Person:

Eikermann, Matthias

Objective: To determine whether use of intermediate acting neuromuscular blocking agents during general anesthesia increases the incidence of postoperative respiratory complications. Design: Prospective, propensity score matched cohort study. Setting: General teaching hospital in Boston, Massachusetts, United States, 2006-10. Participants: 18 579 surgical patients who received intermediate acting neuromuscular blocking agents during surgery were matched by propensity score to 18 579 reference patients who did not receive such agents. Main outcome measures: The main outcome measures were oxygen desaturation after extubation (hemoglobin oxygen saturation <90% with a decrease in oxygen saturation after extubation of >3%) and reintubations requiring unplanned admission to an intensive care unit within seven days of surgery. We also evaluated effects on these outcome variables of qualitative monitoring of neuromuscular transmission (train-of-four ratio) and reversal of neuromuscular blockade with neostigmine to prevent residual postoperative neuromuscular blockade. Results: The use of intermediate acting neuromuscular blocking agents was associated with an increased risk of postoperative desaturation less than 90% after extubation (odds ratio 1.36, 95% confidence interval 1.23 to 1.51) and reintubation requiring unplanned admission to an intensive care unit (1.40, 1.09 to 1.80). Qualitative monitoring of neuromuscular transmission did not decrease this risk and neostigmine reversal increased the risk of postoperative desaturation to values less than 90% (1.32, 1.20 to 1.46) and reintubation (1.76, 1.38 to 2.26). Conclusion: The use of intermediate acting neuromuscular blocking agents during anesthesia was associated with an increased risk of clinically meaningful respiratory complications. Our data suggest that the strategies used in our trial to prevent residual postoperative neuromuscular blockade should be revisited.

Introduction: Immobilisation in the intensive care unit (ICU) leads to muscle weakness and is associated with increased costs and long-term functional disability. Previous studies showed early mobilisation of medical ICU patients improves clinical outcomes. The Surgical ICU Optimal Mobilisation Score (SOMS) trial aims to test whether a budget-neutral intervention to facilitate goal-directed early mobilisation in the surgical ICU improves participant mobilisation and associated clinical outcomes. Methods and analysis The SOMS trial is an international, multicentre, randomised clinical study being conducted in the USA and Europe. We are targeting 200 patients. The primary outcome is average daily SOMS level and key secondary outcomes are ICU length of stay until discharge readiness and ‘mini’ modified Functional Independence Measure (mmFIM) at hospital discharge. Additional secondary outcomes include quality of life assessed at 3 months after hospital discharge and global muscle strength at ICU discharge. Exploratory outcomes will include: ventilator-free days, ICU and hospital length of stay and 3-month mortality. We will explore genetic influences on the effectiveness of early mobilisation and centre-specific effects of early mobilisation on outcomes. Ethics and dissemination Following Institutional Review Board (IRB) approval in three institutions, we started study recruitment and plan to expand to additional centres in Germany and Italy. Safety monitoring will be the domain of the Data and Safety Monitoring Board (DSMB). The SOMS trial will also explore the feasibility of a transcontinental study on early mobilisation in the surgical ICU. Results: The results of this study, along with those of ancillary studies, will be made available in the form of manuscripts and presentations at national and international meetings. Registration This study has been registered at clinicaltrials.gov (NCT01363102).

Objective: To evaluate the effects of intraoperative protective ventilation on major postoperative respiratory complications and to define safe intraoperative mechanical ventilator settings that do not translate into an increased risk of postoperative respiratory complications. Design: Hospital based registry study. Setting: Academic tertiary care hospital and two affiliated community hospitals in Massachusetts, United States. Participants: 69 265 consecutively enrolled patients over the age of 18 who underwent a non-cardiac surgical procedure between January 2007 and August 2014 and required general anesthesia with endotracheal intubation. Interventions Protective ventilation, defined as a median positive end expiratory pressure (PEEP) of 5 cmH2O or more, a median tidal volume of less than 10 mL/kg of predicted body weight, and a median plateau pressure of less than 30 cmH2O. Main outcome measure Composite outcome of major respiratory complications, including pulmonary edema, respiratory failure, pneumonia, and re-intubation. Results: Of the 69 265 enrolled patients 34 800 (50.2%) received protective ventilation and 34 465 (49.8%) received non-protective ventilation intraoperatively. Protective ventilation was associated with a decreased risk of postoperative respiratory complications in multivariable regression (adjusted odds ratio 0.90, 95% confidence interval 0.82 to 0.98, P=0.013). The results were similar in the propensity score matched cohort (odds ratio 0.89, 95% confidence interval 0.83 to 0.97, P=0.004). A PEEP of 5 cmH2O and median plateau pressures of 16 cmH2O or less were associated with the lowest risk of postoperative respiratory complications. Conclusions: Intraoperative protective ventilation was associated with a decreased risk of postoperative respiratory complications. A PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O or less were identified as protective mechanical ventilator settings. These findings suggest that protective thresholds differ for intraoperative ventilation in patients with normal lungs compared with those used for patients with acute lung injury.

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.

Background: Patients admitted to intensive care units (ICU) are often treated with intravenous (IV) vasopressors. Persistent hypotension and dependence on IV vasopressors in otherwise resuscitated patients lead to delay in discharge from ICU. Midodrine is an oral alpha-1 adrenergic agonist approved for treatment of symptomatic orthostatic hypotension. This trial aims to evaluate whether oral administration of midodrine is an effective adjunct to standard therapy to reduce the duration of IV vasopressor treatment, and allow earlier discharge from ICU and hospital. Methods: The MIDAS trial is an international, multicenter, randomized, double-blind, placebo-controlled clinical trial being conducted in the USA and Australia. We are targeting 120 patients. Adult patients admitted to the ICU who are resuscitated and otherwise stable on low dose IV vasopressors for at least 24 h will be considered for recruitment. Participants will be randomized to receive midodrine (20 mg) or placebo three times a day, in addition to standard care. The primary outcome is time (hours) from initiation of midodrine or placebo to discontinuation of IV vasopressors. Secondary outcomes include time (hours) from ICU admission to discharge readiness, ICU length of stay (LOS) (days), hospital LOS (days), rates of ICU readmission, and rates of adverse events related to midodrine administration. Discussion Midodrine is approved by the Food and Drug Administration (FDA) for the treatment of symptomatic orthostatic hypotension. In August 2010, FDA proposed to withdraw approval of midodrine because of lack of studies that verify the clinical benefit of the drug. We obtained Investigational New Drug (IND 113,330) approval to study its effects in critically ill patients who require IV vasopressors but are otherwise ready for discharge from the ICU. A pilot observational study in a cohort of surgical ICU patients showed that the rate of decline in vasopressor requirements increased after initiation of midodrine treatment. We hypothesize that midodrine administration is effective to wean IV vasopressors and shorten ICU and hospital LOS. This trial may have significant implications on lowering costs of hospital care and obtaining FDA approval for new indications for midodrine. Trial Registration This study has been registered at clinicaltrials.gov on 02/09/2012 (NCT01531959).

We tested the hypothesis that etomidate and ketamine produce residual effects that modify functional mobility (measured by the balance beam test) and adrenal function (adrenocorticotropic hormone (ACTH) stimulation) immediately following recovery from loss of righting reflex in rats. Intravenous etomidate or ketamine was administered in a randomized, crossover fashion (2 or 4 mg/kg and 20 or 40 mg/kg, respectively) on eight consecutive days. Following recovery of righting reflex, animals were assessed for residual effects on functional mobility on the balance beam, motor behavior in the open field and adrenal function through ACTH stimulation. We evaluated the consequences of the effects of the anesthetic agent-induced motor behavior on functional mobility. On the balance beam, etomidate-treated rats maintained their grip longer than ketamine-treated rats, indicating greater balance abilities (mean ± SD, 21.5 ± 25.1 s vs. 3.0 ± 4.3 s respectively, p < 0.021). In the open field test, both dosages of etomidate and ketamine had opposite effects on travel behavior, showing ketamine-induced hyperlocomotion and etomidate-induced hypolocomotion. There was a significant interaction between anesthetic agent and motor behavior effects for functional mobility effects (p < 0.001). Corticosterone levels were lower after both 40 mg/kg ketamine and 4 mg/kg etomidate anesthesia compared to placebo, an effect stronger with etomidate than ketamine (p < 0.001). Following recovery from anesthesia, etomidate and ketamine have substantial side effects. Ketamine-induced hyperlocomotion with 20 and 40 mg/kg has stronger effects on functional mobility than etomidate-induced hypolocomotion with 2 and 4 mg/kg. Etomidate (4 mg/kg) has stronger adrenal suppression effects than ketamine (40 mg/kg).

Background: Postoperative respiratory complications (PRCs) are associated with significant morbidity, mortality, and hospital costs. Obstructive sleep apnea (OSA), often undiagnosed in the surgical population, may be a contributing factor. Thus, we aimed to develop and validate a score for preoperative prediction of OSA (SPOSA) based on data available in electronic medical records preoperatively. Methods: OSA was defined as the occurrence of an OSA diagnostic code preceded by a polysomnography procedure. A priori defined variables were analyzed by multivariable logistic regression analysis to develop our score. Score validity was assessed by investigating the score’s ability to predict non-invasive ventilation. We then assessed the effect of high OSA risk, as defined by SPOSA, on PRCs within seven postoperative days and in-hospital mortality. Results: A total of 108,781 surgical patients at Partners HealthCare hospitals (2007–2014) were studied. Predictors of OSA included BMI >25 kg*m−2 and comorbidities, including pulmonary hypertension, hypertension, and diabetes. The score yielded an area under the curve of 0.82. Non-invasive ventilation was significantly associated with high OSA risk (OR 1.44, 95% CI 1.22–1.69). Using a dichotomized endpoint, 26,968 (24.8%) patients were identified as high risk for OSA and 7.9% of these patients experienced PRCs. OSA risk was significantly associated with PRCs (OR 1.30, 95% CI 1.19–1.43). Conclusion: SPOSA identifies patients at high risk for OSA using electronic medical record-derived data. High risk of OSA is associated with the occurrence of PRCs. Electronic supplementary material The online version of this article (doi:10.1186/s12871-017-0361-z) contains supplementary material, which is available to authorized users.

Purpose of review Postoperative respiratory complications (PRCs) increase hospitalization time, 30-day mortality and costs by up to $35 000. These outcomes measures have gained prominence as bundled payments have become more common. Recent findings Results of recent quantitative effectiveness studies and clinical trials provide a framework that helps develop center-specific treatment guidelines, tailored to minimize the risk of PRCs. The implementation of those protocols should be guided by a local, respected, and visible facilitator who leads proper implementation while inviting center-specific input from surgeons, anesthesiologists, and other perioperative stakeholders. Summary Preoperatively, patients should be risk-stratified for PRCs to individualize intraoperative choices and postoperative pathways. Laparoscopic compared with open surgery improves respiratory outcomes. High-risk patients should be treated by experienced providers based on locally developed bundle-interventions to optimize intraoperative treatment and ICU bed utilization. Intraoperatively, lung-protective ventilation (procedure-specific positive end-expiratory pressure utilization, and low driving pressure) and moderately restrictive fluid therapy should be used. To achieve surgical relaxation, high-dose neuromuscular blocking agents (and reversal agents) as well as high-dose opioids should be avoided; inhaled anesthetics improve surgical conditions while protecting the lungs. Patients should be extubated in reverse Trendelenburg position. Postoperatively, continuous positive airway pressure helps prevent airway collapse and protocolized, early mobilization improves cognitive and respiratory function.

The rise of electronic medical records has led to a proliferation of large observational studies that examine the perioperative period. In contrast to randomized controlled trials, these studies have the ability to provide quick, cheap and easily obtainable information on a variety of patients and are reflective of everyday clinical practice. However, it is important to note that the data used in these studies are often generated for billing or documentation purposes such as insurance claims or the electronic anesthetic record. The reliance on codes to define diagnoses in these studies may lead to false inferences or conclusions. Researchers should specify the code assignment process and be aware of potential error sources when undertaking studies using secondary data sources. While misclassification may be a short-coming of using large databases, it does not prevent their use in conducting meaningful effectiveness research that has direct consequences on medical decision making.