Oxygen Reserve Index and Arterial Partial Pressure of Oxygen: Relationship in Open Heart Surgery.

BACKGROUND: Mild to moderate hyperoxia is potentially beneficial to patients undergoing open heart surgery. Oxygen Reserve Index (ORI) is a novel parameter that correlates to arterial oxygen tension (PaO2) in the hyperoxic range. This prospective study aimed to assess whether the relationship between ORI and PaO2 remains intact in the setting of open-heart surgery. METHODS: This study included patients undergoing valve, aortic arch and coronary artery bypass grafting (CABG) surgeries, on and off pump, between September 1st 2019 and August 31st 2021. Enrolled patients had arterial blood gas samples collected and analyzed after induction of anesthesia and increases in FiO2 in steps of 0.08 with ORI being recorded at the time of sample collection for cross reference and analysis. RESULTS: ORI values showed a statistically significant correlation with PaO2 values in the 100-200 mmHg range (r = 0.8193, p < 0.001). Additionally, there was a significant correlation between ORI and SpO2 values in the range of 95% and 100% (r = 0.529, p < 0.05). CONCLUSIONS: The preserved relationship between ORI and PaO2 in the mild and moderate hyperoxic range can allow more precise titration of oxygen therapy to guide therapy targeting normoxia, mildly and moderately hyperoxia. Additionally, it could have a potential use as an early warning system for impeding hypoxia.

Scholarly Activity of Radiation Oncologists in High-Income Developing Countries: Saudi Arabia as an Example.

PURPOSE: To examine the trends and quality metrics of publications by radiation oncologists in Saudi Arabia. METHODS: PubMed was searched using names of all Saudi radiation oncologists to retrieve published articles between January 2010 and December 2019. International collaboration, journal impact factor and country of origin, and number of citations were collected. Each article was assessed for epidemiologic type and independently assigned a level of evidence (LOE) by two authors. The trend in publications was examined and compared in the first and second 5-year periods (2010-2014 and 2015-2019) using relevant parameters. RESULTS: A total of 186 publications were found and included. The most common type of research was cohort studies followed by case reports and case series in 24%, 14%, and 13% of all publications, respectively. Dosimetry, clinical, and preclinical studies formed 7%, 8.6%, and 7.5% of the total publications, respectively. The LOE was I, II, III, IV, and not applicable in 8.6%, 22%, 25.8%, 29%, and 14.5% of the included publications, respectively. Comparing the first and second 5-year periods, there was an increase in international collaboration (P < .001) in the second period. The number of citations (P < .001) and journal impact factor (P = .028) were lower in the second period. LOE and publications in international journals were not statistically different between the two periods. CONCLUSION: Although radiation oncology research activity in Saudi Arabia has gained momentum in terms of volume and international collaboration over time, the LOE has not improved. This calls for a national effort to make the contribution to the literature a priority, allocate adequate resources, and apply appropriate measures to enhance research productivity and quality.

Assessment of clinical ability in the removal of teeth among undergraduate dental students: a longitudinal comparative study.

To evaluate the clinical ability of undergraduate students to remove teeth, we have developed a new, structured, and objective assessment scale including 11 items that measure the various skills required on a visual analogue scale (VAS). We did a pilot study to validate the new format and included 10 students, each one of whom was rated by three examiners. The assessment form was then used to evaluate the ability of students taking teeth out throughout the academic year 2017-2018. Results showed high inter-examiner reliability, significant correlation of mean scores (p<0.001), and high internal validity of the assessment form (Cronbach's α from 0.8257 to 0.9191). A total of 340 extractions were assessed (228 by fifth-year, and 112 by fourth-year, students). In addition, 73 students (47 fifth-year, and 26 fourth-year) were assessed halfway through the year and at their final examinations. The fail/pass rate was (64/164) for the fifth-year students, and (43/69) for the fourth year students, with no significant difference between them (chi squared 3.719; p=0.054). Fifth-year students had significantly higher mean scores than fourth-year students in the subscales "use of the elevator" and "confidence" (p=0.004 and 0.003 respectively). Both groups showed significant improvement in their mean scores between the mid-term and final examinations (p=0.001 and 0.010, respectively). The newly developed VAS-based format for assessing the removal of teeth offered an objective, standardised, and feasible method for assessment of clinical skills of undergraduate students for both formative and summative purposes.

Clinical use of botulinum toxins in oral and maxillofacial surgery.

Botulinum toxin (BTX) is a bacterial toxin that could be used as a medicine. Clinical applications of BTX have been expanding over the last 30 years and novel applications reported. Its mechanism of inhibiting acetylcholine release at neuromuscular junctions following local injection is unique for the treatment of facial wrinkles. Other dose-dependent anti-neuroinflammatory effects and vascular modulating properties have extended its spectrum of applications. Conditions such as temporomandibular joint disorders, sialorrhea, headache and neuropathic facial pain, muscle movement disorders, and facial nerve palsy could also be treated with this drug. Further applications of BTX are likely to be developed. This paper reviews the established and emerging applications of BTX in the field of oral and maxillofacial surgery. An overview of the pharmacology, toxicity and preparations of the agent is given.

Impact of race on outcome after definitive radiotherapy for squamous cell carcinoma of the head and neck.

BACKGROUND: The objective of the current study was to evaluate the impact of race (black vs. white) on the outcome of patients with invasive squamous cell carcinoma of the head and neck. METHODS: Between 1983 and 1997, 686 patients completed definitive, twice-daily radiotherapy (RT) alone or combined with a planned neck dissection; no patients received adjuvant chemotherapy. The minimum follow-up was 2 years, and median follow-up was 7 years for living patients. No patients were lost to follow-up. Fifty-five patients were black (8%). RESULTS: Although the two groups had similar 5-year local-regional control rates (black patients vs. white patients: 70% vs. 76%, respectively; P = 0.275), black patients had double the risk for distant recurrence compared with white patients (27% vs. 13%; P = 0.012). The 5-year cause-specific and absolute survival rates were lower for black patients (52% vs. 74% [P = 0.001] and 29% vs. 52% [P < 0.001], respectively). Multivariate analyses revealed that race was an independent predictor of freedom from distant metastasis (P = 0.013), cause-specific survival (P = 0.005), and absolute survival (P < 0.001). CONCLUSIONS: Although equal local-regional control rates can be achieved in black patients and white patients with squamous cell carcinoma of the head and neck, the risk of distant recurrence was significantly higher in black patients and resulted in decreased survival. Reevaluation of current strategies for pretreatment metastatic work-ups and development of more effective systemic therapy will be key to improving the survival disparity in this group.

Does feeding tube placement predict for long-term swallowing disability after radiotherapy for head and neck cancer?

PURPOSE: To evaluate feeding tube use. MATERIALS AND METHODS: Nine hundred thirty-four patients were treated with radiotherapy (RT). RESULTS: Feeding tubes were placed in 235 patients (25%): 212 patients (22.5%) for acute toxicity, 18 patients (2%) for late effects, and 5 patients (0.5%) for both. Median duration of tube dependence for acute toxicity was 3.8 months. Multivariate analysis revealed that feeding tube placement for acute toxicity was increased with higher RT dose (p <.0001), adjuvant chemotherapy (p =.0002), advanced age (p =.0002), and the presence of neck disease (p =.0045). The risk of a feeding tube for late effects was 2% at 5 years. The likelihood of feeding tube placement for late effects was greater for women (p =.0293), higher RT dose (p =.0345), and primary sites, including the hypopharynx and multiple synchronous primary tumors (p =.0360). Feeding tube placement for late effects was unrelated to tube placement for acute toxicity. CONCLUSION: Likelihood of long-term feeding tube dependence was low and unrelated to placement for acute effects.

Distant metastases after definitive radiotherapy for squamous cell carcinoma of the head and neck.

PURPOSE: To analyze parameters that influence the risk of distant metastases after definitive radiotherapy. METHODS: Between 1983 and 1997, 873 patients were treated with definitive radiotherapy and had follow-up for 2 years or more. Univariate and multivariate analyses were performed to evaluate risk factors that might influence the risk of distant metastases. RESULTS: The 5-year distant metastasis-free survival rate was 86%. Univariate analyses revealed that the risk of distant metastases was significantly influenced by gender (p =.0092), primary site (p =.0023), T stage (p <.0001), N stage (p <.0001), overall stage (p <.0001), level of nodal metastases in the neck (p <.0001), histologic differentiation (p =.0096), control above the clavicles (p <.0001), and time to locoregional recurrence (p <.0001). Multivariate analysis of freedom from distant metastases revealed that gender (p =.0390), T stage (p <.0001), N stage (p =.0060), nodal level (p <.0001), and locoregional control (p <.0001) significantly influenced this end point. Multivariate analysis revealed that gender (p =.0049), T stage (p <.0001), N stage (p <.0001), and locoregional control (p <.0001) significantly influenced cause-specific survival. CONCLUSIONS: The risk of distant metastases after definitive radiotherapy is 14% at 5 years and is significantly influenced by gender, T stage, N stage, nodal level, and locoregional control.

Simultaneous determination of plasma prednisolone, prednisone, and cortisol levels by high-performance liquid chromatography.

Recipients of organ transplants remain particularly dependent on prednisolone as part of their maintenance immunosuppression. Despite this, the pharmacokinetics of prednisolone have never been fully characterized in these patients, and consequently dosing remains empirical. Accurate monitoring of prednisolone, its primary metabolite prednisone, and endogenous cortisol suppression in such patients may provide a means of improving the clinical outcome by adjusting for variability in prednisolone pharmacokinetics and pharmacodynamics. Measurement of endogenous cortisol may provide an independent marker of prednisolone pharmacodynamics. A simple isocratic reverse-phase high-performance liquid chromatography procedure, using betamethasone as an internal standard, was developed to quantify plasma prednisolone, prednisone, and cortisol simultaneously. The steroids were extracted from 0.5 mL plasma with 3 mL (1:1 v/v) ethyl acetate/tert-methyl butyl ether and 0.1 mL phosphoric acid, washed in 0.1 mol/L NaOH before a final drying step and reconstitution in mobile phase for injection. Separation was achieved using a Supelcosil LC-18-DB, 150 x 4.6-mm, 5-microm particle size, reverse-phase column attached to a Newguard 15 x 3-mm, RP8 guard column maintained at 25 degreesC, with ultraviolet detector set at 254 nm. The mobile phase consisted of 16% isopropanol in water containing 0.1% trifluoroacetic acid, set at a flow rate of 1.2 mL/min. The assay was linear up to 1,002 microg/L for prednisolone, 982 microg/L for prednisone, and 545 microg/L for cortisol. Mean intra-assay and interassay imprecision levels were 6.0% and 7.2%, respectively, for prednisolone, 5.8% and 7.2% for prednisone, and 5.6% and 7.9% for cortisol. Intra-assay inaccuracy was <7% of nominal values for prednisolone, prednisone, and cortisol. The lower limit of quantification was 7 microg/L for prednisolone and prednisone and 10 microg/L for cortisol. Corticosteroid recoveries were 73%, 74%, and 90% for prednisolone, prednisone, and cortisol, respectively. The authors describe a robust, inexpensive, and simple method suitable for therapeutic drug monitoring or pharmacokinetic studies of prednisolone; it may also be used to measure the suppression of endogenous cortisol production.

Pulmonary blastoma.

Pulmonary blastoma is a rare tumor containing both mesenchymal and/or epithelial elements that mimics the embryonal tissues of the developing lungs. We are presenting two cases of pulmonary blastoma for its rarity and reviewed the literature for clinical features, investigative findings, classification, management and prognosis.

The response of atelectasis from lung cancer to radiation therapy.

Between January 1981 and June 1983, 33 newly diagnosed patients with lung cancer presented with radiological findings of atelectasis. These patients were treated by primary radiation therapy, with doses ranging from 1200 to 6000 cGy. The response of atelectasis to radiation therapy was established on the basis of follow-up chest roentgenograms. Of the 28 patients with non-small cell carcinoma of lung, there were 17 (61%) who had improvement of the atelectasis. Among these, 13 patients were treated with doses ranging from 5000 to 6000 cGy in 5 to 8 weeks; 9 of these (70%) responded. By histological subtype, the numbers, though small, show that three of eight patients with adenocarcinoma responded, as compared to 2 out of 4 with large cell undifferentiated carcinoma and 12 of 16 patients with squamous cell carcinoma. In patients treated by more than 5000 cGy, four of eight (50%) patients with squamous cell carcinoma had a complete response and three (37.5%) had a partial relief of atelectasis, for a total response of 87.5%. The study indicates the importance of radiation therapy in the management of atelectasis caused by primary lung cancer.

Fate of tricuspid regurgitation after closed valvotomy for mitral stenosis.

Rheumatic mitral valve disease is not infrequently associated with tricuspid regurgitation (TR). To determine the fate of TR following closed mitral valvotomy (CMV), we examined the records of 23 patients with variable degrees of TR and significant mitral stenosis (MS). Based on angiocardiographic assessment of TR, patients were divided into two groups: group 1 (15 patients) had mild-to-moderate TR, while group 2 (eight patients) had severe TR. After valvotomy, dyspnea lessened in all patients. Right ventricular (RV) failure signs (jugular venous distension and hepatomegaly) and the amounts of diuretics used diminished in 12 of 15 patients in group 1. Group 2 patients showed insignificant improvement at one-year follow-up period. Cardiac recatheterization was performed in four of group 2 patients three to five years later primarily for persistence of RV failure signs. The mitral valve areas varied from 1.4 to 2.7 cm2. There was mild mitral regurgitation in two patients. There was no deterioration of the left ventricular ejection fraction, but TR was at least moderate in all cases.