Effects of Periodic Positive Airway Pressure by Mask on Postoperative Pulmonary Function

doi:10.1378/chest.89.6.774

Chest

Volume 89, Issue 6, June 1986, Pages 774-781

https://doi.org/10.1378/chest.89.6.774 Get rights and content

Postoperative pulmonary complications, alveolar-arteriolar oxygen difference ([A-a]O₂-diff), peak expiratory flow (PEF) and forced vital capacity (FVC) were compared in patients using continuous positive airway pressure (CPAP) and positive expiratory pressure (PEP) administered by face mask against those of a control group using a deep-breathing device (Triflo). Forty-three consecutive, randomized patients undergoing elective upper abdominal surgery were included. CPAP, PEP and Triflo were administered for 30 consecutive breaths in every waking hour for three days postoperatively. The (A-a)O₂-difference increased equally and significantly in the three groups after surgery, reaching a maximum on the first postoperative day. After this day, however, (A-a)O₂-diff decreased in the CPAP and PEP groups, being significantly lower in the PEP group compared to the control group, two days postoperatively (p<0.05) and significantly lower in both the PEP and CPAP groups three days postoperatively (p<0.001 and p<0.05, respectively.) PEF did not differ significantly between the groups before or after surgery, while FVC was significantly higher in the PEP and CPAP groups, compared to control, on the third postoperative day (p<0.05). Atelectatic consolidation was observed in six of 15 patients in the control group three days postoperatively, the incidence being significantly lower in both the PEP group (0 of 15, p<0.001) and the CPAP group (one of 13, p<0.05). We concluded that periodic face mask administration of CPAP and PEP are superior to deep breathing exercises with respect to gas exchange, preservation of lung volumes and development of atelectasis after upper abdominal surgery. We also conclude that the simple and commercially available PEP mask is as effective as the more complicated CPAP system.

Section snippets

Materials and Methods

Fifty consecutive patients admitted for elective upper abdominal surgery participated in this study. The protocol was approved by the Ethical Committee for Human Studies of the University of Gothenburg and all patients gave their consent. Preoperatively, forced vital capacity (FVC) and peak expiratory flow (PEF) were determined using a wedge spirometer and a peak flow meter. In order to match the groups, patients were stratified according to pulmonary function, age (more or less than 60 yrs),

Results

Seven of the 50 consecutive patients entering the study were excluded. One patient in the control group and three in the CPAP group were excluded because of pulmonary congestion. In the PEP group, one patient was excluded due to pulmonary edema and another due to severe postoperative headache resulting from puncture of the dura mater while inserting the epidural catheter. The third patient discontinued because of severe nausea and postoperative gastric tube irritation.

The characteristics of the

Discussion

Controversy in the literature concerning beneficial prophylactic effects of mechanical devices on postoperative pulmonary function is probably due to the heterogeneous nature of the studied treatment groups and the tremendous variation in how treatment is delivered to patients. It is well known that the incidence of postoperative pulmonary complications varies considerably depending on the types of surgery and abdominal incision.²²^-²⁸ Despite this, treatment groups consist of patients subjected

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Cited by (117)

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2023, Pulmonology
Traditionally, Venturi-based flow generators have been preferred over mechanical ventilators to provide continuous positive airway pressure (CPAP) through the helmet (h-CPAP). Recently, modern turbine-driven ventilators (TDVs) showed to be safe and effective in delivering h-CPAP. We aimed to compare the pressure stability during h-CPAP delivered by Venturi devices and TDVs and assess the impact of High Efficiency Particulate Air (HEPA) filters on their performance.
We performed a bench study using an artificial lung simulator set in a restrictive respiratory condition, simulating two different levels of patient effort (high and low) with and without the interposition of the HEPA filter. We calculated the average of minimal (Pmin), maximal (Pmax) and mean (Pmean) airway pressure and the time product measured on the airway pressure curve (PTPinsp). We defined the pressure swing (Pswing) as Pmax - Pmin and pressure drop (Pdrop) as End Expiratory Pressure - Pmin.
Pswing across CPAP levels varied widely among all the tested devices. During “low effort”, no difference in Pswing and Pdrop was found between Venturi devices and TDVs; during high effort, Pswing (p<0.001) and Pdrop (p<0.001) were significantly higher in TDVs compared to Venturi devices, but the PTPinsp was lower (1.50 SD 0.54 vs 1.67 SD 0.55, p<0.001). HEPA filter addition almost doubled Pswing and PTPinsp (p<0.001) but left unaltered the differences among Venturi and TDVs systems in favor of the latter (p<0.001).
TDVs performed better than Venturi systems in delivering a stable positive pressure level during h-CPAP in a bench setting.
Efficacy of continuous positive airway pressure and incentive spirometry on respiratory functions during the postoperative period following supratentorial craniotomy: A prospective randomized controlled study
2017, Journal of Clinical Anesthesia
Volume controlled ventilation with low PEEP is used in neuro-anesthesia to provide constant PaCO₂ levels and prevent raised intracranial pressure. Therefore, neurosurgery patients prone to atelectasis formation, however, we could not find any study that evaluates prevention of postoperative pulmonary complications in neurosurgery.
A prospective, randomized controlled study.
Intensive care unit in a university hospital in Istanbul.
Seventy-nine ASAI-II patients aged between 18 and 70 years scheduled for elective supratentorial craniotomy were included in the study.
Patients randomized into 3 groups after surgery. The Group IS (n = 20) was treated with incentive spirometry 5 times in 1 min and 5 min per hour, the Group CPAP (n = 20) with continuous positive airway pressure 10 cmH₂O pressure and 0.4 F_iO₂ via an oronasal mask 5 min per hour, and the Group Control (n = 20) 4 L·min^− 1O₂ via mask; all during the first 6 h postoperatively. Respiratory functions tests and arterial blood gases analysis were performed before the induction of anesthesia (Baseline), 30 min, 6 h, 24 h postoperatively.
The IS and CPAP applications have similar effects with respect to FVC values. The postoperative 30 min FEV₁ values were statistically significantly reduced compared to the Baseline in all groups (p < 0.0001). FEV₁ values were statistically significantly increased at the postoperative 24 h compared to the postoperative 30 min in the Groups IS and CPAP (p < 0.0001). This increase, however, was not observed in the Group Control, and the postoperative 24 h FEV₁ values were statistically significantly lower in the Group Control compared to the Group IS (p = 0.015).
Although this study is underpowered to detect differences in FEV₁ values, the postoperative 24 h FEV₁ values were significantly higher in the IS group than the Control group and this difference was not observed between the CPAP and Control groups. It might be evaluate a favorable effect of IS in neurosurgery patients. But larger studies are needed to make a certain conclusion.
Non-invasive mechanical ventilation in postoperative patients: A clinical review
2015, Revista Espanola de Anestesiologia y Reanimacion
La ventilación mecánica no invasiva (VMNI) es un método de asistencia ventilatoria con importancia creciente en el manejo de la insuficiencia respiratoria postoperatoria. Su papel en la prevención y el tratamiento de las atelectasias cobra especial importancia en el postoperatorio de cirugías torácicas y abdominales.
Igualmente, en el paciente trasplantado, la VMNI puede acortar el tiempo de ventilación mecánica invasiva y disminuir el riesgo de complicaciones infecciosas en estos pacientes de alto riesgo.
El presente artículo recoge una revisión de la literatura detallando los aspectos técnicos, las experiencias clínicas y las recomendaciones relativas a la aplicación de la VMNI durante el período postoperatorio.
Non-invasive ventilation (NIV) is a method of ventilatory support that is increasing in importance day by day in the management of postoperative respiratory failure. Its role in the prevention and treatment of atelectasis is particularly important in the in the period after thoracic and abdominal surgeries.
Similarly, in the transplanted patient, NIV can shorten the time of invasive mechanical ventilation, reducing the risk of infectious complications in these high-risk patients.
It has been performed A systematic review of the literature has been performed, including examining the technical, clinical experiences and recommendations concerning the application of NIV in the postoperative period.
Positive expiratory pressure - Common clinical applications and physiological effects
2015, Respiratory Medicine
Citation Excerpt :
Instructions to the patient how to perform the technique vary and include tidal volume breaths [22], somewhat larger than normal [12,18], or deep breaths [23,24], followed by slightly activated expirations towards the resistance [12,18,23]. Patients are coached to reach and maintain a mid-expiratory pressure of 10–20 cm H2O but not to use force at the end of the expiration [12,22,23] (Fig. 1). The duration and number of treatment sessions are individualized, depending on the indications for the treatment and the severity of symptoms, but are series of breaths e.g. 10 in a row repeated once or more or for a specific duration of time [12,23,25].
Breathing out against resistance, in order to achieve positive expiratory pressure (PEP), is applied by many patient groups. Pursed lips breathing and a variety of devices can be used to create the resistance giving the increased expiratory pressure. Effects on pulmonary outcomes have been discussed in several publications, but the expected underlying physiology of the effect is seldom discussed.
The aim of this article is to describe the purpose, performance, clinical application and underlying physiology of PEP when it is used to increase lung volumes, decrease hyperinflation or improve airway clearance.
In clinical practice, the instruction how to use an expiratory resistance is of major importance since it varies. Different breathing patterns during PEP increase or reduce expiratory flow, result in movement of EPP centrally or peripherally and can increase or decrease lung volume. It is therefore necessary to give the right instructions to obtain the desired effects. As the different PEP techniques are being used by diverse patient groups it is not possible to give standard instructions. Based on the information given in this article the instructions have to be adjusted to give the optimal effect. There is no consensus regarding optimal treatment frequency and number of cycles included in each treatment session and must also be individualized.
In future research, more precise descriptions are needed about physiological aims and specific instructions of how the treatments have been performed to assure as good treatment quality as possible and to be able to evaluate and compare treatment effects.
Assessment of the acute effects of different PEP levels on respiratory pattern and operational volumes in patients with Parkinson's disease
2014, Respiratory Physiology and Neurobiology
Citation Excerpt :
Different types of respiratory therapies have been developed recently, with the aim of decreasing or minimizing possible complications caused by lung restriction. The application of Positive expiratory Pressure (PEP) represents a reliable, safe and low-cost intervention that allows increasing lung volumes and intrathoracic pressure (Ricksten et al., 1986; Myers, 2007). Although positive pressure therapy has been used in other respiratory and cardiac diseases (Mortensen et al., 1991; Placidi et al., 2006), the possible physiologic effects that different intensities of PEP may cause in chest volumes in Parkinson's patients remains unknown.
The aim of the study was to determine the acute effects of positive expiratory pressure (PEP) on breathing pattern, operational volumes and shortening velocity of respiratory muscles on patients with Parkinson's disease. It was evaluated 15 patients and healthy controls, by optoelectronic plethysmography, using PEP in three different levels (10, 15 and 20 cmH₂O). Breathing pattern changed in both groups. Parkinson group increased tidal volume in all PEP levels (p < 0.001), but with lower values compared to control. End-inspiratory chest wall volume increased in the Parkinson group at all PEP levels (p < 0.001), end-expiratory chest wall volume show a slightly increase when we compared QB to all PEP levels in Parkinson's. There was an intergroup difference in the index of shortening velocity of abdominal, diaphragm and inspiratory muscles of the rib cage at all PEP levels (p < 0.01). We conclude that Parkinson's disease promotes important alterations in different breathing pattern components and PEP has significant effects on these alterations.
Comparison of gas exchange after lung resection with a Boussignac CPAP or Venturi mask
2014, British Journal of Anaesthesia
Postoperative continuous positive airway pressure (CPAP) can improve lung function. The aim of our study was to assess the efficacy of prophylactic CPAP on the Pa_O₂/FI_O₂ ratio measured the day after surgery in patients undergoing lung resection surgery (LRS).
The study population comprised 110 patients undergoing LRS. On arrival in the postanaesthesia care unit (PACU), patients were randomized to receive CPAP at 5–7 cm H₂O during the first 6 h after surgery (CPAP group) or supplemental oxygen through a Venturi mask (Venturi group). The Pa_O₂/FI_O₂ ratio was measured on arrival in the PACU, 7 h after admission, and the day after surgery. The Pa_O₂/FI_O₂ ratio is the primary endpoint of our study. We also analysed the chest radiograph and assessed the postoperative course. We then analysed the impact of ventilatory management in the PACU depending on the respiratory risk of the patient.
Baseline characteristics were similar in both groups. Patients who received CPAP had significantly higher Pa_O₂/FI_O₂ at 24 h after surgery compared with patients managed conventionally (Venturi group) (48.6±14 vs 42.3±12, P=0.031), but there were no differences at 7 h. On subgroup analysis, we found that the benefits of CPAP were greater in higher risk patients. The incidence of postoperative pulmonary complications and stay in the PACU and hospital were similar in both groups.
In patients undergoing LRS, prophylactic CPAP during the first 6 h after surgery with a pressure of 5–7 cm H₂O improved the Pa_O₂/FI_O₂ ratio at 24 h. This effect was more evident in patients with increased risk of postoperative pulmonary complications.

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Presented at the 18th Congress of the Scandinavian Society of Anesthesiologists, Reykjavik, Iceland, June 25-29, 1985.

Manuscript received September 12; revision accepted December 18.

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Chest

Clinical InvestigationsEffects of Periodic Positive Airway Pressure by Mask on Postoperative Pulmonary Function

Section snippets

Materials and Methods

Results

Discussion

Clinical Investigations
Effects of Periodic Positive Airway Pressure by Mask on Postoperative Pulmonary Function