Postoperative Respiratory Muscle Dysfunction

The impact of adverse events on health care costs for older adults undergoing nonelective abdominal surgery

BACKGROUND

Postoperative complications have been identified as an important and potentially preventable cause of increased hospital costs. While older adults are at increased risk of experiencing complications and other adverse events, very little research has specifically examined how these events impact inpatient costs. We sought to examine the association between postoperative complications, hospital mortality and loss of independence and direct inpatient health care costs in patients 70 years or older who underwent nonelective abdominal surgery.

METHODS

We prospectively enrolled consecutive patients 70 years or older who underwent nonelective abdominal surgery between July 1, 2011, and Sept. 30, 2012. Detailed patient-level data were collected regarding demographics, diagnosis, treatment and outcomes. Patient-level resource tracking was used to calculate direct hospital costs (2012 $CDN). We examined the association between complications, hospital mortality and loss of independence cost using multiple linear regression.

RESULTS

During the study period 212 patients underwent surgery. Overall, 51.9% of patients experienced a nonfatal complication (32.5% minor and 19.4% major), 6.6% died in hospital and 22.6% experienced a loss of independence. On multivariate analysis nonfatal complications (p < 0.001), hospital mortality (p = 0.021) and loss of independence at discharge (p < 0.001) were independently associated with health care costs. These adverse events respectively accounted for 30%, 4% and 10% of the total costs of hospital care.

CONCLUSION

Adverse events were common after abdominal surgery in older adults and accounted for 44% of overall costs. This represents a substantial opportunity for better patient outcomes and cost savings with quality improvement strategies tailored to the needs of this high-risk surgical population.

Non-invasive mechanical ventilation and epidural anesthesia for an emergency open cholecystectomy

Non-invasive ventilation is an accepted treatment modality in both acute exacerbations of respiratory diseases and chronic obstructive lung disease. It is commonly utilized in the intensive care units, or for postoperative respiratory support in post-anesthesia care units. This report describes intraoperative support in non-invasive ventilation to neuroaxial anesthesia for an emergency upper abdominal surgery.

Ineffective airway clearance in adult patients after thoracic and upper abdominal surgery

AIM

The aim of this study is to analyze the accuracy of the defining characteristics of ineffective airway clearance (IAC) in patients after thoracic and upper abdominal surgery.

BACKGROUND

Although numerous studies have described the most prevalent respiratory NANDA-I diagnoses, only few investigates the precision of nursing assessments.

METHODS

A cross-sectional study was conducted with 192 patients in a surgical clinic. Accuracy measures were obtained by the latent class analysis method.

RESULTS

IAC was present in 46.73% of the sample. The defining characteristics with better predictive capacity were changes in respiratory rate and changes in respiratory rhythm. However, other defining characteristics also had high specificity, such as restlessness, cyanosis, excessive sputum, wide-eyed, orthopnea, adventitious breathing sounds, ineffective cough, and difficulty vocalizing.

CONCLUSION

Results can contribute to the improvement of nursing assessments by providing information about the key clinical indicators of IAC.

Development and validation of a score to predict postoperative respiratory failure in a multicentre European cohort: A prospective, observational study

BACKGROUND

Postoperative respiratory failure (PRF) is the most frequent respiratory complication following surgery.

OBJECTIVE

The objective of this study was to build a clinically useful predictive model for the development of PRF.

DESIGN

A prospective observational study of a multicentre cohort.

SETTING

Sixty-three hospitals across Europe.

PATIENTS

Patients undergoing any surgical procedure under general or regional anaesthesia during 7-day recruitment periods.

MAIN OUTCOME MEASURES

Development of PRF within 5 days of surgery. PRF was defined by a partial pressure of oxygen in arterial blood (PaO2) less than 8 kPa or new onset oxyhaemoglobin saturation measured by pulse oximetry (SpO2) less than 90% whilst breathing room air that required conventional oxygen therapy, noninvasive or invasive mechanical ventilation.

RESULTS

PRF developed in 224 patients (4.2% of the 5384 patients studied). In-hospital mortality [95% confidence interval (95% CI)] was higher in patients who developed PRF [10.3% (6.3 to 14.3) vs. 0.4% (0.2 to 0.6)]. Regression modelling identified a predictive PRF score that includes seven independent risk factors: low preoperative SpO2; at least one preoperative respiratory symptom; preoperative chronic liver disease; history of congestive heart failure; open intrathoracic or upper abdominal surgery; surgical procedure lasting at least 2 h; and emergency surgery. The area under the receiver operating characteristic curve (c-statistic) was 0.82 (95% CI 0.79 to 0.85) and the Hosmer-Lemeshow goodness-of-fit statistic was 7.08 (P = 0.253).

CONCLUSION

A risk score based on seven objective, easily assessed factors was able to predict which patients would develop PRF. The score could potentially facilitate preoperative risk assessment and management and provide a basis for testing interventions to improve outcomes.The study was registered at ClinicalTrials.gov (identifier NCT01346709).

Measuring changes in chest wall motion after lung resection using structured light plethysmography: a feasibility study

OBJECTIVES

We describe the use of structured light plethysmography (SLP)-a novel, non-contact, light-based technique for measuring tidal breathing-among a cohort of patients undergoing lung resection. In this feasibility study, we examined whether changes in chest wall motion or in asynchrony between regions of the thoraco-abdominal wall could be identified after surgery.

METHODS

Fifteen patients underwent wedge resection (n = 8) or lobectomy (n = 7). All patients underwent two SLP assessments (before surgery and on Day 1 post-surgery). Each assessment captured data during 5 min of quiet (tidal) breathing.

RESULTS

When data were averaged across all patients, motion on the operated side of the thorax was significantly reduced after surgery (mean change from presurgery ± standard deviation: -14.7 ± 16.5%, P = 0.01), while motion on the non-operated side increased (15.9 ± 18.5%, P = 0.01). Thoraco-abdominal asynchrony also increased (mean change ± standard deviation: 43.4 ± 55.1%, P = 0.01), but no significant difference was observed in right-left hemi-thoracic asynchrony (163.7 ± 230.3%, P = 0.08). When analysed by resection type, lobectomy was associated with reduced and increased motion on the operated and non-operated side, respectively, and with an increase in both right-left hemi-thoracic and thoraco-abdominal asynchrony. No significant changes in motion or asynchrony were identified in patients who underwent wedge resection.

CONCLUSIONS

SLP was able to detect changes in chest wall motion and asynchrony after thoracic surgery. Changes in this small group of patients were consistent with the side of the incision and were most apparent in patients undergoing lobectomy.

Effects of obstructive sleep apnoea risk on postoperative respiratory complications: protocol for a hospital-based registry study

INTRODUCTION

Obstructive sleep apnoea (OSA), the most common type of sleep-disordered breathing, is associated with significant immediate and long-term morbidity, including fragmented sleep and impaired daytime functioning, as well as more severe consequences, such as hypertension, impaired cognitive function and reduced quality of life. Perioperatively, OSA occurs frequently as a consequence of pre-existing vulnerability, surgery and drug effects. The impact of OSA on postoperative respiratory complications (PRCs) needs to be better characterised. As OSA is associated with significant comorbidities, such as obesity, pulmonary hypertension, myocardial infarction and stroke, it is unclear whether OSA or its comorbidities are the mechanism of PRCs. This project aims to (1) develop a novel prediction score identifying surgical patients at high risk of OSA, (2) evaluate the association of OSA risk on PRCs and (3) evaluate if pharmacological agents used during surgery modify this association.

METHODS

Retrospective cohort study using hospital-based electronic patient data and perioperative data on medications administered and vital signs. We will use data from Partners Healthcare clinical databases, Boston, Massachusetts. First, a prediction model for OSA will be developed using OSA diagnostic codes and polysomnography procedural codes as the reference standard, and will be validated by medical record review. Results of the prediction model will be used to classify patients in the database as high, medium or low risk of OSA, and we will investigate the effect of OSA on risk of PRCs. Finally, we will test whether the effect of OSA on PRCs is modified by the use of intraoperative pharmacological agents known to increase upper airway instability, including neuromuscular blockade, neostigmine, opioids, anaesthetics and sedatives.

ETHICS AND DISSEMINATION

The Partners Human Research Committee approved this study (protocol number: 2014P000218). Study results will be made available in the form of manuscripts for publication and presentations at national and international meetings.

Perioperative sleep apnea: a real problem or did we invent a new disease?

Depending on the subpopulation, obstructive sleep apnea (OSA) can affect more than 75% of surgical patients. An increasing body of evidence supports the association between OSA  and perioperative complications, but some data indicate important perioperative outcomes do not differ between patients with and without OSA. In this review we will provide an overview of the pathophysiology of sleep apnea and the risk factors for perioperative complications related to sleep apnea. We also discuss a clinical algorithm for the identification and management of OSA patients facing surgery.

Acquired Muscle Weakness in the Surgical Intensive Care Unit

Muscle weakness is common in the surgical intensive care unit (ICU). Low muscle mass at ICU admission is a significant predictor of adverse outcomes. The consequences of ICU-acquired muscle weakness depend on the underlying mechanism. Temporary drug-induced weakness when properly managed may not affect outcome. Severe perioperative acquired weakness that is associated with adverse outcomes (prolonged mechanical ventilation, increases in ICU length of stay, and mortality) occurs with persistent (time frame: days) activation of protein degradation pathways, decreases in the drive to the skeletal muscle, and impaired muscular homeostasis. ICU-acquired muscle weakness can be prevented by early treatment of the underlying disease, goal-directed therapy, restrictive use of immobilizing medications, optimal nutrition, activating ventilatory modes, early rehabilitation, and preventive drug therapy. In this article, the authors review the nosology, epidemiology, diagnosis, and prevention of ICU-acquired weakness in surgical ICU patients.

Comparison of Sugammadex versus Neostigmine Costs and Respiratory Complications in Patients with Obstructive Sleep Apnoea

OBJECTIVE

To compare sugammadex and neostigmine regarding the efficacy in reversing rocuronium-induced neuromuscular block, the incidence of post-operative respiratory complications and costs in patients undergoing surgery for the treatment of obstructive sleep apnoea (OSA).

METHODS

After obtaining ethical approval and patient consent, 74 patients in ASA physical status I or II were randomised into two groups to receive 2-mg kg(-1) sugammadex (Group S) or 0.04-mg kg(-1) neostigmine+0.5-mg atropine (Group N). Groups were compared regarding time to TOF (train-of-four) 0.9, operating room time, post-anaesthesia care unit (PACU) stay, post-operative respiratory complications, costs related to neuromuscular block reversal, anaesthesia care and complication treatment.

RESULTS

Patient demographics, anaesthesia, surgical data and total rocuronium doses were similar between groups. Time to TOF 0.9 was shorter for group S [Group N: 8 (5-18) min; Group S: 2 (1.5-6) min (p<0.001)]. Operating room time [Group S: 72.4±14.3 min; Group N: 96.6±22.8 min (p<0.001)] and PACU stay [Group S: 22.9±10.1 dk; Group N: 36.3±12.6 dk (p<0.001)] were also shorter in Group S. After extubation, desaturation was observed in 12 (32.4%) patients in group N and in 4 (8%) patients in group S (p=0.048). In group N, three patients were reintubated; there were eight (21.6%) unplanned intensive care unit (ICU) admissions. There was one unplanned ICU admission in group S. Negative pressure pulmonary oedema was observed in one patient in group N. The results regarding costs were as follows. The reversal cost was higher in the sugammadex group (vial cost 98.14 TL) than that in the neostigmine group (ampoule cost 0.27 TL; total 6147.88 TL vs. 3569.5 TL); however, complication treatment cost and total cost were lower in group S than those in group N (199.5 TL vs. 3944.6 TL) (staff anaesthesia doctor cost was 0.392 TL per min and the cost of nurse anaesthetist was 0.244 TL per min).

CONCLUSION

This study confirmed the efficacy of sugammadex over neostigmine for the reversal of rocuronium-induced neuromuscular block. Sugammadex decreases the incidence of post-operative respiratory complications and related costs in patients with OSA.

Electromyographic activity of the diaphragm during neostigmine or sugammadex-enhanced recovery after neuromuscular blockade with rocuronium: a randomised controlled study in healthy volunteers

BACKGROUND

The use of neuromuscular blocking agents has been associated with severe postoperative respiratory morbidity. Complications can be attributed to inadequate reversal, and reversal agents may themselves have adverse effects.

OBJECTIVE

To compare the electromyographic activity of the diaphragm (EMGdi) during recovery from neuromuscular blockade using neostigmine and sugammadex. The hypothesis was that there would be better neuromuscular coupling of the diaphragm when sugammadex was used.

DESIGN

A randomised, controlled, parallel-group, single-centre, double-blinded study.

SETTING

District general hospital in Belgium.

PARTICIPANTS

Twelve healthy male volunteers.

INTERVENTIONS

Individuals were anaesthetised with propofol and remifentanil. After rocuronium 0.6 mg kg, a transoesophageal electromyography (EMG) recorder was inserted. For reversal of neuromuscular blockade, volunteers received sugammadex 2 mg kg (n = 6) or neostigmine 70 μg kg (n = 6).

MAIN OUTCOME MEASURES

EMGdi, airway pressure and flow were continuously measured during weaning from the ventilator until tracheal extubation. Arterial blood gas samples were obtained for PaO2 and PaCO2 analysis at the first spontaneous breathing attempt and after tracheal extubation.

RESULTS

During weaning, 560 breaths were retained for analysis. The median (95% CI) peak EMGdi was 1.1 (0.9 to 1.5) μV in the neostigmine group and 1.6 (1.3 to 1.9) μV in the sugammadex group (P < 0.001). Individuals in the neostigmine group had 125 of 228 (55%) breaths with associated EMGdi at least 1 μV vs. 220 of 332 (66%) breaths in the sugammadex group (P = 0.008). The median (95% CI) tidal volume was 287 (256 to 335) ml after neostigmine and 359 (313 to 398) ml after sugammadex (P = 0.013). The median (95% CI) PaO2 immediately after extubation was 30.5 (22.8 to 37.1) kPa after sugammadex vs. 20.7 (12.9 to 27.5) kPa after neostigmine (P = 0.03).

CONCLUSION

EMGdi, tidal volume and PaO2 following tracheal extubation were increased after sugammadex compared with neostigmine, reflecting diaphragm-driven inspiration after sugammadex administration. Sugammadex may free more diaphragmatic acetylcholine receptors than neostigmine, which has an indirect effect.

TRIAL REGISTRATION

EudraCT ref: 2013-002078-30.

[Tracheotomy or planned prolonged intubation after surgery for patients with OSAS]

BACKGROUND

Patients suffering from obstructive sleep apnea syndrome (OSAS) and obesity have an elevated risk of postoperative complications independent of each other. Within the framework of expert opinions for courts the question arose whether postoperative prolonged intubation or tracheotomy are standard routine approaches which are to be carried out in the normal course of operations on patients with OSAS.

MATERIAL AND METHODS

A search of the literature was performed using PubMed, Web of Science, Scopus, EMBASE, the Cochrane database of systematic reviews and the Cochrane central register of controlled trials. Furthermore, 78 German otorhinolaryngology (ENT) departments participated in a nationwide survey.

RESULTS

The results of the survey showed that after normal complication-free surgery planned postoperative prolonged intubation is not performed in the majority of ENT departments and no department performs a tracheotomy. In contrast, the standard approach for patients with OSAS and obesity who undergo two-level surgery is intubation and subsequent monitoring without ventilation for the first postoperative day. In the literature no evidence of a scientific basis for carrying out prolonged intubation or a tracheotomy could be found.

CONCLUSION

Neither tracheotomy nor prolonged intubation are standard procedures for OSAS patients with obesity after complication-free surgery.

Dose-dependent Association between Intermediate-acting Neuromuscular-blocking Agents and Postoperative Respiratory Complications

Background:

Duration of action increases with repeated administration of neuromuscular-blocking agents, and intraoperative use of high doses of neuromuscular-blocking agent may affect respiratory safety.

Methods:

In a hospital-based registry study on 48,499 patients who received intermediate-acting neuromuscular-blocking agents, the authors tested the primary hypothesis that neuromuscular-blocking agents are dose dependently associated with the risk of postoperative respiratory complications. In the secondary analysis, the authors evaluated the association between neostigmine dose given for reversal of neuromuscular-blocking agents and respiratory complications. Post hoc, the authors evaluated the effects of appropriate neostigmine reversal (neostigmine ≤60 μg/kg after recovery of train-of-four count of 2) on respiratory complications. The authors controlled for patient-, anesthesia-, and surgical complexity–related risk factors.

Results:

High doses of neuromuscular-blocking agents were associated with an increased risk of postoperative respiratory complications (n = 644) compared with low doses (n = 205) (odds ratio [OR], 1.28; 95% CI, 1.04 to 1.57). Neostigmine was associated with a dose-dependent increase in the risk of postoperative respiratory complications (OR, 1.51; 95% CI, 1.25 to 1.83). Post hoc analysis revealed that appropriate neostigmine reversal eliminated the dose-dependent association between neuromuscular-blocking agents and respiratory complications (for neuromuscular-blocking agent effects with appropriate reversal: OR, 0.98; 95% CI, 0.63 to 1.52).

Conclusions:

The use of neuromuscular-blocking agents was dose dependently associated with increased risk of postoperative respiratory complications. Neostigmine reversal was also associated with a dose-dependent increase in the risk of respiratory complications. However, the exploratory data analysis suggests that the proper use of neostigmine guided by neuromuscular transmission monitoring results can help eliminate postoperative respiratory complications associated with the use of neuromuscular-blocking agents.

Predicting postoperative pulmonary complications: implications for outcomes and costs

PURPOSE OF REVIEW

This review of progress toward reliable prediction of postoperative pulmonary complications (PPCs) discusses risk assessment against the background of patient management strategies, clinical outcomes, and cost of healthcare.

RECENT FINDINGS

Among the variety of conditions grouped as PPCs are pneumonia, aspiration pneumonitis, respiratory failure, reintubation within 48 h, weaning failure, pleural effusion, atelectasis, bronchospasm, and pneumothorax. PPC incidence rates range from 2 to 40% depending on context. These events increase mortality, postoperative length of stay, ICU admissions, hospital readmissions, and costs. PPC-associated mortality varies, but can reach as high as 48% in some contexts. ICU admission rates are between 9.5 and 91% higher in patients with PPCs. The mean increase in PPC-related postoperative length of stay is approximately 8 days. The cost of surgery can be two-fold to 12-fold higher when PPCs develop. Strategies proposed to reduce the impact of modifiable risk factors include alcohol and smoking abstinence before surgery, shortening the duration of surgery, and physiotherapy and incentive spirometry techniques; however, little scientific evidence supports them at this time.

SUMMARY

PPCs are associated with a higher incidence of life-threatening events and higher costs. Reliable PPC risk-stratification tools are essential for guiding clinical decision-making in the perioperative period. The care team can act on modifiable factors and optimize vigilance over nonmodifiable ones. It would be useful to focus resources on determining whether low-cost preemptive interventions improve outcomes satisfactorily or new strategies need to be developed.

The CC genotype of the delta-sarcoglycan gene polymorphism rs13170573 is associated with obstructive sleep apnea in the Chinese population

Obstructive sleep apnea (OSA) is a highly heterogeneous sleep disorder, and increasing evidence suggests that genetic factors play a role in the etiology of OSA. Airway muscle dysfunction might promote pharyngeal collapsibility, mutations or single nucleotide polymorphisms (SNPs) in the delta-sarcoglycan (SCGD) gene associated with muscle dysfunction. To evaluate if SCGD gene SNPs are associated with OSA, 101 individuals without OSA and 97 OSA patients were recruited randomly. The genotype distributions of SNPs (rs157350, rs7715464, rs32076, rs13170573 and rs1835919) in case and control populations were evaluated. The GG, GC and CC genotypes of rs13170573 in control and OSA groups were 51.5% and 37.1%, 36.6% and 35.1%, and 11.9% and 27.8%, respectively. Significantly fewer OSA patients possessed the GG genotype and significantly more possessed the CC genotype compared with controls. Further multivariate logistic regression analysis showed that the CC genotype was an independent risk factor for OSA, with an odds ratio (OR) of 2.17 (95% confidence interval [CI]: 1.19-6.01). Other factors, such as age ≥ 50 years, male gender, body mass index (BMI) ≥ 25 kg/m(2), low-density lipoprotein cholesterol (LDL-C) level ≥ 3.33 mg/dL, smoking and hypertension, were also independent risk factors for OSA in our multivariate logistic regression model.

[Non-invasive mechanical ventilation and epidural anesthesia for an emergency open cholecystectomy]

Non-invasive ventilation is an accepted treatment modality in both acute exacerbations of respiratory diseases and chronic obstructive lung disease. It is commonly utilized in the intensive care units, or for postoperative respiratory support in post-anesthesia care units. This report describes intraoperative support in non-invasive ventilation to neuroaxial anesthesia for an emergency upper abdominal surgery.

Postoperative respiratory failure: pathogenesis, prediction, and prevention

PURPOSE OF REVIEW

This review discusses our present understanding of postoperative respiratory failure (PRF) pathogenesis, risk factors, and perioperative-risk reduction strategies.

RECENT FINDINGS

PRF, the most frequent postoperative pulmonary complication, is defined by impaired blood gas exchange appearing after surgery. PRF leads to longer hospital stays and higher mortality. The time frame for recognizing when respiratory failure is related to the surgical-anesthetic insult remains imprecise, however, and researchers have used different clinical events instead of blood gas measures to define the outcome. Still, studies in specific surgical populations or large patient samples have identified a range of predictors of PRF risk: type of surgery and comorbidity, mechanical ventilation, and multiple hits to the lung have been found to be relevant in most of these studies. Recently, risk-scoring systems for PRF have been developed and are being applied in new controlled trials of PRF-risk reduction measures. Current evidence favors carefully managing intraoperative ventilator use and fluids, reducing surgical aggression, and preventing wound infection and pain.

SUMMARY

PRF is a life-threatening event that is challenging for the surgical team. Risk prediction scales based on large population studies are being developed and validated. We need high-quality trials of preventive measures, particularly those related to ventilator use in both high risk and general populations.

Adverse respiratory events in a post-anesthesia care unit

INTRODUCTION

Adverse respiratory events (ARE) are a leading causes of postoperative morbidity and mortality. This study investigated the incidence and determinants of postoperative ARE.

METHODS

This observational prospective study was conducted in a post anesthesia care unit (PACU). A total of 340 adult subjects were admitted consecutively, and AREs were measured after elective surgery. Population demographics, perioperative parameters, ARE occurrence, and length of stay in the postoperative PACU and in hospital were recorded. Data were analyzed descriptively using the Mann-Whitney U-test and the Chi-square or Fisher's exact test. Multivariate analyses were carried outusing logistic binary regression, and the odds ratio (OR) and 95% confidence interval (CI) were calculated.

RESULTS

Postoperative AREs occurred in 67 subjects (19.7%). AREs were more frequent after high-risk procedures (42% vs 24%; P=.003), in patients undergoing major surgery (37% vs 25%; P=.041), those receiving general anesthesia (85% vs 67%; P=.004), and in patients administered intraoperative muscle relaxants (79% vs 55%; P<.001) and neostigmine (69% vs 49%; P=.002). Hypoactive emergence (13% vs 5%; P=.015) and residual neuromuscular blockade (46% versus 11%; P<.001) were more frequent in subjects with postoperative ARE. On multivariate analyses, residual neuromuscular blockade was an independent risk factor for ARE in the PACU (OR 6.4; CI 3.0-13.4; P<.001).

CONCLUSIONS

ARE is an important and common postoperative complication. Residual neuromuscular blockade was an independent risk factor for ARE in the PACU.

Perioperative management of interscalene block in patients with lung disease

Interscalene nerve block impairs ipsilateral lung function and is relatively contraindicated for patients with lung impairment. We present a case of an 89-year-old female smoker with prior left lung lower lobectomy and mild to moderate lung disease who presented for right shoulder arthroplasty and insisted on regional anesthesia. The patient received a multimodal perioperative regimen that consisted of a continuous interscalene block, acetaminophen, ketorolac, and opioids. Surgery proceeded uneventfully and postoperative analgesia was excellent. Pulmonary physiology and management of these patients will be discussed. A risk/benefit discussion should occur with patients having impaired lung function before performance of interscalene blocks. In this particular patient with mild to moderate disease, analgesia was well managed through a multimodal approach including a continuous interscalene block, and close monitoring of respiratory status took place throughout the perioperative period, leading to a successful outcome.