To the Editor:—
Morbidly obese patients undergoing procedures with general anesthesia are at increased risk for deep venous thrombosis (DVT) and subsequent pulmonary embolism. Because of the extreme lower extremity dimension in these patients, properly fitting pneumatic compression devices for the prevention of DVT may not be available. We describe how this problem can be resolved by the combination of two standard-size pneumatic compression cuffs for which inflation is regulated by a single pump.
A 50-yr-old man was scheduled for elective ventral hernia repair during general anesthesia. The patient had multiple high risk factors for the development of DVT: history of DVT, chronic lower extremity phlebitis, morbid obesity (245 kg), and anesthesia was anticipated to last longer than 30 min. 1Immediately before the procedure, it was noted that the standard-size Flowtron pneumatic compression cuff (Huntleigh Healthcare, Manalapan, NJ) was too small for the circumference of the patient’s calf. Because it was believed to be important to provide this regimen of prophylaxis in the patient, two standard-size Flowtron single-chamber cuffs were joined using Velcro closures (Velcro Industries B.V., Manchester, NH) and applied to each calf (Fig. 1).
The two hoses from this assembly were then connected to the two hoses of a Flowtron pump. Because the Flowtron pump alternates inflation between the two hoses, this approach created a dual-chamber sequential cuff and allowed for proper fitting to the large-circumference calf. Postoperatively, the patient was administered subcutaneous heparin for DVT prophylaxis. Clinical signs of DVT or pulmonary embolism were not observed in this patient throughout his 5-day hospital stay and 2-month follow-up period.
Pneumatic compression is a safe and cost-effective method that is equally as effective as heparin for the prevention of DVT. 1Compression therapy augments peak venous velocity in the deep venous system by 87–302%, reduces stasis, and stimulates intrinsic thrombolytic activity. 2,3To evaluate the effectiveness of compression therapy using the aforementioned combination of two standard-size Flowtron single chamber cuffs, Doppler flow velocities were measured in a morbidly obese volunteer (213 kg; calf circumference, 56 cm). The positive effect of this approach was confirmed; peak venous velocity was augmented from 19.1 to 31.4 cm/s (164%) per compression in the femoral vein and from 11.0 to 30.6 cm/s (278%) per compression in the greater saphenous vein.
In conclusion, the approach we describe allows for effective pneumatic compression therapy in morbidly obese patients in whom standard-size compression cuffs are inadequate.