Be careful what you say in the clinical setting. That truism was brought home to me recently by a patient who burst into tears in a preoperative area.
Be careful what you say in the clinical setting. That truism was brought home to me recently by a patient who burst into tears in a preoperative area. She was awaiting a D&C for a missed abortion and had obviously overheard a conversation that a colleague (K.R. Kahn) and I were having about the colleague's new baby. We promptly and profusely apologized for our insensitivity, but our chagrin lingered throughout the day.
As I rued my unfortunately loose lips, I remembered another time when an overheard conversation had clinical consequences. That incident involved a uterine thermal ablation balloon.
Bucking the balloon system
Hysteroscopy confirmed that the woman had submucosal fibroids and a cavity length of 10 cm. After insertion of a thermal ablation balloon and instillation of 25 mL D5W, intrauterine pressures were in the range of 160 to 170 mm Hg. Four minutes after we started treatment, the anesthesiologist heard someone make a comment about time. She took that to mean that the procedure was about to end and lightened the anesthesia. The patient promptly gave an athletic buck, which drove her intrauterine pressure well over the 210 mm Hg shutoff level for the machine.
We were then faced with a partly treated patient and no more balloons. We elected to reuse the original balloon and restart the sequence. The procedure was terminated after 4 minutes with no apparent adverse consequences.
The experience got us thinking about the physiology of the Valsalva maneuver. Bearing down clearly helps empty thin-walled viscus, such as the bladder and bowel. Yet our experience shows that the 2.5- to 3.5-cm thickness of the uterus in a woman of reproductive age who is not pregnant apparently can withstand significant extramural forces.
The maneuver described by Valsalva in the 1700s pertains to forced expiration against a closed glottis.1 It occurs often in daily life and we give it little thought. Lifting, urinating, defecating, and the second stage of labor all are examples of the Valsalva maneuver. It has some diagnostic uses in evaluating suspected cardiac abnormalities and identifying abdominal wall hernias.1,2 The maneuver also has therapeutic value in management of premature ejaculation.3 Dang and Gardner reported two cases of global amnesia lasting 6 to 12 hours that followed bearing down during sex.4 They hypothesized that activation of the sympathetic nervous system combined with the Valsalva maneuver increased pressure in the cerebral vessels, resulting in relative hypoxia and transient amnesia.
In a study by Buhimschi and colleagues, a Valsalva maneuver during second-stage contractions increased the explusive force by 55% over a spontaneous contraction alone.5 Monitoring of the intrauterine pressure showed that neither fundal pressure nor bearing down increased it as much as did a contraction. But when those forces were combined, the effects were additive.
Valsalva versus balloon