Effect of deep breathing exercises on oxygenation after major head and neck surgery

Otolaryngology Head and Neck Surgery (2008) 139, 281-285 ORIGINAL RESEARCH HEAD AND NECK CANCER Effect of deep breathing exercises on oxygenation after major head and neck surgery Arzu Genç, PhD, PT, Ahmet Omer Ikiz, MD, MSc, Enis Alpin Güneri, MD, MSc, and Ali Günerli, MD, Izmir, Turkey OBJECTIVES: To investigate respiratory and hemodynamic responses to deep breathing exercise (DBE) during the follow-up period in the intensive care unit after major head and neck surgery. STUDY DESIGN: Prospective study. SUBJECTS AND METHODS: Thirty-five patients were instructed to perform DBE every hour for 3 consecutive hours during the first postoperative day. The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO 2 /FiO 2 ), oxygen saturation (SpO 2 ), respiratory rate (RR), heart rate (HR), and mean arterial pressure (MAP) was recorded. RESULTS: DBE increased the PaO 2 /FiO 2 ratio from 416.7 143.6 to 453.4 141.4 mm Hg and increased SpO 2 from 97.4 1.9 to 99.2 0.9. DBE decreased the RR from 24.1 3.3 to 21.8 2.9 breaths/min (P 0.05). No statistically significant difference in HR or MAP was observed after DBE (P 0.05). CONCLUSION: DBE improves oxygenation after major head and neck surgery, without causing additional harmful hemodynamic effects. 2008 American Academy of Otolaryngology Head and Neck Surgery Foundation. All rights reserved. Surgery to treat cancers of the head and neck carries substantial risk in terms of peri- and postoperative complications. These patients often have preexisting comorbidities that must be recognized to optimize postoperative care. For example, smoking may compromise the patient s respiratory condition, and the pulmonary system is the leading source of postoperative systemic complications. The most important and serious postoperative pulmonary complications include atelectasis, pneumonia, respiratory failure, and the exacerbation of underlying lung disease, which arise in approximately 10% to 15% of cases. 1-5 Pulmonary complications can be reduced via the optimization of pulmonary function, intensive pulmonary hygiene, and early ambulation. 1 Chest physiotherapy plays an important role in the treatment of atelectasis and preventing its progression to more significant pulmonary complications following major surgeries. Physiotherapists use various techniques to improve lung volume and to clear pulmonary secretion in postoperative patients. 6,7 Although numerous studies have investigated the effects of chest physiotherapy in abdominal and thoracic surgery patients, only one publication to our knowledge has addressed this topic in head and neck surgery patients. 7-11 Therefore, we investigated the respiratory and hemodynamic effects of deep breathing exercise (DBE) during recuperation in the intensive care unit (ICU) after major head and neck surgery. SUBJECTS AND METHODS This study included 35 patients who underwent major head and neck surgery and were monitored in the ICU from December 1999 to January 2002. The patients ranged in age from 40 to 75 years, with a mean standard deviation (SD) of 58.8 8.9 years. The group consisted of 34 men (97.1%) and one woman (2.9%). The study was approved by the Ethics and Human Research Committee of Dokuz Eylül University Hospital (Izmir, Turkey). Exclusion criteria included active pulmonary pathology (eg, exacerbation of chronic obstructive pulmonary disease [COPD]) and unstable cardiovascular condition. A mean arterial pressure (MAP) of less than 65 mm Hg, arterial pressure fluctuation of 15 mm Hg with position change, and a heart rate (HR) exceeding 130/min were used as indicators of unstable cardiovascular condition. One patient with postoperative exacerbation of COPD had to be excluded from the study. As a result, we gathered data for 35 of the 36 patients initially enrolled. Eighteen patients showed no underlying conditions. Of the remaining 17 patients, 11 had cardiovascular conditions, four had pulmonary conditions, one patient had a neurological condition, and one patient had diabetes mellitus. Thirty of 35 patients were smokers with a mean SD pack-year history of 42.5 23.0. Thirty-four patients belonged to the American Society of Anesthesiologists (ASA) Class I and one to Class II. The mean duration of anesthesia was 8.4 2.3 hours and the mean time spent in the ICU was 22.8 8.8 hours. Received November 4, 2007; revised April 10, 2008; accepted April 21, 2008. 0194-5998/$34.00 2008 American Academy of Otolaryngology Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2008.04.025

282 Otolaryngology Head and Neck Surgery, Vol 139, No 2, August 2008 The location of the primary tumor was the larynx in 18 patients, the oral cavity in six patients, the tonsils in three patients, the hypopharynx and skin in two patients, and the parotid gland in one patient. Three patients had metastatic neck masses from an unknown primary tumor. Appropriate surgical treatment was performed for the primary lesion as dictated by tumor site and stage. All patients underwent neck dissections: unilaterally in 26 patients and bilaterally in nine patients. Nineteen radical, five modified radical, and 20 selective neck dissections were performed, and a pectoralis major myocutaneous flap was used to reconstruct a tongue cancer resection defect in one patient. All patients were extubated the day after surgery in the ICU. DBE was initiated approximately 30 minutes after extubation. While resting in a semi-recumbent position, the patients were instructed to inhale as slowly and deeply as possible, hold their breath for 3 seconds, and then exhale in a relaxed manner. With the help of a physiotherapist using proprioceptive input, the patients were encouraged to make each subsequent breath deeper than the previous breath for five to 10 breaths. This period was followed by a rest period (ie, normal breathing), and the cycle was repeated four times per hour for 3 consecutive hours. Before and immediately after DBE, hemodynamic parameters, including HR and MAP, and respiratory parameters, including the respiratory rate (RR) and oxygen saturation (SpO 2 ), were recorded with monitoring equipment (Draeger Medical Systems, Inc. Danvers, MA). The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO 2 /FiO 2 ) was also calculated from arterial blood samples taken before and 30 minutes after the intervention. Because all patients received oxygen therapy to prevent desaturation (SpO 2 90%), FiO 2 values were recorded, and the PaO 2 /FiO 2 ratio was calculated to determine pulmonary gas exchange. All patients were successfully weaned from the ventilator and then transferred to the Department of Otorhinolaryngology Head and Neck Surgery on the day after surgery. Statistical Analysis Data were analyzed with the Statistical Package for the Social Sciences for Windows, version 11.0 (SPSS Inc, Chicago, IL). Hemodynamic and respiratory parameters before and after DBE were compared by repeated measures of analysis of variance. When a significant time effect was found, paired sample t tests with Bonferroni correction were used to detect significantly different time periods. Changes in arterial blood gas were analyzed by dependent sample t tests. Differences in hemodynamic and respiratory parameters between smokers and nonsmokers were compared by Mann-Whitney U tests. A P value of 0.05 was considered statistically significant. Table 1 Hemodynamic and respiratory parameters before and after DBE in all patients (mean SD) RESULTS n 35 BDBE ADBE P HR (bpm) 80.3 12.7 81.7 12.4 0.156 MAP (mm Hg) 88.8 15.4 87.9 15.0 0.387 PaO 2 /FiO 2 (mm Hg) 416.7 143.6 453.4 141.4 0.000 SpO 2 (%) 97.4 1.9 99.2 0.9 0.000 RR (breaths/min) 24.1 3.3 21.8 2.9 0.000 BDBE, Before deep breathing exercises; ADBE, after deep breathing exercises; HR, heart rate; bpm, beats per minute; MAP, mean arterial pressure; PaO 2 /FiO 2, ratio of partial pressure of arterial oxygen to fraction of inspired oxygen; SpO 2, oxygen saturation; RR, respiratory rate. Boldface P values are statistically significant. Effect of DBE on Respiratory Parameters DBE resulted in a statistically significant increase in the PaO 2 /FiO 2 ratio by a mean value of 36.6 50.1 mm Hg (8.7%) compared with pretreatment baseline values (P 0.05). DBE also resulted in a statistically significant increase in SpO 2 by a mean value of 1.8 1.4 (1.9%), and a statistically significant decrease in the RR by a mean value of 2.2 2.9 breaths per minute (9.2%) compared with pretreatment values (P 0.05; Table 1). No statistically significant differences were observed between smokers and nonsmokers in comparisons of the effects of DBE on respiratory parameters (P 0.05; Table 2). In addition, none of our patients experienced postoperative pulmonary complications while hospitalized. Effect of DBE on Hemodynamic Parameters No statistically significant differences were observed in hemodynamic parameters after DBE compared with pretreatment resting values (P 0.05). Compared with pretreatment values, a slight increase in HR (1.4 5.9 beats/ min, or 1.8%) and a slight decrease in MAP (0.8 5.7 mm Hg, or 0.9%) were observed, but these difference were not statistically significant (P 0.05; Table 1). No statistically significant differences were observed between smokers and nonsmokers in comparisons of the effect of DBE on hemodynamic parameters (P 0.05; Table 2). DISCUSSION Pulmonary complications contribute to morbidity, mortality, and increased treatment costs as a result of prolonged hospitalization following major head and neck surgery. The reported rates for pulmonary complications after head and neck cancer surgery are 2% for adult respiratory distress syndrome, 3% for failure to wean, and 4% to 15% for

Genç et al Effect of deep breathing exercises on oxygenation... 283 Table 2 Comparison of hemodynamic and respiratory parameter changes before and after DBE between the smoker and nonsmoker groups (mean SD) Smokers (n 30) Nonsmokers (n 5) BDBE ADBE BDBE ADBE P HR (bpm) 79.2 13.2 81.4 13.0 87.0 6.2 83.8 19.5 0.170 MAP (mm Hg) 90.4 15.8 89.8 15.2 79.0 9.1 76.8 8.2 0.449 PaO 2 /FiO 2 (mm Hg) 418.3 146.0 452.0 143.0 407.0 143.4 461.4 147.1 0.278 SpO 2 (%) 97.4 1.7 99.2 1.0 97.4 3.2 99.4 0.8 0.904 RR (breaths/min) 24.1 3.5 21.8 3.0 24.0 2.8 22.4 2.1 0.557 BDBE, Before deep breathing exercises; ADBE, after deep breathing exercises; HR, heart rate; bpm, beats per minute; MAP, mean arterial pressure; PaO 2 /FiO 2, ratio of partial pressure of arterial oxygen to fraction of inspired oxygen; SpO 2, oxygen saturation; RR, respiratory rate. pneumonia. 12 Even in a case series reporting a relatively low incidence of pneumonia (3.26%), the mortality rate for this morbidity approached 10.94%. 13 Thus, every effort to improve ventilation capacity, which in turn should decrease postoperative pulmonary complications, is invaluable. Risk factors and avoidance strategies for postoperative pulmonary complications after major surgeries have been discussed in various studies, but the majority of these investigations focused on thoracic and abdominal surgery. 8-10,14 These types of surgeries directly interfere with pulmonary function by invading the pleural space or transgressing the respiratory muscles with the surgical incision. However, this is rarely the case in head and neck surgery patients. Instead, respiratory dysfunction in this group may be the result of phrenic nerve inhibition by a reflex mechanism or postoperative pain, both of which may lead to reduced tidal volume, vital capacity, total lung capacity, and, subsequently, insufficient cough. The inability to cough effectively may cause atelectasis in the basal lung segments and a decrease in functional residual capacity (FRC), which in turn negatively affects the gas exchange properties of the lung by increasing the ventilation/perfusion mismatch. 6,15 In a comparison of upper abdominal surgery with head and neck surgery, Campbell et al 16 found a similar pattern of change in vital capacity, but a much greater decrease in oxygenation after head and neck surgery. Hypoxemia was at its worst on the first or second day after surgery and then began to recover. After both surgeries, arterial PaO 2 decreased on the first postoperative day. However, although PaO 2 started to recover by the seventh postoperative day after upper abdominal surgery, PaO 2 did not improve during the same period in head and neck surgery patients. Although the definitive etiology was unclear, poor oxygenation in the head and neck group was attributed to the greater extent of surgery and the need to perform a tracheotomy. Tracheotomy, and the subsequent inhalation of dry air, was thought to decrease FRC by stimulating bronchial secretion and increasing bronchomotor tone. 16 The patients described here also had major surgeries and prolonged operative times, with a mean anesthesia duration of 8.41 hours. Twenty-six of 35 patients also required a tracheotomy. As a method of increasing FRC and preventing respiratory complications, DBE, incentive spirometer (IS), continuous positive airway pressure, intermittent positive pressure breathing (IPPB), and early mobilization are performed during the postoperative period. 6-8 Physiotherapists have successfully used DBE to increase tidal volume and prevent pulmonary complications during the postoperative period in upper abdominal and cardiac surgery patients. Westerdahl et al 9,10 found a significant reduction in atelectatic lung area and improved oxygenation after DBE in coronary artery bypass surgery patients. Jenkins et al 17 found IS and DBE to be superior to mobilization alone after upper abdominal surgery. Celli et al 7 compared an untreated control group with treatment with IPBB, DBE, or IS in a series of 172 patients undergoing elective abdominal surgery. All treatment groups had positive benefits in terms of respiratory parameters compared with the control group. No difference was found among treatment groups in terms of treatment efficacy. To our knowledge, only one study has evaluated the effects of postoperative chest physiotherapy in head and neck surgery patients. Tan 11 reported a positive effect of IS on postoperative forced vital capacity and oxygenation in patients undergoing major head and neck surgery. Lederer et al 18 reported that hourly regular coaching during DBE is more important than the use of any specific device. Patient collaboration and motivation are essential factors in any treatment, and the assistance of a physiotherapist is important in helping patients perform their best. For this reason, we performed DBE with proprioceptive input with the help of a physiotherapist and encouraged patients to make each breath deeper than the previous one. Because oxygenation, gas exchange, and FRC improve in the semirecumbent position, 19 we also used this position in a standardized manner in all interventions. Significant volume displacement occurs between the thoracic and abdominal cavities during surgery, both as a result of placing patients in a supine position and by the admin-

284 Otolaryngology Head and Neck Surgery, Vol 139, No 2, August 2008 istration of general anesthesia. These volume changes affect postoperative pulmonary complications would not present the curvature of the diaphragm, moving it up from its an ethical conflict. natural resting position, which decreases the diaphragm s efficiency as a pressure generator, as reflected by a decrease 15 in FRC from 200 to 300 ml. Consequently, patients AUTHOR INFORMATION lungs and chest wall become stiffer after surgery and more energy is required to expand the lungs and chest wall. From the Dokuz Eylül University School of Physical Therapy and Rehabilitation (Dr Genç); the Dokuz Eylül University School of Medicine, Patients must then increase their RR to maintain minute Department of Ear Nose Throat and Head & Neck Surgery (Drs Ikiz and ventilation in the postoperative period. Such an increase in Güneri); and the Department of Anesthesiology and Reanimation, Dokuz RR may be more easily achieved than an increase in tidal volume. 8,20 DBE helps to remove secretions and relax the patients, and also increases chest wall mobility and promotes surfactant production. As lung compliance improves, alveolar ventilation and oxygenation increase and the work of breathing decreases. 12,21 The improvement in gas -ex change and the reduction in the RR after DBE were both statistically significant in our study. Our results are likely AUTHOR CONTRIBUTIONS related to an increase in tidal volume and chest mobility, as well as a decrease in the work of breathing. Because wearzu Genç: study design, data collection and analysis, primary author; demonstrated that improved ventilation is reflected clinically in a decreased RR, we hypothesize that responses to Ahmet Ömer Ikiz: data analysis and editorial comments on manuscript; Enis Alpin Güneri: editorial comments on manuscript; Ali Günerli: study design and editorial comments on manuscript. DBE can be easily monitored by checking only the RR. DBE improved ventilation to a similar degree in both smokers and nonsmokers. This is particularly important because most head and neck cancer patients are smokers. FINANCIAL DISCLOSURE Thus, DBE can be used without any restriction regarding smoking history. None. Physiotherapy may cause hemodynamic instability by precipitating alterations in cardiovascular parameters, such as blood pressure, HR, or intracranial pressure. Stiller recommended that hemodynamic status be carefully monitored during physiotherapy to prevent detrimental effects. In our study, we observed no significant hemodynamic side effects as a result of DBE, suggesting that this therapy is safe for head and neck surgery patients when performed in an appropriate manner. CONCLUSION Our findings suggest that performing DBE has beneficial effects in the treatment of postoperative hypoxemia after major head and neck surgery. Physiotherapy can be initiated safely in the ICU on the first postoperative day, and physiotherapists should be considered an essential part of the postoperative patient care team. Because all patients are instructed to perform DBE while staying in the ICU at our institution, including a nontreatment group in this study was ethically impossible. Therefore, studying the effects of DBE on patients who are extubated immediately after surgery and sent directly to inpatient departments would also be desirable. Because pulmonary physiotherapy is not routinely performed in this group of patients, including a nontreatment group to compare treatment efficacy or possible 20 Eylül University School of Medicine (Dr Günerli). Corresponding author: Arzu Genç, Dokuz Eylül University School of Physical Therapy and Rehabilitation, 35340 Izmir, Turkey. E-mail address: arzu.genc@deu.edu.tr. REFERENCES 1. Shah JP, Johnson NW, Batsakis JG. Complications and their management. In: Singh B, Shah JP, editors. Oral cancer. 1st ed. London: Martin Dunitz; 2003. p. 367 72. 2. Smetana GW, Lawrence VA, Cornell JE. American College of Physicians. Preoperative pulmonary risk stratification for noncardiothoracic surgery: systematic review for the American College of Physicians. Ann Intern Med 2006;144:581 95. 3. Rao MK, Reilley TE, Schuller DE, et al. Analysis of risk factors for postoperative pulmonary complications in head and neck surgery. Laryngoscope 1992;102:45 7. 4. Bansal A, Miskoff J, Ronald JL. 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