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Biomedical subjects

Allison Williams

Publications and source records attributed to Allison Williams.

At least 19 recordsLinked to original sources
PubMed2007

Early predictors of mortality in hemodynamically unstable pelvis fractures.

OBJECTIVES: To determine reliable, early indicators of mortality and causes of death in hemodynamically unstable patients with pelvic ring injuries. DESIGN: This was a retrospective review of a prospective pelvic database. METHODS: In all, 187 hemodynamically unstable patients with pelvic fractures (persistent systolic blood pressure <90 mm Hg after receiving 2 L of intravenous crystalloid) admitted from April 1998 to November 2004 were included. Intervention was Level 1 Trauma Center-Pelvis Fracture standardized protocol. Main outcome measurements were: Injury Severity Score (ISS), Revised Trauma Score (RTS), age, blood transfusion, mortality, and multisystem organ failure (MOF). RESULTS: Group 1 (39 patients) did not survive their injury. Group 2 (148 patients) survived their injury. Fracture pattern (chi(2) = 9.1, P = 0.33), and treatment with angiography/embolization (chi(2) = 0.054, P = 0.84) were not predictive of death. Patients requiring more blood had a statistically significant higher mortality rate. The ISS (t = -5.62, P < 0.001), RTS (t = 6.10, P < 0.001), age >60 years old (chi(2) = 5.4, P = 0.03), and transfusion (t = -2.70, P = 0.010) were statistically significant independent predictors of mortality. A logistic regression analysis and receiver operating characteristic curves indicated that of these variables, RTS was the most predictive independent variable. However, a model including all four variables was superior at predicting mortality. Most deaths were attributed to exsanguination (74.4%) or MOF (17.9%). CONCLUSIONS: Predictors of mortality in pelvis fracture patients should be available early in the course of treatment in order to be useful. Death within 24 hours was most often a result of acute blood loss while death after 24 hours was most often caused by MOF. Improved survival will depend upon the evolution of early hemorrhage control and resuscitative strategies in patients at high mortality risk.

Aged↗
PubMed2007

Continuity of care and general wellbeing of patients with comorbidities requiring joint replacement.

AIM: The aim of this paper is to examine the continuity of care and general wellbeing of patients with comorbidities undergoing elective total hip or knee joint replacement. BACKGROUND: Advances in medical science and improved lifestyles have reduced mortality rates in most Western countries. As a result, there is an ageing population with a concomitant growth in the number of people who are living with multiple chronic illnesses, commonly referred to as comorbidities. These patients often require acute care services, creating a blend of acute and chronic illness needs. For example, joint replacement surgery is frequently performed to improve impaired mobility associated with osteoarthritis. METHOD: A purposive sample of twenty participants with multiple comorbidities who required joint replacement surgery was recruited to obtain survey, interview and medical record audit data. Data were collected during 2004 and 2005. FINDINGS: Comorbidity care was poorly co-ordinated prior to having surgery, during the acute care stay and following surgery and primarily entailed prescribed medicines. The main focus in acute care was patient throughput following joint replacement surgery according to a prescribed clinical pathway. General wellbeing was less than optimal: participants reported pain, fatigue, insomnia and alterations in urinary elimination as the chief sources of discomfort during the course of the study. CONCLUSION: Continuity of care of comorbidities was lacking. Comorbidities affected patient general wellbeing and delayed recovery from surgery. Acute care, clinical pathways and the specialisation of medicine and nursing subordinated the general problem of patients with comorbidities. Systems designed to integrate and co-ordinate chronic illness care had limited application in the acute care setting. A multidisciplinary, holistic approach is required. Recommendations for further research conclude this paper.

Aged↗
PubMed2006

Metabolic changes after polytrauma: an imperative for early nutritional support.

Major trauma induces marked metabolic changes which contribute to the systemic immune suppression in severely injured patients and increase the risk of infection and posttraumatic organ failure. The hypercatabolic state of polytrauma patients must be recognized early and treated by an appropriate nutritional management in order to avoid late complications. Clinical studies in recent years have supported the concept of "immunonutrition" for severely injured patients, which takes into account the supplementation of Omega-3 fatty acids and essential aminoacids, such as glutamine. Yet many aspects of the nutritional strategies for polytrauma patients remain controversial, including the exact timing, caloric and protein amount of nutrition, choice of enteral versus parenteral route, and duration. The present review will provide an outline of the pathophysiological metabolic changes after major trauma that endorse the current basis for early immunonutrition of polytrauma patients.

Journal Article↗
PubMed2006

An evaluation of an early warning clinical marker referral tool.

OBJECTIVES: The purpose of this study was to evaluate the introduction of a clinical marker tool using a pre- and post-test design in a tertiary university-affiliated hospital. The clinical marker tool was designed to assist in the early identification of unstable patients in the general surgical and medical ward environment based on abnormal vital signs. METHODS: A pre- and post-test design of the clinical marker tool was undertaken over a 3-year period. All unstable ward patients who were admitted to the Intensive Care Unit (ICU) from 1 February 2002 to 31 January 2003 (pre- implementation period) and from 1 February 2003 to 31 January 2005 (post-implementation period) were included in the study. A secondary analysis was performed on annual medical emergency calls made to the resuscitation team and mortality from such events from 1 January 2002 to 31 December 2004. RESULTS: Prior to implementing the clinical marker tool, 63 (41.2%) unplanned ICU admissions from the ward had clinical markers present for > or =6h. Following implementation of the clinical marker tool, 101 (24.5%) patients had clinical markers present for > or =6h (p=0.0002). There was no difference in ICU or hospital length of stay or hospital mortality for unplanned admissions to the ICU following implementation of the clinical marker tool. The number of patients found to be still breathing with a pulse on arrival of the resuscitation team was significantly increased from 56 (47.9%) patients to 181 (64.6%) patients post-implementation of the clinical marker tool (p=0.0024). Additionally, we found an associated increase in survival of this group of patients discharged home from 33 (59%) patients to 136 (75.1%) patients post-implementation of the clinical marker tool (p=0.0003). CONCLUSIONS: The clinical marker tool implemented by an ICU Liaison Team improved the management of patients in the ward environment, including proactive admission of patients to the ICU. Additionally, implementation of the clinical marker tool was associated with a reduction in the number of cardiac arrests and improvement in hospital mortality for patients experiencing a medical emergency call. The timeframe of instability on the ward prior to the ICU admission may be used as a quality indicator to measure ICU Liaison Team performance. Further research is required to substantiate these findings.

Biomarkers↗
PubMed2006

Expandable intramedullary nailing for tibial and femoral fractures: a preliminary analysis of perioperative complications.

OBJECTIVE: To report the results of using the expandable nailing system in the treatment of femoral and tibial shaft fractures. DESIGN: Prospective, cohort series. SETTING: Two level-1 university trauma centers. PARTICIPANTS: Forty-eight patients with acute, traumatic diaphyseal fractures of the tibia or femur. INTERVENTION: Internal fixation of lower extremity long bone fractures using expandable intramedullary nailing. MAIN OUTCOME MEASUREMENTS: Perioperative complications and time to healing. RESULTS: Forty-nine long bone fractures were treated: 22 femoral fractures (OTA classification: 4 type A1, 6 A2, 7 A3, 1 B1, and 4 B2) and 27 tibial fractures (OTA classification: 4 type A1, 11 A2, 9 A3, 0 B1, and 3 B2). There were 13 open fractures and 37 closed fractures. Healing occurred in 37 (75%) fractures without additional interventions. There were 2 tibial delayed unions and 1 femoral and 1 tibial nonunion. Five tibial shaft fractures and 6 femoral fractures shortened by 1.0 cm or more postoperatively. In 3 tibias and 4 femurs, shortening occurred after fractures judged to be length-stable became unstable because of fracture propagation during nail expansion. Five tibias and 3 femurs were converted to standard locked nails because of shortening. The average time to healing, excluding nonunion, was 15 weeks in the tibia and 16 weeks in the femur. The expandable nail resulted in an unplanned reoperation in 12 cases (25%). CONCLUSION: We found a high complication rate because of shortening, which was independent of fracture classification. Consequently, we cannot recommend the use of an unlocked, expandable nail in diaphyseal fractures of the femur or tibia.

Female↗
PubMed2006

Canada's Compassionate Care Benefit: views of family caregivers in chronic illness.

AIM: Based on a pilot evaluation of Canada's recently introduced Compassionate Care Benefit (CCB), the purpose of this paper is to highlight the experiences of family caregivers caring for people with non-malignant advanced chronic illness. DESIGN: Using Patton's (1997) utilization-focused evaluation approach, 25 telephone interviews were conducted with three groups of family caregivers: those who had successfully applied for the CCB; those who were unsuccessful in their applications; those who had never applied for the benefit. FINDINGS: The CCB has a number of limitations, particularly for caregivers of patients diagnosed with non-malignant advanced chronic illness. The central limitations are: difficulties associated with accurate prognostication; limited definition of "family member"; insufficient length of the funding period. CONCLUSION: By modelling similar programmes internationally, such as those in Sweden, Norway, and the Netherlands, Canada would likely find the CCB to have greater relevance and accessibility to Canadian caregivers, particularly those caring for people with non-malignant advanced chronic illness.

Canada↗
PubMed2006

Studies on sporozoite-induced and chronic infections with Plasmodium fragile in Macaca mulatta and New World monkeys.

Plasmodium fragile continues to be investigated because of its biologic similarities to the human malaria parasite, Plasmodium falciparum. Two strains of P. fragile are available for study; one strain is able to infect mosquitoes, whereas the other strain is transmissible only by blood inoculation. The Sri Lanka strain of P. fragile was transmitted to Macaca mulatta, Macaca fascicularis, Aotus lemurinus griseimembra, Aotus nancymaae, Aotus vociferans, and Saimiri boliviensis monkeys via sporozoites that developed to maturity only in Anopheles dirus mosquitoes. The prepatent periods ranged from 12 to 35 days for macaques and from 15 to 30 days for New World monkeys after intravenous injection of sporozoites. Eight rhesus monkeys were infected with the Nilgiri strain and followed for 482 days. Parasitemia in 6 animals persisted at relatively high density through the period of observation. Erythrocyte, hematocrit, and hemoglobin values reached their lowest levels 3 wk after infection and slowly recovered; however, the values did not approach preinfection levels as long as parasitemia persisted in the monkeys. The mean corpuscular volume and corpuscular hemoglobin concentration reached their peak and lowest values, respectively, at day 38 and then returned to the preinfection level. The mean corpuscular hemoglobin value decreased to its lowest level at day 87 and then returned to preinfection level.

Animals↗
PubMed2006

Aotus nancymaae as a potential model for the testing of anti-sporozoite and liver stage vaccines against Plasmodium falciparum.

The Santa Lucia strain of Plasmodium falciparum was transmitted to Aotus lemurinus griseimembra, A. azarae boliviensis, A. vociferans, and A. nancymaae monkeys by bite and by intravenous inoculation of sporozoites dissected from Anopheles freeborni, An. stephensi, An. gambiae, An. albimanus, and An. maculatus mosquitoes. The data obtained from these infections indicate that A. nancymaae can be considered a suitable host model when combined with the Santa Lucia strain of P. falciparum for the testing of candidate anti-sporozoite and liver stage vaccines.

Animals↗
PubMed2005

Observations on the Vietnam Palo Alto strain of Plasmodium vivax in two species of Aotus monkeys.

Thirty-three splenectomized Aotus lemurinus griseimembra monkeys with no previous experience with malaria were infected with the Vietnam Palo Alto strain of Plasmodium vivax. The median maximum parasite count was 280,000/microl. Nine splenectomized monkeys with previous infection with Plasmodium falciparum had median maximum parasite counts of 120,000/microl. Splenectomized Aotus nancymai monkeys supported infections at a lower level. Transmission via the bites of Anopheles dirus mosquitoes was obtained in a splenectomized A. lemurinus griseimembra, with a prepatent period of 31 days. It is estimated that between 1.5 x 10(8) and 1.6 x 10(9) parasites can be removed from an infected animal for molecular or diagnostic antigenic studies.

Animals↗
PubMed2005

Studies on two strains of Plasmodium cynomolgi in New World and Old World monkeys and mosquitoes.

Infections that cause the Gombak and Smithsonian strains of Plasmodium cynomolgi were induced in Macaca mulatta, Aotus lemurinus griseimembra, Aotus nancymai, and Saimiri boliviensis monkeys. Transmission of the Gombak strain to Aotus spp. monkeys was obtained by the injection of sporozoites dissected from the salivary glands of experimentally infected Anopheles dirus and by the bites of infected An. dirus and Anopheles farauti mosquitoes. Two S. boliviensis monkeys were infected via the injection of sporozoites dissected from An. dirus. Prepatent periods in New World monkeys ranged from 14 to 44 days, with a median of 18 days. The Smithsonian strain was transmitted via sporozoites to 1 A. lemurinus griseimembra and 9 A. nancymai monkeys. Prepatent periods ranged from 12 to 31 days.

Adaptation, Physiological↗
PubMed2005

Plasmodium simium and Saimiri boliviensis as a model system for testing candidate vaccines against Plasmodium vivax.

Observations on Plasmodium simium infections in Saimiri boliviensis boliviensis monkeys suggest that this host-parasite combination would be a suitable model for the testing of candidate vaccines against Plasmodium vivax. To evaluate the normal course of infections, parasitemia in 52 splenectomized S. boliviensis boliviensis monkeys infected with P. simium were analyzed. The mean maximum parasite count for 31 monkeys after injection with trophozoite-infected erythrocytes was 77,580/microL. Twenty-one monkeys were infected via sporozoites, and prepatent periods ranged from 14 to 24 days with a median of 15 days. The mean maximum parasite count was 29,234/microL. The mean maximum parasite count for monkeys previously infected with Old World P. vivax was 26,337/microL versus 56,362/microL for those previously infected with New World P. vivax, possibly suggesting a closer antigenic relationship between P. simium and the Old World parasites.

Animals↗
PubMed2004

Patients with comorbidities: perceptions of acute care services.

BACKGROUND: Advances in medical science and improved lifestyles have reduced mortality rates in Australia and most Western countries. As a result, there is an ageing population with a concomitant growth in the number of people living with chronic illnesses. Indeed, a significant number of people will experience multiple chronic illnesses (comorbidities) and may require admission to hospital for acute care that is superimposed on their chronic illnesses. AIM: The aim of this study was to investigate perceptions of quality of care by patients experiencing comorbidities who required an acute hospital stay. METHOD: A qualitative descriptive design was adopted, informed by Colaizzi's phenomenological method. Single semi-structured interviews were conducted with 12 patients within 14 days of being discharged home after an acute illness episode. FINDINGS: Data analysis revealed three themes: poor continuity of care for comorbidities, the inevitability of something going wrong during acute care and chronic conditions persisting after discharge. Combinations of chronic illnesses and treatments affected these patients' experiences of acute care and recovery postdischarge. Medicalized conceptualizations of comorbidity failed to capture the underlying health care needs of these patients. Limitations. No generalizations can be drawn because the findings and conclusions were derived from a purposive sample of patients who agreed to participate. CONCLUSION: These findings have implications for a comprehensive and co-ordinated approach to this group of patients, and inform the body of nursing knowledge about how patients with comorbidities experience nursing care.

Acute Disease↗
PubMed2004

Additional observations on the sporozoite transmission of Plasmodium knowlesi to monkeys.

Saimiri boliviensis monkeys were infected by the intravenous injection of 50 sporozoites of the H strain of Plasmodium knowlesi dissected from the salivary glands of Anopheles dirus mosquitoes; prepatent periods were 11, 12, 13, 13, 13, and 16 days. Sporozoites of P. knowlesi stored frozen for 7 days, 53 days, 20 mo, 7 yr and 7 mo, and 11 yr and 5 mo induced infections in Macaca mulatta monkeys with prepatent periods of 7, 6, 8, 10, and 7 days, respectively. After frozen storage for 11 yr and 5 mo, infections were induced in S. boliviensis with prepatent periods of 10-13 days.

Animals↗
PubMed2004

Rio Meta strain of Plasmodium vivax in New World monkeys and anopheline mosquitoes.

An archived strain of Plasmodium vivax, isolated from Rio Meta, northern Colombia, in 1972 was adapted to grow in splenectomized Aotus lemurinus griseimembra and A. nancymai monkeys. Anopheles freeborni, An. maculatus, An. dirus, An. culicifacies, and An. albimanus were shown to be susceptible to infection by feeding on infected monkeys. Infections were more readily obtained by feeding on A. L. griseimembra than on A. nancymai. Transmission through sporozoites was obtained in an A. l. griseimembra monkey after a prepatent period of 24 days.

Animals↗
PubMed2004

Susceptibility of Anopheles farauti to infection with different species of Plasmodium.

A colony of Anopheles farauti, originally from the island of New Britain in Papua New Guinea, was tested for its receptivity to infection with different species of Plasmodium in comparison with An. freeborni and An. stephensi. This colony adapted well to feeding on monkeys and was infected with New World and Old World strains of P. vivax and P. falciparum, P. ovale, P. cynomolgi, and P. brasilianum.

Animals↗
PubMed2003

A comparison of skinfolds and leg-to-leg bioelectrical impedance for the assessment of body composition in children.

BACKGROUND: This field-based investigation examined the congruence between skinfolds and bioelectrical impedance in assessing body composition in children. METHODS: Subjects were 162 female and 160 male children 10-15 years of age. Skinfold measures obtained at the triceps and medial calf and a leg-to-leg bioelectrical impedance system were used to determine percent fat using child-specific equations. Pearson product moment correlations were performed on the percent fat values obtained using skinfolds and bioelectric impedance for the entire data set. Separate correlations were also conducted on gender and age/gender subsets. Dependent t tests were used to compare the two techniques. RESULTS: Percent fat did not differ between skinfolds and bioelectrical impedance for the total subject pool. Bioelectrical impedance overestimated percent fat in girls by 2.6% and underestimated percent fat in boys by 1.7% (p < 0.01). Correlations between skinfolds and bioelectrical impedance ranged from r = 0.51 to r = 0.90. CONCLUSIONS: Leg-to-leg bioelectrical impedance may be a viable alternative field assessment technique that is comparable to skinfolds. The small differences in percent fat between the two techniques may have limited practical significance in school-based health-fitness settings.

Journal Article↗
PubMed2003

Adaptation of a strain of Plasmodium falciparum from Ghana to Aotus lemurinus griseimembra, A. nancymai, and A. vociferans monkeys.

A strain of Plasmodium falciparum from Ghana was adapted to Aotus lemurinus griseimembra, A. nancymai, and A. vociferans monkeys. Gametocytes in splenectomized A. nancymai were infective to Anopheles freeborni mosquitoes. Sporozoite transmission was accomplished in two splenectomized A. nancymai with prepatent periods of 22 and 25 days. The Ghana III/CDC strain of P. falciparum is susceptible to treatment with chloroquine and mefloquine.

Adaptation, Biological↗