3rd year MBBS lecture

1. SURGICAL INFECTIONS

2. Dr. Masrur Akbar Khan
MBBS, FCPS (Surgery)
Surgery Unit II
Dhaka Medical College

3. BOIL (FURUNCLE)
Acute staphylococcal infection of hair follicle with
perifolliculitis that proceeds to suppuration & central necrosis

5. Pathogenesis

8. TREATMENT
Antibiotics & Drainage of boil

9. Complications - Cellulitis

10. Complications - Lymphadenitis.

11. HIDRADENITIS SUPPURATIVA
A chronic infective & fibrous disease of skin bearing apocrine
sweat glands

12. Apocrine sweat glands are coiled glands which open
into the hair follicles

13. Sites of apocrine
sweat glands
Axilla
Areola,
Umbilicus, Groin,
Perineum

14. AETIOLOGY
Obesity, smoking, poor hygiene, DM, teroids.

15. •Common bacteria
– Staphylococci
– Streptococci
– Staphylococcus
aureus
– Propioni-bacterium
acnes.

16. PATHOGENESIS
Obstruction of duct of apocrine sweat gland by keratin.
Dilatation of the duct of gland.
Infection and abscess formation.
Involvement of subcutaneous tissue and adjacent
apocrine glands.
Fibrosis, scarring, sinus formation.
Spread to surrounding tissues

17. – Common in females 4: 1.
– Commonest site is axilla.
– Multiple discharging sinuses,
with nodules in the skin
which is tender.
– Induration due to fibrosis.

18. Investigation
Discharge study, Biopsy

19. Differential
Diagnoses
– Tuberculous sinus.
– Malignancy (squamous
cell carcinoma of skin).

20. Treatment
Antibiotics
Wide excision of involved area then skin grafting or flaps
Antiandrogen drugs

21. CARBUNCLE
Word meaning of carbuncle is charcoal

22. Infective gangrene of skin & subcutaneous tissue
involving interconnected multiple hair follicle with
multiple discharge caused by S. aureus

23. Infection
Development of small vesicles
Sieve like pattern
Red indurated skin with discharging pus
Many fuse together to form a central necrotic ulcer with
peripheral freshvesicle looking a "rosette" (cribriform).
Skin becomes black due to blockage of cutaneous vessels
Disease spreads to adjacent skin rapidly.
Patient is toxic and in diabetics they are ketotic.
PATHOLOGY OF
CARBUNCLE

24. Pathogenesis

25. Common site
Nape of the neck and back
Common in male diabetics and after forty years of age

26. • Investigation
– Urine sugar
– Urine ketone bodies
– Blood sugar
– Discharge for C/S

27. Treatment
Control of diabetes.
Antibiotics depending on C/S

28. • Drainage and Excision
• Skin grafting

32. IMPETIGO
Highly infectious superficial skin infection caused by
staphylococci/streptococci organisms

33. Usually seen in children,
with formation of multiple blisters that rupture and coalesce,
to cover as honey-coloured crust

34. Treatment
Oral antibiotics & topical antiseptics

35. PYOGENIC GRANULOMA
In a base of healing ulcer develops small capillary loops and
over growth of epithelium protrudes as a friable mass of
tissue following minor trauma and infection also called
infected hemangioma

36. • Usually single, well localised, red, firm, nodule,
which bleeds on touch.
• May or may not be tender.

37. Sites
• Face
• Scalp
• Fingers
• Toes.

38. • Differential
Diagnoses
– Haemangioma.
– Papilloma.
– Skin adnexal
tumours.
– Melanoma (in
recurrent cases)

39. Treatment
Excision, laser surgery.
Histopathological study.

40. POTT'S PUFFY TUMOUR
It is a misnomer. Acute osteomyelitis of frontal bone.
Commonly in frontal region

41. It is formation of diffuse external swelling in the scalp
due to subperiosteal pus formation and scalp oedema

42. • Causes
– Chronic frontal
sinusitis
– Trauma –
subperiosteal
haematoma.
– Chronic
suppurative otitis
media

43. Clinical Features
• Pain and swelling in
frontal region which is
warm, tender
• Toxicity and
drowsiness.

44. Complications
• Osteomyelitis of frontal bone
• Extradural or subdural abscess)
• Features of raised intracranial pressure

45. Investigations
– Total leucocyte count
increased
– ESR raised
– X-ray skull
– CT scan

46. Differential Diagnosis
Secondaries in the skull or brain.

47. • Treatment
• Antibiotics and drainage.
• If extends into cranial
cavity, treated by formal
neurosurgical
decompression (Dandy's
brain cannula)

48. • Osteomyelitis of skull bone- Excision and
reconstruction

49. BACTERAEMIA
Presence of bacteria in blood

50. SEPTICAEMIA
Presence of overwhelming & multiplying bacteria in
blood with toxins causing SIRS or MODS

51. Gram +ve
septicaemia
a. Staphylococci
b. Streptococci
c. Pneumococci
d. Common in children, old
age, diabetics and after
splenectomy.
e. Common origin is skin,
respiratory infection.

52. Gram -ve septicaemia (endotoxic shock)
• common in
a. Peritonitis
b. Abscess
c. urinary infections
d. biliary infections
e. postoperative sepsis.
f. Malnutrition
g. old age
h. Diabetics
i. immunosuppressed people.

53. • Common bacteria
a. E. coli
b. Klebsiella
c. Pseudomonas
d. Proteus.

54. STAGES OF GRAM-NEGATIVE SEPTICAEMIA
1. Warm stage (reversible stage).
• Fever is due to pyrogenic response.
• Patient is toxic with fever, chills and rigors.

55. 2. Cold stage(irreversible stage).
• Fever is not present due to absence of pyrogenic
response.
• Patient is having renal failure, ARDS, liver failure
and multi-organ failure.

56. INVESTIGATIONS
• Urine/pus/discharge culture.
• Blood culture.
• Haematocrit.
• Electrolyte assessment.
• P02 and PCO, analysis.
• Blood urea, serum creatinine, liver function
tests.

57. Treatment
• Antibiotics - cefoperazone, ceftazidime, cefotaxime, amikacin,
tobramycin, metronidazole.
• Fresh blood transfusion.
• Adequate hydration.
• Oxygen supplementation.
• Ventilatory support.
• Electrolyte management.
• Parenteral nutrition (TPN).
• CVP line for monitoring and perfusion.
• FFP or platelets in case of DIC.

58. COMPLICATIONS OF SEPTICAEMIA
• Disseminated intravascular coagulation (DIC)
• ARDS
• Liver dysfunction
• Renal failure
• Bone marrow suppression—
thrombocytopenia
• Multiorgan failure

59. PYAEMIA
• Presence of multiplying bacteria in blood as
emboli which spread and lodge in different
organs in the body
• Liver, lungs, kidneys, spleen, brain causing
pyaemic abscess.
• Multi Organ Dysfunction Syndrome (MODS).

60. CLINICAL FEATURES
• Fever with chills and rigors
• Jaundice, oliguria, drowsiness
• Hypotension, peripheral circulatory collapse
and later coma with MODS

61. COMMON CAUSES
• Urinary infection (most common).
• Biliary tract infection.
• Lower respiratory tract infection.
• Abdominal sepsis of any cause.
• Sepsis in diabetics and immunosuppressed
indi-viduals like HIV, steroid therapy.

62. INVESTIGATIONS
• Total leucocyte count.
• Pus culture.
• Blood culture.
• Urine culture.
• Blood urea and serum creatinine.
• LFT.

63. TREATMENT
• Monitoring of vital parameters.
• Antibiotics
• IV fluids, maintenance of urine output.
• Hydrocortisone.
• Blood and plasma transfusion.
• Nasal oxygen, ventilator support, monitoring
of pulmonary function.

64. METASTATIC ABSCESS
• An abscess which occurs as a spread from other abscess.
• Lung abscess causing metastatic abscess in the brain
(common example).

65. PYAEMIC ABSCESS
• It is from any infective focus causing pyaemic
emboli leading into multiple abscess in
different places e.g.Brain, kidneys, liver

66. • Presentation here, is mainly of systemic
features involving multiple organs with
toxicity

67. SYSTEMIC INFLAMMATORY RESPONSE AND MULTIPLE ORGAN
DYSFUNCTION SYNDROMES (MODS)
• It is the response of the body to a serious infection
Cause
• Secondary peritonitis
• Multiple trauma
• Severe burn
• Acute pancreatitis

68. Pathology
• Lipoplysaccharide endotoxin from gram
negative bacilli (E. coli) or other bacteria or
fungi
• Not to be confused with bacteraemia
• Release of cytokines(IL-6), (TNF α)

69. DEFINITIONS OF SYSTEMIC INFLAMMATORY RESPONSE SYNDROME
(SIRS) AND SEPSIS
SIRS
• Two of:
• hyperthermia (> 38°C) or hypothermia (< 36°C)
• tachycardia (> 90 min–1
, no β-blockers) or tachypnoea
• (> 20 min–1
)
• White cell count > 12 x 109 l–1
or < 4 x 109 l–1

70. Sepsis
• Sepsis is SIRS with a documented infection

71. Severe sepsis or sepsis syndrome
• Sepsis with evidence of one or more organ
failures
• Respiratory (ARDS)
• Cardiovascular (Shock follows compromise of
cardiac function and fall in peripheral vascular
resistance)
• Renal (Acute kidney injury)
• Hepatic (Coagulopathy)

72. MAJOR SSI
•A major SSI is defined
as a wound that either
discharges significant
quantities of pus
spontaneously or needs
a secondary procedure
to drain it

73. • Patient may have systemic signs such as
tachycardia, pyrexia and a raised white count
[systemic inflammatory response syndrome
(SIRS)

74. MINOR SURGICAL SITE INFECTIONS
• Minor wound infections may discharge pus or
infected serous fluid but should not be associated
with excessive discomfort, systemic signs or delay in
return home.

75. • The differentiation between major and minor
and the definition of SSI is important in audit
or trials of antibiotic prophylaxis.

76. • There are scoring systems for the severity of
wound infection, which are particularly useful
in surveillance and research. Examples are the
Southampton and ASEPSIS systems

77. Major wound infections
• Significant quantity of pus
• Delayed return home
• Patients are systemically ill

78. SOUTHAMPTON WOUND GRADING SYSTEM
• Grade Appearance
• 0 Normal healing
• I Normal healing with mild
bruising or erythema
• Ia Some bruising
• Ib Considerable bruising
• Ic Mild erythema
• II Erythema plus other signs of
inflammation
• IIa At one point
• IIb Around sutures
• IIc Along wound
• IId Around wound
• III Clear or haemoserous
discharge
• IIIa At one point only ( 2 cm)
• IIIb Along wound (> 2 cm)
• IIIc Large volume
• IIId Prolonged (> 3 days)
• Major complication
• IV Pus
• IVa At one point only ( 2 cm)
• IVb Along wound (> 2 cm)
• V Deep or severe wound
infection with or without tissue
• breakdown; haematoma
requiring aspiration

79. The ASEPSIS wound score
• Criterion Points
• Additional treatment 0
• Antibiotics for wound infection 10
• Drainage of pus under local anaesthesia 5
• Debridement of wound under general anaesthesia 10
• Serous dischargea Daily 0–5
• Erythemaa Daily 0–5
• Purulent exudatea Daily 0–10
• Separation of deep tissuesa Daily 0–10
• Isolation of bacteria from wound 10
• Stay as in-patient prolonged over 14 days as result of wound
infection

80. Major wound infection and delayed healing presenting as a faecal fistula in
a patient with Crohn’s disease.

81. Delayed healing relating to infection in a patient on highdose steroids.

82. Major wound infection with superficial skin dehiscence.

83. Factors that determine
whether a wound will
become infected
• Host response
• Virulence and inoculum of
infective agent
• Vascularity and health of tissue
being invaded
• Presence of dead or foreign tissue
• Presence of antibiotics during the
‘decisive period’

84. • Causes of reduced host resistance to
infection
• Metabolic: malnutrition (including obesity),
diabetes, uraemia, jaundice
• Disseminated disease: cancer and acquired
immunodeficiency syndrome (AIDS)
• Iatrogenic: radiotherapy, chemotherapy,
steroids

85. SOURCES OF INFECTION
• Primary:
• Acquired from a community or
endogenous source (such as
that following a perforated
peptic ulcer)

86. • Secondary or exogenous
(HAI):
• Acquired from the operating
theatre (such as inadequate
air filtration) or the ward
(e.g. poor hand-washing
compliance) or from
contamination at or after
surgery (such as an
anastomotic leak)

87. Thank You