Noncardiogenic pulmonary edema and venous air embolus as complications of operative hysteroscopy.

A 37-year-old patient undergoing operative hysteroscopy developed noncardiogenic pulmonary edema after fluid absorption of 6 L of Ringer's lactate distension solution. No electrolyte or neurologic sequelae were associated with this fluid absorption. A subsequent 35-year-old patient having similar surgery in which a device was used to control intrauterine pressure and fluid absorption, developed a venous air embolus. The use of Ringer's lactate solution reduces the consequences associated with fluid absorption but it is not without risks. A device to limit intrauterine pressure and fluid absorption does not eliminate other risks.

Functional magnetic resonance imaging identifies somatotopic organization of nociception in the human spinal cord.

Functional magnetic resonance imaging (fMRI) is a technique that uses blood oxygen-level-dependent (BOLD) signals to elucidate discrete areas of neuronal activity. Despite the significant number of fMRI human brain studies, few researchers have applied fMRI technology to investigating neuronal activity within the human spinal cord. Our study goals were to demonstrate that fMRI could reveal the following: (i) appropriate somatotopic activations in response to noxious stimuli in the deep and superficial dorsal horn of the human cervical spinal cord, and (ii) lateralization of fMRI activations in response to noxious stimulation in the right and left upper extremity. We subjected healthy participants to noxious stimulation during fMRI scans. Using a spiral in-out image sequence and retrospective correction for physiologic noise, we demonstrated that fMRI can create high-resolution, neuronal activation maps of the human cervical spinal cord. During nociceptive stimulation of all 4 sites (left deltoid, right deltoid, left thenar eminence and right thenar eminence), we found ipsilateral dorsal horn activation. Stimulation of the deltoid activated C5, whereas stimulation of the thenar eminence activated C6. Our study contributes to creating an objective analysis of pain transmission; other investigators can use these results to further study central nervous system changes that occur in patients with acute and chronic pain.

Continuous peripheral nerve blocks.

Sophisticated regional anesthesia techniques have experienced substantial growth throughout the past 5 years for acute and chronic pain management. The recognition that regional anesthesia leads to superior postoperative outcomes in acute pain management and to an increased understanding of the pathogenesis of chronic pain has led to increased use of continuous peripheral nerve catheters. Furthermore, the availability of new equipment and techniques specifically designed to facilitate effective catheter placement has increased interest and adoption of peripheral nerve catheters to manage painful conditions. This has become particularly relevant as the scope of ambulatory surgery continues to grow. To maximize success rates with continuous peripheral nerve catheters, clinicians must be intimately aware of the pertinent regional anatomy and technical issues surrounding placement and maintenance of continuous nerve blockade. The recent development of outpatient infusion systems and novel anesthetics has been exciting and is likely to lead to an increase in the use of continuous peripheral catheter techniques. The consistent recognition that these techniques dramatically increase patient satisfaction should dictate an increasing presence in the field of pain management throughout the next several years.