Thrombophlebitis suppurée de la veine supérieure avec des métastases pulmonaires et cérébrales chez un enfant gravement brûlé.
RÉSUMÉ. Une enfant de 3 ans avec des brûlures étendues de deuxième degré profond et troisième degré atteignant 45 % de superficie est admise dans notre unité de brûles.Au bout de la quatrième semaine, l'enfant développe une septicémie sévère, dont l'origine est une thrombophlébite suppurative du tronc de la veine cave supérieur secondaire â un cathéter central.Malgré la mise en place immédiate d'une antibiothérapie appropriée, il se développe rapidement une métastase infectieuse par Staphylococcus aureus methicillinerésistant avec survenue de plusieurs abcès cérébraux et pulmonaires ainsi qu'une infection des lésions cutanées.Le traitement conservateur non-chirurgical aboutit â un rétablissement presque complet avec la cicatrisations des brûlures, laissant seulement de séquelles neurologiques mineures deux ans après l'accident.
Mots clés : infection, septicémies, thrombophlébites, accidents neurologiques.
Intravascular cathéter related bloodstream infections are well-known possible complications of intravenous therapy or monitoring of critically ill patients [1,2]. In severely burned patients they can lead to the occurrence of major complications in up to one thirdoffthe involved population. [3,4,5,6,11]
One of these possible major complications is the development of a deep suppurative thrombophlebitis with subsequent metastatic infections. In children the incidence of this complication is rare, however it is a life-threatening condition with a vert' high mortality. [7,8,10]
When - as is the case of our patient - a nearly complete obstruction of the superior vena cava trunk occurs with an immediate formation of cerebral and puhnonary abscesses caused by a bacterial organism with a vert' high résistance towards most antibiotics, the médical staff is confronted with a life-threatening catastrophe in a young child with virtually vert' few feasible treatrnent options.
A three year old female child is admitted in our Burn Unit with third and deep second degree burns covering 45 % of ber total body surface area, caused by a domestic accident in which fire was set to ber clothes.
Évidence of smoke inhalation, afterwards confirmed by bronchoscopy, necessitates endotracheal intubation, full sedation and invasive respiratory and cardiovascular monitoring and treatment. Catheters employed were double lumen catheters 20-22 Gauge. Scar cuts have to bc performed on thé left arm and partially on thé left hemithorax.
Following thé in our centre routinely applied treatment guidelines, thé majority of thé burned surface area is covered temporarily with human donor homograft skin, in order to bc able to reduce ftuid losses and improve wound healing possibilities by providing an artificial barrier against pathogens. According to our existing guidelines thé child receives a prophylactic oral antibiotic treatment with amoxicillin syrup by nasogastric tube, 50 mg /kg/day for Pive days.
An early first burn excision with homografting of thorax, back and abdomen can bc performed on thé sixth day post burn, with no major blood losses or transfusion need. Respiratory weaning with extubation follows without difficulty on day ten post burn.
Due to thé particular spread of thé burned skin area, central venons access is limited to both of thé fémoral veins and thé right subclavian and jugular veins, since we prefer not to insert any cathéter through burned slcin area whenever any other insertion area is accessible. For this reason thé child right subclavian and internal jugular vein were used for central catheter insertion, with an average interval for catheter replacement of seven days, no signs pointing towards problems of catheter related infections origin.
At day 15 post burn, further excision with autografting of thé previously excised thoracal and back area occurs, with an uneventful perioperative period of 48 hours. However on day 18 post burn, suddenly signs of lever and leucocytosis appear and haemocultures reveal thé présence of a methicillin resistant Staphylococcus aureus (MRSA). In spite of instantaneously started antibiotherapy (vancomycin aztreonam), fever increases to well over 40 °C, with all cultures of blood, catheter tips, nose and throat swabs confirming thé présence of MRSA as well as several colony forming units (CFU) of Candida albicans. In view of thé poor response to thé antibiotic regimen started, therapy is sequentially broadened and meropenem, fusidic acid and fluconazole is added.
Computerised tomography of thé brain [figure 1 ] and lungs show a lesion to thé left anterior hypothalamic region and thé présence of several pneumonie abscesses. Nuclear magnetic resonance imaging confirms a hypothalamic infaretion zone as well as thé appearance of multiple bilateral corticocerebral abscesses.
Searching for thé infections focus of origin, echo-Doppler imaging confirmed by digital substraction angiography reveal thé présence of an important thrombosis of thé right axillar and jugular vein with partial thrombotic obstruction of thé vena cava superior [figure 2]. Transoesophageal echocardiography indicates a small patent foramen ovale with all of thé cardiac valves intact. Neurological examination shows a bilateral motor deficit with proportionally a more pronounced involvement of thé right arm.
Due to thé very poor general condition of thé child, surgical treatment of thé infected suppurative thrombotic area is impossible and a conservative medical treatment is thé only remaining option with continuons intravenous heparin and a combination of broad spectrum antibiotics for a period of three weeks, conditions of life threatening critical illness with a very poor general condition continue to exist. Finally overall clinical conditions slowly begin to improve with disappearing of all infections signs and all bacteriological cultures becoming negative, allowing us to stop antibiotic therapy one month after onset of thé infection. However neurologically a residual paresis of all limbs persist as well as a marked dysphasia. Three months post burn thé child can bc discharged from thé Burn Centre, with a fully intact superior vena cava trunk but with remaining corticocerebral infarction zones.
After 24 months these zones have disappeared, a minor paresis of thé right arm and an important dysphasia remaining thé only sequels.
| <% immagine "Fig. 1","gr0000030.jpg","Computerised tomography of thé braie shows several abscesses",230 %> | <% immagine "Fig. 2","gr0000031.jpg","DS Angiography shovving an important thrombosis of the right axillar and jugular vein with partial thrombotic obstruction of thé venu cava superior",230 %> |
The occurrence of a deep suppurative thrombophlebitis complicated by a substantial obstructive involvement of thé superior vena cava trunk [1,9,12], as well as thé responsible pathogen being resistant towards varions currently used antibiotics form a rarely encountered but very lethal combination of complications that cari follow central venous catheterisation in thé intensive care unit (ICU).
Most often thé suppurative thrombophlebitis involves peripheral veins and a fast diagnosis is possible through observations of tenderness, swelling and pus being prescrit at thé cannulation site. This is a phenomenon that very often occurs in a population of burn patients and a high suspicion rate prompts thé médical staff to examine carefully al] previously used catheter insertion sites, whenever clinical signs of sepsis and positive blood cultures appear. In case of involvement of a central vein these clinical signs are not readily observable and even in a hum unit with an overall incidence of suppurative thrombophlebitis known te, bc higher as compared to a general ICU population (4-8 °/o vs 0.14 %) diagnosis cari bc very difficult.
Recommended therapy for this condition is primarily surgical with excision of thé infections focus by peripheral venectomy or by thrombectomy whenever central veins are involved. Throughout thé perioperative period antibiotic and possibly anticoagulant therapy is started. [ 16]
In a retrospective analysis of their 10 year experience with problems of suppurative thrombophlebitis in children, Kahn et al [8]. state that critical care illness, thé performance of invasive procedures as well as thé administration of broad spectrum antibiotics or total parenteral nutrition are known predisposing factors. [5,8,13]
The most common causative pathogens in children are Staphylococcus aureus (44 %) and différent Candida species (17 %) [25]. The aerobic and anaerobic bacterial flora of burn sites in children, as reviewed by Brook [17,18], reveal predominantly thé présence of Staphylococcus aureus and Staphylococcus epidermidis on all extremities. In this study all of thé children were treated by local application of silver sulfadiazine and general antimicrobial therapy was used in 128/180 patients. No statistical correlation could bc withheld as a possible link between thé isolated bacteria and thé antimicrobial agents used.
In a publication by Marie [9] a case of suppurative thrombophlebitis of thé superior vena cava in a 22 year old adult was treated conservatively with antibiotics and heparin but resulted in thé émergence of a resistant mutant strain of thé causative agent leading them finally to thé decision to eradicate thé infection by surgical thrombectomy.
In thé case we report therapeutic options were heavily limited by thé fact that our patient was a 3 year old and by thé rapid spreading of metastatie infection towards thé cerebral region and thé lungs. All ideas towards surgical treatment were rendered impossible by thé very poor general condition of thé child, thé very young age and possible anesthetie management problems related to an increased intracerebral pressure and a very compromised respiratory status. Conservative treatment thus remained thé only option [20,23,24].
Burn patients in general and certainly young children with extensive burns have a very limited intravascular acces. In this case, fearing previously reported higher incidence of infectious events with catheter insertion in fémoral veins, we focussed perhaps too much on catheterisation of alternately thé right subclavian and internal jugular vein through non burned skin. Respecting regular time intervals between catheter changes and in spite of meticulously respected catheter care nursing procedures, a post factum review revealed a period of 21 days during which constantly flow in thé superior vena cava trunk could have been compromised by thé presence of alternately a catheter in thé right subclavian or right internal jugular vein. Undoubtedly we consider this to bc one of thé possible causes of thé deep central venous thrombosis, as well as thé fréquent catheter manipulation and insertion procedures in thé same area.
Especially in a burn centre all cathéter insertion procedures should never become a routine. Catheter care nursing procedures have proved their value in reducing possible catheter related infections morbidity. We would like however to accentuate thé importance of careful medical supervision witb respect to choice of insertion site and interval of catheter replacement timing interval, for which there seems to bc no general agreement. Moreover recent studies in non burned, general ICU patients seem to disagree with previously accepted statements, showing an equal incidence of infections morbidity regardless of thé insertion zone (subclavian, jugular or femoral region) (27). No longer a fixed timing interval between catheter changing is accepted in non burned ICU patients, catheters being changed only whenever clinically warranted [19,21,22].
All of these recent statements should be re-examined with respect to treatment procedures for severely burned patients. Preliminary findings in our centre, reviewing thé data of four severely burned young patients over a 45 day surveillance period show no statistically significant différence of catheter related infections morbidity when comparing central catheter insertion in thé jugular, subclavian or femoral region.
Further evaluation and a greater number of patients are necessary to confirm whether or not these findings are valid to extend data pointing to equal infections morbidity for all insertion zones towards all burn patients with thé sole exception of insertion procedures through burned skin area.
Upon thé admission of burned children we normally cover thé burned skin area as much as possible with temporary human donor homografts, a procedure we perform in order to bc able to reduce thé necessary intravenous fluid load during immediate resuscitation, as well as a protection measure against possible passage of pathogens through damaged skin and an efficient analgesic adjuvant. In our centre all used skin homografts as well as cell cultures are routinely screened for eventual bacterial contamination, serological testing ruling out possible viral donor infections.
Further investigations and carefully designed studies are necessary to confirm thé need for all prophylactic antibiotic treatment. The use of antibiotics in burn patients is a particular point of discussion with most caretakers agreeing not to use prophylactic antibioties. Nevertheless it is a widely accepted policy to prescribe an oral prophylactic antibiotic treatment when applying human donor homografts to temporarily cover burned skin area of young children in thé immédiate post burn phase. In our centre amoxicillin syrup is prescribed in a dose of 50-100 mg/kg/day for a five day course, aiming to provide protection against Gram positive agents.
With respect to thé well known facts that application of broad spectrum antibiotics can contribute to thé emergence of antibiotic resistance, this practice of prophylaxis should perhaps be reviewed since no conclusive scientific data exist to prove thé beneBt of it.
The introduction of standard procedures for central catheter insertion and nursing care have a generally accepted value in all intensive care units.
This case report semis to suggest that we should perhaps less be focussed upon thé catlieter itself and instead give more attention to thé possible impact of thé inserted catheter upon thé dynamic flow properties of thé cannulated vessel.
Especially with smaller blood vessel diameters, as is thé case when cathelerising very young children, meticulous attention should be given to thé correct choice of catheter (length, diameter) with respect to thé patients anthropometric data.
The value of frequent catheter changing in attempting to reduce infections catheter related events, seems to be a point of discussion, while thé number of sequential catheter manipulations certainly can increase thé incidence of thrombotic events.
Long terni catheterisation of thé saine greater central vein should be avoided or ai least carefull\ monitored to avoid possible medical catastrophes. . Finally thé value of antibiotic prophylaxis in donor skin coverage procedures in thé early post burn phase of severely burned young children should perhaps bc critically reviewed since no substantial scientific benefits prove thé value of it and emergence of resistance towards antibiotics is a very alarming event, compromising therapeutic options in intensive care and burn units.
A 3-year old girl with extensive third and deep second degree burns covering 45 % of total body surface area is admitted in our Burn Unit.
Four weeks post burn, thé child develops a severe septicaemia, originating from a suppurative thrombophlebitis of thé right superior vena cava trunk, following a long-lime central vein catheterisation.
In spite of immediate application of a suitable antibiotic therapy, almost instantaneously an infectious metastasis by methicillin-résistant Stapbylococcus aureus results in thé appearance of several cerebral and pulmonary abscesses as well as skin lesions.
Conservative non-surgical treatment leads to a nearly complete recovery with healing of the burn wounds, leaving however minor neurological sequels two years alter the accident.
Key words: infections, septicaemla,thrombophlebitis, neurological sequels.