Pulmonary Hypertension in Patients with COPD

EDITORIAL 283

Pulmonary hypertension in COPD with severe COPD.10 11 A degree of pulmo-

...... nary hypertension was observed in 55% Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from of consecutive respiratory outpatients using Doppler echocardiography.12 The Pulmonary hypertension in patients presence of pulmonary hypertension in patients with COPD is associated with with COPD: NO treatment? increased mortality11 13 and an increase in exacerbation rate and length of hospi- J Pepke-Zaba, N W Morrell tal stay, independent of the degree of air- flow obstruction.14 Although often in- ...... ferred, the precise contribution of pulmonary hypertension to exercise The application of “pulsed” NO combined with LTOT may limitation or quality of life in stable have a role in treating pulmonary hypertension secondary to COPD patients is unknown. Mean pul- COPD. monary artery pressure in patients with COPD is typically mild (in the region of ollowing the identification of nitric exchange based on low ventilation/ 25 mm Hg) at rest but can rise to abnor- oxide (NO) in 1986 as “endothelium perfusion (V/Q) ratios. This includes the mally high levels on exercise. derived relaxing factor”, there has use of NO in patients in intensive care, At present there are no specific treat- F ments recommended for the reduction of been an exponential growth in our neonates with persistent pulmonary understanding of the physiological role hypertension, and in postoperative set- pulmonary artery pressure in COPD. Although long term oxygen therapy of NO culminating in the award of a tings where NO is used to reduce pulmo- (LTOT) improves survival in hypoxaemic Nobel Prize, and the naming of NO as nary vascular resistance and/or improve patients with COPD, it has a negligible “molecule of the decade”.1 Considerable oxygenation—for example, pulmonary effect on pulmonary haemodynamics. research has subsequently been devoted thromboendarterectomy, heart and lung Clearly, other factors in addition to to understanding the role of this mol- transplantation, acute lung injury. alveolar hypoxia contribute to the devel- ecule in vascular biology in general, and In the lungs, one important molecule opment of pulmonary hypertension in the pulmonary vascular system in par- with which NO reacts is oxyhaemoglobin COPD. For example, remodelling of the ticular. (HbO ). The affinity of HbO for NO is 106 2 2 pulmonary vessels is present in many NO is an unstable radical with a low times greater than its affinity for 6 patients with mild COPD who are not blood gas partition coefficient. For dec- oxygen. Oxidative reactions of NO with hypoxaemic and appears to be related to ades NO was considered an environmen- haemoglobin largely limit the effects of cigarette smoking.15 tal contaminant produced by bacteria inhaled NO to the lung vasculature. There are several reports of the use of and internal combustion engines. Be- However, there are reports that high inhaled NO in patients with stable lieved to be highly toxic, it appeared an concentrations of inhaled NO have per- COPD.16–19 NO inhalation alone may unlikely candidate for a major role as a ipheral vascular effects when peripheral worsen V/Q relationships and exacerbate http://thorax.bmj.com/ biological mediator. However, within the endothelial NO synthesis is blocked, systemic hypoxaemia while lowering pul- last 15 years it has become clear that suggesting that at least a portion of monary vascular resistance. However, endogenously produced NO is ubiqui- inhaled NO survives long enough to when NO is delivered to well ventilated 7 tous in mammalian systems, playing an reach tissue remote from the lungs. The alveolar units with fast time constants, important role in both health and major immediate breakdown products of the deleterious impact on gas exchange is disease: in the regulation of blood NO in human plasma are inactive nitrox- avoided.19 This effect can also be achieved – pressure and flow, inflammatory re- ides such as nitrite (NO2 ). The rate of by using “pulsed” delivery of NO where sponses, and neurotransmission. Insight this reaction increases exponentially spikes of NO are added at the beginning into these physiological roles has led to with the concentration of both oxygen

of inspiration. The addition of oxygen to on September 23, 2021 by guest. Protected copyright. 8 its use as a therapeutic agent in a and NO. This has several consequences. NO further prevents hypoxaemia. number of clinical settings. Firstly, low NO concentrations or oxygen The study reported in this issue of There are ample data to support a free environments permit relatively long Thorax by Vonbank et al20 shows that long major role for NO in the regulation of term persistence of NO. Secondly, the term use of pulsed NO with oxygen tone and vascular remodelling in the therapeutic efficacy of inhaled NO may leadstosustainedimprovementinpulmo- normal and diseased pulmonary circula- not rise dramatically with increased nary haemodynamics without worsen- tion. Endothelial NO contributes signifi- doses as the more NO given, the faster it ing hypoxaemia in patients with stable cantly to the normally low pulmonary is oxidised.9 In fact, higher doses of NO COPD. Benefits of the pulsed method vascular tone,2 and dysfunction of en- result in a relatively greater proportion of include the reduced formation of nitro- dothelial NO release has been docu- toxic products with little incremental gen dioxide and methaemoglobinaemia. mented in patients with chronic obstruc- yield of intact NO. Finally, the rapid A further safety issue that needs to be tive pulmonary disease (COPD).34 inactivation of inhaled NO in an oxygen addressed is whether discontinuation of Although nitro-vasodilatation (acting rich environment is what makes NO a long term inhaled NO can lead to severe through the intracellular generation of selective pulmonary vasodilator. Inhala- rebound pulmonary hypertension. Al- NO) has been used effectively since the tion delivers NO to the pulmonary though the results presented by Vonbank 1800s for systemic arterial dilatation resistance vessels before it is oxidised. et al show promise, it remains to be (delivered sublingually, orally, and intra- The seconds before the inhaled NO determined whether pulsed NO/oxygen venously), the prospect of selective pul- enters the systemic circulation are treatment will lead to an improvement in monary nitro-vasodilatation only be- enough for its breakdown by interaction exercise tolerance, quality of life, and came evident in the early 1990s.5 with oxygen and haemoglobin. survival in patients with hypoxaemic Treatment with inhaled NO has subse- Pulmonary hypertension secondary to COPD. Potential disadvantages of the quently been applied in a variety of lung COPD is probably more common than is approach include the delivery system diseases which have in common a degree generally appreciated. Right heart cath- and monitoring systems necessary to of pulmonary vascular endothelial dys- eterisation studies suggest a prevalence ensure accurate dosing and safety. In function and/or abnormalities of gas of up to 40% in selected series of patients addition, long term gas therapies are far

www.thoraxjnl.com 284 EDITORIAL from convenient for the patient. NO 3 Dinh-Xuan AT, Higenbottam TW, Clelland pulmonary hypertension secondary to COPD. CA, et al. Impairment of Eur Respir J 2001;17:350–5. reduces pulmonary vascular resistance Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from endothelium-dependent pulmonary artery 13 Incalzi RA, Fuso L, De Rosa M, et al. by increasing cyclic GMP levels in vascu- relaxation in chronic obstructive lung disease. Electrocardiographic signs of chronic cor lar smooth muscle cells. This effect can N Engl J Med 1991;324:1539–47. pulmonale: a negative prognostic finding in also be achieved by inhibition of the 4 Peinado VI, Barbera JA, Ramirez J, et al. chronic obstructive pulmonary disease. Endothelial dysfunction in pulmonary arteries enzymes that metabolise cyclic GMP. Circulation 1999;99:1600–5. of patients with mild COPD. Am J Physiol Lung 14 Kessler R,FallerM,FourgautG,et al. Inhibitors of the type 5 cyclic GMP phos- Cell Mol Physiol 1998;274:L908–13. Predictive factors of hospitalization for acute phodiesterase such as sildenaﬁl may 5 Pepke-Zaba J, Higenbottam TW, Dinh-Xuan exacerbation in a series of 64 patients with have some selectivity for the pulmonary AT, et al. Inhaled nitric oxide as a cause of chronic obstructive pulmonary disease. Am J selective pulmonary vasodilatation in Respir Crit Care Med 1999;159:158–64. circulation, and it remains to be seen pulmonary hypertension. Lancet 15 Santos S, Peinado VI, Ramirez J, et al. 338 whether these drugs administered orally 1991; :1173–4. Characterization of pulmonary vascular Carlsen E may have an effect equivalent to inhaled 6 , Comroe JH. The rate of uptake of remodelling in smokers and patients with mild carbon monoxide and of nitric oxide by COPD. Eur Respir J 2002;19:632–8. NO. normal human erythrocytes and 16 Zhang W, Yatskievych TA, Cao X, et al. experimentally produced spherocytes. JGen Regulation of Hex gene expression by a Thorax 2003;58:283–284 Physiol 1958;42:83–107. Smads-dependent signaling pathway. J Biol 7 Cannon RO III, Schechter AN, Panza JA, et Chem 2002;277:45435–41...... al. Effects of inhaled nitric oxide on regional 17 Germann P, Ziesche R, Leitner C, et al. Authors’ affiliations blood flow are consistent with intravascular nitric oxidedelivery. J Clin Invest Addition of nitric oxide to oxygen improves J Pepke-Zaba, N W Morrell, Pulmonary 2001;108:279–87. cardiopulmonary function in patients with 114 Vascular Diseases Unit, Papworth Hospital, 8 Ford PC, Wink DA, Stanbury DM. severe COPD. Chest 1998; :29–35. Papworth Everard, Cambridgeshire CB3 8RE, Autoxidation kinetics of aqueous nitric oxide. 18 Katayama Y, Higenbottam TW, Diaz de UK FEBS Lett 1993;326:1–3. Atauri MJ, et al. Inhaled nitric oxide and 9 Kinsella JP, Neish SR, Shaffer E, et al.Low arterial oxygen tension in patients with Correspondence to: Dr N W Morrell, dose inhalation nitric oxide in persistent chronic obstructive pulmonary disease and Department of Medicine, University of pulmonary hypertension of the newborn. severe pulmonary hypertension. Thorax Cambridge School of Clinical Medicine, Lancet 1992;340:819–20. 1997;52:120–4. Addenbrooke’s Hospital, Box 157, Hills Road, 10 Weitzenblum E, Loiseau A, Hirth C, et al. 19 Roger N, Barbera JA, Roca J, et al. Nitric Cambridge CB2 2QQ, UK; [email protected] Course of pulmonary hemodynamics in oxide inhalation during exercise in chronic patients with chronic obstructive pulmonary obstructive pulmonary disease. Am J Respir 156 REFERENCES disease. Chest 1979;75:656–62. Crit Care Med 1997; :800–6. 11 Weitzenblum E, Hirth C, Ducolone A, et al. 20 Vonbank K, Ziesche R, Higenbottam TW, et 1 www.nobel.se/medicine/laureats/1998. Prognostic value of pulmonary artery pressure al. Controlled prospective randomised trial on 2 Stamler JS, Loh E, Roddy MA, et al. Nitric in chronic obstructive pulmonary disease. the effects on pulmonary haemodynamics of oxide regulates basal systemic and pulmonary Thorax 1981;36:752–8. the ambulatory long term use of nitric oxide vascular resistance in healthy humans. 12 Higham MA, Dawson D, Joshi J, et al. Utility and oxygen in patients with severe COPD. Circulation 1994;89:2035–40. of echocardiography in assessment of Thorax 2003;58:289–93.

Childhood asthma efﬁcacy in improving a number of

...... important outcomes including the need http://thorax.bmj.com/ for, and duration of, mechanical ventilation in acute childhood asthma. Second line treatment for severe A study by Roberts et al8 in this edition of Thorax is the ﬁrst to compare the two acute childhood asthma agents using a good trial design. The authors have attempted to study these M South second line treatments in a randomised controlled trial to compare an intra- ......

venous bolus of salbutamol with a load- on September 23, 2021 by guest. Protected copyright. ing dose of aminophylline followed by an The choice of treatment for a child with severe acute asthma intravenous infusion. They have inevita- unresponsive to high dose inhaled bronchodilators and oral or bly come across two of the major intravenous corticosteroids is still the subject of debate. obstacles faced by anyone studying acute Although both salbutamol and aminophylline have been asthma episodes in children: (1) how to study such very sick children and (2) around for a long time and have been the subject of many what outcomes are both measurable and studies, it is still not possible unreservedly to recommend one important in this context? Improvement of these agents over the other as second line treatment. in severity score and reduced length of hospital stay are clearly of interest but are not the main goals of treatment. ost physicians would agree that reach next for intravenous salbutamol or Unfortunately, despite the inclusion of first line treatment for an acute intravenous aminophylline, although five hospitals in the study, their sample Mexacerbation of childhood some will consider other treatments. size is still relatively small with only 44 asthma should be the administration of Salbutamol and aminophylline have subjects. Although this was the required high dose inhaled bronchodilators1 and been shown to be individually better number from the calculations, it is too corticosteroids administered either than placebo in severe acute asthma.34 small to address important outcomes orally or intravenously,2 but when a child Although a recent Cochrane systematic such as the need for intensive care with severe acute asthma is unrespon- review appeared to cast doubt on this admission or mechanical ventilation, sive to such treatment—what should statement for salbutamol,5 many suspect and much too small to examine an come next? This is an important ques- that this is a flaw caused by the inclusion impact on long term morbidity or mor- tion that is faced by doctors every day in of several very weak early studies of tality from severe asthma exacerbations. emergency departments, paediatric salbutamol in the analysis. A large study In their salbutamol group 11% of pa- wards, and intensive care units the world of aminophylline6 and another Cochrane tients required intubation and ventila- over. Most commonly, physicians will systematic review7 have confirmed its tion, while only 4% in the aminophylline

www.thoraxjnl.com EDITORIAL 285 group required such intervention. It is a advantages for efficacy but at the cost of ...... pity that the study is too small to draw any additional adverse effects. There is also Author’s affiliation Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from statistical inference from this difference. very limited evidence about the efficacy M South, Director, Department of General The results of the study are useful but of using intravenous salbutamol and Medicine, Royal Children’s Hospital; Associate Professor and Deputy Head, Department of they could have been even more powerful aminophylline together, although it is quite common practice for them to be Paediatrics, University of Melbourne; Research if the investigators had chosen to use Fellow, Murdoch Children’s Research Institute, each of the agents in an optimal fashion. used in this way. Melbourne, Australia To further complicate decision making For the intravenous salbutamol arm, the in severe acute asthma, a number of Conflict of interest: none. study design would have been better if other treatments present themselves as they had included either repeated bolus Correspondence to: Dr M South, Royal candidates for second line therapy. These Children’s Hospital, Parkville, Victoria 3052, doses or an infusion of salbutamol. For β include alternative 2 agonists (such as Australia; [email protected] the aminophylline arm, the loading dose adrenaline); inhalational anaesthetic given (5 mg/kg) was small and the levels agents (such as halothane); intravenous REFERENCES achieved were probably inadequate to magnesium sulphate; inhaled helium- 1 Plotnick L, Ducharme F. Combined inhaled β fully test the efficacy of the agent. Despite oxygen mixtures; or non-invasive me- anticholinergics and 2 agonists for initial these limitations, the study was well con- chanical respiratory support of various treatment of acute asthma in children (Cochrane Review). In: Cochrane Library. ducted and the results have implications forms such as face mask continuous Issue 4. Oxford: Update Software, 2002. for everyday paediatric practice. positive airway pressure (CPAP). Most of 2 Rowe B, Spooner C, Ducharme F, et al. Early Efficacy is only one issue in choosing these treatments have only a theoretical emergency department treatment of acute basis for their use, or evidence from case asthma with systemic corticosteroids between treatments. For salbutamol and (Cochrane Review). In: Cochrane Library. aminophylline cost differentials and ad- reports or small studies comparing them Issue 4. Oxford: Update Software, 2002. ministration practicalities are irrelevant, with placebo or no treatment. There are 3 Browne GJ, Penna AS, Phung X, et al. Randomised trial of intravenous salbutamol in but differences in drug safety may be no useful comparative studies, and it is going to become increasingly difficult to early management of acute severe asthma in important. Aminophylline has a rela- children. Lancet 1997;349:301–5. evaluate the place of the multitude of Ream RS tively narrow therapeutic margin, with 4 , Loftis LL, Albers GM, et al. Efficacy treatments available with any certainty. of IV theophylline in children with severe status nausea and vomiting being common What is certain is that emergency treat- asthmaticus. Chest 2001;119:1480–8. 5 Travers A, Jones A, Kelly K, et al. Intravenous even with drug levels in the therapeutic ment should not be delayed, and that beta2 agonists for acute asthma in the range. Severe toxicity has been reported any agents chosen must be used both emergency department (Cochrane Review). In: when the drug is given in overdose. optimally and safely. Cochrane Library. Issue 4. Oxford: Update There are a large number of children Software, 2002. The bad news for children with severe 6 Yung M, South M. Randomised controlled worldwide who suffer severe exacerba- acute asthma is that the doctors caring trial of aminophylline for severe acute asthma. tions of asthma each year; both salbuta- for them will have to make decisions Arch Dis Child 1998;79:405–10. mol and aminophylline have been between complex treatment regimens 7 Mitra A, Bassler D, Ducharme FM. Intravenous aminophylline for acute severe around for a long time and many studies with only limited scientific evidence to asthma in children over 2 years using inhaled have been conducted. It is therefore sur- aid them. The good news, however, is bronchodilators (Cochrane Review). In: that the risk of death or an adverse out- Cochrane Library. Issue 4. Oxford: Update http://thorax.bmj.com/ prising that we still cannot unreservedly Software, 2002. recommend which of these agents to come from acute asthma is fortunately 8 Roberts G, Newsom D, Gomez K, et al. choose first when faced with the small once the child has reached a high Intravenous salbutamol bolus compared with quality health care facility. an aminophylline infusion in severe asthma: a scenario described above. On balance, randomised controlled trial. Thorax it seems that aminophylline has Thorax 2003;58:284–285 2003;58:306–10.

Critical care compared with perhaps only two or three on September 23, 2021 by guest. Protected copyright...... nurses looking after 30 patients at night with minimal continuous monitoring on a general medical ward, some patients Improving the care for patients with will be admitted to the ICU who could be managed elsewhere. This is economically acute severe respiratory disease disadvantageous. Alternatively, patients may be looked after in an area in which M W Elliott proper care is not possible. This is an issue of standards of care and clinical ...... governance. In the UK there are a number of drivers towards improving Services to improve the care of patients with acute severe the acute care for medical patients medical conditions in general, and respiratory disease in including two recent reports—one from particular, need to be improved. This includes access to a the Royal College of Physicians of non-invasive ventilation service, available 24 hours per day, in London1 and the other from the NHS Modernisation Agency.2 Patients with all hospitals admitting patients with acute medical conditions. respiratory failure constitute a signiﬁ- cant proportion of medical admissions n the early 1960s the ﬁrst coronary the only options are usually either and the development of appropriate care units (CCU) were established and admission to an intensive care unit services for these patients is important Iare now a “given” in every hospital (ICU) or to a general medical ward. from both the clinical governance and admitting patients with acute cardiac Inevitably, given the differences in staff- the economic perspectives. The provision disease. For patients admitted to hospital ing and facilities with one nurse looking of appropriate facilities for patients with with physiological disturbance due to after one patient with comprehensive acute severe respiratory disease is not non-acute cardiac medical conditions, physiological monitoring on the ICU just an issue in the UK.3

www.thoraxjnl.com 286 EDITORIAL

CLINICAL GOVERNANCE hours of the cardiac arrest. Common 7.35),13 moderate (pH 7.25–7.30),14–17 and 18 The report by the Royal College of Physi- findings included failure of the nurse to severe (pH <7.25) acidotic exacerba- Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from cians (RCP) Working Party looked at the notify a physician of a deterioration in the tions of chronic obstructive pulmonary interface between acute medicine and patient’s mental status or failure of the disease (COPD).11 It is best instituted critical care and highlighted the fact that physician to obtain or interpret an arterial “early” before ventilatory support is the standard of care received by acutely blood gas measurement in the setting of definitely needed but, even when the ill inpatients in the UK has been shown respiratory distress. Cardiac arrests were patient appears to warrant intubation to be suboptimal in a number of recent more common in patients discharged and mechanical ventilation, there is surveys and publications.1 In a confiden- from the ICU. Schein et al7 reported a much to be gained and little to be lost by 18 tial inquiry into quality of care before similar picture with 84% of inpatient car- a trial of NIV. NIV has also been used in admission to the ICU,4 two external diac arrests having documented deterio- patients with hypoxaemic respiratory reviewers assessed the quality of care— ration within 8 hours of the event. There is failure resulting from a variety of differ- 19–22 especially recognition, investigation, therefore a clear need to improve the ent conditions. It has been shown to monitoring, and management of abnor- quality of care afforded to patients with be both more effective and cheaper than 23 malities of airway, breathing and circula- acute non-cardiac medical conditions. intubation and ventilation on the ICU There are a number of solutions,8 and conventional treatment on general tion, oxygen therapy and 24 including better education of medical and wards. It is certainly feasible outside monitoring—in 100 consecutive admis- 13 sions to two UK ICUs. Twenty patients nursing staff and more senior input into the ICU. were deemed by both to have been well the assessment of patients at an early A review of adult critical care services managed and 54 to have received subop- stage in the admission. ICU outreach in the UK published by the Department of Health9 recognised that NIV was one timal management, with disagreement teams are strongly recommended to avert of a number of clinical areas impacting about the remainder. Case mix and admissions by identifying patients who upon the level of critical care provision severity were similar between the are deteriorating and either helping to that required additional evaluation. In groups, but ICU mortality was worse in prevent admission or ensuring that ad- response the NHS Modernisation those who both reviewers agreed re- mission to a critical care bed happens in a Agency Critical Care Team assembled a ceived suboptimal care. Admission to the timely manner to ensure best outcome.9 multiprofessional working group to dis- ICU was considered late in 37 patients in This presupposes that such patients are cuss the issues relating to current prac- brought to the attention of the team and the suboptimal group. Overall, a mini- tice and the resources needed to deliver a mum of 4.5% and a maximum of 41% of this can be helped by the use of early 10 service. Their report and an Executive warning scores. The team needs to be 2 admissions were considered potentially Summary were published in April 2002 avoidable. Suboptimal care contributed available 24 hours per day. The RCP Work- and are available at www.criticalcare. to morbidity or mortality in most in- ing Party recommended that appropriate nhs.uk. A key recommendation was that stances. The main causes were failure of facilities for provision of level 2 care (see “an NIV service be established in each organisation, lack of knowledge, failure box 1) to medical patients be available. acute trust for the management of to appreciate clinical urgency, lack of Ideally this should be in close proximity to patients with acute respiratory fail- supervision, and failure to seek advice. the level 3 facility and suggests the need ure . . ..”. A number of further recom- 5 http://thorax.bmj.com/ In another UK study of patients either for a unit for medical patients, of whom a mendations were made including that dying unexpectedly on a general ward or significant proportion will be those with NIV should be available continuously, requiring admission to the ICU during a respiratory disease. appropriately supported by nursing and 6 month period, 317 of the 477 hospital allied health professional staff, equipped deaths occurred on the general wards of NON-INVASIVE VENTILATION to standards specified by the British which 20 (6%) followed failed attempts There is now a robust evidence base11 12 Thoracic Society25 with data collection at resuscitation. Thirteen of these unex- for the use of non-invasive ventilation and audit facilities and a training facility pected deaths were considered poten- (NIV) in patients with mild (pH 7.31– for all junior medical, nursing, and allied tially avoidable: gradual deterioration

health professional staff. on September 23, 2021 by guest. Protected copyright. was observed in physiological and/or Acute NIV has grown out of home ven- biochemical variables, but appropriate Box 1 Levels of care as defined tilation and the technology necessary to action was not taken. During the same by the Department of Health9 deliver it is easily portable. It could there- period 86 hospital inpatients were ad- fore be argued that it is easy to take the mitted on 98 occasions to the ICU, 31 of Level 0: Patients whose needs can be equipment to the patient and there is no whom received suboptimal care before met through normal ward care in an need to have a specialist unit with NIV the ICU admission either because of acute hospital. being possible for all patients in any clini- non-recognition of (the severity of) the Level 1: Patients at risk of their condition cal area. However, the evidence does not problem or inappropriate treatment. deteriorating, or those recently relo- support this approach for the generality of Mortality rates were signiﬁcantly higher cated from higher levels of care whose patients needing NIV. In a study by Plant in these patients than in well managed needs can be met on an acute ward with et al,13 while it was clear that NIV was fea- patients in both the ICU (52% v 35%) and additional advice and support from the sible on a standard general ward with the hospital (65% v 42%), p<0.0001. The critical care team. usual stafﬁng complement, subgroup authors concluded that patients with Level 2: Patients requiring more detailed analysis suggested that the outcome for obvious clinical indicators of acute dete- observation or intervention including those with a pH of <7.30 using a simple rioration can be overlooked or poorly support for a single failing organ system ventilator according to protocol was not as managed on the ward. or postoperative care and those “step- good as the results seen in patients with 6 In a study from the USA the records of ping down” from higher levels of care. similar illness severity managed in a consecutive inpatients who had a cardiac Level 3: Patients requiring advanced higher dependency setting. There is much arrest over a 20 month period were respiratory support alone or basic respi- more to NIV than the provision of the reviewed. There were 150 cardiac arrests ratory support together with support of necessary hardware and there are many on the medical wards with a hospital at least two organ systems. This level advantages to concentrating the NIV mortality rate of 91%. In 99 cases a nurse includes all complex patients requiring service in one location. Foremost among or physician had documented deteriora- support for multiorgan failure. these is the development of the appropri- tion in the patient’s condition within 6 ate expertise, particularly among the

www.thoraxjnl.com EDITORIAL 287 nursing staff. Whether nurses are the pri- patients, driven by cancelled operations logical way forward. Such units should mary deliverers of NIV or whether an- because of the lack of ICU bed and wait- not function in isolation and clear proto- Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from other professional group such as physi- ing list targets. Physicians as a group cols and coordination with intensive care otherapists or technicians takes the main should certainly be pressing for more units are vital. role, the nurses must be familiar with it level 2 facilities for their patients. How- Thorax 2003;58:285–288 because they are the only healthcare pro- ever, if these are not forthcoming, the fessionals who are with the patient 24 need to improve the standard of care for hours per day. They must be both confi- patients with acute respiratory disease ...... dent about the technique and recognise and to provide an NIV service could be Author’s affiliation when there are problems, particularly of a achieved in respiratory medicine at a M W Elliott, St James’s University Hospital, technical nature. Continued use of skills relatively small extra cost compared with Beckett Street, Leeds LS9 7TF, UK; [email protected] once learnt is important in maintaining many other critical care initiatives. them, and this will be facilitated by The experience of NIV in Continental concentrating all the NIV in one area. European and North American ICUs REFERENCES Plant et al26 showed that if all patients suggests that a nurse to patient ratio of 1 Royal College of Physicians. The interface between acute general medicine and critical needing NIV shortly after admission to an 1:3 or 4 is satisfactory, which compares care. Report of a Working Party of the Royal average district hospital with an acute favourably in economic terms with a College of Physicians. London: Royal College exacerbation of COPD were managed in classical UK HDU in which one nurse is of Physicians, 2002. 2 NHS Modernisation Agency. Critical care two areas, the staff would treat <1 recommended for two patients. Desig- programme: weaning and long term patients per month 20% of the time, nating part—say, one bay—of a larger ventilation. London: NHS Modernisation whereas if it was all delivered in one specialist ward as a mixed sex “acute Agency, 2002. mixed sex location this reduced to 2%. respiratory care unit” would provide a 3 Corrado A, Roussos C, Ambrosino N, et al. Respiratory intermediate care units: a NIV is used for many other conditions, but focus for NIV, as well as the care of level European survey. Eur Respir J patients with an acute exacerbation of 1 and 2 patients with acute severe respi- 2002;20:1343–50. COPD are likely to remain the largest ratory disease. In such a unit staff can be 4 McQuillan P, Pilkington S, Allan A, et al. Confidential inquiry into quality of care before group. A single location also facilitates the used flexibly and there is no need for admission to intensive care. BMJ purchase and use of appropriate monitor- major and expensive building works. It is 1998;316:1853–8. ing equipment and storage of both venti- largely an administrative change, with 5 McGloin H, Adam SK, Singer M. Unexpected lators and consumables. some extra staffing resource and im- deaths and referrals to intensive care of patients on general wards. Are some cases One further approach to consider is proved monitoring. The patients are potentially avoidable? J R Coll Physicians Lond that of an NIV team, perhaps led by a already being cared for within the medi- 1999;33:255–9. nurse consultant, which does indeed cal (usually) bed base; instead of being 6 Franklin C, Mathew J. Developing strategies to prevent inhospital cardiac arrest: analyzing take the technology to the patient. This is dispersed they are now in one location. responses of physicians and nurses in the in keeping with the philosophy behind The beds must be considered in the same hours before the event. Crit Care Med comprehensive critical care—namely, of light as coronary care and other higher 1994;22:244–7. a service rather than a place—but it is dependency beds in terms of bed man- 7 Schein RM, Hazday N, Pena M, et al. Clinical antecedents to in-hospital difficult and expensive to provide such a agement to ensure that the patients who cardiopulmonary arrest. Chest http://thorax.bmj.com/ service 24 hours per day throughout the need acute respiratory care are managed 1990;98:1388–92. year. Because the nurse primarily re- in the right environment. It should no 8 McAuley D, Perkins GD. Training in the management of the acutely ill medical patient. sponsible for the bedside care of the longer be acceptable—even at times of Clin Med 2002;2:323–6. patient is unlikely to be familiar with great pressure when medicine extends 9 Department of Health. Comprehensive NIV or to gain much experience of it over outside its bed base—for acute admis- critical care: a review of adult critical care services. London: Department of Health, time, a lot of “hands on” support will be sions with physiological compromise 2000. required on a “one to one” basis. It may due to respiratory or any other organ 10 Subbe CP, Kruger M, Rutherford P, et al. be difficult for the team if there are a failure to be managed at the end of a Validation of a modified early warning score in medical admissions. QJMed number of patients receiving NIV dis- on September 23, 2021 by guest. Protected copyright. non-acute surgical ward. 2001;94:521–6. persed around the hospital. In practice A further advantage of such units is 11 Peter JV, Moran JL, Phillips-Hughes J, et al. most of the time is needed at initiation of that they can allow earlier discharge of Noninvasive ventilation in acute respiratory NIV13 15 27 and, once patients are estab- some patients with respiratory disease failure: a meta-analysis update. Crit Care Med 2002;30:555–62. lished, they will just need a watching from level 3 beds. Training and education 12 Lightowler JV, Wedzicha JA, Elliott MW, et brief and regular review, but help should are vital,125 and junior medical staff al. Non-invasive positive pressure ventilation be readily available if there are problems. should spend some time in critical care to treat respiratory failure resulting from exacerbations of chronic obstructive The exact model will vary from hospi- areas as part of their general professional pulmonary disease: Cochrane systematic 1225 tal to hospital, but there is now a clear training. Respiratory physicians review and meta-analysis. BMJ requirement to provide an acute NIV must ensure that all junior medical and 2003;326:185–9. service2 in all hospitals admitting emer- nursing staff are adequately trained in 13 Plant PK, Owen JL, Elliott MW. Early use of non-invasive ventilation for acute gency medical patients and to improve the management of acute severe respira- exacerbations of chronic obstructive the standard of care for patients with tory disease. Some consultants who were pulmonary disease on general respiratory acute severe medical conditions appointed before NIV became available wards: a multicentre randomised controlled 1 trial. Lancet 2000;355:1931–5. generally. These requirements may be may need training in this specific area. In 14 Brochard L, Mancebo J, Wysocki M, et al. best met by a general medical or multi- the future the training of more physi- Noninvasive ventilation for acute specialty high dependency unit (HDU). cians with dual accreditation in respira- exacerbations of chronic obstructive pulmonary disease. N Engl J Med However, in a recent survey only 26% of tory medicine and critical care is 1995;333:817–22. 29 30 190 general hospitals with an ICU had an desirable. The requirement to provide 15 Kramer N, Meyer TJ, Meharg J, et al. HDU28; the proportion of beds allocated an acute 24 hour per day NIV service is a Randomized, prospective trial of noninvasive for medical patients was not stated. major driver to improve the standard of positive pressure ventilation in acute respiratory failure. Am J Respir Crit Care Med Anecdotal evidence suggests that there care for all patients with acute severe 1995;151:1799–806. has been a considerable expansion in respiratory disease. The development of 16 Celikel T, Sungur M, Ceyhan B, et al. HDU facilities in the last 2–3 years, but acute respiratory care units, either inte- Comparison of noninvasive positive pressure ventilation with standard medical therapy in there are no firm data on this. Most of grated into a more general HDU or as hypercapnic acute respiratory failure. Chest the extra provision has been for surgical part of an existing respiratory ward, is a 1998;114:1636–42.

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17 Martin TJ, Hovis JD, Costantino JP, et al.A 21 Antonelli M, Conti G, Bufi M, et al. 26 Plant PK, Owen J, Elliott MW. One year randomized, prospective evaluation of Noninvasive ventilation for treatment of acute period prevalance study of respiratory Thorax: first published as 10.1136/thorax.58.4.284 on 1 April 2003. Downloaded from noninvasive ventilation for acute respiratory respiratory failure in patients undergoing solid acidosis in acute exacerbation of COPD: failure. Am J Respir Crit Care Med organ transplantation: a randomized trial. implications for the provision of non-invasive 2000;161:807–13. JAMA 2000;283:235–41. ventilation and oxygen administration. Thorax 18 Conti G, Antonelli M, Navalesi P, et al. 22 Hilbert G, Gruson D, Vargas F, et al. 2000;55:550–4. Nava S Noninvasive vs. conventional mechanical Noninvasive ventilation in immunosuppressed 27 , Evangelisti I, Rampulla C, et al. ventilation in patients with chronic obstructive patients with pulmonary infiltrates, fever, and Human and financial costs of noninvasive acute respiratory failure. N Engl J Med mechanical ventilation in patients affected by pulmonary disease after failure of medical 2001;344:481–7. COPD and acute respiratory failure. Chest treatment in the ward: a randomized trial. 23 Keenan SP, Gregor J, Sibbald WJ, et al. 1997;111:1631–8. Intensive Care Med 2002;28:1701–7. Noninvasive positive pressure ventilation in 28 Edbrooke DL, Stevens VG, Hibbert CL, et al. Antonelli M 19 , Conti G, Rocco M, et al.A the setting of severe, acute exacerbations of High dependency units in England: the lack of comparison of noninvasive positive-pressure chronic obstructive pulmonary disease: more provision and the cost of addressing the ventilation and conventional mechanical effective and less expensive. Crit Care Med shortfall. Care Critically Ill 1997;13:216–9. ventilation in patients with acute respiratory 2000;28:2094–102. 29 Griffiths MJ, Evans TW. The pulmonary failure. N Engl J Med 1998;339:429–35. 24 Plant PK, Owen J, Elliott MW. A cost physician in critical care: towards 20 Confalonieri M, Potena A, Carbone G, et al. effectiveness analysis of non-invasive comprehensive critical care? Thorax Acute respiratory failure in patients with ventilation (NIV) in acute exacerbations of 2002;57:77–8. severe community-acquired pneumonia. A COPD. Thorax 1999;54(Suppl 3):A11. 30 Evans T, Elliott MW, Ranieri M, et al. prospective randomized evaluation of 25 British Thoracic Society. Non-invasive Pulmonary medicine and (adult) critical care noninvasive ventilation. Am J Respir Crit Care ventilation in acute respiratory failure. Thorax medicine in Europe. Eur Respir J Med 1999;160:1585–91. 2002;57:192–211. 2002;19:1202–6.

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