Secondary Peritonitis and Intra-Abdominal Sepsis: An Increasingly Global Disease in Search of Better Systemic Therapies

Secondary peritonitis and intra-abdominal sepsis are a global health problem. The life-threatening systemic insult that results from intra-abdominal sepsis has been extensively studied and remains somewhat poorly understood. While local surgical therapy for perforation of the abdominal viscera is an age-old therapy, systemic therapies to control the subsequent systemic inflammatory response are scarce. Advancements in critical care have led to improved outcomes in secondary peritonitis. The understanding of the effect of secondary peritonitis on the human microbiome is an evolving field and has yielded potential therapeutic targets. This review of secondary peritonitis discusses the history, classification, pathophysiology, diagnosis, treatment, and future directions of the management of secondary peritonitis. Ongoing clinical studies in the treatment of secondary peritonitis and the open abdomen are discussed.

Proceedings of resources for optimal care of acute care and emergency surgery consensus summit Donegal Ireland

BACKGROUND

Opportunities to improve emergency surgery outcomes exist through guided better practice and reduced variability. Few attempts have been made to define optimal care in emergency surgery, and few clinically derived key performance indicators (KPIs) have been published. A summit was therefore convened to look at resources for optimal care of emergency surgery. The aim of the Donegal Summit was to set a platform in place to develop guidelines and KPIs in emergency surgery.

METHODS

The project had multidisciplinary global involvement in producing consensus statements regarding emergency surgery care in key areas, and to assess feasibility of producing KPIs that could be used to monitor process and outcome of care in the future.

RESULTS

Forty-four key opinion leaders in emergency surgery, across 7 disciplines from 17 countries, composed evidence-based position papers on 14 key areas of emergency surgery and 112 KPIs in 20 acute conditions or emergency systems.

CONCLUSIONS

The summit was successful in achieving position papers and KPIs in emergency surgery. While position papers were limited by non-graded evidence and non-validated KPIs, the process set a foundation for the future advancement of emergency surgery.

Erratum to: The management of intra-abdominal infections from a global perspective: 2017 WSES guidelines for management of intra-abdominal infections

[This corrects the article DOI: 10.1186/s13017-017-0141-6.].

Erratum to: Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

[This corrects the article DOI: 10.1186/s13017-016-0089-y.].

Intra-Abdominal Hypertension and Abdominal Compartment Syndrome after Abdominal Wall Reconstruction: Quaternary Syndromes?

Background and Aims:

Reconstruction with reconstitution of the container function of the abdominal compartment is increasingly being performed in patients with massive ventral hernia previously deemed inoperable. This situation places patients at great risk of severe intra-abdominal hypertension and abdominal compartment syndrome if organ failure ensues. Intra-abdominal hypertension and especially abdominal compartment syndrome may be devastating systemic complications with systematic and progressive organ failure and death. We thus reviewed the pathophysiology and reported clinical experiences with abnormalities of intra-abdominal pressure in the context of abdominal wall reconstruction.

Material and Methods:

Bibliographic databases (1950–2015), websites, textbooks, and the bibliographies of previously recovered articles for reports or data relating to intra-abdominal pressure, intra-abdominal hypertension, and the abdominal compartment syndrome in relation to ventral, incisional, or abdominal hernia repair or abdominal wall reconstruction.

Results:

Surgeons should thus consider and carefully measure intra-abdominal pressure and its resultant effects on respiratory parameters and function during abdominal wall reconstruction. The intra-abdominal pressure post-operatively will be a result of the new intra-peritoneal volume and the abdominal wall compliance. Strategies surgeons may utilize to ameliorate intra-abdominal pressure rise after abdominal wall reconstruction including temporizing paralysis of the musculature either temporarily or semi-permanently, pre-operative progressive pneumoperitoneum, permanently removing visceral contents, or surgically releasing the musculature to increase the abdominal container volume. In patients without complicating shock and inflammation, and in whom the abdominal wall anatomy has been so functionally adapted to maximize compliance, intra-abdominal hypertension may be transient and tolerable.

Conclusions:

Intra-abdominal hypertension/abdominal compartment syndrome in the specific setting of abdominal wall reconstruction without other complication may be considered as a quaternary situation considering the classification nomenclature of the Abdominal Compartment Society. Greater awareness of intra-abdominal pressure in abdominal wall reconstruction is required and ongoing study of these concerns is required.

Amended Classification of the Open Abdomen

BACKGROUND

In 2009, a classification system for the open abdomen was introduced. The aim of such a classification is to aid the (1) description of the patient's clinical course; (2) standardization of clinical guidelines for guiding open abdomen management; and (3) facilitation of comparisons between studies and heterogeneous patient populations, thus serving as an aid in clinical research.

METHODS

As part of the revision of the definitions and clinical guidelines performed by the World Society of the Abdominal Compartment Syndrome, this 2009 classification system was amended following a review of experiences in teaching and research and published as part of updated consensus statements and clinical practice guidelines in 2013. Among 29 articles citing the 2009 classification system, nine were cohort studies. They were reviewed as part of the classification revision process. A total of 542 patients (mean: 60, range: 9-160) had been classified. Two problems with the previous classification system were identified: the definition of enteroatmospheric fistulae, and that an enteroatmospheric fistula was graded less severe than a frozen abdomen.

RESULTS

The following amended classification was proposed: Grade 1, without adherence between bowel and abdominal wall or fixity of the abdominal wall (lateralization), subdivided as follows: 1A, clean; 1B, contaminated; and 1C, with enteric leak. An enteric leak controlled by closure, exteriorization into a stoma, or a permanent enterocutaneous fistula is considered clean. Grade 2, developing fixation, subdivided as follows: 2A, clean; 2B, contaminated; and 2C, with enteric leak. Grade 3, frozen abdomen, subdivided as follows: 3A clean and 3B contaminated. Grade 4, an established enteroatmospheric fistula, is defined as a permanent enteric leak into the open abdomen, associated with granulation tissue.

CONCLUSIONS

The authors believe that, with these changes, the requirements on a functional and dynamic classification system, useful in both research and training, will be fulfilled. We encourage future investigators to apply the system and report on its merits and constraints.

The secondary and recurrent abdominal compartment syndrome

INTRODUCTION

The Secondary Abdominal Compartment Syndrome (SACS) refers to cases of the ACS that do not originate from the abdominopelvic region. With greater awareness of the physiologic consequences of raised intra-abdominal hypertension (IAH), cases of the SACS are being increasingly described. The prior treatment or the presence of a partially open abdomen does not preclude the ACS if the abdomen and viscera continue to swell or the clinician is not vigilant in monitoring intra-abdominal pressure (IAP). Such recurrent cases (RACS) have been defined as those which redevelop following the previous medical or surgical treatment of primary or SACS. Although there has been a diverse range of etiologies implicated, these cases seem to be linked by the common occurrence of severe shock requiring aggressive fluid resuscitation. The aim of this paper is to thus to review the historical background, awareness, definitions, pathophysiological implications and treatment options for SACS and RACS.

METHODS

This review will focus on the available literature regarding SACS and RACS. A Medline and Pubmed search was performed using the keywords; secondary abdominal compartment syndrome AND secondary AND tertiary AND recurrent AND abdominal compartment syndrome AND intra-abdominal pressure AND intra-abdominal hypertension. Bibliographies of recovered papers were hand-searched for other appropriate references. The resulting references were included in the current review on the basis of relevance and scientific merit Results: There has been remarkably little specific study of these entities outside of specific groups such as those injured by thermal or traumatic injury. The epidemiology, risk factors for, treatment of and most importantly, strategies for prevention all remain scientifically unknown and therefore based on opinion. Notable, although small, studies suggest that specific resuscitation practices may avert these conditions.

CONCLUSIONS

ACS can occur in any patient who is critically ill and subject to visceral and somatic swelling, regardless of whether the inciting pathology is extra-abdominal. The ACS may also reoccur with recurrent shock and swelling even if previous therapies had partially addressed IAH. Therefore IAP measurements should be considered a routine monitoring for the critically ill, especially those subjected to shock and requiring a subsequent resuscitation. Much further study is required to understand the differences in etiology, diagnosis, pathophysiology, and treatment for all cases of the ACS.

A systematic review and individual patient data meta-analysis on intra-abdominal hypertension in critically ill patients: the wake-up project. World initiative on Abdominal Hypertension Epidemiology, a Unifying Project (WAKE-Up!)

Intra-abdominal hypertension (IAH), defined as a pathologically increase in intraabdominal pressure, is commonly found in critically ill patients. While IAH has been associated with several abdominal as well as extra-abdominal conditions, few studies have examined the occurrence of IAH in relation to mortality. The aim of this paper was to evaluate the prognostic role of IAH and its risk factors at admission in critically ill patients across a wide range of settings and countries. An individual patient meta-analysis of all available data and a systematic review of published (in full or as abstract) medical databases and studies between 1996 and June 2012 were performed. The search was limited to "clinical trials" and "randomized controlled trials", "adults", using the terms "intra-abdominal pressure", "intraabdominal hypertension" combined with any of the terms "outcome" and "mortality". All together data on 2707 patients, representing 21 centers from 11 countries was obtained. Data on 1038 patients were not analysed because of the following exclusion criteria: no IAP value on admission (N.=712), absence of information on ICU outcome (N.=195), age <18 or >95 years (N.=131). Data from 1669 individual patients (19 centers from 9 countries) were analyzed in the meta-analysis. Presence of IAH was defined as a sustained increase in IAP equal to or above 12 mmHg. At admission the mean overall IAP was 9.9±5.0 mmHg, with 463 patients (27.7%) presenting IAH with a mean IAP of 16.3±3.4 mmHg. The only independent predictors for IAH were SOFA score and fluid balance on the day of admission. Five hundred thirteen patients (30.8%) died in intensive care. The independent predictors for intensive care mortality were IAH, SAPS II score, SOFA score and admission category. This systematic review and individual patient data meta-analysis shows that IAH is frequently present in critically ill patients and it is an independent predictor for mortality.

A Systematic Review And Individual Patient Data Meta-Analysis On Intraabdominal Hypertension In Critically Ill Patients: The Wake-Up Project World Initiative on Abdominal Hypertension Epidemiology, a Unifying Project (WAKE-Up!)

Background: Intraabdominal hypertension (IAH), defined as a pathologically increase in intraabdominal pressure, is commonly found in critically ill patients. While IAH has been associated with several abdominal as well as extra-abdominal conditions, few studies have examined the occurrence of IAH in relation to mortality. Objective: To evaluate the prognostic role of IAH and its risk factors at admission in critically ill patients across a wide range of settings and countries. Data sources: An individual patient meta-analysis of all available data and a systematic review of published (in full or as abstract) medical databases and studies between 1996 and June 2012 were performed. The search was limited to "clinical trials" and "randomized controlled trials", "adults", using the terms "intraabdominal pressure", "intraabdominal hypertension" combined with any of the terms "outcome" and "mortality". All together data on 2707 patients, representing 21 centers from 11 countries was obtained. Data on 1038 patients were not analysed because of the following exclusion criteria: no IAP value on admission (n=712), absence of information on ICU outcome (n=195), age <18 or > 95 years (n=131). Results: Data from 1669 individual patients (19 centers from 9 countries) were analyzed in the meta-analysis. Presence of IAH was defined as a sustained increase in IAP equal to or above 12 mmHg. At admission the mean overall IAP was 9.9±5.0 mmHg, with 463 patients (27.7%) presenting IAH with a mean IAP of 16.3±3.4 mmHg. The only independent predictors for IAH were SOFA score and fluid balance on the day of admission. Five hundred thirteen patients (30.8%) died in intensive care. The independent predictors for intensive care mortality were IAH, SAPS II score, SOFA score and admission category. Conclusions: This systematic review and individual patient data meta-analysis shows that IAH is frequently present in critically ill patients and it is an independent predictor for mortality.

Measurement of intra-abdominal pressure in term pregnancy: a pilot study

BACKGROUND

This study was conducted to assess the feasibility of measuring intra-abdominal pressure in term parturients under spinal anesthesia.

METHODS

Intra-abdominal pressure was measured in 20 term parturients after spinal anesthesia for elective caesarean section. Pressure was measured in the supine and 10° left lateral tilt positions with a constant reference point throughout.

RESULTS

Intra-abdominal pressure measurement was feasible and safe to perform. Pressure was significantly lower in the left lateral tilt position than supine (10.9 mmHg ± 4.67 vs. 8.9 mmHg ± 4.87, P=0.0004). The range of intra-abdominal pressure in pregnancy was wide, from 2 to 20 mmHg, with >25% of patients resting with pressures above 12 mmHg in both positions.

CONCLUSIONS

Under spinal anesthesia, intra-abdominal pressure in >25% of healthy term parturients was > 12 mmHg, which has conventionally been defined as intra-abdominal hypertension. The intra-abdominal pressure in term pregnancy should be performed in the left lateral tilt position to avoid falsely elevated pressure measurements.

Recommendations for research from the International Conference of Experts on Intra-abdominal Hypertension and Abdominal Compartment Syndrome

OBJECTIVE

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) have been increasingly recognized in the critically ill over the past decade, and the number of published studies has exploded in recent years. Interpretation of the results and comparison of these studies is difficult, because of incomplete and inconsistent reporting of data and statistics.

DESIGN

An international consensus group of multidisciplinary specialists convened at the third World Congress on Abdominal Compartment Syndrome to develop recommendations for research related to the diagnosis and management of IAH and ACS.

METHODS

Prior to the conference the authors developed a blueprint for consensus definitions and treatment guidelines which were refined both during and after the conference.

RESULTS

Three major types of studies were identified (measurement techniques, epidemiology, and interventions), each with different needs regarding methodology, reporting of data and statistical analysis.

CONCLUSIONS

These recommendations are proposed to guide clinical research in the field of IAH and ACS.

Snowboarding injuries: a review of the literature and an analysis of the potential use of portable ultrasound for mountainside diagnostics

Snowboarding has become a popular recreational and professional sport. Participants suffer a variety of injuries, especially of the extremities, that require medical evaluation. This article reviews the reported injuries to both leisure and elite athletes. To many, an injured extremity requires travel to a medical facility for accurate evaluation. Musculoskeletal ultrasound is an accurate and portable technology that can be used for real time, mountainside diagnoses of these injuries.

Comparison of intermittent and continuous intra-abdominal pressure monitoring using an in vitro model

INTRODUCTION

Intra-abdominal pressure (IAP) is increasingly being considered as an important physiologic parameter to be measured in critically ill patients. Traditional methods of monitoring IAP rely on intermittent IAP (IIAP) measurements using indwelling bladder catheters. Recently, a method of continuous IAP (CIAP) monitoring has been developed using a three-way bladder catheter. This study evaluates the reliability of IIAP and CIAP measurement techniques using an in vitro model.

METHODS

An in vitro model of the abdomen was constructed using a 50 l container with a 100 ml infusion bag at the base to simulate a bladder. A three-way catheter tip was centered within the infusion bag filled with 50 ml saline. To simulate IAP the container was filled with water at 5 cm H(2)O increments from 10 to 25 cm H(2)O. Pressures were recorded by observers from a bedside monitor interfaced with a three-way Foley catheter using alternating intermittent and continuous techniques. Each subject was blinded to the known pressure values. Descriptive statistics and a generalised estimating equation (GEE) was used to describe the relationship of IIAP and CIAP to known pressures.

RESULTS

One hundred and thirty-two (132) observations were made by 20 subjects for both IIAP and CIAP estimates. In 45.5% of IIAP measures, the estimate was correct, and it was never more than 1 cm H(2)O different from the actual. Similarly, in 38.6% of CIAP measures, the estimate was correct, and was never more than 2 cm H(2)O from the actual. The GEE regression coefficients comparing known pressures with IIAP and CIAP were 1.007 and 0.976 respectively. The minimum and maximum pressure deviations never exceeded more than 1.3 cm H(2)O from the actual.

CONCLUSION

Intermittent IAP and CIAP are both reliable and reproducible methods to measure IAP in an in vitro model. There exists a direct and significant association between both measurements and the actual value. Neither measure was shown to be superior.

The secondary and recurrent abdominal compartment syndrome

INTRODUCTION

The Secondary Abdominal Compartment Syndrome (SACS) refers to cases of the ACS that do not originate from the abdomino-pelvic region. With greater awareness of the physiologic consequences of raised intra-abdominal hypertension (IAH), cases of the SACS are being increasingly described. The prior treatment or the presence of a partially open abdomen does not preclude the ACS if the abdomen and viscera continue to swell or the clinician is not vigilant in monitoring intra-abdominal pressure (lAP). Such recurrent cases (RACS) have been defined as those which redevelop following the previous medical or surgical treatment of primary or SACS. Although there has been a diverse range of etiologies implicated, these cases seem to be linked by the common occurrence of severe shock requiring aggressive fluid resuscitation. The aim of this paper is to thus to review the historical background, awareness, definitions, pathophysiological implications and treatment options for SACS and RACS.

METHODS

This review will focus on the available literature regarding SACS and RACS. A Medline and Pubmed search was performed using the keywords; secondary abdominal compartment syndrome AND secondary AND tertiary AND recurrent AND abdominal compartment syndrome AND intra-abdominal pressureAND intra-abdominal hypertension. Bibliographies of recovered papers were hand-searched for other appropriate references. The resulting references were included in the current review on the basis of relevance and scientific merit

RESULTS

There has been remarkably little specific study of these entities outside of specific groups such as those injured by thermal or traumatic injury. The epidemiology, risk factors for, treatment of and most importantly, strategies for prevention all remain scientifically unknown and therefore based on opinion. Notable, although small, studies suggest that specific resuscitation practices may avert these conditions.

CONCLUSIONS

ACS can occur in any patient who is critically ill and subject to visceral and somatic swelling, regardless of whether the inciting pathology is extra-abdominal. The ACS may also reoccur with recurrent shock and swelling even if previous therapies had partially addressed IAH. Therefore IAP measurements should be considered a routine monitoring for the critically ill, especially those subjected to shock and requiring a subsequent resuscitation. Much further study is required to understand the differences in etiology, diagnosis, pathophysiology, and treatment for all cases of the ACS.

Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST)

BACKGROUND

Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role.

METHODS

Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up.

RESULTS

There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3).

CONCLUSION

EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Intensive-care-unit-acquired bloodstream infections in a regional critically ill population

Bloodstream infection (BSI) is a serious complication of critical illness but it is uncertain whether acquisition of BSI in the intensive care unit (ICU) increases the risk of death. A study was conducted among all Calgary health region (population approximately 1 million) adults admitted to ICUs for 48 h or more during a three-year period to investigate the occurrence, microbiology and risk factors for developing an ICU-acquired BSI and to determine whether these infections independently predict mortality. One hundred and ninety-nine ICU-acquired BSI episodes occurred during 4933 ICU admissions for a cumulative incidence of 4% and an incidence density of 5.4 per 1000 ICU days. The most common isolates were Staphylococcus aureus (18%), coagulase-negative staphylococci (11%), and Enterococcus faecalis (8%); 12% of infections were due to antimicrobial-resistant bacteria. Admission to the regional neurosurgery/trauma ICU [odds ratio (OR) 2.86; 95% confidence interval (CI) 2.10-3.90] and increasing Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR 1.05 per point, 95% CI 1.03-1.07) were associated with higher risk, whereas a surgical diagnosis (OR 0.69; 95% CI 0.52-0.93) was associated with lower risk of developing ICU-acquired BSI in logistic regression analysis. The crude in-hospital death rate was 45% for patients with ICU-acquired BSI compared with 21% for those without (P < 0.0001) Development of an ICU-acquired BSI was an independent risk factor for death (OR 1.79; 95% CI 1.3-2.5) and increases the risk of dying from critical illness.

Laparoscopic appendectomy for complicated appendicitis: an evaluation of postoperative factors

BACKGROUND

The use of laparoscopic appendectomy for complicated appendicitis is controversial. Outcomes were compared between patients who had complicated appendicitis and those who had uncomplicated appendicitis.

METHODS

Consecutive patients (n = 304) who underwent laparoscopic appendectomy were studied. Patients undergoing open appendectomies also were compared ad hoc. Analgesia use, length of hospital stay, return to activity, and complication rates for the complicated and uncomplicated appendicitis subgroups were analyzed.

RESULTS

Complete data were available for 243 patients (80%). There were no statistical differences in characteristics between the two groups. The operating times, lengths of hospital stay, return to activity times, complication rates, and analgesia requirements, both in the hospital and after discharge, were equivalent. A greater number of complicated cases required open conversion. Considering those with complicated appendicitis, the open group had a significantly longer mean hospital stay and a higher complication rate than those treated with laparoscopic appendectomy.

CONCLUSIONS

The minimally invasive laparoscopic technique is safe and efficacious. It should be the initial procedure of choice for most cases of complicated appendicitis.

Percutaneous aspiration of fluid for management of peritonitis in space

BACKGROUND

As a medical emergency that can affect even well-screened, healthy individuals, peritonitis developing during a long-duration space exploration mission may dictate deviation from traditional clinical practice due to the absence of otherwise indicated surgical capabilities. Medical management can treat many intra-abdominal processes, but treatment failures are inevitable. In these circumstances, percutaneous aspiration under sonographic guidance could provide a "rescue" strategy.

HYPOTHESIS

Sonographically guided percutaneous aspiration of intra-peritoneal fluid can be performed in microgravity.

METHODS

Investigations were conducted in the microgravity environment of NASA's KC-135 research aircraft (0 G). The subjects were anesthetized female Yorkshire pigs weighing 50 kg. The procedures were rehearsed in a terrestrial animal lab (1 G). Colored saline (500 mL) was introduced through an intra-peritoneal catheter during flight. A high-definition ultrasound system (HDI-5000, ATL, Bothell, WA) was used to guide a 16-gauge needle into the peritoneal cavity to aspirate fluid.

RESULTS

Intra-peritoneal fluid collections were easily identified, distinct from surrounding viscera, and on occasion became more obvious during weightless conditions. Subjectively, with adequate restraint of the subject and operators, the procedure was no more demanding than during the 1-G rehearsals.

CONCLUSIONS

Sonographically guided percutaneous aspiration of intra-peritoneal fluid collections is feasible in weightlessness. Treatment of intra-abdominal inflammatory conditions in spaceflight might rely on pharmacological options, backed by sonographically guided percutaneous aspiration for the "rescue" of treatment failures. While this risk mitigation strategy cannot guarantee success, it may be the most practical option given severe resource limitations.

Endoscopic surgery in weightlessness: the investigation of basic principles for surgery in space

BACKGROUND

Performing a surgical procedure in weightlessness, also called 0-gravity (0-g), has been shown to be no more difficult than in a 1-g environment if the requirements for the restraint of the patient, operator, surgical hardware, are observed. The performance of laparoscopic and thorascopic procedures in weightlessness, if feasible, would offer several advantages over the performance of an open operation. Concerns about the feasibility of performing minimally invasive procedures in weightlessness have included impaired visualization from the absence of gravitational retraction of the bowel (laparoscopy) or thoracic organs (thoracoscopy) as well as obstruction and interference from floating debris such as blood, pus, and irrigation fluid. The purpose of this study was to determine the feasibility of performing laparoscopic and thorascopic procedures and the degree of impaired surgical endoscopic visualization in weightlessness.

METHODS

From 1993 to 2000, laparoscopic and thorascopic procedures were performed on 10 anesthetized adult pigs weighing approximately 50 kg in the National Aeronautics and Space Administration (NASA) Microgravity Program using a modified KC-135 airplane. The parabolic simulation system for advanced life support was used in this project, and 20 to 40 parabolas were used for laparoscopic or thorascopic investigation, each containing approximately 30 s of 0-g alternating with 2-g pullouts. The animal model was restrained in the supine position on a floor-level Crew Medical Restraint System, and the abdominal cavity was insufflated with carbon dioxide. The intraabdominal and intrathoracic anatomy was visualized in the 1-g, 0-g, and 2-g periods of parabolic flight. Bleeding was created in the animals, and the behavior of the blood in the abdominal and thoracic cavities was observed. In the thoracic cavity, gas insufflation and mechanical retraction was used at times unilaterally to decrease pulmonary ventilation enough to increase the thoracic domain.

RESULTS

Visualization was improved in laparoscopy, from tethering of the bowel by the elastic mesentery, and from the strong tendency for debris and blood to adhere to the abdominal wall because of surface tension forces. The lack of adequate thoracic domain made thorascopy more difficult. Fluid in the thoracic cavity did not impair visualization because the fluid at 0-g does not loculate posteriorly, but disperses along the thoracic wall and mediastinal reflections.

CONCLUSIONS

Performing minimally invasive procedures instead of open surgical procedures in a weightless environment has theoretical advantages, especially in the ability to prevent cabin atmosphere contamination from surgical fluids (blood, pus, irrigation). Visualization will become more important and practical as the endoscopic hardware is miniaturized from its current form, as endoscopic technology becomes more advanced, and as more surgically capable medical crew officers are present in future long-duration space exploration missions.

Digital hand-held sonography utilised for the focused assessment with sonography for trauma: a pilot study

OBJECTIVE

To evaluate the accuracy of the focused assessment with sonography for trauma (FAST) exam performed with a digital hand-held ultrasound machine in the emergency evaluation and resuscitation of trauma victims.

INTRODUCTION

The FAST exam is a valuable screening tool in the evaluation of abdominal trauma. New digital ultrasound units have recently become available which can be hand-carried by clinicians responding to the earliest phases of trauma care.

MATERIALS AND METHODS

Forty-seven victims of blunt trauma and 3 victims of penetrating trauma underwent FAST examinations performed by an attending trauma surgeon. Scans were performed with a Sonosite 180, 2.4-kg machine utilising a 5-2 MHz curved array transducer. The results of the hand-held FAST were compared with formal sonographic examinations performed by radiology department personnel, computed tomographic (CT) studies, operative findings and ultimate hospital course.

RESULTS

In victims of blunt trauma, 7 of 8 true fluid collections were detected, and 38 out of 39 cases without the presence of fluid were correctly excluded. There was 1 false positive and 1 false negative determination, resulting in a sensitivity of 86%, specificity of 97%, positive predictive value of 88%, and a negative predictive value of 97%. The overall accuracy was 96% for victims of blunt trauma. The technique expediently detected intra-peritoneal bleeding in 2 victims of lateral penetrating abdominal trauma. Utilised as the initial component of a diagnostic protocol, no inappropriate management strategies were suggested.

CONCLUSIONS

Digital hand-held sonography by clinicians can accurately allow the early performance of FAST exams. This exam may accurately and safely extend the physical senses of the examining physician.

Blunt abdominal aortic trauma in association with thoracolumbar spine fractures

All patients with blunt abdominal aortic disruption (BAAD) in the trauma registries at the three Regional Trauma Centres were retrospectively reviewed over the last decade. From the 11465 trauma admissions ISS>16,194 sustained aortic injuries. Eight cases of BAAD were identified, six with concurrent thoracolumbar spine (TLS) fractures (mean ISS 42). Patients with BAAD and TLS were subject to a detailed analysis. Clinically, three injury types were seen, hemodynamically unstable (uncontained full thickness laceration), stable symptomatic (intimal dissection with occlusion), and stable asymptomatic (contained full thickness laceration or intimal dissection without occlusion). All spinal column fractures involved a distractive mechanism, one with both distractive and translational fracture components. We propose that a distractive force, applied to the aorta lying anterior to the anterior longitudinal ligament, results in an aortic injury spectrum ranging from an intimal tear to a full thickness laceration, as a related injury. Computed tomography (CT) was an important imaging modality in the stable asymptomatic patients. All intimal dissections without occlusion were managed non-operatively. With distractive TLS fractures, BAAD needs to be considered.

Ultrasound evaluation of the magnitude of pneumothorax: a new concept

Pneumothorax is commonly seen in trauma patients; the diagnosis is confirmed by radiography. The use of ultrasound where radiographic capabilities are absent, is being investigated by the National Aeronautics and Space Administration. We investigated the ability of ultrasound to assess the magnitude of pneumothorax in a porcine model. Sonography was performed on anesthetized pigs in both ground-based laboratory (n = 5) and microgravity conditions (0 x g) aboard the KC-135 aircraft during parabolic flight (n = 4). Aliquots of air (50-100 cm3) were introduced into the chest to simulate pneumothorax. Results were videorecorded and digitized for later interpretation. Several distinct sonographic patterns of partial lung sliding were noted including the combination of a sliding zone with a still zone and a "segmented" sliding zone. These "partial lung sliding" patterns exclude massive pneumothorax manifested by a complete separation of the lung from the parietal pleura. In 0 x g, the sonographic picture is more diverse; one x g differences between posterior and anterior aspects are diminished. Modest pneumothorax can be inferred by the ultrasound sign of "partial lung sliding." This finding, which increases the negative predictive value of thoracic ultrasound, may be attributed to intermittent pleural contact, small air spaces, or alterations in pleural lubricant. Further studies of these phenomena are warranted.

Prospective evaluation of thoracic ultrasound in the detection of pneumothorax

BACKGROUND

Thoracic ultrasound may rapidly diagnose pneumothorax when radiographs are unobtainable; the accuracy is not known.

METHODS

We prospectively evaluated thoracic ultrasound detection of pneumothorax in patients at high suspicion of pneumothorax. The presence of "lung sliding" or "comet tail" artifacts were determined in patients by ultrasound before radiologic verification of pneumothorax by residents instructed in thoracic ultrasound. Results were compared with standard radiography.

RESULTS

There were 382 patients enrolled; the cause of injury was blunt (281 of 382), gunshot wound (22 of 382), stab wound (61 of 382), and spontaneous (18 of 382). Pneumothorax was demonstrated on chest radiograph in 39 patients and confirmed by ultrasound in 37 of 39 patients (95% sensitivity); two pneumothoraces could not be diagnosed because of subcutaneous air; the true-negative rate was 100%.

CONCLUSION

Thoracic ultrasound reliably diagnoses pneumothorax. Expansion of the focused abdominal sonography for trauma (FAST) examination to include the thorax should be investigated for terrestrial and space medical applications.

Is clinical examination an accurate indicator of raised intra-abdominal pressure in critically injured patients?

OBJECTIVES

To determine the rate of elevated intra-abdominal pressure (IAP) and to evaluate the accuracy of clinical abdominal examination in the assessment of IAP in the critically injured trauma patient.

DESIGN

A prospective blinded study.

SETTING

The medical-surgical critical care unit of a university-affiliated regional adult trauma centre.

PATIENTS

Forty-two adult blunt trauma victims, who had a mean injury severity score of 36.

INTERVENTIONS

Urinary bladder pressure was measured daily and classified as normal (10 mm Hg or less), elevated (more than 10 mm Hg) or significantly elevated (more than 15 mm Hg). A blinded clinical assessment of abdominal pressure was concurrently performed and recorded as elevated or normal.

MAIN OUTCOME MEASURES

The sensitivity, specificity and accuracy and the positive and negative predictive values of the 2 interventions in identifying elevated IAP.

RESULTS

Twenty-one patients (50%) had an elevated IAP at some point during the study. Of the 147 bladder pressure measurements done in these 42 patients, 47 (32%) were more than 10 mm Hg and 16 (11%) were more than 15 mm Hg. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of clinical abdominal examination for identifying elevated IAP were 40%, 94%, 76%, 77% and 77%, respectively. Clinical abdominal examination had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 56%, 87%, 35%, 94% and 84% respectively, for significantly elevated IAP.

CONCLUSIONS

Urinary bladder pressure was commonly elevated among our population of critically injured adults. Compared with bladder pressure measurements, clinical abdominal assessment showed poor sensitivity and accuracy for elevated IAP. These findings suggest that more routine measurements of bladder pressure in patients at risk for intra-abdominal hypertension should be performed.

Correlation between physiological assessment and outcome after liver transplantation

BACKGROUND

Critical shortages of organ donors for transplantation require appropriate utilization of this scarce resource. The purpose of this study was to assess whether use of physiological parameters of preliver transplant recipients is helpful in determining eventual outcome.

METHODS

Between October 1989 and June 1999, 215 liver transplants were performed on 199 patients at the Vancouver Hospital nad Health Sciences Centre. Thirty-one patients undergoing transplantation between May 1993 and June 1994 were retrospectively evaluated to obtain a minimum 5-year follow-up. Variables examined included pretransplant activation status (status 1, at home; status 2, hospitalized; status 3, admitted to intensive care; status 4, mechanical ventilation), simplified acute physiological score (SAPS), Acute Physiology, Age, and Chronic Health Evaluation (APACHE) II, and APACHE III scores at the time of transplantation. The scores were correlated to posttransplant mortality and functional outcome.

RESULTS

The 5-year mortality for status 1 patients was 14.3% versus 30% for patients listed as status 2 or greater (P = not significant). There were no significant differences in any of the physiological scoring assessments with regard to posttransplant mortality or functional assessment. Of the surviving patients, 18 of 22 who were employed, in school, or active at home pretransplant returned to their pretransplant activity.

CONCLUSIONS

Detailed physiological scoring systems are no more accurate in predicting outcome after liver transplant than current listing status parameters.

Prospective evidence of the superiority of a sonography-based algorithm in the assessment of blunt abdominal injury

BACKGROUND

Although the routine use of FAST (focused assessment with sonography for trauma) in the evaluation of trauma victims is increasing, to our knowledge, a prospective comparison of contemporary adult trauma victims managed with and without FAST has not been reported in North America.

METHODS

Adult victims of blunt trauma for whom there was a suspicion of abdominal injury were managed with one of two diagnostic algorithms, FAST or no-FAST. The two algorithms were compared for diagnostic accuracy, cost, time, and delayed diagnoses.

RESULTS

Among 706 patients (mean Injury Severity Score, 23), 460 were managed with FAST and 246 with no-FAST. The two groups were similar with respect to age, Injury Severity Score, prehospital time, and mortality (p = not significant). There were 3 of 460 (0.7%) delayed diagnoses in the FAST group and 4 of 246 (1.6%) in the no-FAST group (p = not significant). The diagnostic accuracy for the FAST and no-FAST algorithms was 99% and 98%, respectfully. The FAST and no-FAST algorithms led to similar rates of laparotomy, 13% and 14%, respectfully, but nonoperative management was more common in the no-FAST group (p < 0.01). The mean diagnostic cost for the FAST algorithm was $156, compared with $540 with the no-FAST algorithm (p < 0.0001) and the mean time required for diagnostic work-up was 53 minutes with the FAST algorithm, compared with 151 minutes with the no-FAST algorithm (p < 0.0001).

CONCLUSION

This study has provided prospective evidence that a FAST-based algorithm for blunt abdominal injury was more rapid, less expensive, and as accurate as an algorithm that used computed tomography or diagnostic peritoneal lavage only. Trauma centers are encouraged to incorporate a FAST-based algorithm into their initial management of blunt trauma victims.

Hypothermia and the trauma patient

Hypothermia has profound effects on every system in the body, causing an overall slowing of enzymatic reactions and reduced metabolic requirements. Hypothermic, acutely injured patients with multisystem trauma have adverse outcomes when compared with normothermic control patients. Trauma patients are inherently predisposed to hypothermia from a variety of intrinsic and iatrogenic causes. Coagulation and cardiac sequelae are the most pertinent physiological concerns. Hypothermia and coagulopathy often mandate a simplified approach to complex surgical problems. A modification of traditional classification systems of hypothermia, applicable to trauma patients is suggested. There are few controlled investigations, but clinical opinion strongly supports the active prevention of hypothermia in the acutely traumatized patient. Preventive measures are simple and inexpensive, but the active reversal of hypothermia in much more complicated, often invasive and controversial. The ideal method of rewarming is unclear but must be individualized to the patient and institution specific. An algorithm reflecting newer approaches to traumatic injury and technical advances in equipment and techniques is suggested. Conversely, hypothermia has selected clinical benefits when appropriately used in cases of trauma. Severe hypothermia has allowed remarkable survivals in the course of accidental circulatory arrest. The selective application of mild hypothermia in severe traumatic brain injury is an area with promise. Deliberate circulatory arrest with hypothermic cerebral protection has also been used for seemingly unrepairable injuries and is the focus of ongoing research.

Prospective evaluation of the potential role of teleradiology in acute interhospital trauma referrals

BACKGROUND

Teleradiology is one form of telemedicine that would allow the transmission of radiographs before the transfer of acutely traumatized patients between referring and receiving hospitals. The purpose of this study was to evaluate the potential impact of a prehospital teleradiology system on trauma patient management and transfer.

METHODS

Forty-four injured adults referred to a trauma center were included. The history, physical examination, and radiographic findings reported by the referring physician to the receiving physician were documented. The plain radiographs of the chest, pelvis, and cervical spine taken at the referring hospital were obtained after patient transfer. For each case, two reviewers blinded to the case (surgeon [S] and emergency department physician [E]) and one reviewer not blinded to the case were individually presented with the referring physician's report and the radiographs. The reviewers were surveyed as to the implications of viewing the plain radiographs taken at the referring hospital before patient transfer.

RESULTS

Overall, the blinded reviewers felt that viewing the radiographs before transfer would have influenced care in 40% and 38% of cases as judged by (S) and (E), respectively, with a crude agreement of 67.5% (kappa level, 0.32). The blinded reviewers (S and E) commonly noted the following four changes in management as a result of viewing the referred radiographs: requested further clinical history (S, 18%; E, 23%), suggested further pretransfer interventions (S, 38%; E, 30%), suggested further pretransfer diagnostic tests (S, 25%; E, 13%), and emphasized precautions during transfer (S, 28%; E, 30%). The nonblinded reviewer suggested potential influence in the management of at least 65% of the cases.

CONCLUSION

This study suggests that viewing the radiographs of acutely injured trauma patients has the potential to influence many aspects of the management of interhospital transfer.

Lupus-like syndrome caused by 5-aminosalicylic acid in patients with inflammatory bowel disease

BACKGROUND

Although 5-aminosalicylic acid (5-ASA) preparations used to treat inflammatory bowel disease are reported to have fewer side effects than sulphasalazine, increased clinical use of these compounds has resulted in increased reports of significant side effects.

OBJECTIVE

To report four patients with antinuclear antibody-positive migratory arthralgias and acute inflammation unrelated to the underlying inflammatory bowel disease, fulfilling the criteria of a drug-induced lupus-like syndrome.

SETTING

A university-affiliated teaching hospital.

INTERVENTION

Cessation of treatment with 5-ASA compounds.

RESULTS

The cases described constitute a drug-induced lupus-like syndrome. All patients improved rapidly after discontinuation of 5-ASA compounds.

CONCLUSIONS

Reversible lupus-like syndrome appears to be a rare but significant side effect of 5-ASA compounds. Patients treated with 5-ASA compounds who experience acute inflammatory symptoms or clinical deterioration not related to their gastrointestinal disease should be screened to rule out a lupus-like reaction.

The indeterminate abdominal sonogram in multisystem blunt trauma

BACKGROUND

North American trauma centers are beginning to note the limitations of emergent torso sonography. The purpose of this prospective study was to evaluate the frequency, causes, associations, and sequelae of indeterminate (IND) sonograms in blunt trauma.

METHODS

Among adult blunt trauma patients assessed with screening torso sonography, clinician sonographers recorded the abdominal sonogram as positive, negative, or IND for free fluid. Patients with IND sonograms were further investigated with repeat sonography, computed tomography, or diagnostic peritoneal lavage.

RESULTS

Among 417 patients with blunt trauma (mean Injury Severity Score = 21) managed with sonography, there were 28 (6.7%) IND and 389 (93.3%) non-IND sonograms. Sonograms were IND because of patient factors in 71% (20 of 28) and because of operator factors in 29% (8 of 28). None of the 28 patients were managed with repeat sonography alone. All 4 diagnostic peritoneal lavage examinations gave negative results, whereas 8 of 23 computed tomographic scans were abnormal (6 of 8 patients underwent laparotomy). The mean time required for diagnostic workup was 117 minutes in the IND group and 48 minutes in the non-IND group (p < 0.001 in both cases).

CONCLUSION

This prospective study has demonstrated that IND sonograms are not common at our center (6.7%), are usually attributable to patient factors, and are associated with greater diagnostic time. Patients with IND sonograms require further investigation because they often have injuries requiring laparotomy.

Blunt trauma and operative care in microgravity: a review of microgravity physiology and surgical investigations with implications for critical care and operative treatment in space

BACKGROUND

The assembly of the International Space Station in a low earth orbit will soon become a reality. The National Aeronautics and Space Administration envisions inhabited lunar bases and staffed missions to Mars in the future. Increasing numbers of astronauts, construction of high-mass structures, increased extra-vehicular activity, and prolonged if not prohibitive medical evacuation times to earth underscore the need to address requirements for trauma care in nonterrestrial environments.

STUDY DESIGN

A search was carried out to review the relevant literature in the MEDLINE and SPACELINE databases. All related Technical, Corporate, and Flight Test Reports in the KRUG Life Sciences corporate library were also reviewed. Bibliographies of all articles were then reviewed from these papers to identify additional pertinent literature. Senior Russian investigators reviewed the Russian literature and translated Russian publications when appropriate. Personal communication and discussion with active microgravity investigators and ongoing microgravity research supplemented published reports.

RESULTS

A large volume of data exist to document the multiple detrimental physiologic effects of microgravity exposure on human physiology. Organs systems such as cardiovascular, neurohumoral, immune, hematopoetic, and musculoskeletal systems may be particularly affected. These physiologic changes suggest an impaired ability to withstand major systemic trauma. Observational data also suggest adverse changes in numerous aspects of response to wounding and injury, and in areas such as the behavior of hemorrhage, microbiologic flora, and wound healing. In addition to an increased volume of ongoing and anticipated basic science research in microgravity physiology, preliminary studies of clinical diagnosis and therapy have been carried out in microgravity and microgravity laboratories. The feasibility of a wide range of ancillary critical care techniques has been verified in the parabolic flight model of microgravity. Although Russian investigators first performed laparotomies on rabbits in parabolic flight in 1967, only recently have American investigators demonstrated the reproducible feasibility of open and endoscopic surgical procedures under general anesthetic in animal models in a microgravity environment.

CONCLUSIONS

With appropriate instrumentation and personnel, the majority of resuscitative and surgical interventions required to stabilize a severely injured astronaut are feasible in a microgravity environment. Onboard limitations in mass, volume, and power that are ever present in any spacecraft design will limit the realistic capabilities of the medical system. Standard proved and tested trauma and operative management protocols will constitute the basis for extra-terrestrial care. Surgeons should familiarize themselves with the microgravity environment and remain active in planning trauma care for the continued exploration of space.

Bilateral primary breast lymphoma in pregnancy: a case report and literature review

Primary lymphoma of the breast is an uncommon malignant breast tumour, which is seldom distinguished preoperatively from other more common forms of breast cancer. The management differs from the more typical adenocarcinoma of breast in that the emphasis is on systemic chemotherapy. A young white woman presented during the 3rd trimester with bilateral breast enlargement, which failed to involute post partum. Subsequent biopsy revealed primary breast lymphoma of the large cell immunoblastic type. She received systemic chemotherapy and was alive and well with no evidence of recurrence 28 months later.

Surgical treatment of pancreatic cholera: a case report

After surgical resection for rectosigmoid carcinoma a 63-year-old man had secretory diarrhea causing severe metabolic acidosis, hypokalemia, hypercalcemia and dehydration. Subsequent investigations revealed a mass measuring 4 x 5 cm in the uncinate process of the pancreas and an elevated vasoactive intestinal polypeptide concentration. The diarrhea responded to treatment with the somatostatin analogue. Sandostatin, and remained under control during a prolonged preoperative period. The patient underwent a Whipple procedure with immediate lessening of his diarrhea. This report illustrates a classic case of vipoma and demonstrates the need to consider this condition in the differential diagnosis of secretory diarrhea, even in the presence of other gastrointestinal lesions. The effectiveness of somatostatin analogues in stabilizing the diarrhea preoperatively is also well illustrated.

Spondylolysis and spondylolisthesis in military parachutists

This paper reports on three cases of symptomatic low back pain in three paratroopers in association with bilateral L5 spondylolysis and L5 on S1 spondylolisthesis. The controversy regarding the etiology of this lesion as well as the problems of establishing causality when associated with parachuting injuries are discussed. These cases raise the issue of whether routine lumbar spine roentgenography should be performed as part of the pre-course medical screening prior to an individual undertaking basic parachutist training, and stress the need for further study of the relevance of these lesions in military parachuting.