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Paediatric heart transplant in Australia
39 Groetzner J, Reichart B, Roemer U, Reichel S, Kozlik-Feldmann R, Tiete A et al. Cardiac transplantation in pediatric patients: fifteen-year experience of a single center. Ann Thorac Surg 2005; 79: 53–60. 40 Weiss ES, Meguid RA, Patel ND, Russell SD, Shah AS, Baumgartner WA et al. Increased mortality at low-volume orthotopic heart transplantation centers: should current standards change? Ann Thorac Surg 2008; 86: 1250–9. 41 Kilic A, Weiss ES, Yuh DD, Shah AS, Cameron DE, Baumgartner WA et al. Institutional factors beyond procedural volume significantly impact center variability in outcomes after orthotopic
heart transplantation. Ann Surg 2012; 256: 616–23. 42 Arnaoutakis GJ, George TJ, Allen JG, Russell SD, Shah AS, Conte JV et al. Institutional volume and the effect of recipient risk on short-term mortality after orthotopic heart transplant. J Thorac Cardiovasc Surg 2012; 143: 157–67. 43 Webber SA, Naftel DC, Fricker FJ, Olesnevich P, Blume ED, Addonizio L et al. Lymphoproliferative disorders after paediatric heart transplantation: a multi-institutional study. Lancet 2006; 367: 233–9. 44 Dayton JD, Richmond ME, Weintraub RG, Shipp AT, Orjuela M, Addonizio LJ.
Role of immunosuppression regimen in post-transplant lymphoproliferative disorder in pediatric heart transplant patients. J Heart Lung Transplant 2011; 30: 420–5. 45 Abarbanell G, Mulla N, Chinnock R, Larsen R. Exercise assessment in infants after cardiac transplantation. J Heart Lung Transplant 2004; 23: 1334–8. 46 Freier MC, Babikian T, Pivonka J, Burley Aaen T, Gardner JM, Baum M et al. A longitudinal perspective on neurodevelopmental outcome after infant cardiac transplantation. J Heart Lung Transplant 2004; 23: 857–64.
Oxygen prescribing practice at Waikato Hospital does not meet guideline recommendations A. Holbourn and J. Wong Respiratory Department, Waikato District Hospital, Hamilton, New Zealand
Key words oxygen, drug prescription, New Zealand. Correspondence Ailsa Holbourn, 9/3 Cargilfield View, Edinburgh EH4 6SY, UK. Email: [email protected] Received 19 April 2014; accepted 31 July 2014. doi:10.1111/imj.12602
Background: It is the recommendation of the British Thoracic Society oxygen guidelines and the Waikato Hospital prescribing policy that all supplemental oxygen should be prescribed. Aims: The aim of this audit was to evaluate the current oxygen prescribing practices on different specialty wards in the Waikato Hospital. The secondary aim was to evaluate potential harm from oxygen toxicity of the patients whose oxygen was not prescribed appropriately. Methods: One hundred and twenty inpatients receiving oxygen therapy were randomly selected between December 2012 and April 2013. Forty patients were selected from each of the respiratory, surgical and other medical subspecialty wards. Their medication charts, clinical records and laboratory results were reviewed regarding their oxygen prescription, smoking history, diagnoses of chronic respiratory diseases and previous documentation of type 2 respiratory failure. Results: In total, 51.7% of all the patients audited had correct oxygen prescriptions: 77.5% of respiratory, 52.5% of surgical and 25% of other medical specialities. Among the 50 patients whose oxygen was not prescribed, many were classified as having high risk of potential complications of oxygen toxicity: 44% having known chronic respiratory disease, 70% having smoking history and 16% having previous type 2 respiratory failure. Conclusion: Current oxygen prescription rates and practices in Waikato Hospital are not satisfactory and can in turn put patients at risk of oxygen toxicity. There is a significant discrepancy in prescribing practices between specialities. Better education of oxygen prescription is required to raise the awareness and to improve the prescribing practice across the hospital.
© 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
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Holbourn & Wong
Introduction
Methods
The administration of oxygen is an essential component of appropriate management of a range of medical conditions. However, it is a medical therapy and has potential risks when not prescribed correctly. High flow oxygen has well-documented risks including acute and chronic lung parenchymal injury.1 Low flow oxygen, although found to have less risk of toxic effects, can still pose a threat, namely in patients with or at risk of hypercapnic respiratory failure. In these patients, the inappropriate use of oxygen can reduce the hypoxic respiratory drive and loose hypoxia-induced vasoconstriction leading to worsening V/Q mismatch and reduced carbon dioxide elimination. This results in increased carbon dioxide retention and worsens the respiratory acidosis, which can be lethal.2 This is a well recognised risk, which is why the British Thoracic Society (BTS) published guidelines that oxygen should always be prescribed, except in emergency settings where it should be documented after clinical stabilisation.3 It advises that all patients with known chronic obstructive pulmonary disease (COPD) or those at risk of it (e.g. lifelong smokers or history of breathless) should be treated with controlled oxygen and have an oxygen saturation aim of 88–92%.3 However, it is also widely recognised that oxygen prescription in hospital is usually poor. For example, an audit in North Shore Hospital, Wellington New Zealand, showed only 8 out of 100 patients had oxygen prescribed and of them only two had adequate prescriptions.4 Likewise, a recent audit in Wellington in 2008 showed correct oxygen prescription rate of 39.8%, even after specific oxygen prescription charts were introduced.5 Following advice from the BTS guidelines, it is the policy of the Waikato District Health Board that all oxygen should be prescribed. The prescription should include flow rate, delivery device and oxygen saturation aim. The primary aim of this audit was to evaluate oxygen prescription practice at Waikato Hospital, including the different prescribing rates between three groups of specialities: respiratory, surgery and other medical subspecialities. The secondary aim was to evaluate those patients who were not prescribed oxygen correctly to see if they were at high risk of potential harm, by considering if the patient had known respiratory disease, a history of smoking or a previous arterial blood gas (ABG) showing type 2 respiratory failure.
Over a 4-month period between December 2012 and April 2013, random unscheduled reviews of the medical and surgical wards at Waikato Hospital were undertaken. All those patients found to be on oxygen therapy at the time of the ward review were included in the audit. For each patient, the medication chart was reviewed to see if oxygen was prescribed. If it was prescribed, the prescription was examined to see if it was correct, containing flow rate, device and appropriate oxygen saturation aims, considering the patients’ medical history and risk of hypercapnia. All included patients’ notes were reviewed for documented chronic respiratory disease. The hospital laboratory system was searched for previous ABG results showing evidence of type 2 respiratory failure. Both acute respiratory acidosis and chronic compensated respiratory acidosis, with raised serum bicarbonate, were included. Finally, the patients were interviewed by the author regarding smoking history if that was not documented in clinical notes. Forty patients were collected from respiratory, surgical and other medical subspeciality wards (general medicine, renal and cardiology) respectively. To avoid bias, patients from the author’s respiratory team were excluded.
Funding: None. Conflict of interest: None.
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Results Of the total 120 patients selected, 70 patients had their oxygen prescribed (58%); however, only 62 of them were prescribed correctly with corresponding flow rate, device and oxygen saturation aims (51.7%). The prescribing practice of the specialty wards is shown in Figure 1. When evaluating the 40 respiratory patients included in the audit, 31 (77.5%) patients had oxygen prescribed correctly with appropriate oxygen saturation targets recorded. Twenty-seven of the surgical patients had oxygen prescribed; however, six of those did not have appropriate oxygen saturation targets recorded, therefore only 21 had correct prescriptions (52.5%). Of the 40 patients from the medical subspeciality wards, 3 patients were from renal, 10 patients from cardiology and 27 patients from the general medical wards. From them, only 12 patients had oxygen prescribed and of those only 10 had correct prescriptions (25%). The potential high-risk patients who did not have correct oxygen prescriptions were shown in Figure 2. When evaluating the 50 patients without oxygen prescriptions, 22 had known chronic respiratory disease (44%), 35 had current or past history of smoking (70%) and 8 had previous ABGs showing evidence of type 2 respiratory failure (16%). © 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
Oxygen prescribing practice
Figure 1 Correct oxygen prescrition rates. ( ) Precribed correctly; ( ), precribed incorrectly; ( ), not prescribed.
Figure 2 Patients without oxygen prescritions who are high risk. ( ), Not prescribed; ( ), smoking hx; ( ), known lung disease; ( ), type 2 Resp failure on ABG.
Further analysis showed that the vast majority of the patients received oxygen therapy through nasal cannula between 0.5 and 4 L. Only four patients used Hudson masks and no patients were found to be using a Venturi mask.
Discussion Oxygen is used to treat symptomatic and life-threatening hypoxaemia; however, it has been shown to be harmful when given inappropriately especially to patients who are at high risk of hypercapnic acidosis. As a result of this, © 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
both BTS guidelines and Waikato Hospital prescribing policy stipulate that all oxygen therapy should be prescribed. A previous audit in the United Kingdom reported only 55% of patients on a specific respiratory ward had an oxygen prescription and only 7% were correctly charted.6 Even those patients most at risk of complications related to oxygen toxicity still have inadequate prescriptions. This was demonstrated in an audit in 1992 in Christchurch, which reviewed 95 patients admitted with exacerbations of COPD. It found that despite 87% being given supplementary oxygen, only 33% had it prescribed, and of them, many had poor monitoring.7 Current oxygen prescription rates at Waikato Hospital are still poor, with only 51.7% undergoing oxygen therapy having adequate prescriptions. However, it is important to note that this is higher than previously documented prescription rates across New Zealand. At Waikato Hospital, there is a specific section on the prescription charts for oxygen prescription, including separate sections for flow rate, saturation aim and device to be used. This could contribute to the higher prescription rate compared with those documented by previous audits. From evaluating the results, there is a definite disparity between oxygen prescribing practices between different specialities. The respiratory ward has the highest rates of oxygen prescription in comparison with the other wards. This could be partly due to the fact that the junior medical staff are taught the importance of oxygen prescription during the respiratory departmental orientation programme at the beginning of the rotation. However, the orientation programme for other specialties do not contain any education on oxygen prescription. Despite the respiratory ward having the best prescription rates, they still failed to prescribe oxygen for 22.5% of their patients, who may be the most at risk of hypercapnic respiratory failure. On evaluation of the patients without prescriptions, seven (78%) of them had documented COPD, and of them, four (45%) had previously documented ABGs showing type 2 respiratory failure. Therefore, there is definite need for improvement of current prescribing practice on the respiratory ward. Over half of the patients in the surgical ward had correct oxygen prescriptions, the majority of whom have oxygen for a short period of time during postoperative recovery. It is unclear whether the relatively good oxygen prescription is due to surgical policy or anaesthetic input. However, good oxygen prescribing in the surgical setting is vital, as increasingly surgeons are coping with large numbers of high-risk respiratory patients as a consequence of prolonged life expectancy and increasing prevalence of COPD.8 As part of the normal physiological response to surgery, there is a transient and self-limiting impairment in spirometric values, respiratory muscle 1233
Holbourn & Wong
strength and gas exchange. If this physiological change is not managed appropriately with correct oxygen prescription, it can result in hypercapnic respiratory failure.9 The medical subspecialties appear to have the worst oxygen prescription rates with only a quarter of their patients having accurate prescriptions. Of the 28 patients not prescribed oxygen therapy, 10 (36%) had known chronic respiratory disease and 3 (11%) had known previous hypercapnic failure. Ten (36%) further patients had a smoking history. Although they had no definitive diagnosis of COPD, they could theoretically still be at risk of hypercapnic respiratory failure. It is not possible to comment on the individual medical subspecialties prescribing practice due to the small sample size. However, some recent studies questioned the use of oxygen in acute myocardial ischaemia with evidence supporting higher mortality rates in hyperoxic patients.10,11 In addition, patients with respiratory disease often have coexisting cardiac disease, and therefore, it is vital to be aware of this risk and to prescribe oxygen on the other medical subspeciality wards correctly, especially cardiology. The audit is limited due to small sample size and may not be reflective of prescribing practices as a whole throughout each department. Likewise, due to the method of selecting patients on brief ward visits that are on oxygen, this may only give a snapshot of prescribing practices. It means there may be a bias especially on surgical or cardiology wards where patients just returning postoperatively or following cardiac procedures may be on oxygen awaiting ward reviews to correct or prescribe oxygen.
patients. The inadequate safe prescription of oxygen is a reflection on the lack of understanding of the dangers of excessive or poorly managed oxygen therapy, hence it is vital to educate medical and ward staff on the importance of this. It has been recommended to introduce regular education sessions on oxygen prescribing to all ward-based medical and nursing staff. It has also been recommended to introduce it in conjunction with nursefacilitated feedback on oxygen prescription to junior medical staff, as this has been shown previously to improve oxygen prescribing behaviour.12 After the implementation of these recommendations, a follow-up audit will be conducted to assess if the standard of prescription has improved. This audit will also include assessment of patient outcome, specifically to see if any of those patients who were prescribed oxygen incorrectly developed hypercapnia or respiratory acidosis. In summary, this audit demonstrated that oxygen prescription at Waikato Hospital is inadequate and that there is a vast difference in prescribing practice across the different specialities. It is essential to remember that oxygen is a lifesaving treatment and the harm from tissue hypoxia greatly outweighs the harm of type 2 respiratory failure. Therefore, oxygen should not be withheld from a patient who is hypoxic, due to the lack of a prescription. However, there is still need to improve the medical and nursing staff’s current oxygen prescribing practice through education sessions, to re-enforce the existing oxygen prescription guidelines and to highlight the importance of oxygen toxicity.
Conclusion This study showed that there is the need to improve clinical practice to reduce the potential risk of harm to
References 1 Jackson R. Pulmonary oxygen toxicity. Chest 1985; 88: 900–5. 2 Bateman NT, Leach RM. ABC of oxygen: acute oxygen therapy. BMJ 1998; 317: 798–801. 3 O’Driscoll BR, Howard LS, Davison AG. BTS guideline for emergency oxygen use in adult patient. Thorax 2008; 63(Suppl 6): vi1–68. 4 Boyle M, Wong J. Prescribing oxygen therapy. An audit of oxygen prescribing practices on medical wards at North Shore Hospital, Auckland, New Zealand. N Z Med J 2006; 119: U2080. 5 Wijesinge M, Shirtcliffe P, Perrin K et al. An audit of the effect of oxygen
1234
6
7
8
9
prescription charts on clinical practice. Postgrad Med J 2010; 86: 89–93. Dodd ME, Kellet F, Davis A et al. Audit of oxygen prescribing before and after the introduction of a prescription chart. BMJ 2000; 321: 864–5. Neill AM, Epton MJ, Martin IR et al. An audit of the assessment and management of patients admitted to Christchurch Hospital with chronic obstructive pulmonary disease. N Z Med J 1994; 107(Pt 1): 365–7. Halbert RJ, Natoli JL, Gano A et al. Global burden of COPD: systematic review and meta analysis. Eur Respir J 2006; 28: 523–32. Licker M, Schweizer A, Ellenberger C et al. Perioperative medical management
of patients with COPD. Int J Chron Obstruct Pulmon Dis 2007; 2: 493–515. 10 Kilgannon JH, Jones AE, Shapiro NI, Angelos MG, Milcarek B, Hunter K et al. Association between arterial hyperoxia following resuscitation from cardiac arrest and in hospital mortality. JAMA 2010; 303: 2165–71. 11 Westen C. Oxygen therapy in acute myocardial infarction – too much of a good thing? Cochrane Database Syst Rev 2011; ED000006. 12 Medford A, Bowen J, Harvey J. Improved oxygen prescribing using nurse facilitated reminders. Br J Nur 2009; 18: 730–4.
© 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
Paediatric heart transplant in Australia
39 Groetzner J, Reichart B, Roemer U, Reichel S, Kozlik-Feldmann R, Tiete A et al. Cardiac transplantation in pediatric patients: fifteen-year experience of a single center. Ann Thorac Surg 2005; 79: 53–60. 40 Weiss ES, Meguid RA, Patel ND, Russell SD, Shah AS, Baumgartner WA et al. Increased mortality at low-volume orthotopic heart transplantation centers: should current standards change? Ann Thorac Surg 2008; 86: 1250–9. 41 Kilic A, Weiss ES, Yuh DD, Shah AS, Cameron DE, Baumgartner WA et al. Institutional factors beyond procedural volume significantly impact center variability in outcomes after orthotopic
heart transplantation. Ann Surg 2012; 256: 616–23. 42 Arnaoutakis GJ, George TJ, Allen JG, Russell SD, Shah AS, Conte JV et al. Institutional volume and the effect of recipient risk on short-term mortality after orthotopic heart transplant. J Thorac Cardiovasc Surg 2012; 143: 157–67. 43 Webber SA, Naftel DC, Fricker FJ, Olesnevich P, Blume ED, Addonizio L et al. Lymphoproliferative disorders after paediatric heart transplantation: a multi-institutional study. Lancet 2006; 367: 233–9. 44 Dayton JD, Richmond ME, Weintraub RG, Shipp AT, Orjuela M, Addonizio LJ.
Role of immunosuppression regimen in post-transplant lymphoproliferative disorder in pediatric heart transplant patients. J Heart Lung Transplant 2011; 30: 420–5. 45 Abarbanell G, Mulla N, Chinnock R, Larsen R. Exercise assessment in infants after cardiac transplantation. J Heart Lung Transplant 2004; 23: 1334–8. 46 Freier MC, Babikian T, Pivonka J, Burley Aaen T, Gardner JM, Baum M et al. A longitudinal perspective on neurodevelopmental outcome after infant cardiac transplantation. J Heart Lung Transplant 2004; 23: 857–64.
Oxygen prescribing practice at Waikato Hospital does not meet guideline recommendations A. Holbourn and J. Wong Respiratory Department, Waikato District Hospital, Hamilton, New Zealand
Key words oxygen, drug prescription, New Zealand. Correspondence Ailsa Holbourn, 9/3 Cargilfield View, Edinburgh EH4 6SY, UK. Email: [email protected] Received 19 April 2014; accepted 31 July 2014. doi:10.1111/imj.12602
Background: It is the recommendation of the British Thoracic Society oxygen guidelines and the Waikato Hospital prescribing policy that all supplemental oxygen should be prescribed. Aims: The aim of this audit was to evaluate the current oxygen prescribing practices on different specialty wards in the Waikato Hospital. The secondary aim was to evaluate potential harm from oxygen toxicity of the patients whose oxygen was not prescribed appropriately. Methods: One hundred and twenty inpatients receiving oxygen therapy were randomly selected between December 2012 and April 2013. Forty patients were selected from each of the respiratory, surgical and other medical subspecialty wards. Their medication charts, clinical records and laboratory results were reviewed regarding their oxygen prescription, smoking history, diagnoses of chronic respiratory diseases and previous documentation of type 2 respiratory failure. Results: In total, 51.7% of all the patients audited had correct oxygen prescriptions: 77.5% of respiratory, 52.5% of surgical and 25% of other medical specialities. Among the 50 patients whose oxygen was not prescribed, many were classified as having high risk of potential complications of oxygen toxicity: 44% having known chronic respiratory disease, 70% having smoking history and 16% having previous type 2 respiratory failure. Conclusion: Current oxygen prescription rates and practices in Waikato Hospital are not satisfactory and can in turn put patients at risk of oxygen toxicity. There is a significant discrepancy in prescribing practices between specialities. Better education of oxygen prescription is required to raise the awareness and to improve the prescribing practice across the hospital.
© 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
1231
Holbourn & Wong
Introduction
Methods
The administration of oxygen is an essential component of appropriate management of a range of medical conditions. However, it is a medical therapy and has potential risks when not prescribed correctly. High flow oxygen has well-documented risks including acute and chronic lung parenchymal injury.1 Low flow oxygen, although found to have less risk of toxic effects, can still pose a threat, namely in patients with or at risk of hypercapnic respiratory failure. In these patients, the inappropriate use of oxygen can reduce the hypoxic respiratory drive and loose hypoxia-induced vasoconstriction leading to worsening V/Q mismatch and reduced carbon dioxide elimination. This results in increased carbon dioxide retention and worsens the respiratory acidosis, which can be lethal.2 This is a well recognised risk, which is why the British Thoracic Society (BTS) published guidelines that oxygen should always be prescribed, except in emergency settings where it should be documented after clinical stabilisation.3 It advises that all patients with known chronic obstructive pulmonary disease (COPD) or those at risk of it (e.g. lifelong smokers or history of breathless) should be treated with controlled oxygen and have an oxygen saturation aim of 88–92%.3 However, it is also widely recognised that oxygen prescription in hospital is usually poor. For example, an audit in North Shore Hospital, Wellington New Zealand, showed only 8 out of 100 patients had oxygen prescribed and of them only two had adequate prescriptions.4 Likewise, a recent audit in Wellington in 2008 showed correct oxygen prescription rate of 39.8%, even after specific oxygen prescription charts were introduced.5 Following advice from the BTS guidelines, it is the policy of the Waikato District Health Board that all oxygen should be prescribed. The prescription should include flow rate, delivery device and oxygen saturation aim. The primary aim of this audit was to evaluate oxygen prescription practice at Waikato Hospital, including the different prescribing rates between three groups of specialities: respiratory, surgery and other medical subspecialities. The secondary aim was to evaluate those patients who were not prescribed oxygen correctly to see if they were at high risk of potential harm, by considering if the patient had known respiratory disease, a history of smoking or a previous arterial blood gas (ABG) showing type 2 respiratory failure.
Over a 4-month period between December 2012 and April 2013, random unscheduled reviews of the medical and surgical wards at Waikato Hospital were undertaken. All those patients found to be on oxygen therapy at the time of the ward review were included in the audit. For each patient, the medication chart was reviewed to see if oxygen was prescribed. If it was prescribed, the prescription was examined to see if it was correct, containing flow rate, device and appropriate oxygen saturation aims, considering the patients’ medical history and risk of hypercapnia. All included patients’ notes were reviewed for documented chronic respiratory disease. The hospital laboratory system was searched for previous ABG results showing evidence of type 2 respiratory failure. Both acute respiratory acidosis and chronic compensated respiratory acidosis, with raised serum bicarbonate, were included. Finally, the patients were interviewed by the author regarding smoking history if that was not documented in clinical notes. Forty patients were collected from respiratory, surgical and other medical subspeciality wards (general medicine, renal and cardiology) respectively. To avoid bias, patients from the author’s respiratory team were excluded.
Funding: None. Conflict of interest: None.
1232
Results Of the total 120 patients selected, 70 patients had their oxygen prescribed (58%); however, only 62 of them were prescribed correctly with corresponding flow rate, device and oxygen saturation aims (51.7%). The prescribing practice of the specialty wards is shown in Figure 1. When evaluating the 40 respiratory patients included in the audit, 31 (77.5%) patients had oxygen prescribed correctly with appropriate oxygen saturation targets recorded. Twenty-seven of the surgical patients had oxygen prescribed; however, six of those did not have appropriate oxygen saturation targets recorded, therefore only 21 had correct prescriptions (52.5%). Of the 40 patients from the medical subspeciality wards, 3 patients were from renal, 10 patients from cardiology and 27 patients from the general medical wards. From them, only 12 patients had oxygen prescribed and of those only 10 had correct prescriptions (25%). The potential high-risk patients who did not have correct oxygen prescriptions were shown in Figure 2. When evaluating the 50 patients without oxygen prescriptions, 22 had known chronic respiratory disease (44%), 35 had current or past history of smoking (70%) and 8 had previous ABGs showing evidence of type 2 respiratory failure (16%). © 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
Oxygen prescribing practice
Figure 1 Correct oxygen prescrition rates. ( ) Precribed correctly; ( ), precribed incorrectly; ( ), not prescribed.
Figure 2 Patients without oxygen prescritions who are high risk. ( ), Not prescribed; ( ), smoking hx; ( ), known lung disease; ( ), type 2 Resp failure on ABG.
Further analysis showed that the vast majority of the patients received oxygen therapy through nasal cannula between 0.5 and 4 L. Only four patients used Hudson masks and no patients were found to be using a Venturi mask.
Discussion Oxygen is used to treat symptomatic and life-threatening hypoxaemia; however, it has been shown to be harmful when given inappropriately especially to patients who are at high risk of hypercapnic acidosis. As a result of this, © 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
both BTS guidelines and Waikato Hospital prescribing policy stipulate that all oxygen therapy should be prescribed. A previous audit in the United Kingdom reported only 55% of patients on a specific respiratory ward had an oxygen prescription and only 7% were correctly charted.6 Even those patients most at risk of complications related to oxygen toxicity still have inadequate prescriptions. This was demonstrated in an audit in 1992 in Christchurch, which reviewed 95 patients admitted with exacerbations of COPD. It found that despite 87% being given supplementary oxygen, only 33% had it prescribed, and of them, many had poor monitoring.7 Current oxygen prescription rates at Waikato Hospital are still poor, with only 51.7% undergoing oxygen therapy having adequate prescriptions. However, it is important to note that this is higher than previously documented prescription rates across New Zealand. At Waikato Hospital, there is a specific section on the prescription charts for oxygen prescription, including separate sections for flow rate, saturation aim and device to be used. This could contribute to the higher prescription rate compared with those documented by previous audits. From evaluating the results, there is a definite disparity between oxygen prescribing practices between different specialities. The respiratory ward has the highest rates of oxygen prescription in comparison with the other wards. This could be partly due to the fact that the junior medical staff are taught the importance of oxygen prescription during the respiratory departmental orientation programme at the beginning of the rotation. However, the orientation programme for other specialties do not contain any education on oxygen prescription. Despite the respiratory ward having the best prescription rates, they still failed to prescribe oxygen for 22.5% of their patients, who may be the most at risk of hypercapnic respiratory failure. On evaluation of the patients without prescriptions, seven (78%) of them had documented COPD, and of them, four (45%) had previously documented ABGs showing type 2 respiratory failure. Therefore, there is definite need for improvement of current prescribing practice on the respiratory ward. Over half of the patients in the surgical ward had correct oxygen prescriptions, the majority of whom have oxygen for a short period of time during postoperative recovery. It is unclear whether the relatively good oxygen prescription is due to surgical policy or anaesthetic input. However, good oxygen prescribing in the surgical setting is vital, as increasingly surgeons are coping with large numbers of high-risk respiratory patients as a consequence of prolonged life expectancy and increasing prevalence of COPD.8 As part of the normal physiological response to surgery, there is a transient and self-limiting impairment in spirometric values, respiratory muscle 1233
Holbourn & Wong
strength and gas exchange. If this physiological change is not managed appropriately with correct oxygen prescription, it can result in hypercapnic respiratory failure.9 The medical subspecialties appear to have the worst oxygen prescription rates with only a quarter of their patients having accurate prescriptions. Of the 28 patients not prescribed oxygen therapy, 10 (36%) had known chronic respiratory disease and 3 (11%) had known previous hypercapnic failure. Ten (36%) further patients had a smoking history. Although they had no definitive diagnosis of COPD, they could theoretically still be at risk of hypercapnic respiratory failure. It is not possible to comment on the individual medical subspecialties prescribing practice due to the small sample size. However, some recent studies questioned the use of oxygen in acute myocardial ischaemia with evidence supporting higher mortality rates in hyperoxic patients.10,11 In addition, patients with respiratory disease often have coexisting cardiac disease, and therefore, it is vital to be aware of this risk and to prescribe oxygen on the other medical subspeciality wards correctly, especially cardiology. The audit is limited due to small sample size and may not be reflective of prescribing practices as a whole throughout each department. Likewise, due to the method of selecting patients on brief ward visits that are on oxygen, this may only give a snapshot of prescribing practices. It means there may be a bias especially on surgical or cardiology wards where patients just returning postoperatively or following cardiac procedures may be on oxygen awaiting ward reviews to correct or prescribe oxygen.
patients. The inadequate safe prescription of oxygen is a reflection on the lack of understanding of the dangers of excessive or poorly managed oxygen therapy, hence it is vital to educate medical and ward staff on the importance of this. It has been recommended to introduce regular education sessions on oxygen prescribing to all ward-based medical and nursing staff. It has also been recommended to introduce it in conjunction with nursefacilitated feedback on oxygen prescription to junior medical staff, as this has been shown previously to improve oxygen prescribing behaviour.12 After the implementation of these recommendations, a follow-up audit will be conducted to assess if the standard of prescription has improved. This audit will also include assessment of patient outcome, specifically to see if any of those patients who were prescribed oxygen incorrectly developed hypercapnia or respiratory acidosis. In summary, this audit demonstrated that oxygen prescription at Waikato Hospital is inadequate and that there is a vast difference in prescribing practice across the different specialities. It is essential to remember that oxygen is a lifesaving treatment and the harm from tissue hypoxia greatly outweighs the harm of type 2 respiratory failure. Therefore, oxygen should not be withheld from a patient who is hypoxic, due to the lack of a prescription. However, there is still need to improve the medical and nursing staff’s current oxygen prescribing practice through education sessions, to re-enforce the existing oxygen prescription guidelines and to highlight the importance of oxygen toxicity.
Conclusion This study showed that there is the need to improve clinical practice to reduce the potential risk of harm to
References 1 Jackson R. Pulmonary oxygen toxicity. Chest 1985; 88: 900–5. 2 Bateman NT, Leach RM. ABC of oxygen: acute oxygen therapy. BMJ 1998; 317: 798–801. 3 O’Driscoll BR, Howard LS, Davison AG. BTS guideline for emergency oxygen use in adult patient. Thorax 2008; 63(Suppl 6): vi1–68. 4 Boyle M, Wong J. Prescribing oxygen therapy. An audit of oxygen prescribing practices on medical wards at North Shore Hospital, Auckland, New Zealand. N Z Med J 2006; 119: U2080. 5 Wijesinge M, Shirtcliffe P, Perrin K et al. An audit of the effect of oxygen
1234
6
7
8
9
prescription charts on clinical practice. Postgrad Med J 2010; 86: 89–93. Dodd ME, Kellet F, Davis A et al. Audit of oxygen prescribing before and after the introduction of a prescription chart. BMJ 2000; 321: 864–5. Neill AM, Epton MJ, Martin IR et al. An audit of the assessment and management of patients admitted to Christchurch Hospital with chronic obstructive pulmonary disease. N Z Med J 1994; 107(Pt 1): 365–7. Halbert RJ, Natoli JL, Gano A et al. Global burden of COPD: systematic review and meta analysis. Eur Respir J 2006; 28: 523–32. Licker M, Schweizer A, Ellenberger C et al. Perioperative medical management
of patients with COPD. Int J Chron Obstruct Pulmon Dis 2007; 2: 493–515. 10 Kilgannon JH, Jones AE, Shapiro NI, Angelos MG, Milcarek B, Hunter K et al. Association between arterial hyperoxia following resuscitation from cardiac arrest and in hospital mortality. JAMA 2010; 303: 2165–71. 11 Westen C. Oxygen therapy in acute myocardial infarction – too much of a good thing? Cochrane Database Syst Rev 2011; ED000006. 12 Medford A, Bowen J, Harvey J. Improved oxygen prescribing using nurse facilitated reminders. Br J Nur 2009; 18: 730–4.
© 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians
