Systemic vascular air embolus following CT-guided transthoracic needle biopsy: a potentially fatal complication

Following an uncomplicated CT-guided transthoracic biopsy, a patient becomes unconscious and subsequently dies despite immediate cardiac resuscitation. The patient felt well during the procedure but started complaining about dizziness and chest pain when he sat up. When he again was put in a supine position, cardiac arrest was noted. A CT scan performed when the symptoms initiated was afterwards rigorously reviewed by the team and revealed air located in the left ventricle, aorta and right coronary artery.We present a rare but potentially lethal complication following CT-guided transthoracic needle biopsy-systemic vascular air embolus. Knowledge and evidence about the complication are sparse because of low incidence and varying presentation. However, immediate initiation of treatment can save a life, and awareness of the complication is therefore crucial.

Organ-based tube current modulation in chest CT. A comparison of three vendors

INTRODUCTION

Organ-based tube current modulation (OBTCM) is designed for anterior dose reduction in Computed Tomography (CT). The purpose was to assess dose reduction capability in chest CT using three organ dose modulation systems at different kVp settings. Furthermore, noise, diagnostic image quality and tumour detection was assessed.

METHODS

A Lungman phantom was scanned with and without OBTCM at 80-135/140 kVp using three CT scanners; Canon Aquillion Prime, GE Revolution CT and Siemens Somatom Flash. Thermo-luminescent dosimeters were attached to the phantom surface and all scans were repeated five times. Image noise was measured in three ROIs at the level of the carina. Three observers visually scored the images using a fivestep scale. A Wilcoxon Signed-Rank test was used for statistical analysis of differences.

RESULTS

Using the GE revolution CT scanner, dose reductions between 1.10 mSv (12%) and 1.56 mSv (24%) (p < 0.01) were found in the anterior segment and no differences posteriorly and laterally. Total dose reductions between 0.64 (8%) and 0.91 mSv (13%) were found across kVp levels (p < 0.00001). Maximum noise increase with OBTCM was 0.8 HU. With the Canon system, anterior dose reductions of 6-10% and total dose reduction of 0.74-0.76 mSv across kVp levels (p < 0.001) were found with a maximum noise increase of 1.1 HU. For the Siemens system, dose increased by 22-51% anteriorly; except at 100 kVp where no dose difference was found. Noise decreased by 1 to 1.5 HU.

CONCLUSION

Organ based tube current modulation is capable of anterior and total dose reduction with minimal loss of image quality in vendors that do not increase posterior dose.

IMPLICATIONS FOR PRACTICE

This research highlights the importance of being familiar with dose reduction technologies.

Changes in knee joint load indices from before to 12 months after arthroscopic partial meniscectomy: a prospective cohort study

OBJECTIVE

Patients undergoing arthroscopic partial meniscectomy (APM) are at increased risk of knee osteoarthritis (OA). Meniscal damage and/or surgery may alter knee joint loading to increase OA risk. We investigated changes in knee joint loading following medial APM surgery, compared with the contra-lateral leg.

METHODS

We estimated indices of knee joint loading (external peak knee adduction moment (KAM), KAM impulse and peak knee flexion moment (KFM)) normalized to body size (i.e., body mass (BM) and height (HT)) using 3D gait analysis in 23 patients (17 men, mean (SD) 46.2 (6.4) years, BMI 25.8 (3.4) kg/m(2)) without radiographic knee OA before and 12 months after medial APM. Static alignment was assessed by radiography and self-reported outcomes by Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Peak KAM and KAM impulse increased in the APM leg compared to the contra-lateral leg from before to 12 months after surgery (change difference: 0.38 Nm/BM*HT% 95% CI 0.01 to 0.76 (P = 0.049) and 0.20 Nm*s/BM*HT% 95% CI 0.10 to 0.30 (P < 0.001)). Patients self-reported improvements on all KOOS subscales (KOOS pain improvement: 22.8 95% CI 14.5 to 31.0 (P < 0.01)).

CONCLUSIONS

A relative increase in indices of medial compartment loading was observed in the leg undergoing APM compared with the contra-lateral leg from before to 12 months after surgery. This increase may contribute to the elevated risk of knee OA in these patients. Randomized trials including a non-surgical control group are needed to determine if changes in joint loading following APM are caused by surgery or by changes in symptoms.

[Vertigo and ear discomfort caused by a bone defect in os temporalis]

Superior semicircular canal dehiscence is a clinical condition where the bone tissue overlying the superior semicircular canal is absent. The symptoms can be nonspecific and include vertigo, oscillopsia and conductive hearing loss. An audiogram will reveal an air-bone-gap in the lower frequencies in an otherwise healthy ear. Diagnosis is confirmed by performing muscular evoked myogenic potentials examination and temporal bone computed tomography. A case of right side superior semicircular canal dehiscence in a 52-year-old woman and the diagnostic course is described.

[Cerebral cysticerc is a rare cause of hydrocephalus]

We present a case of a 39-year-old woman from Thailand. She presented with dizziness and signs of raised intracranial pressure. Magnetic resonance scanning revealed multiple cysticercs in cerebrum and cerebellum, and one of the cysticercs compressed the cerebral aqueduct resulting in hydrocephalus. The patient was transferred to an infectious disease department, where appropriate treatment with albendazol was initiated. Surprisingly she was found HIV-positive with a CD4 count of approx. 10 m/l. The patient deteriorated over the following week and died due to raised intracranial pressure.

Acute hyperinsulinemia decreases plasma osteoprotegerin with diminished effect in type 2 diabetes and obesity

OBJECTIVE

Osteoprotegerin (OPG) is a soluble tumour necrosis factor-receptor-like molecule present in connective tissues, especially bone and vasculature. It is known to accumulate in the arterial wall in diabetes. As its synthesis in vascular cells is decreased by insulin, we wanted to elucidate the acute effects of insulin on plasma OPG concentrations in individuals with type 2 diabetes and obese individuals compared with lean controls.

DESIGN

The study population consisted of ten type 2 diabetic, ten obese subjects, and ten lean subjects with no family history of diabetes.

METHODS

All subjects underwent a 4-h euglycemic-hyperinsulinemic clamp. Plasma OPG, insulin, lactate, HbA1c, cholesterol, triglycerides, free fatty acids (FFA), and glucose disposal rate were measured before and at the end of the clamp.

RESULTS

Baseline OPG concentrations did not differ significantly between groups. Insulin infusion decreased plasma OPG concentrations in all groups (P<0.01); however, the fall in OPG was 50% less in obese and type 2 diabetic individuals (P=0.007). Baseline OPG correlated with fasting insulin, baseline lactate, and low density lipoprotein cholesterol in the diabetic group, and with baseline FFA in the lean group. The relative change of OPG in response to insulin correlated inversely with HbA1c and baseline FFA in the lean group.

CONCLUSIONS

Acute hyperinsulinemia decreases plasma OPG, but with diminished effect in individuals with type 2 diabetes and obesity. Increased levels of OPG in arteries and plasma in diabetes together with the capability of plasma OPG as a cardiovascular risk predictor may be related to the described effects of insulin.