What makes for a good neurosurgical microscope depends on who you are. Surgeons are interested in the optics, the quality of the light generated and how easy the scope is to use. OR staff and managers are concerned with what it takes to prepare the scope for the next case, how it can improve efficiency and how reliable the system is. In the last few years, manufacturers have added lots of new features to their scopes. But what's really important among all the bells and whistles? Here's a rundown of 8 features that will please your staff as well as your surgeons.

1 Automatic balancing. The head of a surgical microscope is suspended off the horizontal arm, so it needs to be balanced with a counterweight. The amount of weight required for counterbalancing depends on the position of the arm. In the old days, the nurse had to add counterweights by hand. Now most systems have a manual balancing system. Since each surgeon has a preferred configuration, the scope should be balanced before each surgeon uses the scope, and ideally before each case. "If it's not balanced, they can recognize it," says Sherrie Beyer, RN, BSN, CNOR, spine coordinator at the Texas Institute for Surgery in Dallas.

An unbalanced microscope won't stay in place, can become unwieldy and can even be dangerous. This is especially true when the surgeon uses a mouth switch because the unbalanced arm can pull the headpiece away and rip the mouth switch out of the surgeon's mouth. "We had a surgeon who broke a tooth," says Megan Bermudez, RN, BSN, MBA, MSNL, a nurse in the neurosurgery department at St. Joseph's Hospital and Medical Center in Phoenix, Ariz.

The remedy is automatic balancing. Manual balancing requires a bit of a knack, so automatic balancing is a welcome improvement. Automatic balancing lets the nurse properly adjust the microscope's suspension system with the push of a button, a real convenience to have mid-procedure, says Ms. Bermudez.

2 Video output. The microscope's video camera lets other team members see what the surgeon sees. Sending the video image to a monitor lets the surgical tech follow the procedure and prepare instruments and supplies for the next phase of the procedure. This is especially helpful if there's tissue tear or bleeding, because the surgeon won't have to explain what's happening or request an instrument. "They can anticipate what you're going to need next," says Nicholas Theodore, MD, director of the neurosurgery spine program at the Barrow Neurological Institute in Phoenix, Ariz.

At the Scottsdale Healthcare Osborn Medical Center in Arizona, the surgeon's view is routed to a 40-inch monitor. When doing this, consider the type of cable you use, says Nathan Nitzky, RN, CNOR, perioperative coordinator for neuro and spine surgery. Some microscopes have more than one type of video output. Mr. Nitzky suggests avoiding the S-video plug, even though the image generated in this format is supposed to be better quality. "The cables are so fragile that they don't last," he says. Plus, S-video plugs are more expensive and harder to plug in when the OR is dark because of the configuration of the pins. "They have to be hooked up just right."

3 Image capture. Besides sending the image to the monitor, some surgeons like to record their procedures for teaching purposes, marketing or conference presentations. Digital images and videos are useful tools for educating surgeons, staff and patients. "Sometimes it's nice to take a picture and give it to the patient," adds Alan S. Hilibrand, MD, a spine surgeon at the Rothman Institute in Philadelphia, Pa. On some scopes, after the surgeon creates images and videos with the hand control, they can be burned directly to a DVD or CD or saved on a USB flash drive to be viewed on a computer.

4 Mouth switch. As a surgery proceeds, the surgeon sometimes needs to move the microscope to different locations on the spine. A growing number of surgeons are using their mouths to guide the microscope. Using a mouth switch lets the surgeon guide the scope without using hands or setting down any instruments. "Your hands are where they always need to be — in the patient, operating," says Dr. Theodore, who also uses a foot switch to zoom and focus the scope.

5 Rescue bulb. When a microscope bulb goes out, a case can be delayed while the nurse changes the bulb. Even worse, if you don't have a spare bulb you may have to cancel the case or have the surgeon finish the case with a headlamp and a loupe. Ms. Beyer recommends looking for a scope that has a quick-change feature that lets you switch lamps at the push of a button. "If the bulb goes out, you can finish the case," she says.

6 Suction for drapes. Draping a surgical microscope can be a challenge because you have to properly cover each part of the scope and still allow for movement of the components. If you don't do it right, you can easily turn your sterile field into what feels like a plastic tent. "It takes practice," says Ms. Bermudez. Some microscopes feature a motor that sucks the air out from under the draping and draws it close to the scope. "It's out of the way. It's not a baggy pile of plastic," says Mr. Nitzky. Single-use drapes designed for this system cost about $17 each.

7 Laser auto-focus. With a laser auto-focus feature, the surgeon can direct a pair of laser beams to converge on the focal point. If the surgeon moves the microscope, the laser beams adjust to keep that spot in focus. "It's locked on target," says Dr. Theodore. This saves the surgeon the time and loss of attention that it would take after movement of the microscope to identify the spot and then refocus on it.

8 Good field service. Sometimes motors die, fuses burn out and switches stop working. If a microscope isn't working properly and you don't have a backup scope, a whole day's worth of cases is shot. "It affects a lot of people if the scope is not working," says Ms. Beyer. Besides the surgeon and OR staff, the patient and family members have most likely taken time off work, school or other responsibilities to come to the surgical facility. So it's important to have a good relationship with the manufacturer's field rep or service technician. Ideally, it's someone who can come for repairs within a day, says Ms. Beyer, who says she works with a fast-acting service tech. "We have her [business] card on the microscope."

Choosing the right scope
When you're looking for a new surgical microscope, consider all the users. If more than 1 specialty will be using the scope (such as spine and ENT), figure out how long it takes to set up and remove any specialty-specific attachments and reconfigure the scope for the other specialty, says Dr. Hilibrand. Some microscopes are more suited to multi-specialty use than others. Depending on your case volume and procedure mix, you may need 2 scopes to keep things moving. But don't go overboard, says Dr. Hilibrand. "Buy only as much microscope as you need."