Biomedical subjects

Peter Giannoudis

Publications and source records attributed to Peter Giannoudis.

6 recordsLinked to original sources

PubMed2005

Effects of hypothermia and re-warming on the inflammatory response in a murine multiple hit model of trauma.

INTRODUCTION: Although, hypothermia is a frequent event after trauma, it is unclear whether its beneficial or detrimental effects are more important. This study aims to quantify the effects of hypothermia and re-warming on the inflammatory response after fracture/hemorrhage and subsequent fracture stabilization with resuscitation. MATERIALS AND METHODS: Eighty-one male C57Bl/6 mice (aged 8-10 weeks, weighing 22.0+/-3.0 g) underwent femoral fracture and hemorrhage followed by resuscitation and splint fixation of the fracture. Animals were sacrificed 3h after induction of hemorrhage and fracture. Besides a sham group (n=6), four experimental groups were created: A: normothermia (n=12), B: hypothermia after trauma (n=21), C: re-warming after resuscitation and before stabilization (n=21), and D: hypothermia before trauma (n=21). Groups B-D were further subdivided into three subgroups according to the degree of hypothermia (subgroup 1: 35-33 degrees C, subgroup 2: 32.9-30.0 degrees C, and subgroup 3: 29.9-27.0 degrees C). Plasma cytokine (TNF-alpha, IL-6, and IL-10) and chemokine (MCP-1) concentrations were determined by ELISA, pulmonary permeability changes were quantified, and histological analysis of lung and liver tissues was performed. RESULTS: Normothermia resulted in a significantly increased early mortality rate. A significantly increased pro-inflammatory and decreased anti-inflammatory responses were also observed in normothermia as compared to hypothermia. The extent of these changes was most pronounced in the severe hypothermic group. Re-warming after mild hypothermia resulted in a pro-inflammatory response comparable to normothermia. CONCLUSION: Hypothermia has a beneficial effect on early survival after trauma, which appears to be independent of the level of hypothermia and re-warming. Re-warming, however, enhanced the pro-inflammatory response. Further studies with a longer posttraumatic observation period are required to investigate the long term effects of the hypothermia and re-warming-induced changes on the pro- and anti-inflammatory responses.

Animals↗

PubMed2005

Secondary effects of femoral instrumentation on pulmonary physiology in a standardised sheep model: what is the effect of lung contusion and reaming?

Intramedullary nailing is the treatment of choice for patients with femoral shaft fractures. However, there is an ongoing debate in multiple trauma patients with associated lung contusion when primary or secondary definitive stabilisation of the long bone fracture should be performed, as nailing is thought to play an important role in the pathogenesis of adult respiratory distress syndrome (ARDS). In a standardised sheep model, this study aimed to quantify the development of acute pulmonary endothelial changes, to assess the activation of polymorphonuclear leucocytes (PMNL) and to observe the effects on the coagulation system associated with the reamed nailing procedure. Furthermore, the effect of coexisting lung contusion in an experimental model was evaluated. The animals were randomly assigned to one of four different groups (6 animals/group). In control groups, only a sham operation (thoracotomy) was performed, whereas in study groups, lung contusion was induced prior to femoral stabilisation either by external fixation or reamed femoral nailing. Using bronchoalveolar lavage (BAL) pulmonary permeability changes were quantified and PMNL activation was assessed by chemiluminescence. Additionally PMNL diapedesis and interstitial lung oedema were determined by histological analysis. All animals were sacrificed 4 h after the start of the femoral instrumentation. Without an associated lung injury, instrumentation of the femoral canal with the reamed nailing technique induced a transient increase in pulmonary permeability. In the face of an induced lung contusion, reamed femoral nailing resulted in significant increases in PMNL activation, pulmonary permeability and interstitial lung oedema, compared with external fixation. Without pulmonary contusion, reaming of the femoral canal was associated with a transient increase in pulmonary permeability. This was exacerbated in the presence of lung contusion along with increased PMNL activation. External fixation did not provoke similar changes. The findings of this study support the view that reaming of the femoral canal should be avoided in polytrauma patients with severe chest trauma as it could act as an additional stimulus for adverse outcome. Temporary external fixation appears to be a safe method for fracture stabilisation until inflammatory and coagulatory disturbances after trauma have been normalized.

Animals↗

PubMed2005

Impact of hypothermia on the immunologic response after trauma and elective surgery.

An Hypothermia is defined as a decrease in core temperature below 35 degrees C. The well-described deleterious effects of accidental hypothermia on outcome in multiple-trauma patients contrast the beneficial effect of controlled hypothermia on organ function during ischemia in elective surgery. Experimental studies have shown that induced hypothermia during hemorrhagic shock might have beneficial effects on outcome. The beneficial effects of induced hypothermia appear to be partly mediated by the prolongation of the "golden hour" with prevention of hypoxic organ dysfunction. However, hypothermia also has been thought to have an impact on the immunologic response after trauma and elective surgery. Induction of hypothermia seems to decrease the release of pro-inflammatory cytokines believed to influence distant organ damage positively, and is mediated by the interaction of polymorphonuclear leucocytes (PMNL) and capillary endothelial cells. Nevertheless, the incidence of posttraumatic infectious complications may be increased after induction of hypothermia due to an overexpression of anti-inflammatory cytokines. Together with this immunosuppressive profile, coagulopathy and bleeding might limit the use of induced hypothermia after multiple trauma and elective surgery. The purpose of this Chapter is to highlight current knowledge regarding the interaction of hypothermia and posttraumatic immune reactivity. A better understanding of these mechanisms would assist the introduction of preventive and therapeutic strategies into clinical practice.

Brain Injuries↗

PubMed2004

Damage control: extremities.

The principles of fracture management in polytrauma patients continue to be of crucial importance. Over the last five decades, various strategies of fracture treatment in the multiply injured patient have evolved. The various new methodologies remain controversial. In the beginning, early surgical fracture treatment of long bone fractures after multiple trauma was not routinely advocated. It was believed that the polytraumatised patient did not have the physiological reserve to withstand prolonged operations. The introduction of standardised, definitive surgical protocols, led to the concept of early total care (ETC) in the 1980s. This concept was subsequently applied universally, in all patient groups, regardless of injury severity and distribution. Later, it became apparent that certain patients did not appear to benefit from ETC. Indeed, extended operative procedures, during the early phase of multiple trauma recovery, were associated with adverse outcome. This applied for patients with significant thoracic, abdominal and head injuries and those with high injury severity scores (ISS). In response, the concept of damage control orthopaedics (DCO) was developed in the 1990s. DCO methodology is characterised by primary, rapid, temporary fracture stabilization. Secondary definitive management follows, once the acute phase of systemic recovery has passed. We explore the processes underlying the systemic biological impact of fracture fixation, the evolution of operative treatment strategies for major fractures in polytrauma and the current trends toward staged management of these patients.

Acute-Phase Reaction↗

PubMed2003

Hemorrhage in pelvic fracture: who needs angiography?

Pelvic fractures are rare but potentially devastating injuries. An understanding of the bony and peripelvic anatomy along with common patterns and the classification of the injury are of critical importance in their management. These form the basis for a general treatment algorithm for pelvic fracture patients. Angiographic embolization is time-consuming and often delayed. Hemodynamic instability with unstable pelvic fracture is therefore best approached with a combination of pelvic emergency stabilization (C-clamp) and surgical hemostasis by pelvic tamponade. This is especially true for critically injured patients in extremis.

Angiography↗

PubMed2002

The timing of fracture treatment in polytrauma patients: relevance of damage control orthopedic surgery.

Information illustrating the benefits of fracture stabilization after multiple trauma has been gathering for almost a century. At the turn of the last century, the introduction of the Thomas splint clearly demonstrated the importance of skeletal stabilization in the management of these patients. The introduction of standardized surgical treatment for fractures in the early 1950s is considered today as the turning point in the care of the polytraumatized patient. With the knowledge acquired, the application of early operative fixation of fractures in severely injured patients in the 1980s has yielded to the concept of early total care of all fractures. Yet, in distinct patient subgroups with severe thoracic injuries and very high injury severity scores, this concept has been associated with adverse outcomes. Therefore, in a further era that began in the 1990s, a different approach has been favored for these subgroups. It recommends early (initial) temporary stabilization followed by secondary definitive osteosynthesis of major fractures in patients at high risk of developing systemic complications. In the last decade, attempts have been made to determine which patients benefit from early total care and which ones should undergo a secondary definitive approach. This manuscript provides a historical overview on the changing treatment of fractures and summarizes the evolution of "damage control orthopedic surgery."

Embolism, Fat↗