Postoperative Diaphragmatic Dysfunction Research Articles

Early diaphragm dysfunction assessed by ultrasonography after cardiac surgery: a retrospective cohort study

ObjectiveApproximately 10%–70% of patients may develop diaphragmatic dysfunction after cardiac surgery, which may lead to delayed weaning from mechanical ventilation, increased ICU stays, postoperative hospitalization stays, and respiratory complications. However, its impact on prognosis and risk factors remain controversy. Therefore, we conducted a retrospective cohort study in which we evaluated diaphragmatic dysfunction in patients who underwent cardiac surgery via bedside diaphragm ultrasound to investigate its prognosis and possible risk factors.MethodsData from the electronic medical records system included case records and ultrasound images of the diaphragm for 177 consecutive patients admitted to the ICU following cardiac thoracotomy surgeries performed between June and September 2020. Diaphragmatic dysfunction was defined as a diaphragmatic excursion of less than 9 mm in women and less than 10 mm in men at rest, with an average thickening fraction of less than 20%. SPSS 25.0 software was used to analyse the relationships between patients' general information, intraoperative and postoperative factors and diaphragmatic dysfunction, as well as the impact on patients' hospitalization days, mechanical ventilation time and respiratory system complications.ResultsThe incidence of early postoperative diaphragmatic dysfunction after cardiac surgery was 40.7%. Patients with diaphragmatic insufficiency were more likely to sequentially use noninvasive ventilation within 24 h after weaning off mechanical ventilation (3.8% vs. 12.5%, P = 0.029) and to require more oxygen support (23.8% vs. 40.3%, P = 0.019). Although there was no significant difference, the diaphragmatic dysfunction group tended to have longer ICU stays and postoperative hospital stays than did the normal diaphragmatic function group (P = 0.119, P = 0.073). Univariate and multivariate logistic regression analyses both revealed that chest tube drainage placed during surgery accompanied by bloody drainage fluid was an independent risk factor for diaphragmatic dysfunction (univariate analysis: 95% CI: 1.126–4.137, P = 0.021; multivariate analysis: 95% CI: 1.036–3.897, P = 0.039).ConclusionEearly diaphragmatic dysfunction after cardiac surgery increased the proportion of patients who underwent sequential noninvasive ventilation after weaning from mechanical ventilation and who required more oxygen. Chest tube drainage placed during surgery accompanied by bloody drainage fluid was an independent risk factor for diaphragmatic dysfunction, providing evidence-based guidance for respiratory rehabilitation after cardiac surgery.

Diaphragmatic dysfunction is associated with postoperative pulmonary complications in the aged patients underwent radical resection of esophageal cancer: a prospective observational study.

Diaphragmatic dysfunction escalates the susceptibility to postoperative pulmonary complications (PPCs). Currently, no study reports the occurrence of diaphragmatic dysfunction correlated with PPCs following radical resection of esophageal cancer in aged patients. We aimed to diagnose diaphragmatic dysfunction via ultrasonography and analyze diaphragmatic dysfunction's relation with PPCs after radical resection of esophageal cancer surgery in aged patients. This prospective observational study comprised 86 aged patients undergoing radical resection of esophageal cancer. Patient characteristics data and intraoperative details were collected. Ultrasonography was performed before (preoperative) and after (first, third, and fifth day postoperatively) surgery. Outcome measures included PPCs within seven days postoperative, occurrence of diaphragmatic dysfunction, and short-term prognosis. After excluding 14 patients, we finally analyzed clinical data from 72 patients. The prevalence of PPCs was higher in the patients with diaphragmatic dysfunction than those without (19 of 23, 83% vs. 21 of 49, 43%, P=0.004). Postoperative diaphragmatic dysfunction was positively correlated with PPCs in patients who underwent elective radical esophageal cancer surgery (r=0.37, P=0.001). Persistent diaphragmatic dysfunction, furthermore, was positively correlated with the development of multiple PPCs (r=0.43, P<0.001). The logistic regression analysis revealed that age, total open procedure, and postoperative diaphragmatic dysfunction were identified as significant risk factors for PPCs, while total open procedure was an independent risk factor for diaphragmatic dysfunction. Postoperative diaphragmatic dysfunction positively correlates with developing PPCs. Continuous monitoring of postoperative diaphragmatic function can screen high-risk patients with PPCs, which has specific clinical significance. Age, total open procedure, and diaphragmatic dysfunction are identified as risk factors for developing PPCs, while total open procedure specifically increases the risk for postoperative diaphragmatic dysfunction.

Diaphragmatic dysfunction is associated with postoperative pulmonary complications and phrenic nerve paresis in patients undergoing thoracic surgery

PurposeWe aimed to quantify perioperative changes in diaphragmatic function and phrenic nerve conduction in patients undergoing routine thoracic surgery.MethodsA prospective observational study was performed in patients undergoing esophageal resection or pulmonary lobectomy. Examinations were carried out the day prior to surgery, 3 days and 10–14 days after surgery. Endpoints for diaphragmatic function included ultrasonographic measurements of diaphragmatic excursion and thickening fraction. Endpoints for phrenic nerve conduction included baseline-to-peak amplitude, peak-to-peak amplitude, and transmission delay. Measurements were assessed on both the surgical side and the non-surgical side of the thorax.ResultsForty patients were included in the study. Significant reductions in diaphragmatic excursion were seen on the surgical side of the thorax for all excursion measures (posterior part of the right hemidiaphragm, p < 0.001; hemidiaphragmatic top point, p < 0.001; change in intrathoracic area, p < 0.001). Significant changes were seen for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.041) on the surgical side. However, significant changes were also seen on the non-surgical side for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.022). A postoperative reduction in posterior diaphragmatic excursion of more than 50% was significantly associated with postoperative pulmonary complications (coefficient: 2.69 (95% CI [1.38, 4.01], p < 0.001).ConclusionThoracic surgery caused a significant unilateral reduction in diaphragmatic excursion on the surgical side of the thorax, which was accompanied by significant changes in phrenic nerve conduction. However, phrenic nerve conduction was also significantly affected on the non-surgical side to a lesser extent, which was not mirrored in diaphragmatic excursion. Our findings suggest that phrenic nerve paresis plays a role in postoperative diaphragmatic dysfunction, which may be a contributing factor in the pathogenesis of postoperative pulmonary complications.Clinical trials registration numberNCT04507594.

Imaging of the Diaphragm Following Cardiac Surgery: Focus on Ultrasonographic Assessment.

Diaphragm dysfunction is a common complication following cardiac surgery. Its clinical impact is variable, ranging from the absence of symptoms to the acute respiratory failure. Post-operative diaphragm dysfunction may negatively affect patients' prognosis delaying the weaning from the mechanical ventilation (MV), extending the time of hospitalization and increasing mortality. Ultrasonography is a valid tool to evaluate diaphragmatic impairment in different settings, like the Intensive Care Unit, to predict successful weaning from the MV, and the Cardiovascular Rehabilitation Unit, to stratify patients in terms of risk of functional recovery failure. The aim of this review is to describe the pathophysiology of post-cardiac surgery diaphragm dysfunction, the techniques used for its diagnosis and the potential applications of diaphragm ultrasound.

Comparison of Changes in Chest Wall Mechanics and Respiratory Timing Between Patient-Controlled Epidural Analgesia and Intravenous Patient-Controlled Analgesia After Laparoscopic Gastrectomy: A Randomized Controlled Trial.

Upper abdominal surgery is associated with postoperative diaphragmatic dysfunction. Whether patient-controlled epidural analgesia (PCEA) is superior to intravenous patient-controlled analgesia (IV-PCA) in preventing postoperative diaphragmatic dysfunction is still unclear in laparoscopic gastric surgery. Sixteen patients undergoing laparoscopic gastrectomy randomly received either PCEA or IV-PCA. The primary outcomes were the change in chest wall mechanics and respiratory timing, measured by respiratory inductive plethysmography(Respitrace; Ambulatory Monitoring Inc., Ardsley, New York, United States) before and after surgery, and analyzed by a data acquisition system (PowerLab; ADInstruments, Dunedin, New Zealand). Inspiratory time (Ti), expiratory time (Te), total respiratory cycle time (Ttot), proportion of inspiratory time over total respiratory cycle time (Ti/Ttot), respiratory rate (RR), and abdominal contribution to tidal volume (AB/VT [%]) were calculated from the stored data. AB/VT, relative volume contribution of diaphragm to tidal breathing, represents an index of diaphragmatic function.Because the diaphragm is the main contributor to tidal volume, decreases in AB/VT indicate diaphragm dysfunction. Changes in outcomes over time between the two groups were analyzed using a linear mixed model, and two-sided p values < 0.05 were considered statistically significant. The secondary outcomes were postoperative pain score(visual analog scale (VAS)), bowel function recovery, and hospital stay duration. Postoperative AB/VT in the IV-PCA group was significantly decreased compared to preoperative levels. AB/VT in the PCEA group was significantly higher than the IV-PCA group on postoperative day (POD) 1. Change in AB/VT over time between the PCEA group and the IV-PCA group differed significantly (p = 0.01). A decrease of AB/VT during POD 1 to 3 was observed in the IV-PCA group but not in the PCEA group. As for respiratory timing, there were significant increases in RR with a reduction of Te and Ttot compared to preoperative levels on POD 1 in the PCEA group. There were significant decreases in RR and Ti/Ttot with an increase of Te and Ttot compared to preoperative levels on POD 1 in the IV-PCA group. There was a significant difference in the change of the Ttot over time between the two groups (p = 0.046). There were no significant differences in the changes of Te, Ti/Ttot, Ti, and RR over time between the two groups. There was no significant difference in VAS over time at rest and mobilization, recovery of bowel function, and hospital stay between the two groups. Continuous ropivacaine infusion with PCEA partially attenuated diaphragmatic dysfunction after laparoscopic gastrectomy, while pain relief by continuous intravenous administration of fentanyl could not attenuate diaphragmatic dysfunction. This suggests that PCEA might ameliorate postoperative diaphragmatic dysfunction after laparoscopic gastrectomy.

MEASUREMENT OF DIAPHRAGMATIC DYSFUNCTION AND PHRENIC NERVE PALSY IN PATIENTS UNDERGOING THORACIC SURGERY FOR LUNG- OR ESOPHAGEAL CANCER

<h3>Introduction and Objective</h3> Thoracic surgery carries a substantial risk of postoperative pulmonary complications. Recent studies have shown that the risk of postoperative pulmonary complications is significantly higher in patients suffering from postoperative diaphragmatic dysfunction. Diaphragmatic dysfunction may be accompanied by phrenic nerve palsy. However, the extent of phrenic nerve palsy and its association with diaphragmatic dysfunction following thoracic surgery is unknown. Therefore, we aimed to quantify changes in diaphragmatic function and phrenic nerve conductance in patients undergoing thoracic surgery for lung- or esophageal cancer using ultrasonographic measures and phrenic nerve conduction studies. <h3>Design and Methods</h3> This was a prospective observational study including patients scheduled for pulmonary lobectomy or esophageal resection. Examinations were carried out the day prior to surgery and respectively 3 days and 10-14 days after surgery. Endpoints for diaphragmatic function included ultrasonographic measurements of diaphragmatic excursion of the posterior part of the right hemidiaphragm, excursion of the hemidiaphragmatic top point, change in intrathoracic area and diaphragmatic thickening fraction. Ultrasonographic measurements were recorded during a standardized respiration cycle. Endpoints for phrenic nerve conductance included baseline-to-peak amplitude, peak-to-peak amplitude and transmission delay of the diaphragmatic compound muscle action potential (CMAP). Measurements for both diaphragmatic- and phrenic nerve recordings were assessed for both the surgical side and the non-surgical side of the thorax and thus measured over time. <h3>Results</h3> We included 40 patients of which 13 had pulmonary lobectomies and 27 had esophageal resections performed. Significant reductions in diaphragmatic excursion were seen on the surgical side of the thorax for all excursion measures (posterior part of the right hemidiaphragm, p < 0.001; hemidiaphragmatic top point, p < 0.001; change in intrathoracic area, p < 0.001) (Figure 1). Conversely, all ultrasound excursion measures did not change significantly on the non-surgical side. Diaphragmatic thickening fraction did not change significantly on either side. For phrenic nerve measures, significant reductions were seen for both CMAP amplitude measures on the surgical side (baseline-to-peak, p < 0.001; peak-to-peak, p < 0.001) and non-surgical side (baseline-to-peak, p < 0.001; peak-to-peak, p < 0.001). Transmission delay also changed significantly between assessments on both the surgical (p =0.041) and the non-surgical side (p =0.021) (Figure 2). <h3>Conclusion</h3> Thoracic surgery caused a significant unilateral reduction in diaphragmatic excursion on the surgical side of the thorax, whereas the contralateral hemidiaphragm's excursion did not decrease significantly. Diaphragmatic compound muscle action potential amplitude was reduced significantly bilaterally. Therefore, our findings show that a postoperative reduction in diaphragmatic excursion is accompanied by partial phrenic nerve palsy, which may be a contributing factor in the pathogenesis of postoperative pulmonary complications.

Impact of intubated vs. non-intubated anesthesia on postoperative diaphragmatic function: Results from a prospective observational study.

Background: An altered diaphragmatic function was associated with the development of postoperative pulmonary complications following thoracic surgery. Methods: To evaluate the impact of different anesthetic techniques on postoperative diaphragmatic dysfunction, patients undergoing video-assisted thoracoscopic surgery (VATS) lung biopsy for interstitial lung disease were enrolled in a monocentric observational prospective study. Patients received intubated or non-intubated anesthesia according to risk assessment and preferences following multidisciplinary discussion. Ultrasound measured diaphragmatic excursion (DIA) and Thickening Fraction (TF) were recorded together with arterial blood gases and pulmonary function tests (PFT) immediately before and 12 h after surgery. Pain control and postoperative nausea and vomiting (PONV) were also evaluated. Results: From February 2019 to September 2020, 41 consecutive patients were enrolled. Five were lost due to difficulties in collecting postoperative data. Of the remaining 36 patients, 25 underwent surgery with a non-intubated anesthesia approach whereas 11 underwent intubated general anesthesia. The two groups had similar baseline characteristics. On the operated side, DIA and TF showed a lower residual postoperative function in the intubated group compared to the non-intubated group (54 vs. 82% of DIA and 36 vs. 97% of TF; p = 0.001 for both). The same was observed on the non-operated side (58 vs. 82% and 62 vs. 94%; p = 0.005 and p = 0.045, respectively, for DIA and TF). No differences were observed between groups in terms of pain control, PONV, gas exchange and PFT. Conclusion: This study suggests that maintenance of spontaneous breathing during VATS lung biopsy is associated with better diaphragmatic residual function after surgery.

Diaphragm Dysfunction after Cardiac Surgery: Insights from Ultrasound Imaging during Cardiac Rehabilitation.

Diaphragm dysfunction is common after cardiac surgery and can be evaluated with ultrasonography (US). We aimed at assessing with US the incidence of diaphragmatic dysfunction and the impact of cardiovascular rehabilitation (CR) on its recovery. A single-center cohort study was performed. Patients were enrolled after cardiac surgery. The 6-min walking test (6MWT) and diaphragm US were performed at CR admission and after 10 rehabilitative sessions. One hundred eighty-five patients were eligible for final analysis. One hundred thirty-one patients (70.8%) were found to have diaphragm dysfunction (excursion <2 cm). After CR, 68 patients regained normal diaphragmatic function; those with persistent dysfunction had a lower level of functional performance on the 6MWT (metabolic equivalents of tasks: 3.3 vs. 3.6, p =0.013). The patients who underwent combined surgery (adjusted odds ratio [aOR]=4.09, p=0.001) and those with post-operative pneumothorax (aOR=3.02, p=0.042) were at increased risk of failure to improve diaphragmatic excursion. US parameters were more powerful tools in predicting diaphragmatic evolution compared with the 6MWT indexes: baseline diaphragm excursion and thickening fraction were associated with complete diaphragmatic functional recovery after CR (aOR=9.101, p < 0.001, and aOR=1.058, p=0.020 respectively). US is a valuable tool for the assessment of post-operative diaphragmatic dysfunction and can identify patients at risk of diaphragmatic recovery failure.

Clinical impact of preoperative diaphragm dysfunction on early outcomes and ventilation function in lung transplant: a single-center retrospective study

BackgroundClinical impact of preoperative diaphragm dysfunction on lung transplantation has not been studied. We aimed to evaluate how preoperative diaphragm dysfunction affects clinical outcomes and ventilation function after transplantation.MethodsWe retrospectively enrolled 102 patients. Ultrasound for diagnosis of diaphragm dysfunction was performed on all patients both before and after lung transplantation. The primary outcome was to compare prolonged mechanical ventilation after transplantation according to the preoperative diaphragm dysfunction. Secondary outcomes compared global inhomogeneity index and lung volume after transplantation. Multivariate regression analysis were used to evaluate the association between preoperative diaphragm dysfunction and prolonged mechanical ventilation after transplantation.ResultsA total of 33 patients (32.4%) had preoperative diaphragm dysfunction, and half of them (n = 18) recovered their diaphragm function after transplantation. In contrast, 15 patients (45.5%) showed postoperative diaphragm dysfunction. The ratio of prolonged mechanical ventilation after transplantation was significantly higher in the preoperative diaphragm dysfunction group (p = 0.035). The postoperative durations of mechanical ventilation, intensive care unit and hospital stays were higher in the preoperative diaphragm dysfunction group, respectively (p < 0.05). In the multivariate regression analysis, preoperative diaphragm dysfunction was significantly associated with prolonged mechanical ventilation after transplantation (Odds ratio 2.79, 95% confidence interval 1.07–7.32, p = 0.037). As well, the preoperative diaphragm dysfunction group showed more inhomogeneous ventilation (p < 0.05) and lower total lung volume (p < 0.05) after transplantation. In addition, at 1 month and 3 months after transplantation, FVC was significantly lower in the preoperative diaphragm dysfunction group (p < 0.05).ConclusionsPreoperative diaphragm dysfunction was associated with prolonged mechanical ventilation after lung transplantation.

Incidence of early diaphragmatic dysfunction after lung transplantation: results of a prospective observational study.

Diaphragmatic dysfunction is common after cardiothoracic surgery, but few studies report its incidence and consequences after lung transplantation. We aimed to estimate the incidence of diaphragmatic dysfunction using ultrasound in lung transplant patients up to 3months postoperatively and evaluated the impact on clinical outcomes. This was a single-center prospective observational cohort study of 27 lung transplant recipients using diaphragmatic ultrasound preoperatively, at 1day, 1week, 1month, and 3months postoperatively. Diaphragmatic dysfunction was defined as excursion<10mm in men and<9mm in women during quiet breathing. Clinical outcomes measured included duration of mechanical ventilation, length of stay (LOS) in Intensive Care (ICU), and hospital LOS. Sixty-two percentage of recipients experienced new, postoperative diaphragmatic dysfunction, but the prevalence fell to 22% at 3months. No differences in clinical outcomes were found between those with diaphragmatic dysfunction compared to those without. Patients who experienced diaphragmatic dysfunction at 1day postoperatively were younger and had a lower BMI than those who did not. Diaphragmatic dysfunction is common after lung transplant, improves significantly within 3months, and did not impact negatively on duration of mechanical ventilation, LOS in ICU or hospital, or discharge destination.

Diaphragm Dysfunction After Cardiac Surgery: Reappraisal

The aim of this study was to re-investigate the incidence, risk factors, and outcomes of postoperative diaphragmatic dysfunction (DD) with actual cardiac surgery procedures. Single-center, retrospective, observational study based on a prospectively collected database. Tertiary care cardiac surgery center. Patients who underwent cardiac surgery between January 2016 and September 2019. None. The DD group included patients with clinically perceptible diaphragmatic paralysis, which was confirmed by chest ultrasound (amplitude of the diaphragm movement in time-motion mode at rest, after a sniff test). The primary endpoint was the incidence of DD. Among 3,577 patients included, the authors found 272 cases of DD (7.6%). Individuals with DD had more arterial hypertension (64.3% v 52.6%; p < 0.0001), higher body mass index (BMI) (28 [25-30] kg/m2v 26 [24-29] kg/m2; p < 0.0002), and higher incidence of coronary bypass grafting (CABG) (58.8% v 46.6%; p = 0.0001). DD was associated with more postoperative pneumonia (23.9% v 8.7%; p < 0.0001), reintubation (8.8% v 2.9%; p < 0.0001), tracheotomy (3.3% v 0.3%; p < 0.0001), noninvasive ventilation (45.6% v 5.4%; p < 0.0001), duration of mechanical ventilation (five [four-11] hours v four [three-six] hours; p < 0.0001), and intensive care unit and hospital stays (14 [11-17] days v 13 [11-16] days; p < 0.0001). In multivariate analysis, DD was associated with CABG (odds ratio [OR] 1.9 [1.5-2.6]; p = 0.0001), arterial hypertension (OR 1.4 [1.1-1.9]; p = 0.008), and BMI (OR per point 1.04 [1.01-1.07] kg/m2; p = 0.003). The incidence of symptomatic DD after cardiac surgery was 7.6%, leading to respiratory complications and increased ICU stay. CABG was the principal factor associated with DD.

Diaphragmatic Dysfunction After Elective Cardiac Surgery: A Prospective Observational Study

To determine the incidence of postoperative diaphragm dysfunction as diagnosed by ultrasonography. Explorative prospective observational study. University intensive care unit. One hundred consecutive patients undergoing elective cardiac surgery. Diaphragm ultrasound was performed the day before surgery during unassisted breath (D-1), at the first spontaneous breathing trial attempt (DSBT), 24 hours after surgery (D+1), and at intensive care unit (ICU) discharge (DICU). Diaphragm displacement, inspiratory and expiratory thickness, and the thickening fraction were measured at all timepoints. Primary outcome was assessing the rate of postoperative diaphragm dysfunction, defined as a thickening fraction <20% at DSBT. Secondary outcomes were the number of difficult-to-wean patients, the need for rescue noninvasive ventilation, the reintubation rate, and the ICU length of stay. Thirty-eight patients showed diaphragm dysfunction at DSBT, which resolved over time. No differences in preoperative characteristics and comorbidities were found between patients who developed postoperative diaphragm dysfunction and patients without postoperative disorders. The duration of cardiopulmonary bypass (103 ± 34 v 55 ± 34 min; P < 0.001) was significantly associated with the development of postoperative diaphragm dysfunction. When compared with patients without postoperative diaphragm disorders, patients with diaphragm dysfunction were characterized by a higher rate of difficult weaning (32% v 5%; P < 0.001), lower extubation rate at 24 hours after surgery (50% v 92%; P < 0.001), and longer ICU length of stay (19 [16; 88] v 16 [15; 18] hours; P < 0.001). The incidence of postoperative diaphragm dysfunction after elective cardiac surgery is high and might contribute to prolonging ICU length of stay.

Explantation of Left Ventricular Assist Device as Bridge Therapy is Associated with Diaphragm Dysfunction after Heart Transplantation

Diaphragm dysfunction due to phrenic nerve injury following cardiac surgery has been attributed to surgical trauma or topical hypothermia. The close proximity of the left phrenic nerve to the adjacent left ventricle makes it particularly vulnerable to insult following left ventricular assist device (LVAD) explantation during heart transplantation (HT). We aimed to evaluate the incidence of diaphragm dysfunction in patients after HT and correlate to LVAD support. A review of the HT patients at our Center in 2000-2019 identified those with postoperative diaphragm dysfunction, diagnosed by chest X-ray or ultrasound during the two months following HT. Patients with diaphragm dysfunction pre-HT were excluded from the analysis. Of the 204 HT patients, 54 were bridged with LVAD and 150 were not (NoLVAD). In the LVAD group, there was a higher history of smoking (56 vs 35%, p=0.013), more men (89 vs 75%, p=0.047), and more re-do operations (mean/patient 1.1 vs 0.24, p<0.001). Donor characteristics were similar. Diaphragm dysfunction was diagnosed in a significantly higher number of LVAD patients [21(49%) LVAD vs 2 (1.5%) NoLVAD; p<0.001]. Most of the patients had isolated left (19, 82.6%) vs isolated right (2, 8.7%) or bilateral (2, 8.7%) diaphragm dysfunction. Multivariate analysis, adjusted for potential confounders, showed LVAD support to be independently associated with a significant ∼50-fold increased risk for diaphragm dysfunction (OR 46.62, 95%CI 11.93-313.2, p<0.001). No differences in early and late clinical outcomes were found between the diaphragm dysfunction and no diaphragm dysfunction groups (Table). Phrenic nerve injury is a relatively common complication in HT recipients bridged with LVAD. However, the resulting diaphragm dysfunction is not associated with untoward early and late outcomes.

Point of Care Ultrasound to Identify Diaphragmatic Dysfunction after Thoracic Surgery.

Postoperative diaphragmatic dysfunction after thoracic surgery is underestimated due to the lack of reproducible bedside diagnostic methods. We used point of care ultrasound to assess diaphragmatic function bedside in patients undergoing video-assisted thoracoscopic or thoracotomic lung resection. Our main hypothesis was that the thoracoscopic approach may be associated with lower incidence of postoperative diaphragm dysfunction as compared to thoracotomy. Furthermore, we assessed the association between postoperative diaphragmatic dysfunction and postoperative pulmonary complications. This was a prospective observational cohort study. Two cohorts of patients were evaluated: those undergoing video-assisted thoracoscopic surgery versus those undergoing thoracotomy. Diaphragmatic dysfunction was defined as a diaphragmatic excursion less than 10 mm. The ultrasound evaluations were carried out before (preoperative) and after (i.e., 2 h and 24 h postoperatively) surgery. The occurrence of postoperative pulmonary complications was assessed up to 7 days after surgery. Among the 75 patients enrolled, the incidence of postoperative diaphragmatic dysfunction at 24 h was higher in the thoracotomy group as compared to video-assisted thoracoscopic surgery group (29 of 35, 83% vs. 22 of 40, 55%, respectively; odds ratio = 3.95 [95% CI, 1.5 to 10.3]; P = 0.005). Patients with diaphragmatic dysfunction on the first day after surgery had higher percentage of postoperative pulmonary complications (odds ratio = 5.5 [95% CI, 1.9 to 16.3]; P = 0.001). Radiologically assessed atelectasis was 46% (16 of 35) in the thoracotomy group versus 13% (5 of 40) in the video-assisted thoracoscopic surgery group (P = 0.040). Univariate logistic regression analysis indicated postoperative diaphragmatic dysfunction as a risk factor for postoperative pulmonary complications (odds ratio = 5.5 [95% CI, 1.9 to 16.3]; P = 0.002). Point of care ultrasound can be used to evaluate postoperative diaphragmatic function. On the first postoperative day, diaphragmatic dysfunction was less common after video-assisted than after the thoracotomic surgery and is associated with postoperative pulmonary complications.

Role for Assessment of Diaphragm Function Prior to Lung Transplant

Post-operative diaphragm dysfunction is a potential complication of lung transplant. This is most commonly associated with intraoperative phrenic nerve injury, but surgery itself is not the only risk factor for diaphragm dysfunction. It has been postulated that patients with interstitial lung disease (ILD) are at increased risk for diaphragm dysfunction. This could be due to malposition of the diaphragm in the setting of severe restrictive lung disease or from subpleural fibrosis affecting innervation and motility of the diaphragm. The goal of this study is to assess the prevalence of pre-operative diaphragm abnormalities in patients with ILD who underwent lung transplant and to determine if there is a correlation with prolonged ventilator dependence post-operatively.

Complications respiratoires postopératoires

Respiratory complications are common after surgery. Several complex mechanisms such as postoperative diaphragmatic dysfunction, ventilation perfusion mismatching, atelectasis and pulmonary infection are responsible for such complications. Several scoring scales allow to evaluate the risk of postoperative pulmonary complications that depends especially of the surgical procedure performed (upper abdominal and thoracic surgery). Smoking cessation as soon as possible, chest physiotherapy, incitative spirometry and peroperative protective ventilation are the main preventive measures. Postoperative epidural analgesia plays a role but its impact is vanishing with the decreasing incidence of respiratory complications. Non-invasive ventilation, incitative spirometry and physiotherapy need to be maintained postoperatively in patients at risk.

Neurally adjusted ventilatory assist improves patient-ventilator synchrony during prophylactic helmet ventilation following aortic surgery

IntroductionDuring postoperative non-invasive ventilation (NIV), following abdominal aortic surgery, leaks and diaphragmatic dysfunction jeopardize patient-ventilator interaction. We hypothesized that neurally adjusted ventilatory assist (NAVA) would be efficient to perform NIV with a helmet, and would reduce triggering and cycling-off delays as well as major patient-ventilator asynchronies compared to pressure support ventilation (PSV). MethodsNine postoperative patients receiving NIV with a helmet following abdominal aortic surgery were included. After optimization of ventilator settings, 15-min recording were performed with PSV (H-PSV) and NAVA mode (H-NAVA) in a non-random order. Breathing pattern descriptors, diaphragm electrical activity, leak volume, inspiratory trigger delay and cycling-off delay and the five main asynchronies were quantified. Asynchrony index (AI) and asynchrony index influenced by leaks (AILEAKS) were computed. Data is displayed as a median [25–75 interquartiles]. ResultsTrigger delays were lower with H-NAVA than with H-PSV (respectively 143 [54; 244] and 804 [406; 906] ms, P=0.02), as were the cycling-off delays (respectively −702 [−780; −534] and 437 [176; 695] ms, P=0.004). Although it had no effect on AI, H-NAVA decreased AILEAKS (5 [2; 10] vs. 16 [8; 28] %, P=0.004), mostly due to a drastic reduction of the prevalence of ineffective triggering (0.6 [0.1; 1.15] vs. 1.7 [1.1; 4.5] min−1, P=0.009). Tidal volumes and ventilatory command remained unchanged, but peak pressure level was lower with the H-NAVA than with H-PSV (16 [15–19] vs. 22 [20; 23] cmH2O, P=0.004). ConclusionNAVA mode is sensitive enough to ensure ventilation despite postoperative diaphragmatic dysfunction. In combination with a helmet, NAVA improves patient-ventilator interaction during prophylactic postoperative NIV. The impact on patient outcome remains yet to be determined.

An Evaluation of Diaphragmatic Movement by M-Mode Sonography as a Predictor of Pulmonary Dysfunction After Upper Abdominal Surgery

Diaphragmatic dysfunction is a major factor in the etiology of postoperative pulmonary complications after upper abdominal surgery. M-mode ultrasonography is now an accepted qualitative method of assessing diaphragmatic motion in normal and pathological conditions. In this study, we evaluated whether diaphragmatic inspiratory amplitude (DIA) as measured by M-mode sonography can be a predictor of pulmonary dysfunction. A prospective, single-center, single-unit, observational study was performed in 35 ASA physical status I and II nonsmoking patients undergoing open liver lobectomy. Diaphragmatic movements were assessed by M-mode sonography after a pulmonary function test preoperatively and on postoperative days (PODs) 1, 2, and 7. We measured the DIA (cm) during quiet, deep, and sniff breathing. After liver lobectomy, DIA during deep breathing and vital capacity (VC) showed significant reductions of 60% from their preoperative values on PODs 1 and 2 (P < 0.001). By POD 7, the variables recovered significantly, by 30% from the values on PODs 1 and 2 (P < 0.001). During deep breathing, DIA showed a significant correlation with VC (r = 0.839, P < 0.0001). The best cutoff values of DIA for detecting 30% and 50% decreases of VC from preoperative values, calculated by receiver operating characteristic analysis, were 3.61 and 2.41 cm, with sensitivity of 94% and 81% and specificity of 76% and 91%, respectively (P = 0.0001). Two patients showed postoperative diaphragmatic paralysis but did not complain of respiratory distress symptoms or need supplemental oxygen after being transferred to the general ward. DIA using M-mode sonography showed a linear correlation with VC measured by spirometry throughout the postoperative period. We conclude that using the M-mode sonographic technique at the bedside can be a practical way to investigate postoperative diaphragmatic dysfunction, and may also be an effective bedside screening method for diaphragmatic paralysis.

Parietal Analgesia Decreases Postoperative Diaphragm Dysfunction Induced by Abdominal Surgery

The postoperative analgesic strategy may influence the magnitude of the postoperative diaphragmatic dysfunction (PODD) induced by abdominal surgery. The purpose of this physiologic study was to evaluate the effect of continuous preperitoneal wound infusion (CPWI) of ropivacaine on PODD after open colorectal surgery. Twenty patients with American Society of Anesthesiologists physical status I or II undergoing open colorectal surgery were prospectively included during 2 consecutive 2-month periods. During the first period, we evaluated 10 consecutive patients who received conventional parenteral analgesia (intravenously administered morphine via patient-controlled analgesia and acetaminophen) without parietal analgesia (control group). These patients were compared with 10 consecutive patients who received conventional parenteral analgesia along with parietal analgesia using CPWI of 0.2% ropivacaine at 10 mL/hr for 48 hrs (CPWI group). Diaphragmatic function was assessed preoperatively and at 24 and 48 hrs postoperatively using the sniff nasal inspiratory pressure test (Psniff). Supplemental intravenously administered morphine boluses were administered as needed before Psniff assessments in the control group to reduce differences in pain intensity. Demographic and surgical data did not differ between the 2 groups, nor did preoperative Psniff values (71 cm H2O [SD, 20 cm H2O] vs 65 cm H2O [SD,15 cm H2O] in the control and CPWI groups, respectively). Postoperative Psniff was significantly decreased in the 2 groups, but the reduction was significantly greater in the control group than in the CPWI group both at 24 hrs (-58% [SD, 18%] vs -24% [SD, 19%]; P = 0.001) and at 48 hrs (-44% [SD, 31%] vs -11% [SD, 32%]; P = 0.027). Parietal analgesia delivered via a CPWI of ropivacaine reduces PODD induced by open colorectal surgery.

Previous thoracic surgery does not increase peri-operative mortality in pediatric heart-lung transplant recipients

Background Heart-lung transplant (HLT) is indicated in select children with end-stage cardiopulmonary disease. We sought to determine whether previous thoracic surgery increases peri-operative morbidity and mortality. Methods Retrospective data were analyzed using unpaired Student’s t-test and Fisher’s exact test. Results are reported as mean ± SD. Peri-operative mortality was defined as death at ≤30 days post-transplant. Results From August 1993 through April 2001, 13 patients (mean age 7.9 ± 5.3 years; 9 girls, 4 boys) underwent HLT at our center. Eight of 13 (62%) had previous thoracic surgery and 5 of 13 (38%) did not. Interval of last surgery to transplant date was 45.5 ± 26.4 months (range 6 to 79 months). We compared HLT patients who had previous thoracic surgery to HLT recipients who did not. There was no significant difference in weight (18.6 ± 14.3 vs 36.5 ± 20.7 kg, p = 0.09), age (6.5 ± 4.5 vs 10.2 ± 6.1 years, p = 0.23) or duration of intubation (14.1 ± 12.9 vs 17.0 ± 30.3 days, p = 0.83). There were no caval or tracheal anastomotic stenoses in either group. There was no significant difference in blood products transfused ≤48 hours after HLT: packed red blood cells ( p = 0.16); fresh frozen plasma ( p = 0.13); platelets ( p = 0.59), and cryoprecipitate ( p = 0.27). There was no difference in cardiopulmonary bypass time (129.3 ± 48.2 vs 160.6 ± 73.9 minutes, p 0.39); post-operative diaphragm dysfunction (4 of 8 vs 0 of 5, p = 0.1); re-exploration for bleeding (2 of 8 vs 1 of 5, p = 1.0); or peri-operative mortality (2 of 8 vs 0 of 5, p = 0.48). Conclusions We conclude that previous thoracic surgery in HLT recipients does not significantly increase blood product transfusion, cardiopulmonary bypass time or peri-operative mortality.