Derivation and validation of an automated electronic search algorithm to identify patients at risk for obstructive sleep apnea

Background. Automated extraction of data from electronic health records has allowed high-quality retrospective analyses of large cohorts. Objectives. To derive and validate an automated electronic search algorithm to identify surgical patients with a diagnosis of or at high risk for obstructive sleep apnea (OSA). Methods. From 558 adult patients who underwent surgery from January 1, 2011, through December 31, 2015, we constructed a derivation cohort of 100 subjects selected using the initial search algorithm to have equal numbers of patients with high and low likelihood of having OSA. This algorithm conducted a free-text electronic search of patient diagnoses and interrogated results of a preoperative checklist that specifically queried patients regarding OSA history and screened for OSA risk using Flemons criteria. The derivation cohort was then manually reviewed to identify patients with OSA risk and results were used to refine the algorithm. Second, the algorithm was validated with the other 458 patients (the validation cohort). The sensitivity and specificity were compared again with manual chart review of the respective group. Results. In the derivation cohort, the automated electronic algorithm achieved a sensitivity of 98.2% and a specificity of 100.0% compared with the manual review. In the validation cohort, sensitivity was 100.0% and specificity was 98.4% in this comparison. Conclusion. An automated electronic search algorithm was developed that interrogates electronic health records to identify, with a high degree of accuracy, surgical patients with a diagnosis of or at high risk for OSA

Perioperative Cardiac Arrests

Perioperative cardiac arrests represent the most serious complication of anesthesia and surgery. It is believed that the incidence and mortality of cardiac arrest has declined, however, a more recent review questioned whether these rates have changed over the last 5 decades. It is difficult to compare the reports from different epochs, because medical practice has advanced, surgical acuity increased, and patients in extremes of age undergo surgery today. In the present article we review the information regarding the incidence of perioperative cardiac arrests and predictors of survival covering the period since the first comprehensive report by Beecher and Todd in 1954. We focus on our publications that report perioperative cardiac arrest at Mayo Clinic for adult noncardiac surgery, during regional anesthesia, and arrests in our pediatric surgical practice

Delirium following total joint replacement surgery

Postoperative delirium (POD) is a common complication associated with increased resource utilization, morbidity and mortality. Our institution screens all postsurgical patients for postoperative delirium. The study aim was to perform an automated interrogation of the electronic health records to estimate the incidence of and identify associated risk factors for POD following total joint arthroplasty (TJA). Adult patients who underwent TJA with a multimodal analgesia protocol, including peripheral nerve blockade, from 2008 through 2012, underwent automated chart review. POD was identified by routine nursing assessment and administrative billing codes. Of 11,970 patients, 181 (1.5%) were identified to have POD. Older age (odds ratio, 95% CI 2.20, 1.80–2.71 per decade, p < 0.001), dementia (7.44, 3.54–14.60, p < 0.001), diabetes mellitus (1.70, 1.1.5–2.47, p = 0.009), renal disease (1.68, 1.03–2.65, p = 0.039), blood transfusions (2.04, 1.14–3.52, p = 0.017), and sedation during anesthesia recovery (1.76, 1.23–2.51, p = 0.002) were associated with POD. Anesthetic management was not associated with POD risk. Patients who developed POD required greater healthcare resources. Dementia is strongly associated with POD. The association between POD and transfusions may reflect higher acuity patients or detrimental effect of blood. Postoperative sedation should be recognized as a warning sign of increased risk

Acute phenibut withdrawal: A comprehensive literature review and illustrative case report

Phenibut is a glutamic acid derivative with activity on the γ-aminobutyric acid (GABA) B and A, and β-phenethylamine receptors. It is prescribed in former Communist Bloc countries for anxiolysis and related psychiatric disorders. It can be easily obtained in Western countries, and is thought to have abuse potential. Abrupt discontinuation has been reported to precipitate an abstinence syndrome. A review of the literature identified 22 reported cases, many of which were notable for severe psychomotor agitation and requirements for aggressive pharmacologic treatment. Neurologic and autonomic signs and symptoms may mimic serotonin or neuroleptic malignant syndrome. Patients were typically younger and had coexisting substance abuse disorders to other drugs. Also presented is a case of a 23-year-old male with an acute phenibut abstinence syndrome. This patient exhibited severe psychomotor agitation requiring physical restraints, dexmedetomidine, lorazepam, haloperidol, diphenhydramine, cyproheptadine, melatonin, olanzapine, and baclofen for symptom control

Respiratory depression in the post-anesthesia care unit: Mayo Clinic experience

The anesthesia recovery is a complex physiologic process as systems recover from the effects of surgery and anesthesia. Inadequate recovery of respiratory physiology can lead to severe hypoxemia-induced end-organ damage and even death. Emerging evidence suggests that signs of respiratory depression during early anesthesia recovery may portend increased risk for future severe adverse events. This article briefly reviews the Mayo Clinic research experience and advances in clinical practice. From the implementation of a step-down model of discharge criteria in the post-anesthesia care unit (PACU), consisting of PACU nurses monitoring patients in predetermined periods for signs of respiratory depression, and delaying PACU discharge for patients who exhibit signs of respiratory depression, and early intervention in high-risk patients. Subsequent studies found that even a single episode of respiratory depression in the PACU was strongly associated with subsequent respiratory complications. Further, patient baseline characteristics found to be associated with respiratory depression included obstructive sleep apnea and low body weight, and surgical factors associated with increased risk included the use of preoperative sustained-release opioids, perioperative gabapentinoid use, higher intraoperative opioids, isoflurane as the volatile anesthetic, and longer surgical duration. Based in part of Mayo Clinic research, the FDA issued a warning in 2019 on gabapentinoids use and respiratory complications, increasing the recommended level of respiratory vigilance in patients using this medication. Understanding the complex nature of postoperative respiratory events requires a range of translational and clinical research and constant update of practice

Validity of mortality risk prediction scores in critically ill patients with secondary pulmonary embolism

Herein, we assess the use of the Acute Physiology and Chronic Health Evaluation-IV (APACHE-IV) and pulmonary embolism (PE)–specific risk scores to predict mortality among intensive care unit (ICU) patients who developed secondary PE. This retrospective cohort study used information from 208 United States critical care units recorded in the eICU Collaborative Research Database during 2014 and 2015. We calculated APACHE-IV, Pulmonary Embolism Severity Index (PESI), simplified PESI (sPESI), and ICU-sPESI scores and compared their predicting performance using the area under the receiver operating characteristic (AUROC) curve. Of 812 patients included in our study, 150 died (mortality, 18.5% [95% CI, 15.8%-21.1%]). Compared to survivors, non-survivors had higher APACHE-IV (86 vs 52, P<0.001), PESI (170 vs 129, P<0.001), sPESI (2 vs 2, P<0.001), and ICU-sPESI (4 vs 2, P<0.001) scores. AUROCs were 0.790 (APACHE-IV); 0.737 (PESI); 0.726 (ICU-sPESI); and 0.620 (sPESI). APACHE-IV performed significantly better than all 3 PE-specific mortality scores (APACHE-IV vs PESI, P=0.041; APACHE-IV vs sPESI, P=0.001; and APACHE-IV vs ICU-sPESI, P=0.021). Both the PESI and ICU-sPESI outperformed the sPESI (PESI vs sPESI, P=0.001; ICU-sPESI vs sPESI, P<0.001). APACHE-IV score was found to be the best instrument for predicting mortality risk, but PESI and ICU-sPESI scores may be used when APACHE-IV is unavailable. sPESI AUROC suggests absence of sufficient discriminative value to be used as a predictor of mortality in patients with secondary PE.

Survival prediction of high-risk outborn neonates with congenital diaphragmatic hernia from capillary blood gases

BACKGROUND: The extent of lung hypoplasia in neonates with congenital diaphragmatic hernia (CDH) can be assessed from gas exchange. We examined the role of preductal capillary blood gases in prognosticating outcome in patients with CDH. ----- METHODS: We retrospectively reviewed demographic data, disease characteristics, and preductal capillary blood gases on admission and within 24 h following admission for 44 high-risk outborn neonates. All neonates were intubated after delivery due to acute respiratory distress, and were emergently transferred via ground ambulance to our unit between 1/2000 and 12/2014. The main outcome measure was survival to hospital discharge and explanatory variables of interest were preductal capillary blood gases obtained on admission and during the first 24 h following admission. ----- RESULTS: Higher ratio of preductal partial pressure of oxygen to fraction of inspired oxygen (PcO2/FIO2) on admission predicted survival (AUC = 0.69, P = 0.04). However, some neonates substantially improve PcO2/FIO2 following initiation of treatment. Among neonates who survived at least 24 h, the highest preductal PcO2/FIO2 achieved in the initial 24 h was the strongest predictor of survival (AUC = 0.87, P = 0.002). Nonsurvivors had a mean admission preductal PcCO2 higher than survivors (91 ± 31 vs. 70 ± 25 mmHg, P = 0.02), and their PcCO2 remained high during the first 24 h of treatment. ----- CONCLUSION: The inability to achieve adequate gas exchange within 24 h of initiation of intensive care treatment is an ominous sign in high-risk outborn neonates with CDH. We suggest that improvement of oxygenation during the first 24 h, along with other relevant clinical signs, should be used when making decisions regarding treatment options in these critically ill neonates

Survival of outborns with congenital diaphragmatic hernia: the role of protective ventilation, early presentation and transport distance: a retrospective cohort study

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a congenital malformation associated with life-threatening pulmonary dysfunction and high neonatal mortality. Outcomes are improved with protective ventilation, less severe pulmonary pathology, and the proximity of the treating center to the site of delivery. The major CDH treatment center in Croatia lacks a maternity ward, thus all CDH patients are transferred from local Zagreb hospitals or remote areas (outborns). In 2000 this center adopted protective ventilation for CDH management. In the present study we assess the roles of protective ventilation, transport distance, and severity of pulmonary pathology on survival of neonates with CDH. ----- METHODS: The study was divided into Epoch I, (1990-1999, traditional ventilation to achieve normocapnia), and Epoch II, (2000-2014, protective ventilation with permissive hypercapnia). Patients were categorized by transfer distance (local hospital or remote locations) and by acuity of respiratory distress after delivery (early presentation-occurring at birth, or late presentation, ≥ 6 h after delivery). Survival between epochs, types of transfers, and acuity of presentation were assessed. An additional analysis was assessed for the potential association between survival and end-capillary blood CO2 (PcCO2), an indirect measure of pulmonary pathology. ----- RESULTS: There were 83 neonates, 26 in Epoch I, and 57 in Epoch II. In Epoch I 11 patients (42%) survived, and in Epoch II 38 (67%) (P = 0.039). Survival with early presentation (N = 63) was 48 % and with late presentation 95% (P <0.001). Among early presentation, survival was higher in Epoch II vs. Epoch I (57% vs. 26%, P = 0.031). From multiple logistic regression analysis restricted to neonates with early presentation and adjusting for severity of disease, survival was improved in Epoch II (OR 4.8, 95%CI 1.3-18.0, P = 0.019). Survival was unrelated to distance of transfer but improved with lower partial pressure of PcCO2 on admission (OR 1.16, 95%CI 1.01-1.33 per 5 mmHg decrease, P = 0.031). ----- CONCLUSIONS: The introduction of protective ventilation was associated with improved survival in neonates with early presentation. Survival did not differ between local and remote transfers, but primarily depended on severity of pulmonary pathology as inferred from admission capillary PcCO2

Postoperative respiratory depression after hysterectomy

To investigate if sex-specific physiologic characteristics could impact postoperative respiratory depression risks in women, we studied incidence and risk factors associated with postoperative respiratory depression in a gynecologic surgical cohort. Only hysterectomies performed under general anesthesia from 2012 to 2017 were included to minimize interprocedural variability. Respiratory depression was defined as episodes of apnea, hypopnea, hypoxemia, pain-sedation mismatch, unplanned positive airway pressure device application, or naloxone administration in the post-anesthesia care unit. Multivariable logistic regression was used to explore the association with clinical characteristics. From 1,974 hysterectomies, 253 had postoperative respiratory depression, yielding an incidence of 128 (95% confidence interval, 114–144) per 1,000 surgeries. Risk factors associated with respiratory depression were older age (odds ratio 1.22 [95% confidence interval 1.02–1.46] per decade increase, p = 0.03), lower body weight (0.77 [0.62–0.94] per 10 kg/m2, p = 0.01), and higher intraoperative opioid dose (1.05 [1.01–1.09] per 10 mg oral morphine equivalents, p = 0.01); while sugammadex use was associated with a reduced risk (0.48 [0.30–0.75], p = 0.002). Respiratory depression was not associated with increased hospital stay, postoperative complications, or mortality. Postoperative respiratory depression risk in women increased with age, lower weight, and higher intraoperative opioids and decreased with sugammadex use; however, it was not associated with postoperative pulmonary complications

Influence of tobacco use on postoperative opiate analgesia requirements in patients undergoing coronary artery bypass graft surgery

Introduction. The objective of this study was to test the hypothesis that tobacco use status is independently associated with postoperative opioid requirements in patients undergoing coronary artery bypass grafting (CABG) when important demographic variables such as age and gender are taken into account. Methods. A retrospective chart review of patients who underwent CABG surgery over a one year period at Mayo Clinic in Rochester, MN was performed. Tobacco users (N=69) were compared to nonusers (N=345) with regards to opiate requirements and the occurrence of severe pain during the first 48 hours postoperatively. For comparison, all postoperative opiates were converted to oral morphine equivalents (OME). Adjusted analysis for age and gender was also performed. Results. Tobacco users were younger than nonusers (P < 0.001), and a greater proportion of former users were male compared to never users (P = 0.003). Tobacco users had greater mean opiate requirements 401 ± 284 than nonusers 314 ± 240 mg OME, (P = 0.009). However, the association between tobacco use and greater postoperative opiate requirements lost significance after adjustment for age and gender. Tobacco use was not associated with increased risk of the development of severe pain (P = 0.51). Conclusions. Although current tobacco users undergoing CABG surgery utilize more opioid analgesics in the first 48 hours following extubation than nonusers of tobacco, when adjusted for age and gender, tobacco use was not independently associated with differences in postoperative opioid use