Paradoxical cerebral embolisation. An explanation for fat embolism syndrome

Fat embolism occurs following fractures of a long bone or arthroplasty. We investigated whether paradoxical embolisation through a venous-to-arterial circulation shunt (v-a) could lead to cerebral embolisation during elective hip or knee arthroplasty. Transcranial Doppler ultrasound (TCD), following the intravenous injection of microbubble contrast, identified the presence of a shunt in 41 patients undergoing hip (n = 20) or knee (n = 21) arthroplasty. Intra-operative cerebral embolism was detected during continuous TCD monitoring. Of the 41 patients, 34 had a v-a shunt of whom 18 had an embolism and embolism only occurred in patients with a shunt (p = 0.012). Spontaneous and larger shunts were associated with a greater number of emboli (rs = 0.67 and rs = 0.71 respectively, p < 0.01). Observations in two patients with large spontaneous shunts revealed 368 and 203 emboli and unexplained post-operative confusion and pancreatitis. Paradoxical cerebral embolisation only occurred in patients with a shunt and may explain both postoperative confusion and fat embolism syndrome following surgery.     

Paradoxical embolism complicating massive pulmonary embolus.

Paradoxical embolism is an unusual but well recognized complication of venous thromboembolic disease. This case report of a patient with massive pulmonary embolism, who had a paradoxical embolus through a patent foramen ovale, emphasizes that in these circumstances surgical intervention is indicated.     

Paradoxical cerebral embolism in a patient with Paget-Schroetter syndrome.

A 28-year-old man presented with transient speech disturbance and right hemiplegia. Computed tomography of the brain revealed a low-density area in the right cerebellum. A ventilation/perfusion lung scintiscan detected multiple perfusion defects in the both lungs and catheterization revealed pulmonary hypertension. Venography of the upper extremities revealed obstruction of the left subclavian vein. Furthermore, Doppler echocardiography revealed a right-to-left shunt via a patent foramen ovale. Those examinations demonstrated paradoxical cerebral embolism caused by Paget-Schroetter syndrome, which is a rare complication of the disorder. We hypothesize that the source of thrombi was the left subclavian vein and surgery was needed to prevent further thromboembolic events. At surgery, the upper half of the sternum was incised in the midline, and the left brachiocephalic vein was ligated. No thromboembolic episodes have occurred postoperatively.     

Low sodium haemodialysis reduces interdialytic fluid consumption but paradoxically increases post-dialysis thirst.

BACKGROUND: Interdialytic weight gain (IDWG) can be reduced by lowering the dialysate sodium concentration ([Na]) in haemodialysis patients. It has been assumed that this is because thirst is reduced, although this has been difficult to prove. We compared thirst patterns in stable haemodialysis patients with high and low IDWG using a novel technique and compared the effect of low sodium dialysis (LSD) with normal sodium dialysis (NSD). METHODS: Eight patients with initial high IDWG and seven with low IDWG completed hourly visual analogue ratings of thirst using a modified palmtop computer during the dialysis day and the interdialytic day. The dialysate [Na] was progressively reduced by up to 5 mmol/l over five treatments. Dialysis continued at the lowest attained [Na] for 2 weeks and the measurements were repeated. The dialysate [Na] then returned to baseline and the process was repeated. RESULTS: Baseline interdialytic day mean thirst was higher than the dialysis day mean for the high IDWG group (49.9+/-14.0 vs 36.2+/-16.6) and higher than the low weight gain group (49.9+/-14.0 vs 34.1+/-14.6). This trend persisted on LSD, but there was a pronounced increase in post-dialysis thirst scores for both groups (high IDWG: 46+/-13 vs 30+/-21; low IDWG: 48+/-24 vs 33+/-18). The high IDWG group demonstrated lower IDWG during LSD than NSD (2.23+/-0.98 vs 2.86+/-0.38 kg; P<0.05). CONCLUSIONS: Our results indicate that patients with high IDWG experience more intense feelings of thirst on the interdialytic day. LSD reduces their IDWG, but paradoxically increases thirst in the immediate post-dialysis period.     

Paradoxical embolism: an underestimated entity. A plea for comprehensive work-up

Forty-one cases of arterial embolism were reviewed. The work-up included M + 2D echocardiography in 29 patients (71%), arteriography in 22 (54%), both echocardiography and arteriography in 19 (46%), and abdominal aortic ultrasound in 18 (43%). The sources of emboli were probable cardiac (8 = 20%)--mural cardiac thrombus detected by echocardiogram; possible cardiac (12 = 29%)--arrhythmias or other cardiac pathology detected without mural thrombus; probable arterio-arterial (7 = 17%)--proximal arterial thrombus detected; probable paradoxical embolism (2 = 5%)--fulfills the Johnson criteria with cardiac defect and right-to-left shunt detected by contrast echo in one patient and cardiac catheterization in the other; possible paradoxical embolism (3 = 7%)--meets two of three Johnson criteria without evidence of other source; and unknown source (9 = 22%)--conventional work-up negative or incomplete. Five of nine patients (56%) less than 50 years old had probable or possible paradoxical embolism, while in two patients (22%), the origin was unknown. Conclusion: (1) A significant proportion of patients with an arterial embolus are discharged with the source of emboli unknown, (2) paradoxical embolism must be considered and contrast saline or transesophageal echocardiogram should be done in patients under 50 years old.     

HIV/AIDS-related hyponatremia: an old but still serious problem

Hyponatremia is the most common electrolyte disorder in hospitals. Many medical illnesses, including congestive heart failure, liver failure, renal failure and pneumonia, may be associated with hyponatremia. In addition, hyponatremia in patients with the acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) was first reported in 1993. The evidence suggests that severe hyponatremia is associated with increased morbidity and mortality in human immunodeficiency virus (HIV)/AIDS patients; however, the incidence of hyponatremic syndrome in HIV/AIDS patients remains very high in clinical practice, as almost 40% of HIV/AIDS inpatients in Xinjiang, a developing region of China, are hyponatremic. A method for identifying the pathogenesis and therapeutic treatments for hyponatremia in HIV/AIDS patients is needed. This review focuses on the clinical and pathophysiological aspects of hyponatremia and highlights the causes, presentation and treatment recommendations for hyponatremic patients with HIV/AIDS.     

Paradoxical air embolism during orthoptic liver transplantation: diagnosis by transoesophageal echocardiography.

We describe a case of paradoxical air embolism during orthotopic liver transplantation, early diagnosis, using intra-operative transoesophageal echocardiography after a circulatory failure, allowed early management by hyperbaric oxygen therapy.     

Port-site closure: a new problem, an old device.

OBJECTIVE: Trocar-site incisional hernias and their complications are reported in 1% to 6% of patients. Such hernias are attributed to the difficulty of applying standard suturing techniques to wound closure. We report our experience with a simple device, the Deschamps ligature needle. METHODS: The Deschamps needle has a handle and a tip (sharp or blunt), with an opening to pass suture. The blunt tip is very effective for closing trocar sites. Disposable needles are obviously sharp, but can bend on the needle holder and break in a deep small incision. The Deschamps needle is a rigid, noncutting instrument that can be forced through fascia and peritoneum (around the surgeon's fingertip) avoiding loss of pneumoperitoneum. A full-thickness closure is accomplished. We perform closure under direct vision through the scope. Tactile sense is provided by the surgeon's finger. The last trocar site is closed in the same manner without the scope. RESULTS: We have used the Deschamps needle since 1992 in all (1400) laparoscopic procedures. We close 10-mm and 5-mm trocar sites and have not observed wound dehiscence or hernias at these sites. CONCLUSION: The Deschamps needle is effective in preventing incisional hernias and wound dehiscence. It is cost-effective. Disposable, single-use devices vary in price from $30 to $75 each. The Deschamps needle is sold in Italy at approximately $35 each. Considering that it may have been in the trays of most operating rooms for years (as in our case), and the number of procedures performed, we conclude that the real cost of this instrument is almost negligible.     

Keloids: An old problem still searching for a solution

An increasing number of patients with keloids present to the plastic surgeon and dermatologist practising in a predominantly black population such as ours. The black and Asian races are more affected than Caucasians. Apart from the aesthetic, psychological and social consequences, keloids may be symptomatic, causing severe itching, pain and tenderness, restriction of chest movement (presternal keloid), sleep disturbances, infection and suppuration. The multiplicity of treatment modalities suggests that there is no satisfactory therapy, with frustration to both the patients and physician. This paper reviews the current state of knowledge of the pathophysiology and the various approaches to treatment. Research efforts are still ongoing to discover more effective therapeutic intervention.     

Thoracic, but not lumbar, epidural anesthesia improves cardiopulmonary function in ovine pulmonary embolism.

We hypothesized that sympathetic stimulation is the main mechanism contributing to hemodynamic failure in pulmonary embolism. We investigated the effects of epidural anesthesia-induced sympathetic blockade, restricted to thoracic and lumbar levels, during pulmonary embolism. Two experiments were performed in chronically instrumented ewes. In the first experiment, six sheep received 6 mL bupivacaine 0.175% (Thoracic Epidural Anesthesia [TEA] group), and six sheep received 6 mL saline 0.9% (TEA-Control group), respectively, via an epidural catheter (T3 level). In the second experiment, six sheep received 2.8 mL bupivacaine 0.375% (Lumbar Epidural Anesthesia [LEA] group), and six sheep received 2.8 mL saline 0.9% (LEA-Control group) epidurally (L4 level). Embolization was performed by IV injection of autologous blood clots (Experiment 1, 0.75 mL/kg; Experiment 2, 0.625 mL/kg). TEA was associated with significantly slower heart rates, decreased mean pulmonary artery pressures and central venous pressures, and significantly higher stroke volume index and oxygenation in comparison with the TEA-Control group. By contrast, LEA was associated with significantly faster heart rates and increased central venous pressures and with a significantly lower stroke volume index in comparison with the LEA-Control group. TEA significantly reduced, and LEA significantly increased, hemodynamic deterioration, suggesting beneficial effects of TEA on cardiopulmonary function during pulmonary thromboembolism. IMPLICATIONS: Thoracic (but not lumbar) epidural anesthesia was associated with beneficial cardiopulmonary effects during experimental pulmonary thromboembolism in sheep.