Biomedical subjects
Publications and source records attributed to J A Morris.
Intra-abdominal hypertension is a lethal syndrome that can be treated. It is most often seen in critically ill surgical patients. The cornerstone of therapy is reduction of intra-abdominal pressure. Unfortunately, even with appropriate treatment, mortality is still high.
To determine outcome in young, healthy blunt trauma patients with isolated pulmonary contusion, and to identify factors associated with poor outcome, we reviewed 6012 consecutive adult (aged 16-49) blunt trauma admissions. Ninety-four (7.9%) presented with an isolated pulmonary contusion defined by chest radiograph and Injury Severity Score < 25; they compromise the study group. Poor outcome was defined as death, prolonged hospitalization (> 7 days), or a severe complication (pneumonia, empyema, atelectasis requiring bronchoscopy, or bronchopleural fistula). None of the 94 study patients died. Admission chest radiograph demonstrated no contusion in 34 patients (36%). Fifteen patients (16%) required intubation, but 13 were extubated within 48 hours. Forty-one patients (44%) required insertion of a chest tube, and 20 patients (21%) had a PaO2/FiO2 ratio of < 250 on admission. Post-injury atelectasis (n = 17), pneumothorax (n = 17), effusion (n = 8), pneumonia (n = 2), empyema (n = 1), and Staphylococcal bacteremia (n = 1) complicated hospitalizations. The following clinical factors were identified as predisposing to poor outcome by univariate analysis: 1) Pulmonary contusion on admission chest radiograph (P = 0.035); 2) Three or more rib fractures (P = 0.002); 3) chest tube insertion (P = 0.010) and drainage (P = 0.020); and 4) hypoxia on admission (PO2 < 70 torr [P = .021], PaO2/FiO2 < 250 [P < 0.001]). Only PaO2/FiO2 < 250 on admission was an independent predictor of poor outcome in a multivariate analysis (P = 0.040). Our conclusion was that isolated pulmonary contusion in young, healthy patients is not associated with mortality.(ABSTRACT TRUNCATED AT 250 WORDS)
Injury to the innominate or subclavian artery is an uncommon but difficult management problem. Review of trauma admissions from August 1983 to August 1992 revealed 21 patients who sustained injury to the innominate or subclavian artery. Eight patients sustained blunt trauma, while 13 patients sustained penetrating injuries. The mechanism of injury was variable, and associated injuries were common in both blunt and penetrating trauma. Injuries involved the right innominate or subclavian artery in 10 patients and the left subclavian artery in 11 patients. Twenty patients were managed operatively. Primary repair was preferred for penetrating injuries, whereas a bypass graft was more common for blunt injuries (P = 0.41). Patients with penetrating injury were more unstable at presentation (admission systolic blood pressure 73 mm Hg vs 119 mm Hg, P = 0.006; preoperative evaluation time 66 min vs 319 min, P = 0.002) and required more blood transfusions (5 units vs 26 units, P = 0.007) than patients with blunt injuries. Mortality for the entire series was 24 per cent (0% blunt vs 38% penetrating, P = 0.047). Hospital days (28 vs 48) and ICU days (8 vs 14) were longer for survivors of penetrating injuries (P = NS). Complications were common in both groups. Innominate/subclavian artery injury remains a significant cause of mortality and morbidity.
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The records of 555 patients who underwent elective abdominal aortic reconstruction were analysed to identify risk factors predisposing to cardiac complications. Perioperative myocardial infarction occurred in 35 patients (6.3 per cent), of whom 12 (2.2 per cent) died. Using multiple logistic regression, four preoperative factors that were independently predictive for postoperative myocardial infarction were identified with the following relative risk ratios: history of transient ischaemic attacks, 5.08; raised serum creatinine level, 3.66; age > 60 years, 3.00; and angina requiring regular treatment, 2.74. A scoring system using these four factors was devised that identified 150 of the 555 patients as at high risk, and included 69 per cent of those with myocardial infarction after operation and 83 per cent of those who died. A clinical risk score is a practical first step in identifying patients at risk of myocardial infarction; it would also reduce the number of patients for whom sophisticated tests of cardiac function were necessary.
OBJECTIVE: This article describes the important clinical events and decisions surrounding the reconstruction/unpacking portion of the staged celiotomy for trauma. METHODS: Of 13,817 consecutive trauma admissions, 1175 received trauma celiotomies. Of these, 107 patients (9.1%) underwent staged celiotomy with abdominal packing. The authors examined medical records to identify and characterize: (1) indications and timing of reconstruction, (2) criteria for emergency return to the operating room, (3) complications after reconstruction, and (4) abdominal compartment syndrome (ACS). RESULTS: Fifty-eight patients (54.2%) survived to reconstruction, 43 (74.1%) survived to discharge; 9 patients (15.5%) were returned to the operating room for bleeding; 13 patients required multiple packing procedures. There were 117 complications; 8 patients had positive blood cultures, abdominal abscesses developed in 6 patients, and ACS developed in 16 patients. CONCLUSIONS: 1. Reconstruction should occur after temperature, coagulopathy, and acidosis are corrected, usually within 36 hours after the damage control procedure. 2. Emergent reoperation should occur in any normothermic patient with unabated bleeding (greater than 2 U packed cells/hr). 3. ACS occurs in 15% of patients and is characterized by high peak inspiratory pressure, CO2 retention, and oliguria. Lethal reperfusion syndrome is common but preventable.
To determine patient-perceived functional outcome after lower extremity fracture (LEF), a prospective, follow-up study of patients managed at three level I trauma centers was conducted. Patients with unilateral LEF involving the acetabulum and distally were eligible for the study. A total of 444 patients were enrolled. Of these, 363 (82%) were interviewed at 6 months postdischarge. Study patients were predominantly young (mean age 34 years), white (72%) men (71%) who had been working preinjury (78%). Their injuries resulted primarily from motor vehicle crashes (73%); 30% had more than one fracture to the same extremity. Functional status was measured using the Sickness Impact Profile (SIP), a well-validated, general health status instrument. Mean 6-month SIP scores were significantly worse (higher) than those based on preinjury activities (9.8 vs. 2.5) (p < 0.01). Overall disability levels were moderate compared with other health conditions. Analysis of the 12 subscores comprising the SIP indicated particularly high scores in ambulation (16.2 postdischarge vs. 1.1 preinjury), sleep/rest (13.1 vs. 5.1), household management (14.5 vs. 2.6), recreation (17.6 vs. 4.2), emotional well-being (9.9 vs. 2.1), and most significantly work (33.2 vs. 8.8). Of those working preinjury, only 49% had returned by 6 months. SIP scores were highest for persons with three or more fractures to the same extremity and for fracture patterns typical of high-energy forces.
To determine functional outcomes after lower extremity fracture (LEF), a prospective follow-up study of patients admitted to three level I trauma centers for treatment of unilateral LEFs was conducted. In this paper we describe outcomes at 6 months after discharge from the initial hospitalization and examine the relationship between impairment and disability. A total of 444 patients met the entry criteria for the study. Of these 376 (85%) were successfully located and interviewed at 6 months; 302 (68%) returned to the trauma center at 6 months for a clinical assessment by a physical therapist. Study patients were predominantly young (mean age = 32.4), white (72%) men (70%) who were working before the injury (77%). The fractures resulted primarily from motor vehicle crashes (71%); mean hospital LOS was 12 days. Disability was measured using the Sickness Impact Profile (SIP), a well validated patient assessment of health status. The overall SIP score averaged for all patients was 10.2, denoting a moderate level of dysfunction or disability. Analysis of the 12 subscores that constitute the SIP indicate particularly high scores for ambulation (16.7 postdischarge vs. 1.2 preinjury), sleep and rest (14.0 vs. 5.1), emotional behavior (10.5 vs. 2.2), home management (15.1 vs. 2.6), recreation and pastimes (19.0 vs. 4.4), and most notably, work (33.2 vs. 8.3). Further analysis of the subgroup of patients working before the injury shows that 48% had returned to work at 6 months. Correlations between lower extremity impairment (range of motion, muscle strength, and pain) and the ambulation subscore of the SIP were high. However, correlations between impairment and more global areas of activity such as home management, work, and recreation were considerably lower. These results suggest that other factors, over and above the extent of physical impairment, significantly influence broader disability outcomes such as return to work. Further research is needed to define these factors so that effective interventions after acute care can be identified and appropriately targeted.
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1. An ethical dilemma can be defined as either a difficult problem seemingly incapable of a satisfactory solution or a situation involving choice between equally unsatisfactory alternatives. 2. When designing drug testing policies for current employees, the occupational health nurse may face ethical dilemmas related to the scope of testing, the selection of a test methodology, and the assurance of confidentiality. 3. This article demonstrates the application of bioethical theories to these dilemmas. It may assist the occupational health nurse who is developing or revising a worksite policy to analyze alternatives and reach appropriate decisions.
Base deficit is an expeditious and sensitive measure of both the degree and duration of inadequate perfusion, and has utility in the clinical evaluation and management of victims of trauma. It is rapid, accurate, and widely available, and as such may be very useful in the initial evaluation of these patients; it may also be used to help guide and assess the adequacy of volume resuscitation. It has in addition both clinical value and research potential in predicting outcome in these patients, and may be a useful tool to both the clinician and the researcher.
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Specimens of neoplastic and non-neoplastic human urothelium were rapidly frozen against a copper block immersed in liquid nitrogen, planed in a cryoultramicrotome and then examined by low-temperature scanning electron microscopy (LTSEM) following coating by aluminium. Energy dispersive X-ray microanalysis (XRMA) was performed on the superficial urothelial cells and on gelatin blocks mounted in parallel which had known concentrations of sodium, potassium, chloride, and phosphorus. The neoplastic urothelial cells had significantly less phosphorus (P less than 0.05) than non-neoplastic cells and the ratios K+/P,K+/Na+, and K+/Cl- were significantly higher in neoplastic cells than in non-neoplastic cells (P less than 0.00001). These results are consistent with those expected in cells with a sustained increase in intracellular pH caused by stimulation of Na+/H+ ion membrane exchange.
Concepts from information theory are applied to human ageing. An equation is derived, based on the general properties of information systems, which closely predicts the mortality rate in old age. The same equation predicts that infection will be increasingly severe when first exposure to micro-organisms is delayed leading to diseases which peak in early and middle age. A parameter of the equation is the level of redundancy in human information processing. Observed mortality rates show that this is sevenfold and it is suggested that seven is a fundamental dimensionless biological constant.
STUDY OBJECTIVE: To determine injury and illness patterns and occurrence rates during wilderness recreation. DESIGN: Prospective injury and illness surveillance study. SETTING: Wilderness areas throughout the Western hemisphere. TYPE OF PARTICIPANTS: All students and instructors on National Outdoor Leadership School courses over a five-year period. MAIN RESULTS: A single fatality occurred, resulting in a death rate of 0.28 per 100,000 person-days of exposure. Injuries occurred at a rate of 2.3 per 1,000 person-days of exposure. Sprains and strains and soft tissue injuries accounted for 80% of the injuries. The illness rate was 1.5 per 1,000 person-days of exposure. Sixty percent of illnesses were due to nonspecific viral illnesses or diarrhea; hygiene appeared to have a significant impact on the incidence of these illnesses. Thirty-nine percent of the injuries and illnesses required evacuation (1.5 per 1,000 person-days of exposure). CONCLUSION: The injury and illness patterns indicate that wilderness medical efforts should concentrate on wilderness hygiene and management of musculoskeletal injuries and soft tissue wounds. The data also indicate that wilderness activities can be conducted relatively safely, but the decision to participate should be individualized, with an understanding of risks versus benefits.
The evaluation and management of patients with minor head injury (MHI: history of loss of consciousness or posttraumatic amnesia and a GCS score greater than 12) remain controversial. Recommendations vary from routine admission without computed tomographic (CT) scanning to mandatory CT scanning and admission to CT scanning without admission for selected patients. Previous reports examining this issue have included patients with associated non-CNS injuries who confound the interpretation of the data and affect outcome. We hypothesized that patients with MHI and no other reason for admission with normal neurologic examinations and normal CT scans would have a negligible risk of neurologic deterioration requiring surgical intervention. To validate this hypothesis we studied 2766 patients with an isolated MHI admitted to seven trauma centers between January 1, 1988, and December 31, 1991. There were 1898 male patients and 868 female patients; injury was blunt in 99%. A neurologic examination and a CT scan were performed on 2166 patients; 933 patients had normal neurologic examinations and normal CT scans and none required craniotomy; 1170 patients had normal CT scans and none required craniotomy; 2112 patients had normal neurologic examinations and 59 required craniotomy. The sensitivity of the CT scan was 100%, with positive predictive value of 10%, negative predictive value of 100%, and specificity of 51%. The use of CT alone as a diagnostic modality would have saved 3924 hospital days, including 814 ICU days, and $1,509,012 in hospital charges. Based on these data, we believe that CT scanning is essential in the management of patients with MHI and that if the neurologic examination is normal and the scan is negative patients can be safely discharged from the emergency room.
OBJECTIVE: To determine the association of base deficit with mortality and other factors affecting mortality. DESIGN: Retrospective review. SETTING: Tertiary care center. PARTICIPANTS: Consecutive samples of 3791 trauma patients admitted with an arterial blood gas sample taken in the first 24 hours. MAIN OUTCOME MEASURES: Age, injury mechanism, head injury, shock (systolic blood pressure less than 90 mm Hg), Revised Trauma Score, TRISS probability of survival Ps, and mortality. RESULTS: Most (3038) patients (80.1%) exhibited a base deficit. Base deficit, age, injury mechanism, and head injury were associated with mortality using logistic regression. Age less than 55 years, no head injury, and a base deficit of -15 mmol/L were associated with 25% mortality. Age greater than or equal to 55 years with no head injury or age less than 55 years with a head injury and a base deficit of -8 mmol/L were associated with a 25% mortality. When shock was added to the model, all factors remained significant, and base deficit was supplemental to blood pressure. Base deficit also added significantly to the Revised Trauma Score and TRISS measurements. CONCLUSIONS: The base deficit is an expedient and sensitive measure of both the degree and the duration of inadequate perfusion. It is useful as a clinical tool and enhances the predictive ability of both the Revised Trauma Score and TRISS.
AIM: To test the hypothesis that sudden infant death syndrome (SIDS) may be caused by toxins of commonly occurring bacteria in infants lacking developed immunity. METHODS: Nasopharyngeal microbial isolates from 22 pairs of SIDS cases and healthy infants matched for age (by month), sex, and sampling time (by month) were compared for lethal toxigenicity. Crude toxin preparations were made from isolates cultured on dialysis membrane overlaid on agar, and these preparations were then tested for lethality by intravenous injection into 11 day old chick embryos. RESULTS: Fifteen (68%) of the SIDS cases were each found to have at least one lethally toxigenic organism in their nasopharyngeal flora; only eight (36%) of the flora of normal infants included a lethally toxigenic species. CONCLUSION: Infants who have died of SIDS have a significantly higher (p less than 0.05) probability than matched healthy infants of having a lethally toxigenic bacterial species in their nasopharyngeal flora.