PubMed Health⌕ Search

Biomedical subjects

A W Kirkpatrick

Publications and source records attributed to A W Kirkpatrick.

At least 19 recordsLinked to original sources
PubMed2004

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.

Abdominal Abscess↗
PubMed2004

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.

APACHE↗
PubMed2004

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.

Adult↗
PubMed2002

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.

Animals↗
PubMed2001

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.

Animals↗
PubMed2001

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.

Abdominal Injuries↗
PubMed2001

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.

Humans↗
PubMed2001

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.

Animals↗
PubMed2001

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.

Abdominal Injuries↗
PubMed2000

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.

APACHE↗
PubMed2000

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.

Abdominal Injuries↗
PubMed1999

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.

Humans↗
PubMed1999

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.

Abdominal Injuries↗
PubMed1999

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.

Adult↗