VOW NO4 DECEMBER 1992
AUSTRALIAN CRmCAL CARE
ABSTRACT
Anaerobic necrotizing soft tissue infections are known for their devastating effects of tissue destruction and death. These infections may occur as a result of trauma, surgical intervention or occur spontaneously in predisposed individuals. They are caused by a wide range of anaerobic organisms and may be categorised according to the tissue involvement as Necrotizing Fasciitis and Myonecrosis. A five year review of patients admitted for hyperbaric oxygen (HBO) therapy and requiring intensive care revealed a patient group numbering 25, roughly equally divided between the two classifications of tissue involvement. Trauma was an aetiological factor in 5 of these cases. Cancer and diabetes mellitus were also prominent aetiological factors. Treatment consisted of the triad of early selective/aggressive surgery, high dose antibiotic therapy and HBO therapy. The mortality of the group was 25%. Delay in treatment was associated with increased mortality. Nursing care, for this particular patient group is demanding, requiring particular attention to wound care, analgesia, transport, psychosocial care of patient with
mutilating wounds, nutrition and temperature homeostasis.
Gangreneu and Fasciitisu.
It is a cause for concern that two cases occurred after elective orthopaedic procedures requiring the application of plaster of paris (POP) cast over a leg.
Due to the presence of a large multiplace Hyperbaric Oxygen (HBO) chamber within the facility of Prince Henry Hospital the ICU receives referrals for the treatment of soft tissue infections. These referrals come from a broad geographic area encompassing New South Wales and the south east region of Queensland.
INTRODUCTION
A retrospective review was undertaken of patients admitted to the Intensive Care Unit (ICU) of Prince Henry Hospital with the admission diagnosis of "Gas
I
AETIOLOGICAL FACTOR
"Necrotizing
This article will present a description of the classification, aetiology,
I
PREDISPOSING FACTOR
TRAUMA compound fracture GlT trauma burns minor puncture wounds laceration abrasion injection non penetrating blunt trauma
Cancer Diabetes Peripheral Vascular Disease
SURGERY appendix biliary tract colon small intestine upper GIT
SPONTANEOUS (see pdisposing factom) r
Perirectal abscess lleus Cholecystitis
1
TABLE 1 AETOLOGICAL AND PREDISPOSING FACTORS
AUSTRALIAN CRITICAL CARE
VOL5 NO4 DECEmER 1992
MYONECROSIS
Clostridium species; C. perfrlngens, C. septicum. These organisms are ubiquitous in the environment (soil contaminant). Normal flora of gut, perineum and skin. They easily endogenously contaminate skin surfaces and gut. (commonly contaminate wounds) may be associated with organisms, E-coli, Enterobacter, Enterococci, as contaminants. Non-Clostridial as for Necrotizing Fasciitis but involving muscle. NECROTIZING FASCllTlS
Anaerobic. Bacteroides, Peptostreptococcus associated with facultative anaerobic bacteria (E-coli, Streptococcus, Enterobacter, Klebsiella, Proteus and occassionally Pseudomonas) may be predominantly monomicrobial (Haemolytic Strep. + or - other species). Streptococcus + Staphylococcus in synergistic combination. Also known as - Melaney's Gangrene - Fournier's Gangrene (affecting male genitalia)
necessary is determined by the tissue involvement. Indeed defining the infection can often only be done after initial surgical inspection and debridement. This system classifies the infection under the headings of Necrotizing Cellulitis, Necrotizing Fasciitis and Myonecrosis (Table 3). Infection usually results from a breach of a mucocutaneous barrier resulting in displacement of normal flora or contamination by exogenous organisms (9,lO). Predisposing factors such as tissue injury, haematoma, altered host response, and bacterial synergy are usually present and allow the infective process to establish itself (Table 1). Once established the infection may be self propagating, as in the case of Clostridial Myonecrosis, because of
TABLE 2
ORGANISMS INVOLVED pathophysiology and treatment of necrotizing soft tissue infection and then review the ICU experience of the nursing care requirements of this patient group. Necrotizing soft tissue infections can be considered as multiple disease entities that require a similar treatment approach(1). These infections are known for their devastating effects of tissue destruction and death, and require extensive surgical debridement (including amputation) (1,2,3,4,5). "Gas gangrene" is a term commonly applied to necrotizing soft tissue infections and Clostridial species (usually C. perfringens) are the pathological organisms associated with this term. Historically these infections have been associated with battlefield injuries, natural disasters and trauma (1,2,6,7). However the term "gas gangrene" and the association of this term with Clostridial infection does not encompass and reflect the range of
causative organisms, tissue involvement and aetiological factors associated with necrotizing soft tissue infections. Several reviews and case studies have highlighted the multimicrobialnature of causative organisms and the variety of aetiological factors (1,3,4,5). Classification of necrotizing soft tissue infections has been centred either around the causative organism(s) or the tissues affected. These classifications have ranged from comprehensive separation and definition of clinical syndromes to the use of a single category to encompass all progressive necrotizing infections (1,5,8). Another form of classification is to divide the infections into clostridial and non-clostridial ( 1 3 . In the authors' opinion the most clinically useful classification is one proposed by Patino and Castro(1) that reflects the fact that the treatment approach is the same but the degree of debridement
1. NECROTlZlNG CELLULITE
Skin lesion - subcutaneous tissue spared Usually monomicrobial 2. NECROTlZlNG FASCllTlS
Subcutaneous tissue infection Skin is relatively spared until advanced stages Muscle and muscle fascia not affected Usually polymicrobial (synergistic) Can be monomicrobial(Strep.) 3. MYONECROSIS
Muscle involvement The most serious Severe systemic toxicity is characteristic Usually Clostridial but may result from other anaerobes. (Strep. Bacteroides, Klebsiella, E-coli, Proteus.)
TABLE 3 CLASSIFICATION O F INFECTION
VOL5 NO4 DECEMBER1992
AUSTRALIAN CRmCAL CARE
the elaboration of toxin and gas(3) (Table 4). The local effects are swelling, pain, necrosis, tissue liquifaction and spread. Systemic effects occur as a result of released toxin and the systemic response which may lead to a full blown sepsis syndrome. The treatment of these infections centres around the triad of surgery, antibiotics and HBO. Recognition of the infection must be early and followed by aggressive surgical intervention in which all necrotic tissue is excised. The importance of a "2nd look" within the first 24 hours and further debridment if necessary is well recognised (1,11). Broadspectrum antibiotics are given
until gram stain and culture results become available. This approach reflects the usual polymicrobial nature of the infection and its rapid progression necessitating the commencement of treatment as soon as possible.
HBO as an adjunctive therapy has proven effective in the treatment of Clostridial Myonecrosis and there is some support for its use in Non-Clostridial soft tissue infection (3,12,13). Table 5 summarises the role of HBO therapy in the treatment of soft tissue infections.
MATERIALS AND METHODS A retrospective Study of patients admitted to the ICU at Prince Henry Hospital with a diagnosis of anaerobic soft tissue infection during the five year period, 1987-1991, was undertaken by review of the patients' hospital record. During this period 29 patients were referred to the hospital's hyperbaric unit for treatment of soft tissue infection, 25 of these patients required admission to the ICU. This study is comprised of 24 of these 25 patients as one set of medical records were unavailable. The age
CLOSTRlDlAL MYONECROSIS
NECROTlZlNG FASCllTlS
incubation 1-2 days
incubation 1-4 days
severe pain, marked tachycardia
moderate pain, oedema of skin +++, skin anaesthesia resulting from subcutaneous destruction.
appearance; oedema +++, tense skin, magenta-bronze hue to skin, bulae containing dark serosanguinous "mousey" smelling fluid. organism requires low oxygen reduction potential for propagation ie. diminished blood supply, foreign body, tissue necrosis, haeniorrhage, infection with other organisms. release exotoxin when proliferate; toxins destroy host tissue, increase capillary permeability, cause haemolysis. carbon dioxide and hydrogen gas released causing dissection of tissue and facilitating spread.
occlusion of skin nutrient vessels results in skin necrosis and blisters as infection progresses. characteristic of pathology is: severe extensive necrosis of superficial fascia and subcutaneous tissue, destruction of tissue and liquifaction of fat. systemic toxicity may display crepitation
subcutaneous
any part of body affected but favours extremeties, abdomen, groin and perineum.
TABLE 4 PRESENTATION AND PATHOLOGICAL PROCESS
High pressure environment in which oxygen administration produces high tissue oxygen pressure. Inhibits toxin production Counteracts hypoxic environment in which Clostridia thrive. Perioxidase develops in the infecting organisms as a result of HBO and causes inactivation and killing of pathogens. Clostridia produces the enzyme catalase from dead muscle and blood. This enzyme inactives perioxidase and therefore necrotic tissue and haematoma must first be removed.
HBO may be useful in demarcation of necrotic and viable tissue.
TABLE 5 HYPERBARIC OXYGEN IN CLOSTRlDlAL INFECTION
range of patients was 11 to 78 years. There were 4 females and 20 males. They were referred for treatment from the Sydney metropolitan area, country New South Wales and from Queensland. In order to indicate the severity of illness and the need for nursing care of this patient group we determined the following: 1. APACHE IIscore; 2. Length of stay in ICU (LOS); 3. N u m b e r of operative procedures whilst in ICU (this includes debridements and amputations); 4. Number of days ventilated; 5. Number of days on inotropic support (adrenaline, dopamine, noradrenalhe); 6. T h e need for renal replacement therapy (CVVHD, haemodialysis, peritoneal dialysis). Management of all patients was based upon the recognised
regimen of high dose antibiotics, early aggressive surgery and HBO therapy.
MYONECROSIS
ANALYSIS OF DATA
The descriptive statistics used were the range and median. The Mann Whitney U test was used to compare age, APACHE II score, LOS, number of operative procedures, days ventilated, days on inotropes and mortality for the two diagnostic groups.
Age (years) APACHE ll LOS (days) Operations Ventilated Ventilation (days) lnotropes lnotropes (days on) Dialysis (patients) HBO (treatments)
The null hypothesis tested was that there would be no difference between the two groups for these factors. The null hypothesis was rejected at a p < 0.05.
NECROTIZING FASCllllS
RANGE
RANGE
(MEDIAN)
(MEDIAN)
11-67 (61) 4-29 (17) 1-14 (7) 0-5 (2) n=9 1-14 (3) n-10 1-13 (2) n=3 1-11 (4)
11-76 (64) 3-30 (18) 1-44 (6) 0-13 (1) n=8 1-30 (3) n=7 1-24 (1) n-1 0-5 (2)
SIG n/s nls n/s n/s n/s n1s pm.0075
nls = not significant
TABLE 7 COMPARISON
RESULTS Classlflcatlon
Aetlologlcal Factors
For the purposes of this study the classification system, proposed by Patino and Castro(1), based upon tissue involvement was the most useful (Table 3).
We identified five aetiological factors within our patient series. Table 6 identifies these factors and relates them to patient age.
None of the patients in our series fitted into the Necrotising cellulitis category, 45% (n-1 1) had Necrotising Fasciitis and 55% (n=l3) had Myonecrosis. These classifications were based upon Operating Room report descriptions of the extent of tissue involvement.
Cancer was an aetiological factor in three cases. Four patients developed soft tissue infections following surgery, one following drainage of a perianal abscess, one after arthroscopy and two after elective orthopaedic procedures requiring the use of Plaster of Paris casts. Both these latter patients
AGE
CANCER
1-(
1 2 3 4 5 6 7 8
1
OPERATIVE PROCEDURE
DIABETES
1
1 1 1
1
TOTAL
1 1
2
3
4
TRAUMA
1
OTHER
TOTAL
1
1 4 3
1
1 1 1
8
5
4
TABLE 6 INCIDENCE OF AETIOLOGICAL FACTORS AND AGE
0 3 2 2 0 3 8 6
were found sometime postoperatively with "blue" feet, one of them died, and the other, an 11 year old boy, required a leg amputation. Diabetes mellitus was the most common aetiological factor, accounting for eight patients. These patients had developed ulcers which subsequently became infected leading to fasciitis or myonecrosis. These patients were from the older age groups. A traumatic incident was identifiable as a factor in five patients. The type of trauma varied greatly:
-
-
one patient fell off a chair and sustained a carpet graze to the elbow one patient fell on a bamboo stick one patient cut her hand whilst preparing dog meat one patient was involved in a motor vehicle accident one patient fell on the footpath
One patient developed necrotising fasciitis subsequent to appendix rupture while another developed this infection as a sequelae of an
VOW Nor m
AUSTRALIAN CRITICAL CARE
untreated perianal abscess. Both these patients had no identifiable aetiological factor other than the initiating infection. Aetiological factors did not vary significantly between the myonecrosis and the necrotizing fasciitis groups.
Severlty of Illness and nurslng care requirement The two groups, myonecrosis and necrotizing fasciitis, were compared with respect to factors indicating severity of illness and nursing care requirement. The only significant difference found was in the HBO treatments received by the two groups. This difference represents a clinical choice in therapy. These resutts are shown in Table 7.
Mlcroblology
as soon as possible.
- 3 to 5 million units of penicillin as an initial dose followed by up to 3 million units hourly was used. Such high doses are required because in dead or dying non-perfused tissue penicillin is diffused rather than perfused. 3. HBO therapy. The HBO protocol used was three treatments at 2.8 atmospheres absolute (ATA) in the first 24 hours, each treatment lasted 120 minutes.
2. high dose antibiotics
Further treatments were undertaken according to the clinical judgement of the surgeons and intensivists. One patient was not submitted to HBO treatment because of severe cardiovascular instability and died shortly after ICU admission.
Table 8 shows the organisms cultured from the patients' wounds. As can be noted some initial gram stains revealed rods or cocci only, not specific organisms. In some cases specific organisms were never able to be grown. The culture results when available were usually not obtainable until after treatment had begun. Most patients in this series had polymicrobial infection. It is evident that a clostridium species was present in six of the patients in the myonecrosis group, with a further six patients in this group growing gram positive rods. It may be assumed from this that twelve of the thirteen patients in this group had clostridial infection.
Management The intensive care management of the patient group revolved around the three previously mentioned, widely accepted practices:1 . selective/aggressive surgery
-
The overall mortality for the group This figure was 25% (n=6). compares favourably with other published series (3,5,6,7). There was no significant difference in mortality between the necrotizing fasciitis (27%) and myonecrosis groups (23%). Three patients died from each group. Interestingly a MYONECROSIS (n=13)
4 1 1 6 1 3 4 1 1 2
R 1992
common feature in the patients who died was a relatively long period of delay between infection and definitive treatment. Half the patients who died did so within the initial 24 hours of admission to ICU.
Nurslng Conslderatlons Apart from the general nursing measures appropriate for any intensive care patient some considerations are more salient in this patient group, and thus warrant particular mention. Dressings - these are often major, time consuming procedures, usually involving more than one person to hold the patient in position and to position the dressings. Generally a hypochlorite solution (Milton 1:80), where chemical debridement is required, or normal saline soaked packs are used with zinc cream to protect the wound margins. Dressing frequency varies, but two to three times per day is common. Observation of the area of involvement is important so that early identification of any extension of the infection can be made. Recording of this observation is essential to allow comparison from shift to shift.
Analgesia
-
is especially important
NECROTIZING FASCllTlS (n-11)
frequency Clostridium Clostridium perf. Clostridium sept. Gram +ve rods. Gram +ve cocci Gram -ve rods Strep. faecalis Strep. pyrog. Bacteroides E-coli
E
frequency Gram +ve rods Gram +ve cocci Gram -ve rods Strep. faecalis Strep. melleri A&B haemolytic Strep. Bacteroides E-coli Mixed coliforms Staph. aureus Clostridium
TABLE 8 ORGANISMS ISOLATED
4 3 5 2 1 1 2 3 1 1 1
VOW NO4 DECEmER 1992
AUSTRALIAN C R ~ C MCARE
in this patient group as the wounds are extremely painful. Opiate infusions (morphine, fentanyl titrated to effect) were used with bolus doses of opiates or entonox inhalation prior to dressing changes given as appropriate.
Transport - must be considered as organisation of time is required. The patients may go to theatre daily for debridement as well as to the HBO chamber up to three times a day in the initial stage. Interruption to treatment must be minimised eg antibiotic doses must not be missed, infusions must not run out etc.
causative conditions in patients who may or may not be compromised. These infections are of rapid onset and progression and have significant systemic manifestations and resultant mortality. The development of infection in the setting of plaster of paris casts in two patients in this series emphasises the fact that there can be no complacency i n wound or post-operative observation.
The relationship between delay in definitive treatment and mortality indicates that outcomes from these infections can still be improved with Psychosoclal - the wounds and greater awareness, surveillance and speed of response especially in surgery are often very mutilating and the patients' body image will be situations where aetiology factors affected. Reassurance and support associated with the development of and explanation of the ongoing these infections have been identified. need for plastic surgery are of prime importance. Referral to more REFERENCES specific resources such as rehabilitation services, Amputee 1. Patino JF, Castro D. Necrotizing Society or to a psychologist/counsellor may be lesions of soft tissues: a review. required. World J Surg, 1991; 15:235-239
Nutrltlon - the infective process causes a hypermetabolic state, therefore attention to nutritional needs is important. Dietitian advice, nasogastric feeding andlor Total Parinteral Nutrition (TPN) are utilised according to patient needs.
-
Temperature maintenance of body temperature is important. The massive open wounds that often exist predispose the patients to heat loss. Plastic coverings are placed over wounds to minimise this. It needs to be emphasised that these are specific factors that require particular nursing attention in this patient group, all other general ICU nursing measures are also relevant.
2. Corry M, Montoya L. Gas gangrene: certain diagnosis or certain death. Crit Care Nurse, 1989; 9(10) : 30-38 3. Cline KA, Tumbull TL. Clostridial myonecrosis. Ann Emerg Med, 1985 (5); 14:459-466
4. Swartz MN. Subcutaneous tissue infections and abscesses. In: Mandell GL, Douglas RG, Bennett JE eds. Principles and practice of infectious diseases. 3rd ed. NY: Churchill Livingstone, 1990; 808-816 5. Freischlag JA, Ajalat GI Busuttil RW. Treatmeat of necrotizing soft tissue infections. The need for a new approach. Am J Surg, 1985; 149:751-755
CONCLUSION Necrotizing soft tissue infections can arise as a result of numerous
6. Unsworth IP, Sharp PA. Gas gangrene; an 11-year review of 73 cases managed with
hyperbaric oxygen. Med J Aust, March 3 1984: 256-260 7. Patino JF, Castro Dl Valencia A, Morales P. Necrotizing soft tissue lesions after a volcanic cataclysm. World J Surg, 1991; 15: 240-247 8. Dorai CR, Kandasami PK. Fournier's gangrene: it's aetiology and management. Aust NZ J Surg, 1991; 61 :370-372 9. Bartlett JG. Anaerobic bacteria: general concepts. In: Mandell GL, Douglas RG, Bennett JE. eds. Principles and practice of infectious diseases. 3rd ed. NY:Churchill Livingstone, 1990; 1828-1833 10. Bartlett JC. Gas gangrene (other clostridium-associated diseases). In: Mandell GL, Douglas RG, Bennett JE. eds. Principles and practice of infectious diseases. 3rd ed. NY: Churchill Livingstone, 1990; 1850-1856 11. Sudarsky LA, Laschinger JC, Coppa GF, Spencer FC. Improved results from a standardised approach i n treating patients with necrotizing fasciitis. Ann Surg, Nov 1987; 206(5): 661-665 12. Hart GB, Lamb RC, Strauss MB. Gas gangrene: 1. a collective review. Trauma, 1983; 23(11): 991-995 13. Fischer B, Jain KK, Braun El Lehl S. Handbook of hyperbaric oxygen therapy. Berlin: Springer-Verlag 1988; 94-99
AUSTRALIAN CRmCAL CARE
ABSTRACT
Anaerobic necrotizing soft tissue infections are known for their devastating effects of tissue destruction and death. These infections may occur as a result of trauma, surgical intervention or occur spontaneously in predisposed individuals. They are caused by a wide range of anaerobic organisms and may be categorised according to the tissue involvement as Necrotizing Fasciitis and Myonecrosis. A five year review of patients admitted for hyperbaric oxygen (HBO) therapy and requiring intensive care revealed a patient group numbering 25, roughly equally divided between the two classifications of tissue involvement. Trauma was an aetiological factor in 5 of these cases. Cancer and diabetes mellitus were also prominent aetiological factors. Treatment consisted of the triad of early selective/aggressive surgery, high dose antibiotic therapy and HBO therapy. The mortality of the group was 25%. Delay in treatment was associated with increased mortality. Nursing care, for this particular patient group is demanding, requiring particular attention to wound care, analgesia, transport, psychosocial care of patient with
mutilating wounds, nutrition and temperature homeostasis.
Gangreneu and Fasciitisu.
It is a cause for concern that two cases occurred after elective orthopaedic procedures requiring the application of plaster of paris (POP) cast over a leg.
Due to the presence of a large multiplace Hyperbaric Oxygen (HBO) chamber within the facility of Prince Henry Hospital the ICU receives referrals for the treatment of soft tissue infections. These referrals come from a broad geographic area encompassing New South Wales and the south east region of Queensland.
INTRODUCTION
A retrospective review was undertaken of patients admitted to the Intensive Care Unit (ICU) of Prince Henry Hospital with the admission diagnosis of "Gas
I
AETIOLOGICAL FACTOR
"Necrotizing
This article will present a description of the classification, aetiology,
I
PREDISPOSING FACTOR
TRAUMA compound fracture GlT trauma burns minor puncture wounds laceration abrasion injection non penetrating blunt trauma
Cancer Diabetes Peripheral Vascular Disease
SURGERY appendix biliary tract colon small intestine upper GIT
SPONTANEOUS (see pdisposing factom) r
Perirectal abscess lleus Cholecystitis
1
TABLE 1 AETOLOGICAL AND PREDISPOSING FACTORS
AUSTRALIAN CRITICAL CARE
VOL5 NO4 DECEmER 1992
MYONECROSIS
Clostridium species; C. perfrlngens, C. septicum. These organisms are ubiquitous in the environment (soil contaminant). Normal flora of gut, perineum and skin. They easily endogenously contaminate skin surfaces and gut. (commonly contaminate wounds) may be associated with organisms, E-coli, Enterobacter, Enterococci, as contaminants. Non-Clostridial as for Necrotizing Fasciitis but involving muscle. NECROTIZING FASCllTlS
Anaerobic. Bacteroides, Peptostreptococcus associated with facultative anaerobic bacteria (E-coli, Streptococcus, Enterobacter, Klebsiella, Proteus and occassionally Pseudomonas) may be predominantly monomicrobial (Haemolytic Strep. + or - other species). Streptococcus + Staphylococcus in synergistic combination. Also known as - Melaney's Gangrene - Fournier's Gangrene (affecting male genitalia)
necessary is determined by the tissue involvement. Indeed defining the infection can often only be done after initial surgical inspection and debridement. This system classifies the infection under the headings of Necrotizing Cellulitis, Necrotizing Fasciitis and Myonecrosis (Table 3). Infection usually results from a breach of a mucocutaneous barrier resulting in displacement of normal flora or contamination by exogenous organisms (9,lO). Predisposing factors such as tissue injury, haematoma, altered host response, and bacterial synergy are usually present and allow the infective process to establish itself (Table 1). Once established the infection may be self propagating, as in the case of Clostridial Myonecrosis, because of
TABLE 2
ORGANISMS INVOLVED pathophysiology and treatment of necrotizing soft tissue infection and then review the ICU experience of the nursing care requirements of this patient group. Necrotizing soft tissue infections can be considered as multiple disease entities that require a similar treatment approach(1). These infections are known for their devastating effects of tissue destruction and death, and require extensive surgical debridement (including amputation) (1,2,3,4,5). "Gas gangrene" is a term commonly applied to necrotizing soft tissue infections and Clostridial species (usually C. perfringens) are the pathological organisms associated with this term. Historically these infections have been associated with battlefield injuries, natural disasters and trauma (1,2,6,7). However the term "gas gangrene" and the association of this term with Clostridial infection does not encompass and reflect the range of
causative organisms, tissue involvement and aetiological factors associated with necrotizing soft tissue infections. Several reviews and case studies have highlighted the multimicrobialnature of causative organisms and the variety of aetiological factors (1,3,4,5). Classification of necrotizing soft tissue infections has been centred either around the causative organism(s) or the tissues affected. These classifications have ranged from comprehensive separation and definition of clinical syndromes to the use of a single category to encompass all progressive necrotizing infections (1,5,8). Another form of classification is to divide the infections into clostridial and non-clostridial ( 1 3 . In the authors' opinion the most clinically useful classification is one proposed by Patino and Castro(1) that reflects the fact that the treatment approach is the same but the degree of debridement
1. NECROTlZlNG CELLULITE
Skin lesion - subcutaneous tissue spared Usually monomicrobial 2. NECROTlZlNG FASCllTlS
Subcutaneous tissue infection Skin is relatively spared until advanced stages Muscle and muscle fascia not affected Usually polymicrobial (synergistic) Can be monomicrobial(Strep.) 3. MYONECROSIS
Muscle involvement The most serious Severe systemic toxicity is characteristic Usually Clostridial but may result from other anaerobes. (Strep. Bacteroides, Klebsiella, E-coli, Proteus.)
TABLE 3 CLASSIFICATION O F INFECTION
VOL5 NO4 DECEMBER1992
AUSTRALIAN CRmCAL CARE
the elaboration of toxin and gas(3) (Table 4). The local effects are swelling, pain, necrosis, tissue liquifaction and spread. Systemic effects occur as a result of released toxin and the systemic response which may lead to a full blown sepsis syndrome. The treatment of these infections centres around the triad of surgery, antibiotics and HBO. Recognition of the infection must be early and followed by aggressive surgical intervention in which all necrotic tissue is excised. The importance of a "2nd look" within the first 24 hours and further debridment if necessary is well recognised (1,11). Broadspectrum antibiotics are given
until gram stain and culture results become available. This approach reflects the usual polymicrobial nature of the infection and its rapid progression necessitating the commencement of treatment as soon as possible.
HBO as an adjunctive therapy has proven effective in the treatment of Clostridial Myonecrosis and there is some support for its use in Non-Clostridial soft tissue infection (3,12,13). Table 5 summarises the role of HBO therapy in the treatment of soft tissue infections.
MATERIALS AND METHODS A retrospective Study of patients admitted to the ICU at Prince Henry Hospital with a diagnosis of anaerobic soft tissue infection during the five year period, 1987-1991, was undertaken by review of the patients' hospital record. During this period 29 patients were referred to the hospital's hyperbaric unit for treatment of soft tissue infection, 25 of these patients required admission to the ICU. This study is comprised of 24 of these 25 patients as one set of medical records were unavailable. The age
CLOSTRlDlAL MYONECROSIS
NECROTlZlNG FASCllTlS
incubation 1-2 days
incubation 1-4 days
severe pain, marked tachycardia
moderate pain, oedema of skin +++, skin anaesthesia resulting from subcutaneous destruction.
appearance; oedema +++, tense skin, magenta-bronze hue to skin, bulae containing dark serosanguinous "mousey" smelling fluid. organism requires low oxygen reduction potential for propagation ie. diminished blood supply, foreign body, tissue necrosis, haeniorrhage, infection with other organisms. release exotoxin when proliferate; toxins destroy host tissue, increase capillary permeability, cause haemolysis. carbon dioxide and hydrogen gas released causing dissection of tissue and facilitating spread.
occlusion of skin nutrient vessels results in skin necrosis and blisters as infection progresses. characteristic of pathology is: severe extensive necrosis of superficial fascia and subcutaneous tissue, destruction of tissue and liquifaction of fat. systemic toxicity may display crepitation
subcutaneous
any part of body affected but favours extremeties, abdomen, groin and perineum.
TABLE 4 PRESENTATION AND PATHOLOGICAL PROCESS
High pressure environment in which oxygen administration produces high tissue oxygen pressure. Inhibits toxin production Counteracts hypoxic environment in which Clostridia thrive. Perioxidase develops in the infecting organisms as a result of HBO and causes inactivation and killing of pathogens. Clostridia produces the enzyme catalase from dead muscle and blood. This enzyme inactives perioxidase and therefore necrotic tissue and haematoma must first be removed.
HBO may be useful in demarcation of necrotic and viable tissue.
TABLE 5 HYPERBARIC OXYGEN IN CLOSTRlDlAL INFECTION
range of patients was 11 to 78 years. There were 4 females and 20 males. They were referred for treatment from the Sydney metropolitan area, country New South Wales and from Queensland. In order to indicate the severity of illness and the need for nursing care of this patient group we determined the following: 1. APACHE IIscore; 2. Length of stay in ICU (LOS); 3. N u m b e r of operative procedures whilst in ICU (this includes debridements and amputations); 4. Number of days ventilated; 5. Number of days on inotropic support (adrenaline, dopamine, noradrenalhe); 6. T h e need for renal replacement therapy (CVVHD, haemodialysis, peritoneal dialysis). Management of all patients was based upon the recognised
regimen of high dose antibiotics, early aggressive surgery and HBO therapy.
MYONECROSIS
ANALYSIS OF DATA
The descriptive statistics used were the range and median. The Mann Whitney U test was used to compare age, APACHE II score, LOS, number of operative procedures, days ventilated, days on inotropes and mortality for the two diagnostic groups.
Age (years) APACHE ll LOS (days) Operations Ventilated Ventilation (days) lnotropes lnotropes (days on) Dialysis (patients) HBO (treatments)
The null hypothesis tested was that there would be no difference between the two groups for these factors. The null hypothesis was rejected at a p < 0.05.
NECROTIZING FASCllllS
RANGE
RANGE
(MEDIAN)
(MEDIAN)
11-67 (61) 4-29 (17) 1-14 (7) 0-5 (2) n=9 1-14 (3) n-10 1-13 (2) n=3 1-11 (4)
11-76 (64) 3-30 (18) 1-44 (6) 0-13 (1) n=8 1-30 (3) n=7 1-24 (1) n-1 0-5 (2)
SIG n/s nls n/s n/s n/s n1s pm.0075
nls = not significant
TABLE 7 COMPARISON
RESULTS Classlflcatlon
Aetlologlcal Factors
For the purposes of this study the classification system, proposed by Patino and Castro(1), based upon tissue involvement was the most useful (Table 3).
We identified five aetiological factors within our patient series. Table 6 identifies these factors and relates them to patient age.
None of the patients in our series fitted into the Necrotising cellulitis category, 45% (n-1 1) had Necrotising Fasciitis and 55% (n=l3) had Myonecrosis. These classifications were based upon Operating Room report descriptions of the extent of tissue involvement.
Cancer was an aetiological factor in three cases. Four patients developed soft tissue infections following surgery, one following drainage of a perianal abscess, one after arthroscopy and two after elective orthopaedic procedures requiring the use of Plaster of Paris casts. Both these latter patients
AGE
CANCER
1-(
1 2 3 4 5 6 7 8
1
OPERATIVE PROCEDURE
DIABETES
1
1 1 1
1
TOTAL
1 1
2
3
4
TRAUMA
1
OTHER
TOTAL
1
1 4 3
1
1 1 1
8
5
4
TABLE 6 INCIDENCE OF AETIOLOGICAL FACTORS AND AGE
0 3 2 2 0 3 8 6
were found sometime postoperatively with "blue" feet, one of them died, and the other, an 11 year old boy, required a leg amputation. Diabetes mellitus was the most common aetiological factor, accounting for eight patients. These patients had developed ulcers which subsequently became infected leading to fasciitis or myonecrosis. These patients were from the older age groups. A traumatic incident was identifiable as a factor in five patients. The type of trauma varied greatly:
-
-
one patient fell off a chair and sustained a carpet graze to the elbow one patient fell on a bamboo stick one patient cut her hand whilst preparing dog meat one patient was involved in a motor vehicle accident one patient fell on the footpath
One patient developed necrotising fasciitis subsequent to appendix rupture while another developed this infection as a sequelae of an
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AUSTRALIAN CRITICAL CARE
untreated perianal abscess. Both these patients had no identifiable aetiological factor other than the initiating infection. Aetiological factors did not vary significantly between the myonecrosis and the necrotizing fasciitis groups.
Severlty of Illness and nurslng care requirement The two groups, myonecrosis and necrotizing fasciitis, were compared with respect to factors indicating severity of illness and nursing care requirement. The only significant difference found was in the HBO treatments received by the two groups. This difference represents a clinical choice in therapy. These resutts are shown in Table 7.
Mlcroblology
as soon as possible.
- 3 to 5 million units of penicillin as an initial dose followed by up to 3 million units hourly was used. Such high doses are required because in dead or dying non-perfused tissue penicillin is diffused rather than perfused. 3. HBO therapy. The HBO protocol used was three treatments at 2.8 atmospheres absolute (ATA) in the first 24 hours, each treatment lasted 120 minutes.
2. high dose antibiotics
Further treatments were undertaken according to the clinical judgement of the surgeons and intensivists. One patient was not submitted to HBO treatment because of severe cardiovascular instability and died shortly after ICU admission.
Table 8 shows the organisms cultured from the patients' wounds. As can be noted some initial gram stains revealed rods or cocci only, not specific organisms. In some cases specific organisms were never able to be grown. The culture results when available were usually not obtainable until after treatment had begun. Most patients in this series had polymicrobial infection. It is evident that a clostridium species was present in six of the patients in the myonecrosis group, with a further six patients in this group growing gram positive rods. It may be assumed from this that twelve of the thirteen patients in this group had clostridial infection.
Management The intensive care management of the patient group revolved around the three previously mentioned, widely accepted practices:1 . selective/aggressive surgery
-
The overall mortality for the group This figure was 25% (n=6). compares favourably with other published series (3,5,6,7). There was no significant difference in mortality between the necrotizing fasciitis (27%) and myonecrosis groups (23%). Three patients died from each group. Interestingly a MYONECROSIS (n=13)
4 1 1 6 1 3 4 1 1 2
R 1992
common feature in the patients who died was a relatively long period of delay between infection and definitive treatment. Half the patients who died did so within the initial 24 hours of admission to ICU.
Nurslng Conslderatlons Apart from the general nursing measures appropriate for any intensive care patient some considerations are more salient in this patient group, and thus warrant particular mention. Dressings - these are often major, time consuming procedures, usually involving more than one person to hold the patient in position and to position the dressings. Generally a hypochlorite solution (Milton 1:80), where chemical debridement is required, or normal saline soaked packs are used with zinc cream to protect the wound margins. Dressing frequency varies, but two to three times per day is common. Observation of the area of involvement is important so that early identification of any extension of the infection can be made. Recording of this observation is essential to allow comparison from shift to shift.
Analgesia
-
is especially important
NECROTIZING FASCllTlS (n-11)
frequency Clostridium Clostridium perf. Clostridium sept. Gram +ve rods. Gram +ve cocci Gram -ve rods Strep. faecalis Strep. pyrog. Bacteroides E-coli
E
frequency Gram +ve rods Gram +ve cocci Gram -ve rods Strep. faecalis Strep. melleri A&B haemolytic Strep. Bacteroides E-coli Mixed coliforms Staph. aureus Clostridium
TABLE 8 ORGANISMS ISOLATED
4 3 5 2 1 1 2 3 1 1 1
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AUSTRALIAN C R ~ C MCARE
in this patient group as the wounds are extremely painful. Opiate infusions (morphine, fentanyl titrated to effect) were used with bolus doses of opiates or entonox inhalation prior to dressing changes given as appropriate.
Transport - must be considered as organisation of time is required. The patients may go to theatre daily for debridement as well as to the HBO chamber up to three times a day in the initial stage. Interruption to treatment must be minimised eg antibiotic doses must not be missed, infusions must not run out etc.
causative conditions in patients who may or may not be compromised. These infections are of rapid onset and progression and have significant systemic manifestations and resultant mortality. The development of infection in the setting of plaster of paris casts in two patients in this series emphasises the fact that there can be no complacency i n wound or post-operative observation.
The relationship between delay in definitive treatment and mortality indicates that outcomes from these infections can still be improved with Psychosoclal - the wounds and greater awareness, surveillance and speed of response especially in surgery are often very mutilating and the patients' body image will be situations where aetiology factors affected. Reassurance and support associated with the development of and explanation of the ongoing these infections have been identified. need for plastic surgery are of prime importance. Referral to more REFERENCES specific resources such as rehabilitation services, Amputee 1. Patino JF, Castro D. Necrotizing Society or to a psychologist/counsellor may be lesions of soft tissues: a review. required. World J Surg, 1991; 15:235-239
Nutrltlon - the infective process causes a hypermetabolic state, therefore attention to nutritional needs is important. Dietitian advice, nasogastric feeding andlor Total Parinteral Nutrition (TPN) are utilised according to patient needs.
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Temperature maintenance of body temperature is important. The massive open wounds that often exist predispose the patients to heat loss. Plastic coverings are placed over wounds to minimise this. It needs to be emphasised that these are specific factors that require particular nursing attention in this patient group, all other general ICU nursing measures are also relevant.
2. Corry M, Montoya L. Gas gangrene: certain diagnosis or certain death. Crit Care Nurse, 1989; 9(10) : 30-38 3. Cline KA, Tumbull TL. Clostridial myonecrosis. Ann Emerg Med, 1985 (5); 14:459-466
4. Swartz MN. Subcutaneous tissue infections and abscesses. In: Mandell GL, Douglas RG, Bennett JE eds. Principles and practice of infectious diseases. 3rd ed. NY: Churchill Livingstone, 1990; 808-816 5. Freischlag JA, Ajalat GI Busuttil RW. Treatmeat of necrotizing soft tissue infections. The need for a new approach. Am J Surg, 1985; 149:751-755
CONCLUSION Necrotizing soft tissue infections can arise as a result of numerous
6. Unsworth IP, Sharp PA. Gas gangrene; an 11-year review of 73 cases managed with
hyperbaric oxygen. Med J Aust, March 3 1984: 256-260 7. Patino JF, Castro Dl Valencia A, Morales P. Necrotizing soft tissue lesions after a volcanic cataclysm. World J Surg, 1991; 15: 240-247 8. Dorai CR, Kandasami PK. Fournier's gangrene: it's aetiology and management. Aust NZ J Surg, 1991; 61 :370-372 9. Bartlett JG. Anaerobic bacteria: general concepts. In: Mandell GL, Douglas RG, Bennett JE. eds. Principles and practice of infectious diseases. 3rd ed. NY:Churchill Livingstone, 1990; 1828-1833 10. Bartlett JC. Gas gangrene (other clostridium-associated diseases). In: Mandell GL, Douglas RG, Bennett JE. eds. Principles and practice of infectious diseases. 3rd ed. NY: Churchill Livingstone, 1990; 1850-1856 11. Sudarsky LA, Laschinger JC, Coppa GF, Spencer FC. Improved results from a standardised approach i n treating patients with necrotizing fasciitis. Ann Surg, Nov 1987; 206(5): 661-665 12. Hart GB, Lamb RC, Strauss MB. Gas gangrene: 1. a collective review. Trauma, 1983; 23(11): 991-995 13. Fischer B, Jain KK, Braun El Lehl S. Handbook of hyperbaric oxygen therapy. Berlin: Springer-Verlag 1988; 94-99
