies but can be expected in about 16.2
percent (Morhasson-Bello et all) to 43 percent of cases(uv Okafor
et all 2008)
 Some causes of post-operative fever are self-limiting requiring only
observation
 In the same vein, some are emergencies and early recognition and
action is key to good outcome.
 Causes could be infectious and non-infectious, however, <50% of
post-op pyrexia are caused by infections.
 Magnitude of the fever does not indicate presence or absence of an
infective cause
 Treatment depends on probable cause
PREDISPOSING FACTORS

 Pre-operative fever
 Extent of surgery:major surgeries e.g. Intrabdominal, intrathoracic
 Factors that increase the risk of infection e.g. Prolonged use of
catheters, drains, prolonged ETT , immunosuppression, prolonged
immobilization
 Medical co-morbidities: obesity, chronic lung diseases, diabetes
mellitus.
PATHOPHYSIOLOGY OF FEVER

 Normal body temperature is primarily regulated by the Preoptic

Anterior Hypothalamus.
 Infectious agents, microbial products (exotoxins and endotoxins),
damaged tissue, hypoxia and compliment components, stimulate
Macrophages, Endothelial cell and the Reticuloendothelial system
to release Pyrogenic Cytokines (TNF, IL-1, IL-6, IFN).
 Spillage into the systemic circulation
 Hypothalamus: cytokines stimulate the cytokine receptors on hypothalamic endothelium
leading to the synthesis of PGE2
 Microbial toxins also directly stimulate the hypothalamic endothelium
 PGE2 raises the thermostatic set point in the hypothalamus to febrile levels.
 The vasomotor centre sends signals for heat conservation (vasoconstriction) and heat
production (shivering).
MECHANISM OF DAMAGE FROM
FEVER
Types and Differentials of Post-op fever

 Types of post-op fever can be considered as follows:

 1. The timing/ onset of the fever
 2. The Surgical 7Ws mnemonic can be used to categorise the
possible causes/differentials:
Wind, Water, Wound, Walking, Wonder drug, Withdrawal and Wonky
gland
 The time frame/onset for fever occurrence is the most critical factor
to consider when making a differential for post-op pyrexia.
 Immediate post-op pyrexia (<48 hours post-op)
 Acute post-op pyrexia (48 hours to 7 days post-op)
 Subacute post-op pyrexia (7 days to 28 days post-op)
 Delayed post-op pyrexia (after 28 days post-op)
IMMEDIATE POST-OPERATIVE FEVER

 Surgery: Inflammatory response to tissue injury from the release

of pyrogenic cytokines. This fever is usually self-limiting resolving
in approximately 2 to 3 days. The severity of fever is
proportional to the degree of the metabolic response to trauma
 Pre-existing medical conditions: Pre-op fever, Surgical stress may
also lead to the exacerbation of certain medical conditions, for
example, thyroid storm or a gouty flare.
 Drug-induced:
 Idiosyncratic reactions: classic examples include the Neuroleptic Malignant
Syndrome and Malignant Hyperthermia from Inhaled Anaesthetics- Halothane,
Succinyl Choline
 Alterations in Thermoregulation: Anticholinergics (↓sweating → ↓heatloss).
 Administration related: Phlebitis, Thrombophlebitis
 Direct pharmacologic action of the drug (drug fever): e.g. antibiotics, heparin,
hydralazine, phenytoin
 Hypersensitivity reactions: immunologically mediated
 Blood transfusion reactions: Immune-mediated
 Complications from surgery: Haematoma, Seroma, Acute
inflammatory reaction to sutures and prosthesis used during surgery
 Cardiovascular causes: Post-op MI, CVA, fat embolism
 Malaria: In Endemic regions, can occur anytime
 Withdrawal from alcohol: May present as Delirium Tremens
ACUTE POST-OP FEVER (>48hours )

 Atelectasis- Collapse of the lung resulting in imbalance in gas

exchange.
 Due to hypoventilation in GA or decreased diaphragmatic
movement due to surgical site pain.
 Fever, tachypnea, tachycardia, dull on percussion over affected area
and decreased breath sounds.
Opacity over
affected area with
compensatory
translucency.
 Unresolved atelectasis results in pneumonia.
 Pneumonia is an inflammation of the lung tissue as a result of
bacterial, viral or other infection.
 Presents with: Fever, Tachypnoea, Tachycardia, Cyanosis in severe
cases, Decreased breath sounds, Rhonchi and Dullness on
percussion.
ACUTE POST-OP FEVER (48hours )

 Infectious causes of postop fever become more likely when postop

fever is discovered after 48 hours
 UTI: urethral catheterization, and genitourinary surgeries.
 Pneumonia: ETT, prolonged ETT, patients with increased risk of
aspiration (use of NG tube, vomiting, depressed gag reflex),
atelectasis
 Superficial thrombophlebitis: patients on intravenous cannula.
 Surgical site infections: usually superficial- wound cellulitis.
 There are, however, 2 organisms that can cause fulminant SSI; can
occur within 48 hours postop
 Group A streptococcal and
 Clostridial infections
 Anastomotic leak
 Deep venous thrombosis and PE
NB: Non-infectious causes of immediate postop pyrexia may alsocause
fever in this period
SUB-ACUTE POST-OPERATIVE FEVER
(7days to 28days)

 Deep vein thrombosis and/or pulmonary embolus from prolonged

immobility
 Deep infections (Pelvic or abdominal abscess)
 Pseudomembranous colitis
 Infectious causes mentioned above (UTI, pneumonia, SSI)
DELAYED POST-OPERATIVE FEVER
(>28days)

 Osteomyelitis after orthopaedic surgery

 Viral infections related to blood products: CMV, hepatitis, HIV1, 2
 Parasitic infections: toxoplasmosis
 Rarely, SSIs can occur in this period caused by indolent organisms,
such as coagulase negative staphylococci
7 W’S OF POST-OPERATIVE FEVER

 Wind: Atelectasis (.48hrs)

 Water: UTI (48- 72hrs)
 Walk: DVT/PE (3-5days)
 Wound: Wound/Surgical site infection (5-10days)
 Wonder drug: Antibiotics, heparin, inhalational anaesthetic drugs,
anticonvulsants (Any TIME)
 Withdrawal: Alcohol (delirium tremens begin 72hrs after last drink)
 Wonky gland: Thyrotoxicosis (thyroid storm), Adrenal insufficiency
EVALUATION OF A
PATIENT WITH POST-
OPERATIVE FEVER
HISTORY

 Consider if patient had fever pre-operatively

 Respiratory: e.g.? Intubation? COPD, cough, sputum,
haemoptysis, chest pain, difficulty in breathing
 Cardiac: e.g. chest pain, palpitation, dizziness
 Urinary: e.g. ?urethral catheterisation? How long? dysuria,
frequency, urgency, haematuria
 GIT: e.g. Nausea, vomiting, diarrhoea, abdominal pain, bleeding
PR
 Related to surgery: Surgical site pain
 MSS: calf pain, pain at IV catheter site
 Immunocompromised? or malnourished?
 Co-morbidities: malignancy, hyperthyroidism, gout, alcohol
addiction
 Charts:
 Onset, pattern, T-max of fever
 Anaesthetic Record for Medication
 Blood products administered during the perioperative period?
 Input/output chart and types of stools
EXAMINATION

 Is patient hot to touch?

 What is the Temperature?
 Surgical Site: inspect and Take off any dressings, discharge,
rawness? Apposition? hyperaemia undue tenderness, abnormal
swelling, fluctuance
 Drains, urethral catheter (cloudy, bloody)
 Lines: e.g. IVC, CVC
 Chest: Tachypnoea, consolidation, crepitation
 Heart: murmurs, tachycardia
 Abdomen: tenderness? Movement with respiration?
 Calf: Unilateral calf tenderness, peripheral oedema
 Skin - rash, jaundice, petechiae, erythema, hematoma, pressure sore
 Rash: toxic shock syndrome
 Petechiae: fat embolism
INVESTIGATION

 Depends on hx and examination findingS:

1. Urinalysis, Urine MSU m/c/s,
2. Wound swab/ biopsy m/c/s
3. MP
4. Sputum m/c/s
5. Blood Culture
6. Aspirate m/c/s
7. FBC, E/U/Cr, LFT
8. CXR, abdominal USS, ECG, CT angiogram
9. Doppler USS
10. Others – specific to clinical suspicion
TREATMENT

 Management of post-op fever depends on the probable cause

 In general, early postop fever requires no intervention if there are
no inciting factors
 Nursing care: exposure, tepid sponging, temperature monitoring
and charting
 Antipyretics, Rehydration, Antiemetic
Atelectasis:
 Adequate pain control
 Early ambulation
 Incentive spirometry for prophylaxis
 Chest physiotherapy
 Semi-recumbent position
 No need for antibiotics
 Non invasive +ve pressure ventilation like CPAP or BiPAP
 Infective causes:
 Pneumonia: sputum mcs, chest xray
 Surgical site infection: wound swab/ biopsy, local wound care
 UTI: take m/c/s, change catheter/ site one if indicated
 Early Emperic antibiotics is very crucial
 Treat with empirical antibiotics while awaiting m/c/s),
 Remove/replace lines promptly if in tissue(IV cannula, CVC: send
tip for culture)
 Timely removal of urethral catheter, drains
 Drainage of abscess, seroma, haematoma
 Debridement
 Transfusion/Drug related - STOP transfusion, further transfusion with washed cells if
immunologically mediated, Discontinue Offending drug
 Thromboembolic: Treat with anticoagulation
 VTE prophylaxis and wearing of pneumatic stocking for prevention
 Malignant hyperthermia: IV Dantrolene Na, Supportive Care
Note: increase in caloric and fluid requirement following prolonged
high grade fever due increase in metabolism and insensible fluid loss
CASE SCENARIO (ANSWER)

 A 66year old woman underwent hemi-colectomy after a perforation due to diverticulitis.

 1 Day post-op, the patient complains of cough and is noted to have temperature spike
 She was intubated for the procedure with a laryngeal mask airway.
 Vitals: BP:130/80; HR:102/min; RR:19/min; T:39.2oC
 O/E: chest ;Dull on percussion over LLLZ; Breath sounds diminished
 What is your diagnosis?
 Immediate Post operative Fever secondary to lung Atelectasis or Pneumonia
CONCLUSION

 Postoperative fever is a common postoperative surgical complication

 Fever may be infectious or non-infectious
 Early empiric antibiotics is extremely important
 Knowledge of differential diagnosis, as well as systematic approach,
proves useful in narrowing down the diagnosis and instituting proper
management
 When indicated antibiotics should be judiciously used depending on
the possible infectious cause.
THANK YOU
REFERENCES

 1. Bailey’s & Love, 27th edition

 D O Irabor et all 2003 (The Nigerian journal of surgical research vol 5)
 Imran o morhasson bello et all 2009 (Nigerian journal of clinical practice
 Uv Okafor et all 2013 (Nigerian journal of medicine vol 22)
 . CSD, 14th edition
 . RCS manual, 4th edi
 . Sabiston, 19th edi
 . Some online journals