Natural Language Mapping of Electrocardiogram Interpretations to a Standardized Ontology.

BACKGROUND: Interpretations of the electrocardiogram (ECG) are often prepared using software outside the electronic health record (EHR) and imported via an interface as a narrative note. Thus, natural language processing is required to create a computable representation of the findings. Challenges include misspellings, nonstandard abbreviations, jargon, and equivocation in diagnostic interpretations. OBJECTIVES: Our objective was to develop an algorithm to reliably and efficiently extract such information and map it to the standardized ECG ontology developed jointly by the American Heart Association, the American College of Cardiology Foundation, and the Heart Rhythm Society. The algorithm was to be designed to be easily modifiable for use with EHRs and ECG reporting systems other than the ones studied. METHODS: An algorithm using natural language processing techniques was developed in structured query language to extract and map quantitative and diagnostic information from ECG narrative reports to the cardiology societies' standardized ECG ontology. The algorithm was developed using a training dataset of 43,861 ECG reports and applied to a test dataset of 46,873 reports. RESULTS: Accuracy, precision, recall, and the F1-measure were all 100% in the test dataset for the extraction of quantitative data (e.g., PR and QTc interval, atrial and ventricular heart rate). Performances for matches in each diagnostic category in the standardized ECG ontology were all above 99% in the test dataset. The processing speed was approximately 20,000 reports per minute. We externally validated the algorithm from another institution that used a different ECG reporting system and found similar performance. CONCLUSION: The developed algorithm had high performance for creating a computable representation of ECG interpretations. Software and lookup tables are provided that can easily be modified for local customization and for use with other EHR and ECG reporting systems. This algorithm has utility for research and in clinical decision-support where incorporation of ECG findings is desired.

Regional Anesthesia for Pediatric Ophthalmic Surgery: A Review of the Literature.

Ophthalmic pediatric regional anesthesia has been widely described, but infrequently used. This review summarizes the available evidence supporting the use of conduction anesthesia in pediatric ophthalmic surgery. Key anatomic differences in axial length, intraocular pressure, and available orbital space between young children and adults impact conduct of ophthalmic regional anesthesia. The eye is near adult size at birth and completes its growth rapidly while the orbit does not. This results in significantly diminished extraocular orbital volumes for local anesthetic deposition. Needle-based blocks are categorized by relation of the needle to the extraocular muscle cone (ie, intraconal or extraconal) and in the cannula-based block, by description of the potential space deep to the Tenon capsule. In children, blocks are placed after induction of anesthesia by a pediatric anesthesiologist or ophthalmologist, via anatomic landmarks or under ultrasonography. Ocular conduction anesthesia confers several advantages for eye surgery including analgesia, akinesia, ablation of the oculocardiac reflex, and reduction of postoperative nausea and vomiting. Short (16 mm), blunt-tip needles are preferred because of altered globe-to-orbit ratios in children. Soft-tip cannulae of varying length have been demonstrated as safe in sub-Tenon blockade. Ultrasound technology facilitates direct, real-time visualization of needle position and local anesthetic spread and reduces inadvertent intraconal needle placement. The developing eye is vulnerable to thermal and mechanical insults, so ocular-rated transducers are mandated. The adjuvant hyaluronidase improves ocular akinesia, decreases local anesthetic dosage requirements, and improves initial block success; meanwhile, dexmedetomidine increases local anesthetic potency and prolongs duration of analgesia without an increase in adverse events. Intraconal blockade is a relative contraindication in neonates and infants, retinoblastoma surgery, and in the presence of posterior staphylomas and buphthalmos. Specific considerations include pertinent pediatric ophthalmologic topics, block placement in the syndromic child, and potential adverse effects associated with each technique. Recommendations based on our experience at a busy academic ophthalmologic tertiary referral center are provided.

Tramadol-associated hallucinations: a systematic review and narrative synthesis of their pathophysiology, diagnosis, and treatment.

BACKGROUND: Recent prescribing trends reflect government-led efforts undertaken in both the U.S. and Canada to decrease opioid use. These provisions reflect a reduction in the use of many potent opioids in favour of tramadol. Despite the purported benefits of tramadol over other opioids, little remains known about tramadol-associated hallucinations (TAH). METHODS: We conducted a systematic literature search in Embase, Medline, Cochrane CENTRAL, CINAHL, PubMed, Scopus, PAHO Virtual Health Library, MedNar, and ClinicalTrials.gov to find reported cases of hallucinations associated with the use of tramadol. For all corresponding cases reporting hallucinations secondary to tramadol use, we extracted data on patient demographics, medical management, and the details on hallucinations. Cases were categorized as "probable TAH" if the evidence supported an association between hallucinations and tramadol use, or "possible TAH" if hallucinations were attributed to tramadol use but the supporting evidence was weak. The "probable TAH" cases were further classified as "isolated TAH" if hallucinations were the primary complaint, or "other existing medical condition" if concurrent signs and symptoms alluded to a diagnosis of an existing medical condition. We then conducted a narrative synthesis of the available literature to contextualize these results. RESULTS: A total of 941 articles were identified in the initial search. No observational studies or randomized clinical trials were identified with our systematic review; only case reports were found. After a thorough screening, 34 articles comprising 101 patients reported an association between tramadol use and hallucinations. Among these 101 cases, 31 were "probable TAH" and 70 were "possible TAH". Of the 31 cases of "probable TAH", 16 cases were "isolated TAH" while the remaining 15 cases belonged to "other existing medical condition". CONCLUSIONS: Tramadol-associated hallucinations can result in auditory or visual disturbances, although multisensory symptoms have also been reported. The mechanism underlying TAH remains poorly understood and likely involves numerous receptor types. The relative risk of hallucinations from tramadol compared with other opioids remains unclear.

Airway Management of Near-Complete Tracheal Transection by Through-the-Wound Intubation: A Case Report.

We present an approach to airway management in a patient with machete injuries culminating in near-complete cricotracheal transection, in addition to a gunshot wound to the neck. Initial airway was established by direct intubation through the cricotracheal wound. Once the airway was secured, a bronchoscopy-guided orotracheal intubation was performed with simultaneous retraction of the cricotracheal airway to optimize the surgical field. This case offers insight into a rarely performed approach to airway management. Furthermore, our case report demonstrates that, in select airway injuries, performing through-the-wound intubation engenders a multitude of benefits.

K+ efflux and retention in response to NaCl stress do not predict salt tolerance in contrasting genotypes of rice (Oryza sativa L.).

Sudden elevations in external sodium chloride (NaCl) accelerate potassium (K(+)) efflux across the plasma membrane of plant root cells. It has been proposed that the extent of this acceleration can predict salt tolerance among contrasting cultivars. However, this proposal has not been considered in the context of plant nutritional history, nor has it been explored in rice (Oryza sativa L.), which stands among the world's most important and salt-sensitive crop species. Using efflux analysis with (42)K, coupled with growth and tissue K(+) analyses, we examined the short- and long-term effects of NaCl exposure to plant performance within a nutritional matrix that significantly altered tissue-K(+) set points in three rice cultivars that differ in salt tolerance: IR29 (sensitive), IR72 (moderate), and Pokkali (tolerant). We show that total short-term K(+) release from roots in response to NaCl stress is small (no more than 26% over 45 min) in rice. Despite strong varietal differences, the extent of efflux is shown to be a poor predictor of plant performance on long-term NaCl stress. In fact, no measure of K(+) status was found to correlate with plant performance among cultivars either in the presence or absence of NaCl stress. By contrast, shoot Na(+) accumulation showed the strongest correlation (a negative one) with biomass, under long-term salinity. Pharmacological evidence suggests that NaCl-induced K(+) efflux is a result of membrane disintegrity, possibly as result of osmotic shock, and not due to ion-channel mediation. Taken together, we conclude that, in rice, K(+) status (including efflux) is a poor predictor of salt tolerance and overall plant performance and, instead, shoot Na(+) accumulation is the key factor in performance decline on NaCl stress.

Silver ions disrupt K⁺ homeostasis and cellular integrity in intact barley (Hordeum vulgare L.) roots.

The heavy metals silver, gold, and mercury can strongly inhibit aquaporin-mediated water flow across plant cell membranes, but critical examinations of their side effects are rare. Here, the short-lived radiotracer (42)K is used to demonstrate that these metals, especially silver, profoundly change potassium homeostasis in roots of intact barley (Hordeum vulgare L.) plants, by altering unidirectional K(+) fluxes. Doses as low as 5 µM AgNO(3) rapidly reduced K(+) influx to 5% that of controls, and brought about pronounced and immediate increases in K(+) efflux, while higher doses of Au(3+) and Hg(2+) were required to produce similar responses. Reduced influx and enhanced efflux of K(+) resulted in a net loss of >40% of root tissue K(+) during a 15 min application of 500 µM AgNO(3), comprising the entire cytosolic potassium pool and about a third of the vacuolar pool. Silver also brought about major losses of UV-absorbing compounds, total electrolytes, and NH(4)(+). Co-application, with silver, of the channel blockers Cs(+), TEA(+), or Ca(2+), did not affect the enhanced efflux, ruling out the involvement of outwardly rectifying ion channels. Taken together with an examination of propidium iodide staining under confocal microscopy, the results indicate that silver ions affect K(+) homeostasis by directly inhibiting K(+) influx at lower concentrations, and indirectly inhibiting K(+) influx and enhancing K(+) efflux, via membrane destruction, at higher concentrations. Ni(2+), Cd(2+), and Pb(2+), three heavy metals not generally known to affect aquaporins, did not enhance K(+) efflux or cause propidium iodide incorporation. The study reveals strong and previously unknown effects of major aquaporin inhibitors and recommends caution in their application.