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Noninvasive mechanical ventilation in the postoperative cardiac surgery period: update of the literature

Lucas Lima FerreiraI; Naiara Maria de SouzaII; Ana Laura Ricci VitorII; Aline Fernanda Barbosa BernardoII; Vitor Engrácia ValentiIII; Luiz Carlos Marques VanderleiIII

DOI: 10.5935/1678-9741.20120074

ABSTRACT

This study aimed to update knowledge regarding to noninvasive ventilation (NVI) on postoperative of cardiac surgery in addition at investigating if exists superiority of any modalities NVI in relation to the others. The literature review was performed on the period between 2006 and 2011, on PubMed, SciELO and Lilacs databases crossing the keywords: artificial respiration, continuous positive airway pressure, intermittent positive-pressure ventilation, cardiac surgery and their corresponding in English. Based on the criteria adopted, nine articles were selected being six of them use NVI, through the modalities such as continuous positive airway pressure, positive pressure with bilevel pressure and intermittent positive-pressure ventilation in postoperative of cardiac surgery; only three of them performed comparisons between different modalities. The NVI modalities that were described on the literature had showed satisfactory results. A few studies compare different NVI modalities; however some of them showed superiority in relation to the others, such as the intermittent positive-pressure ventilation to threat hypoxemia and to positive pressure with bilevel pressure to increase oxygenation, respiratory rate and heart rate in these patients, when compared with other modalities.

RESUMO

Este estudo objetivou atualizar os conhecimentos em relação à utilização da ventilação mecânica não-invasiva (VMNI) no pós-operatório de cirurgia cardíaca e identificar se há indícios da superioridade de uma forma de modalidade de VMNI em relação à outra. Foi realizada revisão da literatura entre 2006 a 2011, a partir das bases de dados PubMed, SciELO e Lilacs, utilizando os descritores respiração artificial, pressão positiva contínua nas vias aéreas, ventilação com pressão positiva intermitente e cirurgia cardíaca, e seus correspondentes na língua inglesa, os quais foram pesquisados em cruzamentos. A partir dos critérios adotados, foram selecionados nove artigos, dos quais seis demonstraram aplicações de VMNI, por meio de modalidades como pressão positiva contínua nas vias aéreas, pressão positiva com dois níveis pressóricos e respiração com pressão positiva intermitente, no pós-operatório de cirurgia cardíaca, e, três realizaram comparações entre as diferentes modalidades. As modalidades de VMNI descritas na literatura foram utilizadas com resultados satisfatórios. Estudos que comparam diferentes modalidades são escassos, contudo alguns demonstraram superioridade de uma modalidade de VMNI, como é o caso da respiração com pressão positiva intermitente na reversão da hipoxemia e da pressão positiva com dois níveis pressóricos na melhora da oxigenação, da frequência respiratória e frequência cardíaca desses pacientes, em comparação a outras modalidades.

ABBREVIATIONS AND ACRONYMS

BiPAP®: Bi-level positive airway pressure

C S: Cardiac surgery

CPB: Cardiopulmonary bypass

CPAP: Continuous positive airway pressure

VC: Vital capacity

C O: Cardiac output

CVD: Cardiovascular diseases

DeCS: Descriptors in Health Sciences

HR: Heart rate

CRP: Conventional respiratory physioterapy

IS: Incentive spirometry

RespF: Respiratory failure

MeSH: Medical Subject Headings

RM: Recruitment maneuver

PO: Postoperative

CABG: Coronary artery bypass grafting

IPPB: Intermittent positive pressure breathing

VPR: Ventilation perfusion rating

MV: Mechanical ventilation

NIV: Noninvasive mechanical ventilation

INTRODUCTION

Cardiovascular diseases (CVD) are among the leading causes of death in developed countries and their incidence has increased in epidemic form in emerging countries [1]. Among the options for the treatment of these diseases, cardiac surgery (CS) has shown good results, contributed to rising expectations and improving the quality of life of patients with CVD [1-3].

Changes in lung function may occur after CS, which are responsible for increased postoperative (PO) morbidity and mortality [4] and are resulting from multifactorial interaction between anesthesia, surgical trauma, cardiopulmonary bypass (CPB), cardiac arrest, time of surgery, duration of mechanical ventilation (MV) and pain, which may lead, among others, to decrease in functional residual capacity, increased intrapulmonary shunt and enlargement of the alveolar-arterial oxygen [4,5].

In this context, noninvasive ventilation (NIV) has been important in the treatment of POCS, because its use improves alveolar ventilation and gas exchange, decreases ventilatory work, increases lung volumes and decreases the duration of mechanical ventilation, avoiding reintubation and, as a consequence, reducing the length of permanence in intensive care units [6-10].

Furthermore, the application of NIV reduces preload by reducing the venous return, reduces afterload in the left ventricle by reducing its transmural pressure and increases cardiac output (CO), which leads to improved heart performance as a pump [6.11].

The modalities of NIV with positive pressure used in the treatment of postoperative pulmonary complications in the POCS described in the literature are ventilation with continuous positive airway pressure (CPAP), BI-level Positive Airway Pressure (BiPAP ®) and intermittent positive pressure breathing (IPPB) [12,13]. The superiority of one modality over another NIV has not been clearly established in the literature [13].

In view of the above considerations, we understand the importance of studies that add new elements in the literature regarding this issue. Therefore, we aimed to update the literature regarding the use of NIV in the POCS and to identify if there is evidence of the superiority of NIV modality.

 

METHODS

Search strategy

The revisions were performed on April 2012, the references used were situated between January 2006 and December 2011. The Pubmed, Lilacs and SciELO databases were searched using the following subject keywords: artificial respiration, continuous positive airway pressure, intermittent positive-pressure ventilation, cardiac surgery. These words were defined by the Health Sciences Descriptors (DeCS) and their corresponding in English -Medical Subject Headings (MeSH).

The term noninvasive ventilation, while not considered a descriptor by the NLM - MESH, was included due to its wide use as a keyword. All references were also reviewed for completion of the research. The studies were selected by a reviewer and supervised by a senior reviewer.

Exclusion and Inclusion Criteria

We included studies published in the last five years, in English and Portuguese, with humans over 18 years old with heart diseases who have undergone some type of surgical intervention. We included randomized and nonrandomized controlled trials.

Abstracts of dissertations or academic thesis, studies in children and adolescents, and studies using NIV in other pathological conditions other than heart were excluded.

Selection Strategy

We initially performed the screening of titles related to the topic. This selection was based on titles that dealt as main idea: the application of NIV in POCS, several types of NIV used, the performances of physiotherapy on cardiac patients undergone CS and, finally, to present evidence of some NIV term information related to this word such as ventilation with continuous positive airway pressure, BI-level Positive Airway Pressure. At the end of the search, we excluded repeated titles, as this was performed in several databases. Then we read detailed summaries of articles in order to select those that addressed only the application of NIV in POCS. We excluded abstracts not related to the issue, the full texts were assessed and those that did not fit the exclusion criteria were included as the final result of the search.

Data Analysis

Data were qualitatively assessed and presented in tabular form with the description of the following profile: author and year of study, clinical characteristics of the population, the study objectives, ventilatory mode applied, variables and conclusions found.

 

RESULTS

The search in the databases resulted in 1447 titles. The first selection eliminated 1398 titles. Then we proceeded to assess the content of the summaries of the remaining 49 studies, of which 38 were eliminated for not meeting the criteria previously established. The 11 remaining articles were read in full and composed the review.

We found eight studies that used some modality of NIV in the POCS, which are described in Table 1.

 

 

Only three of the articles compared different NIV modalities in the POCS and were used to assess possible evidence of superiority of one NIV technique. These studies are described in Table 2.

 

 

DISCUSSION

Application of NIV in the CSPO.

Regarding the application of NIV in the POCS, eight studies demonstrated its application through the following modalities: CPAP, BiPAP ®, IPPB + PEEP and PSV, and most of the studies assessed showed positive evidence of the implementation of those modalities in the cardiac PO patients.

Figueiredo et al. [14] compared the rates of gas exchange after surgery in patients undergoing coronary artery bypass grafting (CABG) with or without CPAP during cardiopulmonary bypass (CPB) and found that the use of CPAP, although it resulted in better values in PaO2/FiO2 30 minutes after CPB, it showed no significant sustained effect on postoperative pulmonary gas exchange. The authors reported that was not possible to demonstrate that the application of CPAP during CPB prolonged beneficial effect on gas exchange during the PO. The authors cited as limitation the small population sample used, which may have influenced the results.

Other authors [15] assessed the efficacy of prophylactic CPAP, performed with a nasal mask at a pressure of 10 cmH2O airway for six hours, compared with standard treatment in patients undergoing elective CS, and found that the prophylactic CPAP improved oxygenation pressure, reduced the incidence of pulmonary complications and decreased the rate of readmission in the intensive care unit. The authors attributed these results to airway pressures high enough (10 cmH2O) throughout the respiratory cycle and maintaining such pressure for longer periods of time (six hours), which led to reduction in atelectasis.

The pulmonary effects of CPAP with or without intermittent recruitment maneuver (RM) in patients after CABG surgery were assessed by a randomized clinical trial, in which it was found that the RM provided higher blood oxygen level during the MV and after extubation compared with other interventions. Oxygenation was better in groups using CPAP compared to the control group and pulmonary function of NIV groups on the 2nd postoperative day was better than the other groups. The authors reported that CPAP has been used intermittently to avoid gastric distension, restricted oral intake, nausea and vomiting, and that NIV improved radiological scores of atelectasis [16].

A randomized clinical trial assessed the safety and compliance of preventive application of BiPAP ® in spontaneous mode with IPAP 8-12 cmH2O and EPAP at 6 cm H2O, twice daily for 30 minutes associated with conventional respiratory therapy (CRT) in patients in the immediate postoperative [17]. The authors found that the application of BiPAP ® was beneficial to restore lung function, especially vital capacity (VC), safely, and well accepted by patients, due to higher comfort with the sensation of pain during the execution of CRT and the use of BiPAP ® leads to an increase in the incursion chest with consequent improvement in the efficacy of cough, increased secretion clearance and airway patency, by improving the peak flow [17].

The preventive efficacy of NIV in the pressure support ventilation combined with positive end expiratory pressure (PEEP + PSV) for two hours, was assessed in the immediate POCS in a randomized controlled trial, which showed significant results in hemodynamic and ventilatory variables assessed after NIV compared to post-extubation [6]. The hemodynamic benefits were attributed to the increase in VC, accompanied with increase in lung volume and decreased respiratory work, and maintenance of HR within the normal range [6].

Most studies assessed positive evidence of the NIV application in POCS such as: improvement in arterial oxygenation [14-16], cough improvement [15,16], reestablishment of lung function with increased VC [6 , 17], reduced incidence of pulmonary complications [15], benefic effects on readmission rates in intensive care units [15], and also increased clearance of secretions and airway permeability [6.15].

Comparison of different modalities of NIV in the POCS

We found only three studies that indicated any superiority of one NIV modality over another. Assessing hemodynamic and ventilatory parameters induced by the application of IPPB and incentive spirometry (IS) in patients undergoing CABG, Romanini et al. [19] showed that IPPB was more efficient in reversing hypoxemia earlier, and it was also more effective to improve the strength of the respiratory muscles. According to the authors the IPPB is a passive process of lung expansion that does not require active work of breathing, which in the initial stage of recovery from surgery may lead to increased pain, restrict respiratory expansion and change the ventilationperfusion (V/Q), factors that may lead to the hypoxemia development [19].

Another comparison of different modalities of NIV in POCS was performed in patients with hypoxemic respiratory failure (RF), who were randomized in the CPAP, PSV + PEEP or BiPAP® modalities. Oxygenation variables and respiratory rate showed improvement only in the groups with two modalities pressure levels. However, regarding the occurrence of success and failure characterized as return or no return to mechanical ventilation, there was no significant difference between the modalities. The authors attributed this mechanism to the different causes that lead to RR, that in POCS, and it presents as main causes processes collapse and pulmonary infiltrates [20].

The effects of IPPB (Müller Resuscitator [MRI]) were compared with CPAP in patients in the PO period of CABG and it was verified that, when seeking the pulmonary reexpansion with lower imposed workload, the MRI was more effective due to its faster action, with lower levels of dyspnea, respiratory rate and accessory muscle activity [21]. Leaks or air leaks are common situations in the application of CPAP, but also the possibility of aerophagia; such a situation, in MRI is suppressed by the safety valve that prevents a higher pressure, providing a synchronism between the operator and the patient, respecting the patient's respiratory cycle and offering a perfect fit of the mask, causing higher VC gain and pulmonary expansion [21].

In summary, comparative studies have shown some results that point to signs of better effects with the application of a NIV modality over the other. However, the extrapolation of these data for all patients undergoing CS does not present strong scientific evidence.

 

CONCLUDING REMARKS

The NIV modalities conventionally described in the literature, as CPAP, BiPAP® and IPPB were used in postoperative surgery, added to a current modality, PSV + PEEP, with satisfactory results. Studies that compare different NIV modalities are scarce, although some studies have been demonstrated to be better in the case of IPPB to reverse hypoxemia and in the case of BiPAP ® to improve oxygenation, respiratory rate and heart rate in these patients.

REFERENCES

1. Cavenaghi S, Ferreira LL, Marino LH, Lamari NM. Respiratory physiotherapy in the pre and postoperative myocardial revascularization surgery. Rev Bras Cir Cardiovasc. 2011;26(3):455-61. [MedLine] View article

2. Garbossa A, Maldaner E, Mortari DM, Biasi J, Leguisamo CP. Effects of physiotherapeutic instructions on anxiety of CABG patients. Rev Bras Cir Cardiovasc. 2009;24(3):359-66. [MedLine] View article

3. Keenan TD, Abu-Omar Y, Taggart DP. Bypassing the pump: changing practices in coronary artery surgery. Chest. 2005;128(1):363-9. [MedLine]

4. Luchesa CA, Greca FH, Guarita-Souza LC, dos Santos, Aquim EE. The role of electroanalgesia in patients undergoing coronary artery bypass surgery. Rev Bras Cir Cardiovasc. 2009;24(3):391-6. [MedLine] View article

5. Renault JA, Costa-Val R, Rossetti MB. Respiratory physiotherapy in the pulmonary dysfunction after cardiac surgery. Rev Bras Cir Cardiovasc. 2008;23(4):562-9. [MedLine] View article

6. Mazullo-Filho JBR, Bonfim VJG, Aquim EE. Ventilação mecânica não invasiva no pós-operatório imediato de cirurgia cardíaca. Rev Bras Ter Intensiva. 2010;22(4):363-8.

7. Mehta S, Hill NS. Noninvasive ventilation. Am J Respir Crit Care Med. 2001;163(2):540-77. [MedLine]

8. Brochard L, Mancebo J, Elliott MW. Noninvasive ventilation for acute respiratory failure. Eur Respir J. 2002;19(4):712-21. [MedLine]

9. Kramer N, Meyer TJ, Meharg J, Cece RD, Hill NS. Randomized, prospective trial of noninvasive positive pressure ventilation in acute respiratory failure. Am J Respir Crit Care Med. 1995;151(6):1799-806. [MedLine]

10. Meyer TJ, Hill NS. Noninvasive positive pressure ventilation to treat respiratory failure. Ann Intern Med. 1994;120(9):760-70. [MedLine]

11. Maurat MM. Avaliação dos benefícios da ventilação não invasiva nos pacientes em pós-operatório de cirurgia cardíaca. Rev SOCERJ. 2003;16(3):142.

12. Schettino GPP, Reis MAS, Galas F, Park M, Franca S, Okamoto V. III Consenso Brasileiro de Ventilação Mecânica: ventilação mecânica não invasiva com pressão positiva. J Bras Pneumol. 2007;33(Supl.2):S92-S105. [MedLine]

13. Ferreira FR, Moreira FB, Parreira VF. Ventilação não invasiva no pós-operatório de cirurgias abdominais e cardíacas: revisão da literatura. Rev Bras Fisioter. 2002;6(2):69-76.

14. Figueiredo LC, Araújo S, Abdala RCS, Abdala A, Guedes CAV. CPAP de 10 cmH2O durante a circulação extracorpórea não melhora a troca gasosa pós-operatória. Rev Bras Cir Cardiovasc. 2008;23(2):209-15. [MedLine]

15. Zarbock A, Mueller E, Netzer S, Gabriel A, Feindt P, Kindgen-Milles D. Prophylactic nasal continuous positive airway pressure following cardiac surgery protects from postoperative pulmonary complications: a prospective, randomized, controlled trial in 500 patients. Chest. 2009;135(5):1252-9. [MedLine]

16. Celebi S, Köner O, Menda F, Omay O, Günay I, Suzer K, et al. Pulmonary effects of noninvasive ventilation combined with the recruitment maneuver after cardiac surgery. Anesth Analg. 2008;107(2):614-9. [MedLine]

17. Franco AM, Torres FC, Simon IS, Morales D, Rodrigues AJ. Assessment of noninvasive ventilation with two levels of positive airway pressure in patients after cardiac surgery. Rev Bras Cir Cardiovasc. 2011;26(4):582-90. [MedLine] View article

18. Mendes RG, Borghi-Silva A. Eficácia da intervenção fisioterapêutica associada ou não à respiração por pressão positiva intermitente (RPPI) após cirurgia cardíaca com circulação extracorpórea. Fisioter Mov. 2006;19(4):73-82.

19. Romanini W, Muller AP, Carvalho KAT, Olandoski M, Faria-Neto JR, Mendes FR, et al. Os efeitos da pressão positiva intermitente e do incentivador respiratório no pós-operatório de revascularização miocárdica. Arq Bras Cardiol. 2007;89(2):105-10.

20. Coimbra VRM, Lara RA, Flores EG, Nozawa E, Auler-Júnior JOC, Feltrim MIZ. Aplicação de ventilação não invasiva em insuficiência respiratória aguda após cirurgia cardiovascular. Arq Bras Cardiol. 2007;89(5):298-305.

21. Müller AP, Olandoski M, Macedo R, Constantini C, Souza LCG. Estudo comparativo entre a pressão positiva intermitente (Reanimador de Müller) e contínua no pós-operatório de cirurgia de revascularização do miocárdio. Arq Bras Cardiol. 2006;86(3):232-9. [MedLine]

Article receive on Monday, June 11, 2012

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