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P G Lawlor

Publications and source records attributed to P G Lawlor.

10 recordsLinked to original sources
PubMed2002

Effect of liquid feeding weaned pigs on growth performance to harvest.

Four experiments were undertaken to examine the effect of feeding postweaning diets as dry pelleted feed, fresh liquid feed, acidified liquid feed, and fermented liquid feed on pig performance from weaning (26 d) to harvest. In Exp. 1 (n = 12 replicates) and 2 (n = 10 replicates), the treatments were 1) dry pelleted feed and 2) fresh liquid feed. In Exp. 1, 2 kg of starter diet (16.7 MJ of DE/kg and 1.6% lysine) per pig and 5 kg of transition diet (16.7 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) were offered to 27 d after weaning. In Exp. 3 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) fresh liquid feed, and 3) acidified liquid feed. In Exp. 4 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) acidified liquid feed, and 3) fermented liquid feed. In Exp. 2, 3, and 4, 3 kg of starter diet (16.1 MJ of DE/kg and 1.74% lysine) per pig and 6 kg of transition diet (15.3 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) was offered to 27 d after weaning. All treatments were balanced for boars and gilts and diets were offered for ad libitum consumption. Acidified liquid feed was produced by adding lactic acid to the liquid feed so that its pH was decreased to 4.0. Fermented liquid feed was produced by adding an inoculum of Lactococcus lactis subsp. cremoris 303 (1.3%, vol/wt) to the first mix. In Exp. 1, ADG from weaning to d 27 after weaning was 338 and 286 g/d (SEM = 10; P < 0.01) and DM gain/feed in the same period was 888 and 594 g/kg (SEM = 23.1; P < 0.001) for dry pelleted feed and fresh liquid feed, respectively. In Exp. 2, ADG was 391 and 352 g/d (SEM = 6.4; P < 0.01) and DM gain/feed was 856 and 642 g/kg (SEM = 9.9; P < 0.001) for dry pelleted feed and fresh liquid feed, respectively, during the period from weaning to d 27 after weaning. In Exp. 3, ADG was 408, 416, and 433 g/d (SEM = 12.7; P > 0.05) and DM gain/feed was 865, 755, and 789 g/ kg (SEM = 14.5; P < 0.001) for dry pelleted feed, fresh liquid feed, and acidified liquid feed, respectively. In Exp. 4, ADG was 361, 389, and 347 g/d (SEM = 13.2; P = 0.11) and DM gain/feed was 888, 749, and 733 g/ kg (SEM = 15.8; P < 0.001) for dry pelleted feed, acidified liquid feed, and fermented liquid feed, respectively, during the period from weaning to d 27 after weaning. It is concluded that although feeding acidified liquid feed may have some merit in the first 27 d after weaning, this benefit is lost in the subsequent period. No benefit arose from feeding fresh liquid feed or fermented liquid feed. Growth performance from d 28 after weaning to harvest was not improved by any liquid feed treatment.

Animal Feed↗
PubMed2001

The impact of delirium on the circadian distribution of breakthrough analgesia in advanced cancer patients.

Most cancer patients will experience pain requiring opioid therapy during their illness. Standard opioid therapy includes fixed scheduled doses and so-called "rescue" doses for breakthrough pain. Circadian rhythms seem to influence the expression of pain and the responsiveness to analgesic medication. Delirium is a common complication in advanced cancer patients and it also may modify the expression of pain and the use of analgesic medication. We reviewed the circadian distribution of breakthrough analgesia (BTA) doses in 104 advanced cancer patients who were part of a prospective study of the occurrence of delirium. We found that the circadian distribution of BTA is significantly different from a random distribution in the case of patients with and without delirium. Patients without delirium tended to use more BTA (P < 0.001) in the morning, whereas patients with delirium tended to use more BTA in the evening and at night (P = 0.02). We conclude that delirium is associated with changes in the circadian distribution of BTA, which is possibly related to reversal of the normal circadian rhythm.

Aged↗
PubMed2000

Clinical utility, factor analysis, and further validation of the memorial delirium assessment scale in patients with advanced cancer: Assessing delirium in advanced cancer.

BACKGROUND: Delirium is a common neuropsychiatric complication in patients with advanced cancer. The Memorial Delirium Assessment Scale (MDAS) is a recently developed 10-item severity rating instrument. The purpose of the current prospective study was to further assess the clinical utility, factor structure, and validity of the MDAS in a relatively homogeneous population of patients with advanced cancer. METHODS: Study entry of 104 patients occurred on their consecutive admission to a tertiary-level, acute palliative care unit in a university-affiliated teaching hospital. Patients underwent regular cognitive screening using the Mini-Mental State Examination, and serial monitoring of delirium using standardized semistructured interviews and MDAS ratings, up to the study endpoints of either patient discharge or death. RESULTS: Seventy-one patients met Diagnostic and Statistical Manual (of Mental Disorders)-IV criteria for a first episode of delirium. In 15 of 71 (21%) patients with a first episode of delirium, the first MDAS ratings were prorated because of dyspnea, fatigue, or profound delirium. In the remaining 56 patients (79%), the first MDAS ratings were rated fully and therefore evaluable. Correlations among the scale items ranged from moderate to low (correlation coefficient [r] = 0.68-0.02). Analysis of the pattern of factor loadings identified two primary correlated factors: global cognitive (Factor I) and neurobehavioral (Factor II) (r = 0.33). Cronbach alpha coefficients for Factors I and II were 0.8 and 0.66, respectively, indicating a relatively high level of correlation for items within each. The Cronbach alpha coefficient for all 10 items was 0.78, suggesting a general underlying factor. In a larger sample of complete MDAS ratings (n = 330) a cutoff total MDAS score of 7 of 30 yielded the highest sensitivity (98%) and specificity (96%) for delirium diagnosis. The MDAS was correlated moderately with the Mini-Mental State Examination (r = 0.55). CONCLUSIONS: The authors concluded that the MDAS structure is representative of the many features of delirium, broadly grouped as global cognitive and neurobehavioral dimensions. Prorating item scores is necessary in approximately 20% of advanced cancer patients with delirium. This poses potential limitations on the applicability of the MDAS in research. Conversely, the ability to prorate item scores confers a clinical advantage to the instrument when assessing delirium in a patient population with advanced cancer.

Aged↗
PubMed2000

Occurrence, causes, and outcome of delirium in patients with advanced cancer: a prospective study.

CONTEXT: Delirium impedes communication and contributes to symptom distress in patients with advanced cancer. There are few prospective data on the reversal of delirium in this population. OBJECTIVES: To evaluate the occurrence, precipitating factors, and reversibility of delirium in patients with advanced cancer. DESIGN: Prospective serial assessment in a consecutive cohort of 113 patients with advanced cancer. Precipitating factors were examined using standardized criteria; 104 patients met eligibility criteria. SETTING: Acute palliative care unit in a university-affiliated teaching hospital. MAIN OUTCOME MEASURES: Delirium occurrence and reversal rates, duration, and patient survival. Strengths of association of various precipitating factors with reversal were expressed as hazard ratios (HRs) in univariate and multivariate analyses. RESULTS: On admission, delirium was diagnosed in 44 patients (42%), and of the remaining 60, delirium developed in 27 (45%). Reversal of delirium occurred in 46 (49%) of 94 episodes in 71 patients. Terminal delirium occurred in 46 (88%) of the 52 deaths. In univariate analysis, psychoactive medications, predominantly opioids (HR, 8.85; 95% confidence interval [CI], 2.13-36.74), and dehydration (HR, 2.35; 95% CI, 1.20-4.62) were associated with reversibility. Hypoxic encephalopathy (HR, 0.39; 95% CI, 0.19-0.80) and metabolic factors (HR, 0.44; 95% CI, 0.21-0.91) were associated with nonreversibility. In mulitivariate analysis, psychoactive medications (HR, 6.65; 95% CI, 1.49-29.62), hypoxic encephalopathy (HR, 0.32; 95% CI, 0.15-0.70), and nonrespiratory infection (HR, 0.23; 95% CI, 0.08-0.64) had independent associations. Patients with delirium had poorer survival rates than controls (P<.001). CONCLUSIONS: Delirium is a frequent, multifactorial complication in advanced cancer. Despite its terminal presentation in most patients, delirium is reversible in approximately 50% of episodes. Delirium precipitated by opioids and other psychoactive medications and dehydration is frequently reversible with change of opioid or dose reduction, discontinuation of unnecessary psychoactive medication, or hydration, respectively.

Aged↗
PubMed1998

Dose ratio between morphine and methadone in patients with cancer pain: a retrospective study.

BACKGROUND: Current equianalgesic reference tables, based largely on single dose studies, give dose ratios of 1:1 to 4:1 for oral morphine to oral methadone, which possibly are inaccurate in patients with cancer pain who are exposed to multiple doses of these opioids. The purpose of this study was to determine the equianalgesic dose ratio between morphine and methadone in patients with cancer pain and to establish whether the dose ratio changes as a function of previous opioid dose. METHODS: A retrospective analysis of consecutive rotations involving morphine and methadone using standard selection criteria identified a total of 20 evaluable rotations (14 from morphine to methadone and 6 from methadone to morphine). Opioid doses and pain intensity levels pre- and postrotation were analyzed. RESULTS: Median dose ratios (lower-upper quartiles) for morphine to methadone and methadone to morphine rotations were 11.36 (range, 5.98-16.27) and 8.25 (range, 4.37-11.3), respectively (P = 0.23). Combining all 20 rotations, a unified median dose ratio of 11.2 (range, 5.06-13.24) was calculated. There was no significant difference in pain intensity levels pre- and postrotation as recorded on a visual analogue scale. Univariate correlational analysis of dose ratio and the level of daily morphine dose prior to rotation revealed a Spearman correlation coefficient of 0.86 (P = 0.0001). In patients receiving >1165 mg per day prior to methadone rotation, a median dose ratio of 16.84 (range, 12.25-87.95) was observed, which was approximately 3 times higher compared with a median dose ratio of 5.42 (range, 2.95-9.09) (P = 0.007) for the 50% of patients receiving lower morphine doses. CONCLUSIONS: The results highlight the general underestimation of methadone potency and the consequent risk of potential life-threatening toxicity. The strongly positive correlation between dose ratio and previous morphine dose suggests the need for a highly individualized and cautious approach when rotating from morphine to methadone in patients with cancer pain.

Administration, Oral↗
PubMed1998

Side-effects of opioids in chronic pain treatment.

The emergence of opioid-induced neurotoxicity has gained increasing recognition in the literature in the past decade. Exciting developments at the receptor and intracellular level have revealed some insights into the potential mechanisms underlying this phenomenon. The hitherto reported clinical benefits of opioid rotation and dose reduction in the treatment of opioid toxicity warrant further clarification in prospective studies, particularly in relation to their relative value.

Journal Article↗
PubMedDate not supplied

The effects of orchidectomy and the role of testosterone in determining the growth of male mice selected for increased body weight.

Male mice selected for increased body weight and unselected controls were compared with intact littermates at 10 weeks of age following bilateral orchidectomy at 21 days post partum. Castrated mice were lighter in both lines and orchidectomy abolished approximately half the increase in body weight brought about by selection. The lungs were unaffected but there were decreases in the weights of the heart, liver and kidney and of the biceps brachii and tibialis anterior muscles in both lines. The decreases in body weight, organ weight and muscle weight, both absolute and relative, were greater in high growth than in unselected mice. Orchidectomy affected the size but not the number of cells in the liver and kidney. These results support the hypothesis that the increased level of circulating testosterone reported previously in male mice selected for increased body weight is responsible for that proportion of their greater body weight which is attributable to increased cell size.

Animals↗