Relationship of body condition score, live weight, stocking rate and grazing system to the mortality of Angora goats from hypothermia and their use in the assessment of welfare risks

Body condition scoring is widely used for sheep and cattle but the practice is included in only one Code of Practice for the welfare of goats in Australia. There is no published scientific evidence to support or defend its use in the assessment of welfare risks to farmed goats.

PROCEDURE: The significance of stocking rate, grazing system, body condition score (CS) and live weight were investigated in explaining the risk of mortality of individual and flocks of grazing Angora goats from hypothermia following a severe weather event in April. This event occurred 5 weeks after shearing the goats. Angora goats and Saxon Merino sheep were grazed alone, or mixed together in equal numbers at each of three stocking rates.

RESULTS: There was no mortality amongst Angora goats provided they grazed at the lowest stocking rate even when their CS was < or = 2.0. Mortality in flocks of Angora goats was most related to the CS reached during the preceding 2 months. For flocks of Angora goats there was no mortality at CS > or = 2.5 and mortality increased sharply at mean CS < 2.0. For individual Angora goats, mortality increased as CS declined and stocking rate and grazing combinations were additive in effect on mortality. Grazing with sheep increased mortality of Angora goats at higher stocking rates. The individual goat mortality rate was not dependent on individual plot effects suggesting that these results are applicable widely. Live weight loss was not related to mortality rates of goats once CS had been accounted for.
CONCLUSION: It was concluded that CS and stocking rate were highly significant determinants of welfare risk in Angora goats.

The haemodynamic status of cardiac surgical patients in the initial 2-h recovery period

Background
Critical care nurses caring for cardiac patients in the immediate postoperative period continually make decisions about the implications and treatment of their patients' haemodynamic status.

Aim
The aim of this study was to describe the haemodynamic status of patients on admission to critical care and over the 2-h period following cardiac surgery.

Methods
A quantitative, descriptive design was used. Data were collected using non-participant observation and an observation tool. The sample consisted of 38 patients.

Results
Analysis of data revealed the dynamic nature of the haemodynamic status of postoperative cardiac patients. On admission, 60% of patients (n = 23) were haemodynamically unstable. The instability in these patients (n = 23) was due to hypotension (34%), bleeding (21%) and hypoxaemia (18%). During the 2-h recovery period, 55% of patients were hypotensive, 16% of patients had low cardiac output syndrome and 16% of patients had low systemic vascular resistance (SVR) syndrome. Twenty-one percent of patients experienced bleeding complications. Shivering was a clinically significant problem in terms of occurrence (23%) and duration (X = 45, S.D. = 30 min). Twenty-nine percent of patients (n = 11) had a profound deterioration in haemodynamic status, necessitating urgent interventions.

Conclusion
Haemodynamic parameters indicate that 95% of patients in this study were haemodynamically unstable at some time during the initial 2-h recovery period. These findings inform resourcing decisions by organisations and have implications for nurses' assessment and interventional haemodynamic decision making.

Characteristics and outcomes of patients requiring unplanned transfer from subacute to acute care

The study aims to identify the reasons for, and outcomes from, unplanned transfers from subacute care to acute care. A retrospective patient record review of patients requiring unplanned transfer from subacute to an acute care emergency department (ED) from 1 July 2008 to 30 June 2009 was undertaken. Data collected included patient demographics, clinical characteristics in preceding transfer, and on ED arrival and outcome data. There were 136 patients included in the study with a median age of 81 years. The most common reasons for transfer were respiratory problems and altered conscious state. In the 24 h preceding transfer, 92.6% of patients had ≥ 1 physiological abnormality and 10.3% of patients had no physiological parameters documented. On ED arrival, 75% of patients had physiological abnormalities. Hospital admission occurred in 75% of patients and the inpatient mortality rate was 14.7%. Factors associated with inpatient mortality were tachypnoea and severe hypoxaemia in 24 h preceding transfer and tachypnoea, hypoxaemia, hypoxaemia, severe hypoxaemia and hypothermia on ED arrival. Patients requiring unplanned transfer had higher inpatient mortality than older hospital users. Reasons for unplanned transfer reflect known predictors of in-hospital adverse events so predictive use of physiological data and patient characteristics might optimize patient safety.

A pilot assessment of alpha-stat vs pH-stat arterial blood gas analysis after cardiac arrest

PURPOSE: Resuscitated cardiac arrest (CA) patients typically receive therapeutic hypothermia, but arterial blood gases (ABGs) are often assessed after adjustment to 37°C (alpha-stat) instead of actual body temperature (pH-stat). We sought to compare alpha-stat and pH-stat assessment of PaO2 and PaCO2 in such patients. MATERIALS AND METHODS: Using ABG data obtained during the first 24 hours of intensive care unit admission, we determined the impact of measured alpha vs calculated pH-stat on PaO2 and PaCO2 on patient classification and outcomes for CA patients. RESULTS: We assessed 1013 ABGs from 120 CA patients with a median age of patients 66 years (interquartile range, 50-76). Median alpha-stat PaO2 changed from 122 (95-156) to 107 (82-143) mm Hg with pH-stat and median PaCO2 from 39 (34-46) to 35 (30-41) mm Hg (both P < .001). Using the categories of hyperoxemia, normoxemia, and hypoxemia, pH-stat estimation of PaO2 reclassified approximately 20% of patients. Using the categories of hypercapnia, normocapnia, and hypocapnia, pH stat estimation of PaCO2 reclassified approximately 40% of patients. The mortality of patients in different PaO2 and PaCO2 categories was similar for pH-stat and alpha-stat. CONCLUSIONS: Using the pH-stat method, fewer resuscitated CA patients admitted to intensive care unit were classified as hyperoxemic or hypercapnic compared with alpha-stat. These findings suggest an impact of ABG assessment methodology on PaO2, PaCO2 , and patient classification but not on associated outcomes.

Effects of 22ᵒc muscle temperature on voluntary and evoked muscle properties during and after high intensity exercise

The purpose of this study was to investigate the effect of 22 °C local muscle temperature of intact human plantar flexors performing fatiguing contractions on evoked and voluntary contractile properties before and after fatigue. Twelve subjects were tested on plantar flexor voluntary torque, percent muscle activation derived from twitch interpolation, integrated electromyographic (iEMG) activity, and evoked torque and temporal characteristics of maximal twitch and tetanic stimulations before fatigue and 1, 5, and 10 min after intermittent, high-intensity, isometric fatigue under both normothermic and hypothermic conditions. Hypothermic and normothermic changes between time points were analysed by repeated-measures analysis of variance. Normothermic fatigue induced small to large effects (Cohen’s d: 0.29–3.06) on voluntary and evoked contractile properties, whereas most effects of unfatigued hypothermia were limited to rate-dependent processes (Cohen’s d: 0.78–1.70). Most tetanic properties were potentiated 1 min after normothermic fatigue, but remained unchanged by hypothermic fatigue, resulting in significant differences between the two conditions. Soleus iEMG significantly declined 1 min after normothermic fatigue (–29%), but not after hypothermic fatigue. Twitch torque was potentiated by 29% one minute after fatigue while normothermic, but was potentiated by 46% while hypothermic; rate of twitch torque development and time to peak twitch were potentiated by 39% and 10% while normothermic, but 89% and 28% while hypothermic. Although voluntary contractile properties are generally impaired soon after normothermic fatigue, most were not after hypothermic fatigue. Furthermore, evoked contractile properties were generally higher 1 min after hypothermic fatigue. We conclude that the hypothermic condition slows the recovery of potentiated evoked contractile properties back to baseline values.