Evaluation of nasopharyngeal oxygen, nasal prongs and facemask oxygen therapy devices in adult patients: a randomised crossover trial

Nasopharyngeal oxygen (NPO) therapy may overcome some of the difficulties associated with nasal prongs and facemask oxygen delivery devices. In response to a lack of published studies of NPO therapy in adults, we conducted a prospective randomised crossover trial to compare the effectiveness of NPO, nasal prongs (NP) and facemasks (FM) when used in an adult population (n=37) from the intensive care unit and general hospital wards. We measured oxygen saturation (Sp[O.sub.2]) using pulse oximetry, oxygen flow (litres per minute), respiration rate (per minute) and comfort using a horizontal visual analogue scale. All three devices were effective in maintaining a Sp[O.sub.2] of [greater than or equal to]95% (NP 97.0[+ or -]1.9, NPO 97.7[+ or -]1.7, FM 98.8[+ or -]1.3%). NPO therapy consumed less oxygen than NP and FM therapy (NP 2.6[+ or -]1.0, NPO 2.2[+ or -]0.9, FM 6.1[+ or -]0.4 l/min, P <0.001). There was no significant difference in patients' respiratory rates (NP 19.9[+ or -]3.2, NPO 19.9[+ or -]3.0, FM 19.8[+ or -]3.1 per minute, P=0.491). In terms of comfort, patients rated NP higher than NPO and FM using a horizontal visual analogue scale (100 mm=most comfortable) (NP 65.5[+ or -]14.3, NPO 62.8[+ or -]19.4, FM 49.4[+ or -]21.4 mm, P <0.001). We conclude that for adult patients, nasal prongs and nasopharyngeal oxygen therapy consume less oxygen and provide greater comfort than facemasks while still maintaining Sp[O.sub.2] [greater than or equal to]95%.

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.

Descriptive analysis of emergency department oxygen use in acute exacerbation of chronic obstructive pulmonary disease

Background: Inconsistencies in oxygen therapy recommendations in acute exacerbation of chronic obstructive pulmonary disease (COPD) may result in variability in emergency department (ED) oxygen management of patients with COPD. The aim of this study was to describe oxygen management in the first 4 h of ED care for patients with exacerbation of COPD.
Methods: A retrospective medical record audit was conducted at four public and one private ED in Melbourne, Australia. Participants were 273 adult ED patients with COPD presenting with a primary complaint of shortness of breath from July 2006 to July 2007. Outcome measures were physiological data, including oxygen saturation (SpO2), oxygen delivery devices and flow rates on ED arrival, 1 and 4 h.
Results: Oxygen was used in 82.0% of patients. Patients who required oxygen had higher incidence of ambulance transport (P < 0.001), triage category 2 (P = 0.006), home oxygen use (P < 0.001), and increased work of breathing on ED arrival (P < 0.001), and higher median respiratory rate (P < 0.001) and heart rate (P = 0.001). SpO2 > 90% occurred in the majority of patients (87.5%; 96.4%; 95.6%); however, a considerable number of patients with SpO2 < 90% were not given oxygen (61.8%; 30%; 45.5%).
Conclusions: A number of patients with documented hypoxaemia were not given oxygen and there may be variables other than oxygen saturation that may influence oxygen use. Future research should focus on increasing the evidence-based supporting
oxygen use and better understanding of clinicians’ oxygen decision-making in patients with COPD.

The role of nurses in preventing adverse events related to respiratory dysfunction: literature review

Aims. This paper reports a literature review examining the relationship between specific clinical indicators of respiratory dysfunction and adverse events, and exploring the role of nurses in preventing adverse events related to respiratory dysfunction.

Background. Adverse events in hospital are associated with poor patient outcomes such as increased mortality and permanent disability. Many of these adverse events are preventable and are preceded by a period during which the patient exhibits clearly abnormal physiological signs. The role of nurses in preserving physiological safety by early recognition and correction of physiological abnormality is a key factor in preventing adverse events.

Methods. A search of the Medline and CINAHL databases was conducted using the following terms: predictors of poor outcome, adverse events, mortality, cardiac arrest, emergency, oxygen, supplemental oxygen, oxygen therapy, oxygen saturation, oxygen delivery, assessment, patient assessment, physical assessment, dyspnoea, hypoxia, hypoxaemia, respiratory assessment, respiratory dysfunction, shortness of breath and pulse oximetry. The papers reviewed were research papers that demonstrated a relationship between adverse events and various clinical indicators of respiratory dysfunction.

Results. Respiratory dysfunction is a known clinical antecedent of adverse events such as cardiac arrest, need for medical emergency team activation and unplanned intensive care unit admission. The presence of respiratory dysfunction prior to an adverse event is associated with increased mortality. The specific clinical indicators involved are alterations in respiratory rate, and the presence of dyspnoea, hypoxaemia and acidosis.

Conclusions. The way in which nurses assess, document and use clinical indicators of respiratory dysfunction is influential in identifying patients at risk of an adverse event and preventing adverse events related to respiratory dysfunction. If such adverse events are to be prevented, nurses must not only be able to recognise and interpret signs of respiratory dysfunction, but must also take responsibility for initiating and evaluating interventions aimed at correcting respiratory dysfunction.

Can written nursing practice standards improve documentation of initial assessment of ED patients?

Introduction: There is wide variation in emergency nursing practice in terms of initial patient assessment and the interventions implemented in response to these patient assessment findings. It is hypothesised that written ED nursing practice standards will reduce variability in documentation standards related to initial patient assessment.

Aim: This study aimed to examine the effect of written ED nursing practice standards augmented by an in-service education programme on the documentation of the initial nursing assessment.

Method: A pre-test/post-test design was used. Initial patient assessment was assessed using the Emergency Department Observation Chart. All adult patients (>18 years) who presented with chest pain and who were triaged to the general adult cubicles were eligible for inclusion in the study. Random sampling was used to select the patients for the pre-test (n = 78) and post-test groups (n = 74).

Results: There was significant improvement in documentation of all aspects of symptom assessment except quality and historical variables: pre-hospital care, cardiac risk factors, and past medical history. Improvements in documentation of elements of primary survey assessment were variable. There were significant increases in documentation of respiratory effort, chest auscultation findings, capillary refill and conscious state. There was a significant 18.3% decrease in the frequency of documentation of respiratory rate and no significant changes in documentation of oxygen saturation, heart rate or blood pressure.

Conclusion: Written ED nursing practice standards were effective in improving the documentation of some elements of initial nursing assessment for patients with chest pain. Active implementation strategies are important to ensure effective uptake of written practice standards and the relationship between nursing documentation and actual clinical practice warrants further consideration using a naturalistic approach in real practice settings.

Nurses' critical event risk assessments : a judgement analysis

Aims. To explore and explain nurses' use of readily available clinical information when deciding whether a patient is at risk of a critical event.

Background. Half of inpatients who suffer a cardiac arrest have documented but unacted upon clinical signs of deterioration in the 24 hours prior to the event. Nurses appear to be both misinterpreting and mismanaging the nursing-knowledge 'basics' such as heart rate, respiratory rate and oxygenation. Whilst many medical interventions originate from nurses, up to 26% of nurses' responses to abnormal signs result in delays of between one and three hours.

Methods. A double system judgement analysis using Brunswik's lens model of cognition was undertaken with 245 Dutch, UK, Canadian and Australian acute care nurses. Nurses were asked to judge the likelihood of a critical event, 'at-risk' status, and whether they would intervene in response to 50 computer-presented clinical scenarios in which data on heart rate, systolic blood pressure, urine output, oxygen saturation, conscious level and oxygenation support were varied. Nurses were also presented with a protocol recommendation and also placed under time pressure for some of the scenarios. The ecological criterion was the predicted level of risk from the Modified Early Warning Score assessments of 232 UK acute care inpatients.

Results. Despite receiving identical information, nurses varied considerably in their risk assessments. The differences can be partly explained by variability in weightings given to information. Time and protocol recommendations were given more weighting than clinical information for key dichotomous choices such as classifying a patient as 'at risk' and deciding to intervene. Nurses' weighting of cues did not mirror the same information's contribution to risk in real patients. Nurses synthesized information in non-linear ways that contributed little to decisional accuracy. The low-moderate achievement (Ra) statistics suggests that nurses' assessments of risk were largely inaccurate; these assessments were applied consistently among 'patients' (scenarios). Critical care experience was statistically associated with estimates of risk, but not with the decision to intervene.

Conclusion. Nurses overestimated the risk and the need to intervene in simulated paper patients at risk of a critical event. This average response masked considerable variation in risk predictions, the need for action and the weighting afforded to the information they had available to them. Nurses did not make use of the linear reasoning required for accurate risk predictions in this task. They also failed to employ any unique knowledge that could be shown to make them more accurate. The influence of time pressure and protocol recommendations depended on the kind of judgement faced suggesting then that knowing more about the types of decisions nurses face may influence information use.

Relevance to clinical practice. Practice developers and educators need to pay attention to the quality of nurses' clinical experience as well as the quantity when developing judgement expertise in nurses. Intuitive unaided decision making in the assessment of risk may not be as accurate as supported decision making. Practice developers and educators should consider teaching nurses normative rules for revising probabilities (even subjective ones) such as Bayes' rule for diagnostic or assessment judgements and also that linear ways of thinking, in which decision support may help, may be useful for many choices that nurses face. Nursing needs to separate the rhetoric of 'holism' and 'expertise' from the science of predictive validity, accuracy and competence in judgement and decision making.

An evidence-based practice approach to improving nursing care of acute stroke in an Australian emergency department

Aims. The aim of this study was to improve the emergency nursing care of acute stroke by enhancing the use of evidence regarding prevention of early complications.
Background. Preventing complications in the first 24–48 hours decreases stroke-related mortality. Many patients spend considerable part of the first 24 hours following stroke in the Emergency Department therefore emergency nurses play a key role in patient outcomes following stroke.
Design. A pre-test/post-test design was used and the study intervention was a guideline for Emergency Department nursing management of acute stroke.
Methods. The following outcomes were measured before and after guideline implementation: triage category, waiting time, Emergency Department length of stay, time to specialist assessment, assessment and monitoring of vital signs, temperature and blood glucose and venous-thromboembolism and pressure injury risk assessment and interventions.
Results. There was significant improvement in triage decisions (21Æ4% increase in triage category 2, p = 0Æ009; 15Æ6% decrease in triage category 4, p = 0Æ048). Frequency of assessments of respiratory rate (p = 0Æ009), heart rate (p = 0Æ022), blood pressure (p = 0Æ032) and oxygen saturation (p = 0Æ001) increased. In terms of risk management, documentation of pressure area
interventions increased by 28Æ8% (p = 0Æ006), documentation of nil orally status increased by 13Æ8% (ns), swallow assessment prior to oral intake increased by 41Æ3% (p = 0Æ003), speech pathology assessment in Emergency Department increased by 6Æ1% (ns) and there was 93Æ5 minute decrease in time to speech pathology assessment for admitted patients (ns).
Relevance to clinical practice. An evidence-based guideline can improve emergency nursing care of acute stroke and optimise patient outcomes following stroke. As the continuum of stroke care begins in the Emergency Department, detailed recommendations for evidence-based emergency nursing care should be included in all multidisciplinary guidelines for the management of acute stroke.