Skin temperature as a noninvasive marker of haemodynamic and perfusion status in adult cardiac surgical patients : an observational study

Objective
Foot temperature has long been advocated as a reliable noninvasive measure of cardiac output despite equivocal evidence. The aim of this pilot study was to investigate the relationship between noninvasively measured skin temperature and the more invasive core-peripheral temperature gradients (CPTGs), against cardiac output, systemic vascular resistance, serum lactate, and base deficit.

Research methodology
The study was of a prospective, observational and correlational design. Seventy-six measurements were recorded on 10 adults postcardiac surgery. Haemodynamic assessments were made via bolus thermodilution. Skin temperature was measured objectively via adhesive probes, and subjectively using a three-point scale.

Setting
The study was conducted within a tertiary level intensive care unit.

Results
Cardiac output was a significant predictor for objectively measured skin temperature and CPTG (p = .001 and p = .004, respectively). Subjective assessment of skin temperature was significantly related to cardiac output, systemic vascular resistance, and serum lactate (p < .001, respectively).

Conclusions
These results support the utilisation of skin temperature as a noninvasive marker of cardiac output and perfusion. The use of CPTG was shown to be unnecessary, given the parallels in results with the less invasive skin temperature parameters. A larger study is however required to validate these findings.

Assessing advanced life support (ALS) competence: Victorian practices

Advanced life support (ALS) assessments are performed to assess nurses’ abilities to recognize cardiac arrest events, and appropriately manage patients according to resuscitation guidelines. Although there is evidence for conducting assessments after initial ALS education, there is little evidence to guide educators about ongoing assessments in terms of methods, format and frequency.

The aim of this study was to determine methods used by educators to assess ALS skills and knowledge for nurses in Victorian intensive care units. This descriptive study used telephone interviews to collect data. Data were analysed using content analysis. Twenty intensive care educators participated in this study. Thirteen educators (65%) were employed in public hospitals, and 7 educators (35%) worked in private hospitals across 12 Level 3 (60%) and 8 Level 2 (40%) intensive care units.

Results showed all educators used scenarios to assess ALS skills, with 12 educators (60%) including an additional theoretical test. There was variability in ALS assessment frequency, assessment timing in relation to initial/ongoing education, person performing the assessment, and the assessor/participant ratio. Nineteen educators (95%) reported ALS skill competency assessments occurred annually; 1 educator (5%) reported assessments occurred every 2 years. Assessments were conducted during a designated month (n = 10), numerous times throughout the year (n = 8), or on nurses’ employment anniversaries (n = 2). All educators reported many nurses avoided undertaking assessments.

Variability in ongoing ALS assessment methods was evident in Victorian intensive care units with some units applying evidence-based practices. Consideration should be given to the purposes and methods of conducting annual ALS assessments to ensure resources and strategies are directed appropriately. To encourage nurses to retain ALS skills and knowledge, regular practices are recommended as an alternative to assessments. However, further research is required to support this notion.

Tracheostomy decannulation failure rate following critical illness : a prospective descriptive study

Background : Tracheostomy is a well established and practical approach to airway management for patients requiring extended periods of mechanical ventilation or airway protection. Little evidence is available to guide the process of weaning and optimal timing of tracheostomy tube removal. Thus, decannulation decisions are based on clinical judgement. The aim of this study was to describe decannulation practice and failure rates in patients with tracheostomy following critical illness.

Methods : A prospective descriptive study was conducted of consecutive patients who received a tracheostomy at a tertiary metropolitan public hospital intensive care unit (ICU) between March 2002 and December 2006. Data were analysed using descriptive and inferential tests.

Results : Of the 823 decannulation decisions, there were 40 episodes of failed decannulation, a failure rate of 4.8%. These 40 episodes occurred in 35 patients: 31 patients failed once, 3 patients failed twice and 1 patient failed three times. There was no associated mortality. Simple stoma recannulation was required in 25 episodes, with none of these patients readmitted to ICU. Translaryngeal intubation and readmission to ICU took place for the remaining 15 episodes. The primary reason for decannulation failure was sputum retention. Twenty-four patients (60%) failed decannulation within 24 h, with 14 of these occurring within 4 h.

Conclusions : Clinical assessments coupled with professional judgement to decide the optimal time to remove tracheostomy tubes in patients following critical illness resulted in a failure rate comparable with published data. Although reintubation and readmission to ICU was required in just over one third of failed decannulation episodes, there was no associated mortality or other significant adverse events. Our data suggest nurses need to exercise high levels of clinical vigilance during the first 24 h following decannulation, particularly the first 4 h to detect early signs of respiratory compromise to avoid adverse outcomes.

Oxygen delivery to patients after cardiac surgery : a medical record audit

OBJECTIVE: To describe how intensive care nurses manage the administration of supplemental oxygen to patients during the first 24 hours after cardiac surgery.
METHODS: A retrospective audit was conducted of the medical records of 245 adult patients who underwent cardiac surgery between 1 January 2005 and 31 May 2008 in an Australian metropolitan hospital. Physiological data (oxygen saturation measured by pulse oximetry and respiratory rate) and intensive care unit management data (oxygen delivery device, oxygen flow rate and duration of mechanical ventilation) were collected at hourly intervals over the first 24 hours of ICU care.
RESULTS: Of the 245 patients whose records were audited, 185 were male; mean age was 70 years (SD, 10), and mean APACHE II score was 17.5 (SD, 5.14). Almost half the patients (122, 49.8%) were extubated within 8 hours of ICU admission. The most common oxygen delivery device used immediately after extubation was the simple face mask (214 patients, 87%). Following extubation, patients received supplemental oxygen via, on average, two different delivery devices (range, 1-3), and had the delivery device changed an average of 1.38 times (range, 0-6) during the 24 hours studied. Twenty-two patients (9%) received non-invasive ventilation or high-flow oxygen therapy, and 16 (7%) experienced one or more episode of hypoxaemia during mechanical ventilation. A total of 148 patients (60%) experienced one or more episodes of low oxygenation or abnormal respiratory rate during the first 24 hours of ICU care despite receiving supplemental oxygen.
CONCLUSION: These findings suggest that the ICU environment does not protect cardiac surgical patients from suboptimal oxygen delivery, and highlights the need for strategies to prompt the early initiation of interventions aimed at optimising blood oxygen levels in cardiac surgical patients in the ICU.

Patients and nurses' perspective on oxygen therapy : a qualitative study

Aim. This paper is a report of a study to describe patients' and nurses' perspectives on oxygen therapy.
Background. Failure to correct significant hypoxaemia may result in cardiac arrest, need for mechanical ventilation or death. Nurses frequently make clinical decisions about the selection and management of low-flow oxygen therapy devices. Better understanding of patients' and nurses' experiences of oxygen therapy could inform clinical decisions about oxygen administration using low-flow devices.
Methods. Face-to-face interviews with a convenience sample of 37 adult patients (17 cardio-thoracic: 20 medical surgical) and 25 intensive care unit nurses were conducted from February 2007 to September 2007. Interviews were audio-taped, transcribed verbatim and then analysed using a thematic analysis approach.
Findings. The patients identified three key factors that underpinned their compliance with oxygen therapy: (i) device comfort; (ii) ability to maintain activities of daily living; and (iii) therapeutic effect. The nurses identified factors, such as: (i) therapeutic effect, (ii) issues associated with compliance, (iii) strategies to optimize compliance, (iv) familiarity with device, (v) triggers for changing oxygen therapy devices, as being key to the effective management of oxygen therapy.
Conclusion. Differences between the patients' and nurses' perspective of oxygen therapy illustrate the variety of factors that impact on effective oxygen administration. Further research should seek to provide a further in-depth understanding of the current oxygen administration practices of nurses and the patient factors that enhance or hinder effectiveness of oxygen therapy. Detailed information about nurse and patient factors that influence oxygen therapy will inform a sound evidence base for nurses' oxygen administration decisions.