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

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

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

Anesthesia and Patients with Congenital Hyposensitivity to Pain

Background: Congenital hyposensitivity to pain or hereditary sensory and autonomic neuropathy represents a variety of disorders characterized by decreased perception of nociception, loss of other modalities of sensation, and variable expression of autonomic dysfunction. Sensory loss, especially that of pain, is associated with self-mutilations that may require frequent operations. Little is known about the safety of anesthesia for these patients. Methods: The authors performed a computerized search of the Mayo Clinic medical records database between January 1996 and November 2005 for patients with congenital hyposensitivity to pain and related disorders who underwent general anesthesia. Medical records were reviewed for demographics, anesthetic techniques and agents, use of opioids, and perioperative complications. In addition, the authors conducted a comprehensive review of the literature to summarize the current knowledge regarding anesthesia for patients with congenital hyposensitivity to pain, and compared it with the patients with hyposensitivity to pain identified at the Mayo Clinic. Results: The authors identified seven patients with hereditary sensory and autonomic neuropathy II, IV, or V and undefined variants of congenital pain hyposensitivity who generated 17 anesthesia records: 12 for orthopedic operations, 3 for sural nerve biopsies, and 2 for ophthalmologic procedures. In all patients, standard doses of volatile agents were used during anesthesia. Small amounts of opioids were used during the course of eight operations. Most patients experienced mild hypothermia (lowest temperature 34.7°C), and none experienced hyperthermia. All patients were hemodynamically stable during otherwise uneventful anesthesia. During recovery from anesthesia, opioids were given to only one patient, a single dose of 1 mg morphine. Even after major orthopedic operations, the patient did not require additional analgesia. Conclusions: The patients with profound congenital hyposensitivity to pain underwent anesthesia without any adverse events. The authors found that despite reduced pain perception, the requirements for volatile anesthetics were within the expected range for population with normal pain perception, but they did not require opioids postoperatively. Intraoperative mild hypothermia was easily managed by adjustment of environmental temperature

Prediction of Opioid-Induced Respiratory Depression on Inpatient Wards Using Continuous Capnography and Oximetry: An International Prospective, Observational Trial

Background: Opioid-related adverse events are a serious problem in hospitalized patients. Little is known about patients who are likely to experience opioid-induced respiratory depression events on the general care floor and may benefit from improved monitoring and early intervention. The trial objective was to derive and validate a risk prediction tool for respiratory depression in patients receiving opioids, as detected by continuous pulse oximetry and capnography monitoring. Methods: PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) was a prospective, observational trial of blinded continuous capnography and oximetry conducted at 16 sites in the United States, Europe, and Asia. Vital signs were intermittently monitored per standard of care. A total of 1335 patients receiving parenteral opioids and continuously monitored on the general care floor were included in the analysis. A respiratory depression episode was defined as respiratory rate ≤5 breaths/min (bpm), oxygen saturation ≤85%, or end-tidal carbon dioxide ≤15 or ≥60 mm Hg for ≥3 minutes; apnea episode lasting >30 seconds; or any respiratory opioid-related adverse event. A risk prediction tool was derived using a multivariable logistic regression model of 46 a priori defined risk factors with stepwise selection and was internally validated by bootstrapping. Results: One or more respiratory depression episodes were detected in 614 (46%) of 1335 general care floor patients (43% male; mean age, 58 ± 14 years) continuously monitored for a median of 24 hours (interquartile range [IQR], 17-26). A multivariable respiratory depression prediction model with area under the curve of 0.740 was developed using 5 independent variables: age ≥60 (in decades), sex, opioid naivety, sleep disorders, and chronic heart failure. The PRODIGY risk prediction tool showed significant separation between patients with and without respiratory depression (P < .001) and an odds ratio of 6.07 (95% confidence interval [CI], 4.44-8.30; P < .001) between the high- and low-risk groups. Compared to patients without respiratory depression episodes, mean hospital length of stay was 3 days longer in patients with ≥1 respiratory depression episode (10.5 ± 10.8 vs 7.7 ± 7.8 days; P < .0001) identified using continuous oximetry and capnography monitoring. Conclusions: A PRODIGY risk prediction model, derived from continuous oximetry and capnography, accurately predicts respiratory depression episodes in patients receiving opioids on the general care floor. Implementation of the PRODIGY score to determine the need for continuous monitoring may be a first step to reduce the incidence and consequences of respiratory compromise in patients receiving opioids on the general care floor

International multicenter observational study on assessment of ventilatory management during general anaesthesia for robotic surgery and its effects on postoperative pulmonary complication (AVATaR) : study protocol and statistical analysis plan

Introduction: Robotic-assisted surgery (RAS) has emerged as an alternative minimally invasive surgical option. Despite its growing applicability, the frequent need for pneumoperitoneum and Trendelenburg position could significantly affect respiratory mechanics during RAS. AVATaR is an international multicenter observational study aiming to assess the incidence of postoperative pulmonary complications (PPC), to characterise current practices of mechanical ventilation (MV) and to evaluate a possible association between ventilatory parameters and PPC in patients undergoing RAS. Methods and analysis: AVATaR is an observational study of surgical patients undergoing MV for general anaesthesia for RAS. The primary outcome is the incidence of PPC during the first five postoperative days. Secondary outcomes include practice of MV, effect of surgical positioning on MV, effect of MV on clinical outcome and intraoperative complications. Ethics and dissemination: This study was approved by the Institutional Review Board of the Hospital Israelita Albert Einstein. The study results will be published in peer-reviewed journals and disseminated at international conferences. Trial registration number: NCT02989415; Pre-results