Prevention Of Collapse Research Articles

Progressive Collapse Resistance of Axially-Restrained Frame Beams

Twelve specimens representing reinforced concrete frame beams were tested to investigate their gravity load-carrying capacity against progressive collapse. In these tests, the beams within the frame subassemblies were restrained longitudinally against axial deformation. The tests indicated that the compressive arch action due to longitudinal restraint can significantly enhance the flexural strength of a beam subjected to vertical loads. The compressive arch action was observed to be a function offlexural reinforcement ratio and ratio of beam span to depth. The test results validated an analytical model that has considered the axial restraining effects on beam loading capacity. The application of compressive arch effect to the prevention of progressive collapse is discussed.

Prevention of Collapse of Community Health Care in the Teaching Hospital in Japan

Prevention of Collapse of Community Health Care in the Teaching Hospital in Japan

FIRE RESISTANCE OF JAPANESE TRADITIONAL TIMBER-FRAME SOIL INTERNAL WALLS EXPOSED TO BOTH-SIDES HEATING

Mechanical fire resistance of internal load bearing walls under both-sides heating is important for the prevention of collapse of a dwelling in a fire. Feasibility of the 45 minutes mechanical fire resistance with Japanese traditional timber-frame soil internal wall is studied for this purpose. The tests were initiated with intermediate scale specimens for the examination of the charring and internal temperature field of the column and then loaded tests under both-sides exposure were conducted on two 1-story tall bare-timber wall specimens. The tests suggest significant influence of the mortises of columns for horizontal timber bars on the buckling of walls. The conventional predictive method of the mechanical fire resistance of bare timber walls is then modified for the tested configuration.

Incorporating modeling uncertainties in the assessment of seismic collapse risk of buildings

The primary goal of seismic provisions in building codes is to protect life safety through the prevention of structural collapse. To evaluate the extent to which current and past building code provisions meet this objective, the authors have conducted detailed assessments of collapse risk of reinforced-concrete moment frame buildings, including both ‘ductile’ frames that conform to current building code requirements, and ‘non-ductile’ frames that are designed according to out-dated (pre-1975) building codes. Many aspects of the assessment process can have a significant impact on the evaluated collapse performance; this study focuses on methods of representing modeling parameter uncertainties in the collapse assessment process. Uncertainties in structural component strength, stiffness, deformation capacity, and cyclic deterioration are considered for non-ductile and ductile frame structures of varying heights. To practically incorporate these uncertainties in the face of the computationally intensive nonlinear response analyses needed to simulate collapse, the modeling uncertainties are assessed through a response surface, which describes the median collapse capacity as a function of the model random variables. The response surface is then used in conjunction with Monte Carlo methods to quantify the effect of these modeling uncertainties on the calculated collapse fragilities. Comparisons of the response surface based approach and a simpler approach, namely the first-order second-moment (FOSM) method, indicate that FOSM can lead to inaccurate results in some cases, particularly when the modeling uncertainties cause a shift in the prediction of the median collapse point. An alternate simplified procedure is proposed that combines aspects of the response surface and FOSM methods, providing an efficient yet accurate technique to characterize model uncertainties, accounting for the shift in median response. The methodology for incorporating uncertainties is presented here with emphasis on the collapse limit state, but is also appropriate for examining the effects of modeling uncertainties on other structural limit states.

Correction: Prevention of Hypovolemic Circulatory Collapse by IL-6 Activated Stat3

Correction: Prevention of Hypovolemic Circulatory Collapse by IL-6 Activated Stat3

Proximal junctional acute collapse cranial to multi-level lumbar fusion: a cost analysis of prophylactic vertebral augmentation

Background context Limited data are available regarding incidence of proximal junctional acute collapse after multilevel lumbar spine fusion. There are no data regarding the cost of prophylactic vertebral augmentation adjacent to long lumbar fusions compared with the costs of performing revision fusion surgery for patients suffering with this complication. Purpose To perform a cost analysis of prophylactic vertebral augmentation for prevention of proximal junctional acute collapse after multilevel lumbar fusion. Study design Retrospective chart review and cost analysis. Patient sample All female patients older than 60 years undergoing extended lumbar fusions were reviewed to establish the incidence of proximal junctional acute collapse. Outcome measures Cost estimates for two-level vertebroplasty, two-level kyphoplasty, and revision instrumented fusion were calculated using billing data and cost-to-charge ratios. Methods Cost comparisons of prophylactic vertebral augmentation versus extension of fusion for patients suffering from proximal junctional acute collapse were performed. Results Twenty-eight female patients older than 60 years underwent lumbar fusions from L5 or S1 extending to the thoracolumbar junction (T9–L2). Fifteen of the 28 patients had prophylactic vertebroplasty cranial to the fused segment. Proximal junctional acute collapse requiring revision surgery occurred in 2 of the 13 patients (15.3%) treated without prophylactic vertebroplasty. None of the 15 patients undergoing cement augmentation experienced this complication. Assuming a 15% decrease in the incidence of proximal junctional acute collapse, the estimated cost to prevent a single proximal junctional acute collapse was $46,240 using vertebroplasty and $82,172 using kyphoplasty. Inpatient costs associated with a revision instrumented fusion averaged $77,432. Conclusions Prophylactic vertebral augmentation for the prevention of proximal junctional acute collapse may be a cost effective intervention in elderly female patients undergoing extended lumbar fusions. Further efforts are needed to determine more precisely the incidence of proximal junctional acute collapse and the effects of various risk factors on increasing this incidence, as well as methods of prevention.

Myeloperoxidase suppresses apoptosis of human neutrophils

Myeloperoxidase (MPO), a heme protein abundantly expressed in the azurophilic granules in neutrophils mediates killing of bacteria and oxidative tissue injury. Since elevated plasma MPO levels and prolonged survival of neutrophils are characteristic features of inflammatory diseases, we studied the impact of MPO on neutrophil apoptosis. Culture of neutrophils with MPO at clinically relevant concentrations (10–160 nM) markedly enhanced neutrophil viability by suppressing apoptosis. These actions were prevented by an anti‐CD11b antibody, but not by 4‐aminobenzoic acid hydrazide, an inhibitor of the enzymatic activity of MPO. MPO evoked concurrent activation of the ERK and phosphatidylinositol 3‐kinase/Akt signaling pathways, leading to phosphorylation of Bad at Ser112 and Ser136, respectively. These led to prevention of collapse of mitochondrial transmembrane potential and cytochrome c release, resulting in decreased caspase‐3 activity. Consistently, pharmacological inhibition of either ERK or phosphatidylinositol 3‐kinase almost completely blocked the responses to MPO. MPO and the pan‐caspase inhibitor z‐VAD‐fmk (20 μM) did not produce additive suppression of neutrophil apoptosis. Our results identify MPO as a survival signal for neutrophils by delaying intrinsic neutrophil apoptosis and thus may contribute to amplification of the inflammatory response. (Supported by CIHR MOP‐64283).

Mechanisms underlying air aspiration in patients undergoing left atrial catheterization

Air embolism in patients undergoing percutaneous interventions requiring access to the left atrium (LA) represents a potentially fatal complication. Here we tested if a decline in LA pressures following sedation represents an important mechanistic link underlying air intrusion into the LA. Left atrial pressures were measured in 26 consecutive patients (49 +/- 14 years; 27% male), who underwent percutaneous atrial septal occlusion for persistent foramen ovale or secundum atrial septal defects. Patients either received sedation by propofol allowing for guidance by transesophageal echocardiography (n = 13) or underwent occluder implantation without sedation and under fluoroscopic control only (n = 13). Whereas mean expiratory LA pressures remained unchanged in either group, sedation provoked a marked decline in the mean inspiratory LA pressure as compared to non-sedated patients (Delta p 6.9 +/- 8.6 mm Hg vs. 0.1 +/- 1.2 mm Hg in nonsedated patients, P < 0.001). Ex vivo experiments evaluating the air-tightness of different sheaths in response to negative pressures revealed air aspiration at -13.4 +/- 1.2 mm Hg of suction in all cases, once a guide wire was inserted. Negative LA pressures in conjunction with air-leaking sheaths are identified as potentially important factors for air intrusion into the LA with the patient's sedation being a primary risk factor to lower LA pressure levels. The results advocate close monitoring of LA pressures during intervention, prevention of airway collapse and protection of LA sheaths from communication with the atmosphere, during procedures under sedation.

Prevention of Hypovolemic Circulatory Collapse by IL-6 Activated Stat3

Half of trauma deaths are attributable to hypovolemic circulatory collapse (HCC). We established a model of HCC in rats involving minor trauma plus severe hemorrhagic shock (HS). HCC in this model was accompanied by a 50% reduction in peak acceleration of aortic blood flow and cardiomyocyte apoptosis. HCC and apoptosis increased with increasing duration of hypotension. Apoptosis required resuscitation, which provided an opportunity to intervene therapeutically. Administration of IL-6 completely reversed HCC, prevented cardiac dysfunction and cardiomyocyte apoptosis, reduced mortality 5-fold and activated intracardiac signal transducer and activator of transcription (STAT) 3. Pre-treatment of rats with a selective inhibitor of Stat3, T40214, reduced the IL-6-mediated increase in cardiac Stat3 activity, blocked successful resuscitation by IL-6 and reversed IL-6-mediated protection from cardiac apoptosis. The hearts of mice deficient in the naturally occurring dominant negative isoform of Stat3, Stat3β, were completely resistant to HS-induced apoptosis. Microarray analysis of hearts focusing on apoptosis related genes revealed that expression of 29% of apoptosis related genes was altered in HS vs. sham rats. IL-6 treatment normalized the expression of these genes, while T40214 pretreatment prevented IL-6-mediated normalization. Thus, cardiac dysfunction, cardiomyocyte apoptosis and induction of apoptosis pathway genes are important components of HCC; IL-6 administration prevented HCC by blocking cardiomyocyte apoptosis and induction of apoptosis pathway genes via Stat3 and warrants further study as a resuscitation adjuvant for prevention of HCC and death in trauma patients.

Primary Posterior Fixation For Tuberculosis Of The Spine

Tuberculosis of the spine is a very frequent case in the practice of spine surgeons in the developing world, and is set to pose a challenge to the developed world in near future. Only anterior surgery seems to be falling short in potential for correction of the kyphotic deformity as well as of preventing gradual collapse later on. Posterior fixation has shown an excellent potential for correction of deformity and prevention of secondary collapse when combined with anterior reconstruction and fusion in cases of trauma and deformity, and its potential is now being tested worldwide for tuberculous spine. We treated 100 patients with tuberculosis of various spinal levels with different levels of neurological impairments with primary posterior corrective fixation and second stage anterior debridement, decompression and reconstruction and followed them up for an average of 41 months. We didn't face any graft related problems, could mobilize the patient immediate after the surgery and achieved solid fusion in all cases. We faced only 4 un-acceptable adverse events in these cases in form of infection (2), neurological injury (1) and non-fusion (1). The mean preoperative kyphotic angle was 36.6 degrees and correction of a mean of 10.375 degrees (36.6%) was maintained at final follow up of 41 months. We find that for cases of exudative stage tuberculosis of spine, primary posterior fixation and second stage anterior debridement and reconstruction provides good neurological decompression, early bony fusion and correction and/or prevention of deformity, allows early and better rehabilitation and is a recommendable strategy of surgical treatment for carefully selected patients.

Prediction of pre- and post-peak behavior of concrete-filled square steel tube columns under cyclic loads using fiber element method

The cyclic load–deformation relationships of columns in the post-peak region need to be investigated in the prevention of collapse of the buildings under earthquake excitation. This paper provides an efficient method of prediction of the pre- and post-peak hysteretic behavior of concrete-filled square steel tube columns subjected to a combination of constant axial load and cyclic lateral load. For this purpose, the simplified nonlinear fiber element method is used to obtain the uni-axial stress and strain relationship of materials in terms of the composite action between the steel tube and the concrete. The accuracy of the proposed computational technique is verified by comparing the results from this technique with existing experimental results, which are briefly reviewed in this paper.

Aspirin-Triggered Lipoxins Override the Apoptosis-Delaying Action of Serum Amyloid A in Human Neutrophils: A Novel Mechanism for Resolution of Inflammation

Elevated plasma levels of the acute-phase reactant serum amyloid A (SAA) have been used as a marker and predictor of inflammatory diseases. SAA regulates leukocyte activation; however, it is not known whether it also modulates neutrophil apoptosis, which is critical to the optimal expression and resolution of inflammation. Culture of human neutrophils with SAA (0.1-20 microg/ml) markedly prolonged neutrophil longevity by delaying constitutive apoptosis. SAA evoked concurrent activation of the ERK and PI3K/Akt signaling pathways, leading to phosphorylation of BAD at Ser(112) and Ser(136), respectively, and to prevention of collapse of mitochondrial transmembrane potential, cytochrome c release, and caspase-3 activation. These actions were abrogated by pharmacological inhibition of the formyl peptide receptor, ERK or PI3K. Furthermore, aspirin-triggered 15-epi-lipoxin A(4) (15-epi-LXA(4)) and its stable analog 15-epi-16-p-fluorophenoxy-LXA(4), which binds to the same receptor as SAA, effectively overrode the antiapoptosis signal from SAA even when neutrophils were treated with 15-epi-LXA(4) at either 1 or 4 h postculture with SAA. 15-Epi-LXA(4) itself did not affect neutrophil survival and apoptosis. Our results indicate that SAA at clinically relevant concentrations promotes neutrophil survival by suppressing the apoptotic machinery, an effect that can be opposed by 15-epi-LXA(4). The opposing actions of SAA and aspirin-triggered 15-epi-LXA(4) may contribute to the local regulation of exacerbation and resolution of inflammation, respectively.

Preventing Disproportionate Collapse

“Disproportionate collapse” is structural collapse disproportionate to the cause; it is often, though not always, progressive, where “progressive collapse” is the collapse of all or a large part of a structure precipitated by damage or failure of a relatively small part of it. There have been many attempts to develop design guidelines and criteria that would reduce or eliminate the susceptibility of buildings to this form of failure. In recent years, the particular focus has been on the prevention of progressive collapse due to deliberate attack. The present study suggests, however, that these guidelines and criteria may be of limited value. Arguably the most important deficiency in the state of the art of design to prevent disproportionate or progressive collapse is uncertainty about the design event: We have the technology now to design for almost anything, but most recent building failures due to explosions and terrorist attacks have involved insults to the building not anticipated in design guidelines and criteria.

Minimally Invasive Techniques for the Treatment of Osteoporotic Vertebral Fractures

Osteoporotic vertebral compression fractures are a leading cause of disability and morbidity in the elderly. The consequences of these fractures include pain, progressive vertebral collapse with resultant spinal kyphosis, and systemic manifestations. Nonsurgical measures have proved unsuccessful in a portion of this population and for this group, minimally invasive vertebral augmentation can be beneficial. Vertebroplasty is designed to address vertebral fracture pain. It involves percutaneous injection of polymethylmethacrylate (PMMA) directly into a fractured vertebral body with the goals of pain relief and prevention of further collapse of the fractured vertebra. Kyphoplasty is designed to address the kyphotic deformity as well as the fracture pain. It involves the percutaneous insertion of an inflatable bone tamp into a fractured vertebral body. Bone tamp inflation works to elevate the end plates and create a cavity to be filled with PMMA with the goals of pain relief, restoration of vertebral body height, and reduced kyphotic deformity. Optimizing surgical technique can improve outcomes and decrease complication rates, and decrease radiation exposure to the patient and surgical team. Obtaining a biopsy prior to cement injection has proved efficacious and may result in the diagnosis of occult pathology underlying a seemingly routine vertebral fracture. As competence and surgical success are acquired, the indications will continue to expand to encompass more challenging pathologies. Recently, vertebral augmentation during spinal decompression and instrumented fusion for burst fracture with neurologic insult has been reported to be successful.

Cowardly lions: missed opportunities to prevent deadly conflict and state collapse

What would have happened had the road not taken been the chosen action in past conflict interventions? What can we learn from a close look at alternatives that were not selected? Drawing on six detailed case studies (the Balkans, Haiti, Lebanon, Liberia, Somalia, and Zaire/Congo), I. William Zartman identifies a series of missed options that arguably would have provided feasible and better outcomes for the reduction of violent conflict and the prevention of state collapse. Zartman specifies potential solutions within the entire trajectory of each conflict, considering in each instance why the indicated decisions were not taken. The principles and mechanisms that he develops in the course of his analysis have profound implications for the actions of the international community in preventing conflicts from escalating to violence, and for managing violent situations when they do occur.

Titanium Membranes in Prevention of Alveolar Collapse After Tooth Extraction

The resorption of alveolar bone following tooth extraction results in a narrowing and shortening of the residual ridge, which leads to esthetic and restorative problems, and reduces the bone volume available for implant therapy. The aim of this study was to evaluate the prevention of alveolar collapse after tooth extraction, using titanium membrane (Frios Boneshield; DENTSPLY Friadent, Mannheim, Germany), associated (or not) with autologous bone graft. A total of 10 nonsmoking healthy subjects, ranging from 35 to 60 years old, were selected for this study. Each patient had a minimum of 2 uni-radicular periodontally hopeless teeth, which were scheduled for extraction. After the procedure, 2 titanium pins were fixed on the vestibular bone surfaces that were used as references for the initial measures (depth, width, and height) of the socket. Of the sockets,1 was randomly chosen to be filled with autologous bone graft (test) removed from superior maxillary tuber, and the other one did not receive the graft (control). A titanium membrane was adapted and fixed, covering the sockets, which remained for at least 10 weeks. After a 6-month healing, the final measures were performed. There was exposure of the membrane in 5 of the 10 treated subjects. Average bone filling (+/-standard deviation) among the 10 subjects was 8.80 +/- 2.93 mm (range 4-13) in the control group and 8.40 +/- 3.35 mm (range 4-13) in the test group. Average bone loss in width in both group was 1.40 +/- 1.97 mm (range -4-1) in the control group and 1.40 +/- 0.98 mm (range -4-0) in the test group. There was no significant statistical difference between groups considering the evaluated standards. The use of titanium membrane, alone or in association with autogenous bone, favored the prevention of alveolar ridge after tooth extraction. This membrane seems to be a possible and safe alternative to other nonresorbable membranes when the prevention of alveolar ridge resorption is the objective.

Pamidronate Treatment of Steroid Associated Osteonecrosis in Young Patients Treated for Acute Lymphoblastic Leukaemia - Two-Year Outcomes

To assess outcomes of young patients with osteonecrosis (ON) treated with pamidronate in terms of relief of pain, prevention of progress and bony collapse of involved area. A non-randomised interventional study in six patients with a history of acute lymphoblastic leukaemia (ALL) for which treatment protocols included long-term, high dose use of glucocorticoids. Subsequent development of ON was treated with a bisphosphonate (pamidronate) for 2 years. Mobility and pain control were assessed regularly with MRI and X-ray of affected areas at 0, 12 and 24 months. Reduction in pain was reported in four of six patients in the first year with increased mobility. Two patients who had radiological evidence of joint destruction prior to treatment and when continued on corticosteroids reported no improvement in pain or mobility. In the second year, patients who started treatment in the first few months after diagnosis were stable while patients who had treatment initiated later deteriorated but had less pain than prior to treatment with pamidronate. MRIs of affected areas were completely unchanged over 2 years. X-rays revealed no new bony collapse in four of six patients after 12 months of treatment. However, three of six patients continued to undergo extensive collapse of femoral heads (one at 12 months, two at 24 months) and all these required urgent hip replacement. Pamidronate treatment has a palliative effect in control of pain and may delay the natural history of bony collapse in the acute phase of ON, especially in early treated patients, but does not prevent late bone collapse and joint destruction in corticosteroid treated patients with ALL. Larger studies are needed to provide evidence as to whether bisphosphonate is indicated for treatment of ON for patients using corticosteroids.

Vascularized Compared with Nonvascularized Fibular Grafts for Large Osteonecrotic Lesions of the Femoral Head

Many authors have reported good results with the use of vascularized fibular grafts to treat large osteonecrotic lesions of the femoral head. To our knowledge, there have been no prospective case-controlled studies comparing the effectiveness of vascularized fibular grafting with that of nonvascularized fibular grafting for the prevention of progression and collapse of the lesion. Nineteen patients (twenty-three hips) with a large osteonecrotic lesion of the femoral head (Stage IIC in ten hips, Stage IIIC in two, and Stage IVC in eleven, according to the classification system of Steinberg et al.) underwent vascularized fibular grafting. This group was retrospectively matched according to the etiology, stage, and size of the lesion to a group of nineteen patients (twenty-three hips) who underwent nonvascularized fibular grafting during the same time period. A prospective case-controlled study of the two groups, with a mean duration of follow-up of four years, was then performed. The mean Harris hip score improved for 70% of the hips treated with a vascularized graft and 35% of the hips treated with a nonvascularized graft (p < 0.05). At the time of the final follow-up, nine of the ten hips with a Stage-IIC lesion treated with a vascularized fibular graft had not collapsed whereas seven of the thirteen hips with a larger lesion (Stage IIIC or IVC) had collapsed. Three hips (13%) were converted to a total hip replacement. The mean dome depression measured 2.8 mm. In the group treated with a nonvascularized graft, five of the ten Stage-IIC hips had not collapsed and eleven of the thirteen hips with a larger lesion had collapsed. Five (22%) of the hips were converted to a total hip replacement. The mean dome depression measured 4.3 mm. The rates of radiographic progression and collapse were significantly lower and the mean dome depression was significantly less in the group treated with a vascularized fibular graft (p < 0.05). Vascularized fibular grafting was associated with better clinical results and was more effective than nonvascularized fibular grafting for the prevention of collapse of the femoral head in a matched population with a Steinberg Stage-IIC or larger osteonecrotic lesion. The results of vascularized grafting were best when the procedure was used to treat precollapse lesions (Steinberg Stage IIC).

VASCULARIZED COMPARED WITH NONVASCULARIZED FIBULAR GRAFTS FOR LARGE OSTEONECROTIC LESIONS OF THE FEMORAL HEAD

Background: Many authors have reported good results with the use of vascularized fibular grafts to treat large osteonecrotic lesions of the femoral head. To our knowledge, there have been no prospective case-controlled studies comparing the effectiveness of vascularized fibular grafting with that of nonvascularized fibular grafting for the prevention of progression and collapse of the lesion. Methods: Nineteen patients (twenty-three hips) with a large osteonecrotic lesion of the femoral head (Stage IIC in ten hips, Stage IIIC in two, and Stage IVC in eleven, according to the classification system of Steinberg et al.) underwent vascularized fibular grafting. This group was retrospectively matched according to the etiology, stage, and size of the lesion to a group of nineteen patients (twenty-three hips) who underwent nonvascularized fibular grafting during the same time period. A prospective case-controlled study of the two groups, with a mean duration of follow-up of four years, was then performed. Results: The mean Harris hip score improved for 70% of the hips treated with a vascularized graft and 35% of the hips treated with a nonvascularized graft (p < 0.05). At the time of the final follow-up, nine of the ten hips with a Stage-IIC lesion treated with a vascularized fibular graft had not collapsed whereas seven of the thirteen hips with a larger lesion (Stage IIIC or IVC) had collapsed. Three hips (13%) were converted to a total hip replacement. The mean dome depression measured 2.8 mm. In the group treated with a nonvascularized graft, five of the ten Stage-IIC hips had not collapsed and eleven of the thirteen hips with a larger lesion had collapsed. Five (22%) of the hips were converted to a total hip replacement. The mean dome depression measured 4.3 mm. The rates of radiographic progression and collapse were significantly lower and the mean dome depression was significantly less in the group treated with a vascularized fibular graft (p < 0.05). Conclusions: Vascularized fibular grafting was associated with better clinical results and was more effective than nonvascularized fibular grafting for the prevention of collapse of the femoral head in a matched population with a Steinberg Stage-IIC or larger osteonecrotic lesion. The results of vascularized grafting were best when the procedure was used to treat precollapse lesions (Steinberg Stage IIC). Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Maternal collapse

This review will summarize the latest publications on the causes, prevention and treatment of maternal collapse during pregnancy and the postpartum period. It will also explore some future trends particularly in the area of education and team working. Active management of the third stage of labour has been shown to decrease the incidence of postpartum haemorrhage. Inadequate or prolonged resuscitation following major postpartum haemorrhage can lead to myocardial damage. Guidelines that are followed and the use of drills and simulators may increase effective team working and lead to earlier recognition and treatment of maternal collapse. Some cases of amniotic fluid embolism resemble anaphylaxis and should be treated as such. Important evidence-based guidelines on the management of antithrombolytic prophylaxis and the management of pulmonary embolism have recently been published, which should help clinicians clarify their medical care plans. New resuscitation guidelines in the UK will probably mean that all healthcare workers (including obstetricians and midwives) will need appropriate training every year. Understanding the causes of maternal collapse, its early recognition and prompt resuscitation should decrease both maternal and fetal morbidity and mortality. There is increasing evidence that effective preventative measures and improved multidisciplinary team working may have an important impact on maternal and fetal well-being.