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Introduction Patients with undiagnosed anterior mediastinal tumors commonly undergo surgery for diagnosis and treatment. However, determining the optimal therapeutic strategy is difficult for tumors with substantial invasion, such as lesions touching the aortic arch (AA). Case presentation A 76-year-old man of Asian descent presented to our hospital because chest computed tomography (CT) revealed an anterior mediastinal tumor. This tumor surrounded the left subclavian vein and touched the AA. We suspected the tumor to be malignant. We therefore decided to resect the tumor with preparation for total arch replacement (TAR). The operation was performed in three steps. First, we performed a mediastinal sternotomy. However, the tumor had invaded the subclavian vein, so we resected this vein after adding a transmanubrial approach. However, because of invading the AA we needed next step. Second, we shifted the patient to the right lateral decubitus position. We performed partial resection of the left upper lobe and exfoliated the distal AA. Third, we shifted the patient to the dorsal position and implanted an artificial cardiopulmonary device, after which we performed TAR, and pulmonary artery (PA) trunk plasty with a pericardial patch. The operation was successful, with no major adverse events. Pathologically, the tumor was diagnosed as diffuse large B-cell lymphoma. Discussion If oncologically complete resection is preferable for tumors with substantial invasion, complete resection should be attempted even if the surgery is difficult. Conclusion We performed complete resection of an anterior mediastinal tumor with TAR and PA trunk plasty using a pericardial patch., Highlights • We performed complete resection of a malignant tumor through TAR and PA trunk plasty with a pericardial patch. • Discrimination between ML and thymoma is frequently difficult. • If complete resection is preferable for tumors, the surgery should be attempted even if the surgery is difficult.

PURPOSE Evaluation of data obtained during diurnal intraocular pressure (IOP) measurements by means of the Goldmann Applanation tonometer in sitting and lateral decubitus positions. PATIENTS AND METHODS Retrospective cohort study of 41 consecutive untreated subjects (82 eyes) with ocular hypertension or suspicious discs. The IOP was measured by Goldmann Applanation tonometer in sitting position at 9 AM, 12 AM, 3 PM, and 6 PM; and in right lateral decubitus position around 12:15 PM. RESULTS In the right eye (RE) mean peak IOP was 22.19±4.68 mm Hg. In the left eye (LE) peak mean IOP was 22.19±3.8 mm Hg. In 91.5% of the eyes, the IOP increased in the lateral decubitus position. The average change in the RE was an increment of 4.22±2.67 mm Hg (P

Surgical positioning is accompanied by numerous anesthetic considerations, particularly its potential effects on the cardiovascular, respiratory, and nervous systems. Clinical studies have shown that lateral positioning does not affect hemodynamics; however, with the addition of trunk flexion, there is a decrease in cardiac output, which may be secondary to caval compression. In this report, we describe a unique case of hypotension that arose in a patient positioned only in the right lateral decubitus position with flexion and that was exacerbated by an abnormally narrow inferior vena cava.

There is a lack of consensus as to whether there is a difference in the amount of gastroesophageal reflux when lying with the right versus the left side down. In an attempt to answer this question we conducted a two-part study. The first consisted of a questionnaire distributed to 103 gastroenterologists with a special interest in the esophagus. The second was a randomized study in 20 normal subjects given a high-fat meal to induce reflux. Postprandial reflux was monitored by esophageal pH testing for 4 h after random assignment to either the left or right lateral decubitus position (left or right side down) on different days. Of the 87 gastroenterologists responding to our survey, 45 were uncertain as to which position was associated with worse reflux. Among the 42 who did specify, 27 (64%) favored the right lateral decubitus position as associated with more reflux symptoms. The direct comparison of the two positions demonstrated that the total amount of reflux time was significantly (p < 0.05) greater with subjects in the right decubitus position (231 min) than in the left (117 min). Although total episodes of reflux were greater when lying on the right side (227), compared with the left (198), the difference was not significant. In addition, average overall acid clearance was significantly (p < 0.001) prolonged with right side down (0.77 +/- 0.14 min/episode) compared with left side down (0.29 +/- 0.08 min/episode).

Case: A thirty-six-year-old man fell off a ladder and sustained an open fracture of the distal end of the left humerus. He was taken to the operating room for irrigation, debridement, and fixation of the fracture and was placed in the right lateral decubitus position for over seven hours. He subsequently developed right deltoid compartment syndrome, necessitating emergency compartment release. One year later, he had limited function, with a Disabilities of the Arm, Shoulder and Hand score of 81.3 points. Conclusion: Deltoid compartment syndrome can occur from operative positioning, with poor long-term outcomes as a result. Expeditious surgery, additional padding, and repeat checks are necessary for at-risk patients.

With the subject in the right lateral decubitus position, changes of central venous pressure can be recorded accurately and conveniently from a vein in the antecubital fossa of the dependent arm. Theoretically the hydrostatic, pressure transforms the venous bed between the heart and the site of puncture into uninterrupted wide channels with relatively low distensibility. Simultaneous recordings of pressure by the method described and by catheterization of the central veins showed that induced changes of central venous pressure were identically recorded from both sites. The mean pressure gradient between the peripheral and central veins was 35 mm. of water.

The effects of passive tilting on the circulatory pressures and on the magnitude of shunts across chronic atrial septal defects were studied in 11 dogs with closed chests. These determinations were performed with the dogs in four positions: 45-degree head-up, 45-degree head-down, right lateral decubitus, and left lateral decubitus. Control values were obtained with the animals in the supine horizontal position. The 45-degree head-up tilt position was associated with an increase in the magnitude of the right-to-left shunt detected after injections of indicator into the inferior vena cava, while change from supine to the 45-degree head-down tilt resulted in a decrease or disappearance of a pre-existing right-to-left shunt detected after similar injections. These effects on the right-to-left shunt were not demonstrable after injections of indicator into the superior vena cava, either during the head-up or head-down tilt, in spite of identical alterations in circulatory pressures. A significant interanimal correlation between the magnitude of the changes in systemic or right atrial pressures and the magnitude of the changes in right-to-left shunts could not be demonstrated. Passive changes in posture from supine to 45-degree head-up or head-down positions were not associated with demonstrable systematic effects on the magnitude of the left-to-right shunts. It is postulated that the descent of the heart and diaphragm during the head-up tilt results in a closer anatomical relation between the ostium of the inferior vena cava and the defect in the atrial septum and consequently an increase in the preferential shunting of inferior caval blood through this defect. In these animals, changing the body position from the supine to the right lateral decubitus position was consistently associated with an increase in the magnitude of the left-to-right shunts across the atrial septal defect and an increase in pulmonary blood flow. Since these animals have preferential shunting of blood from the right lung in the left-to-right direction, it is believed that the increase in blood flow through the dependent right lung is responsible for the observed increase in the left-to-right shunt. The left lateral decubitus position was not associated with appreciable effects on pulmonary blood flow or left-to-right shunting of blood across the atrial septal defect.

Forty patients scheduled for elective cesarean section were studied. Epidural administration of 0.5% bupivacaine, 95-135 mg, was performed with the patients in right lateral decubitus position. In randomized order, half of the patients remained on the same side for 30 minutes. The other half were turned to the left lateral decubitus position for 30 minutes immediately after the epidural injection. Then all patients were turned to the left lateral “tilt” position for surgery. The spread of analgesia was tested by pinprick, and plasma bupivacaine concentrations were measured from mother and infant. The differences in the spread of anesthesia between the groups and sides (mean maximum cephalad spread was T4-T5) of the patients were small and not significant. Neither were there differences in plasma bupivacaine concentrations between the groups.

This is the first case that demonstrates that the specificity of a SPECT thallium study may be improved by imaging the patient prone instead of supine. Improved specificity is most likely due to better separation of the diaphragm and inferior wall, similar to the improvement seen in planar studies when patients are imaged in the right lateral decubitus position.

The effect of flow of inspired gas on intrapulmonary gas distribution was examined by analysis of regional pulmonary 133Xe clearances and of total pulmonary 133Xe clearance measured at the mouth after equilibration of the lungs with 133Xe. Five awake healthy volunteers (24 to 40 yr of age) and another 5 healthy, anesthetized-paralyzed volunteers (26 to 28 yr of age) were studied while they were in the right lateral decubitus position. The awake subjects were studied at 3 inspiratory flows (0.4, 0.7, and 1.0 L/s) and the anesthetized-paralyzed subjects at 4 inspiratory flows (0.2, 0.5, 1.1, and 1.6 L/s). Interregional differences in 133Xe clearances along the vertical axis were significantly less during anesthesia-paralysis and mechanical ventilation than during spontaneous breathing in the awake state. No differences in the regional or total pulmonary 133Xe clearances were detected at these different flows in either of the two states, i.e., the difference between the awake and anesthetized-paralyzed states persisted.

Distributions of ventilation and perfusion relative to Va/Q were determined in seven young healthy volunteers (24–33 yr) while they were either in the supine or right lateral decubitus position. The subjects were studied first awake and then while anesthetized-paralyzed and breathing 30% oxygen and again while breathing 100% oxygen. In the awake state, no statistically significant differences were observed in the distribution of ventilation and perfusion relative to Va/Q between the supine and right lateral decubitus positions or on changing the inspired oxygen concentrations. After induction of anesthesia-paralysis, Va/Q mismatching increased significantly but only small right-to-left intrapulmonary shunts developed. Ventilating the lungs with 100% oxygen further increased the dispersion of blood flow distribution during anesthesia-paralysis; lung units with low Va/Q or right-to-left intrapulmonary shunts (or both) developed. With induction of anesthesia-paralysis and intubation of the trachea, the anatomic dead space was decreased and the alveolar dead space increased.

Using a standardized technique, spinal anesthesia was induced in 50 term parturients to study the correlation between patient height, weight, and body mass index (BMI) and the spread of sensory blockade. All patients received 12 mg hyperbaric bupivacaine while in the right lateral decubitus position on a horizontal operating table. Immediately after drug injection, the women were turned to the supine horizontal position with left uterine displacement. Fifteen minutes after drug injection, the level of analgesia to pinprick was measured. Linear regression analysis revealed no significant correlation between height (146-175 cm), weight (57.3-93.6 kg), or body mass index (21-38 kg/m2) and the spread of spinal anesthesia (T7-C8). It is concluded that, in term parturients, patient height, weight, or BMI does not significantly affect the spread of hyperbaric spinal anesthesia.