GlideScope® vs flexible fibreoptic scope for elective intubation in obese patients.

We hypothesised that in obese patients, tracheal intubation with the GlideScope® would be advantageous compared with flexible fibreoptic intubation. Seventy-five anaesthetised obese patients were randomly assigned to oral intubation by either GlideScope or flexible fibreoptic bronchoscope. We compared the two devices for time to intubate (p = 0.19), difficulty of intubation (p = 0.58), successful intubation on first attempt (p = 0.29), number of attempts (p = 0.24), incidence of hypoxaemia (p = 0.57), amount of post-intubation bleeding (p = 0.79) and sore throat (p = 0.82). None differed significantly. Median (IQR [range]) time to intubation was 37 (25-48 [19-81]) s and 95% of the first attempts were successful with the GlideScope, vs 43 (35-58 [26-96]) s and an 86% first-attempt success rate with the flexible fibreoptic bronchoscope. For experienced users, the time required to intubate the trachea in anaesthetised obese patients is similar with the GlideScope and a flexible bronchoscope.

Use of GlideScope® in adults: an overview.

This paper is an overview of the literature concerning the "know how" of the GlideScope® use in adults. We summarized the main evidences of the last 10 years with particular attention to experts' suggestions about clinical practice of the GlideScope®, noticing matters still debated on GlideScope® use. We used PubMed to search publications from January 2003 to June 2013 using the search terms "GlideScope", "video laryngoscope" and "videolaryngoscopy". These publications were searched manually or references to further publication not identified using PubMed. All works that made a point worth including were cited in the discussion. Our research confirms the value of GlideScope® use in airway management and highlights the debate about the use of videolaryngoscopes in routine cases and the operators who may use them in clinical practice.

An evaluation of suloctidil in the prevention of deep vein thrombosis in neurosurgical patients.

Suloctidil (200 mg t.i.d.) was compared with placebo in a randomized, double-blind trial to assess its value in preventing deep venous thrombosis (DVT) in high-risk neurosurgical patients, comprising 136 patients with brain or spinal tumour, head or spinal injury, or subarachnoid or intracranial hemorrhage. 125I fibrinogen leg scanning and impedance plethysmography were performed for up to 14 days to detect DVT. The two groups were also evenly balanced for DVT risk factors. Seventeen of 68 patients (25%) (95% confidence interval, 15-35%) treated with suloctidil and 12 of 68 patients (21%) (95% confidence interval, 11-32%) treated with placebo developed deep venous thrombosis. This observed difference in outcomes is not statistically significant (X2 = 1.096; p = 0.30). The estimated 95% confidence interval for the true difference in the incidence of DVT between suloctidil-treated and placebo-treated patients ranges from an 11% benefit in favour of suloctidil to an 18% benefit in favour of placebo. Major deep vein thrombosis occurred in two patients on suloctidil and three patients in the placebo group; there were no fatal pulmonary emboli during the 14-day study period, during which time four patients in each group died of non-thromboembolic complications. There was no observed difference in hemorrhagic complications. Long-term outcomes at three-months follow-up were similar between the two treatment groups. It is concluded that there is no real evidence that suloctidil (200 mg t.i.d.) is an effective regimen for the prevention of DVT in high-risk neurosurgical patients.

Recurrent respiratory papillomatosis: juvenile versus adult forms.

Recurrent respiratory papillomatosis (RRP) has been described to have a juvenile or aggressive form and an adult or less aggressive form. However, the aggressive form may occur in an adult and vice versa. Some authors have reported a quiescence in the juvenile form with the onset of puberty. In order to further characterize these two forms of RRP and to analyze the effects of puberty, we reviewed the records of 32 patients treated for RRP at our institution over a 10-year period. We found that the aggressive form typically occurs in the very youngest of patients (average of 2 years old as compared to an average of 17 years old in the less aggressive form). Although subglottic involvement universally occurred in our group with aggressive disease, approximately 40% developed subglottic disease very early as compared with 20% of patients with less aggressive disease. Additionally, our data do not support the theory of spontaneous regression with the onset of puberty. These and other findings will be discussed in detail. We also propose a new classification for RRP to eliminate confusion.

Effects of medialization laryngoplasty on airway resistance: a pilot study.

OBJECTIVE: To investigate the effects of medialization laryngoplasty on laryngeal airway resistance at various clinically relevant flow rates. STUDY DESIGN: This study was conducted using a total of 13 laboratory experiments. Two of the experiments were used to validate the cadaveric model employed. Eleven experiments were used to quantify airway resistance relative to increasing medialization laryngoplasty stent size. METHODS: With autopsy consent the authors obtained 13 consecutive and anatomically complete larynges for experimentation. A thyrotomy window measuring 8 x 6 mm was made on the left side of the thyroid cartilage. A #4 laryngeal mask was secured to the pharyngeal airway with sutures. Eleven experiments were conducted at the same flow rates using increasingly larger stents from 1 mm to 11 mm in size. Using the Bernoulli equation, the pressure measured at the proximal end of the laryngeal mask is representative of the pressure drop across the airway. The experimental model was validated in two experiments using flow rates between 5 and 50 L/min and stents measured at 5, 10, 15, and 20 mm. RESULTS: Average results from the 11 experiments indicate that at increasing levels of medialization, from 0 to 11 mm, there is essentially the same pressure drop across the larynx at a given flow rate. CONCLUSION: At physiologic airflow rates in a cadaveric model, medialization laryngoplasty implants of 11 mm or less seem to have no obvious effect on airway resistance.

Changes in human papillomavirus typing of recurrent respiratory papillomatosis progressing to malignant neoplasm.

A patient with recurrent respiratory papillomatosis progressed spontaneously to carcinoma resulting in death. Serial biopsy specimens obtained during a 9-year course of this patient's disease were tested via polymerase-chain reaction and Southern hybridization to detect the human papillomavirus (HPV) types present during the patient's course of disease. Early biopsy specimens were positive for HPV types 6 and 11. As atypia progressed to carcinoma, HPV types 6 and 11 remained present, but the signal decreased and HPV 16 became increasingly positive. The significance of these findings will be discussed.

Spinal cord tissue pressure during spinal cord distraction in dogs.

Spinal column distraction is a known cause of spinal cord injury. Laplace's law predicts that cord interstitial pressure will elevate during spinal cord distraction. To determine the significance of the Laplace predictions a series of in vitro and in vivo experiments examining spinal cord distraction were performed. In vitro experiments were carried out on 10 dog spinal cords in a specially designed distraction apparatus. These experiments verified the Laplace's law demonstrating a close correlation (R(avg) = 0.99) between the tension applied to the cord, and cord interstitial pressure. Cord interstitial pressure strain (elongation) curves show that initial elongation is accompanied by negligible elevations of cord interstitial pressure; the final 20% elongation being responsible for 80% of the elevation in cord interstitial pressure. In vivo experiments were carried out on five beta-blocked dogs. Significant elevations in cord interstitial pressure were obtained during stepwise spinal column distraction. Spinal cord blood flow and somatosensory evoked potentials were well maintained during distraction until cord interstitial pressure reached 47 mm Hg. At this point a simultaneous fall in spinal cord blood flow and somatosensory evoked potentials was noted. Release of the distracting force resulted in return of spinal cord blood flow, somatosensory evoked potentials, and cord interstitial pressure to baseline. The authors conclude that significant elevations in cord interstitial pressure occur with spinal cord distraction and that these cord interstitial pressure elevations are associated with a reversible ischemic response in the cord.

Modeling a medical environment: an ontology for integrated medical informatics design.

Modern medical environments have seen an increase in technological complexity and pressures of handling more patients with fewer resources, resulting in higher demands on medical practitioners. Medical informatics designers will have to focus on the problem of organizing medical information more effectively to enable practitioners to cope with these challenges. This article addresses this research problem for the particular area of medical problem solving in patient care. First, we describe a traditional modeling approach for medical reasoning used as a basis for developing some decision support systems. We argue these models may be faithful to what is known about biomedical knowledge, but they have limitations for human problem solving, especially in unanticipated situations. Second, we present an ontological framework, known as the abstraction hierarchy (Rasmussen, IEEE Trans. Man. Cybernetics 15 (1985) 234-243), for integrating patient representations that are faithful to existing biomedical knowledge and that are consistent with what is known about human problem solving. Through an example of a critical event in the operating room, we reveal how this framework can support medical problem solving in unanticipated situations. Third, we show how to use these representations as a frame of reference for mapping medical roles, responsibilities, sensors, and controls in an operating room context. Finally, we provide some insight for medical informatics designers in using this framework to design novel training programs and human-computer displays.

Ketamine induction and monoamine oxidase inhibitors.

A 42-year-old woman taking tranylcypromine, a monoamine oxidase (MAO) inhibitor, was hypovolemic from a ruptured ectopic pregnancy and required an emergency laparotomy. Anesthetic induction with ketamine, an agent with sympathomimetic properties, was used because of her hypovolemia, despite theoretical concerns of precipitating an adrenergic crisis. The patient's hemodynamic course remained unchanged with induction and intubation, and with further fluid and blood administration, satisfactory hemodynamic conditions were obtained. This report is believed to be the first to describe the use of ketamine in a patient taking MAO inhibitors.

Use of REP-PCR and 16S rRNA gene sequencing for comparison of Mannheimia haemolytica isolates obtained from fatal cases of bovine respiratory disease in the USA and Australia.

OBJECTIVE: Assess the variability of Mannheimia haemolytica isolates obtained from fatal cases of bovine respiratory disease (BRD) in the USA and Australia using repetitive sequence-based PCR (REP-PCR) and sequencing of the 16S ribosomal RNA (rRNA) gene. METHODS: We examined 22 isolates from the USA and 36 isolates from Australia using (GTG)5 and BOX-A1R REP-PCR primers, as well as sequencing a 700-base pair length of the 16S rRNA gene. The discriminatory ability of each typing method was assessed and correlation coefficients were calculated to assess concordance between the results of each approach. RESULTS: All methods appeared to discriminate among isolates, with BOX-A1R being the most sensitive and sequencing the least sensitive. Modest to moderate diversity was seen among the isolates, with as much variation within a continent as between the two. CONCLUSIONS: Using samples from diverse origins may permit extrapolation even to isolates with distant geographic and temporal relationships. Further, this information can serve as a baseline in assessing whether M. haemolytica is an opportunistic pathogen or if there are notable features that distinguish commensal isolates from those more likely to be associated with disease.

Successful emergent reintubation using the Aintree intubation catheter and a laryngeal mask airway.

Tracheal extubation can be potentially catastrophic, especially in patients with difficult airways. This article describes a case where planned extubation in a patient with a large tongue lesion led to complete airway obstruction and subsequent cardiac arrest. Reintubation was facilitated using a laryngeal mask airway and an Aintree intubation catheter.

Imaging of hepatic infections.

Imaging plays a significant role in the detection, characterization and treatment of hepatic infections. Infectious diseases of the liver include pyogenic and amoebic abscesses and parasitic, fungal, viral and granulomatous infections. With increases in worldwide travel, immunosuppression and changing population demographics, identification of cases of hepatic infection is becoming more common in daily practice. Knowledge of the imaging features seen with hepatic infections can assist in early diagnosis and timely initiation of appropriate therapy. This review presents the imaging appearances of hepatic infections, emphasizing specific features that may contribute to the diagnosis. Examples of the imaging findings seen with pyogenic and amoebic abscesses, infection with Echinococcus granulosus (Hydatid), schistosomiasis, candidiasis and tuberculosis (TB) are presented.

An interface to display special physiologic signals on patient monitors.

OBJECTIVE: The objective of this study was to develop an interface to allow special physiologic signals (e.g., in a research setting) to be displayed on the invasive pressure channel of conventional clinical monitors. The interface accepts single-ended high-level signals for display using the pressure channel of patient monitors, which use strain-gauge transducers employing direct current (DC) excitation. METHODS: By studying the electronic circuitry common to most clinical invasive pressure measurement systems (Wheatstone bridge, differential input instrumentation amplifier) it was possible to develop an interface to convert high-level single-ended signals into the low-level differential signal needed for input to an invasive pressure channel. RESULTS AND CONCLUSIONS: The device is useful when it is desired to display signals from special transducers on regular patient monitors. Schematic diagrams and sample results are provided.

Time constant-related capnograph distortion: a theoretical analysis.

A theoretical analysis of time constant-related distortion in side-stream capnographs was carried out using two models of respiratory patterns. It is demonstrated that under circumstances likely to be encountered clinically, significant distortion may occur. This distortion may produce both spurious rebreathing and under estimation of the true end-tidal CO2 concentration.