The amount healed seems too low for such a high DC. This would be most useful at low levels when magical healing can't really keep up with the damage a party takes, but the 20+ DC limits the amount it can help at level 1-5 or so.
Why not just use the Treat Injury skill from D20 Modern? I pasted it below.
[sblock]Treat Injury (Wis)
Check: The DC and effect depend on the task attempted.
Long-Term Care (DC 15): With a medical kit, the successful application of this skill allows a patient to recover hit points and ability points lost to temporary damage at an advanced rate—3 hit points per character level or 3 ability points restored per day of complete rest. A new check is made each day; on a failed check, recovery occurs at the normal rate for that day of rest and care.
A character can tend up to as many patients as he or she has ranks in the skill. The patients need complete bed rest (doing nothing all day). The character needs to devote at least ½ hour of the day to each patient the character is caring for.
Restore Hit Points (DC 15): With a medical kit, if a character has lost hit points, the character can restore some of them. A successful check, as a full-round action, restores 1d4 hit points. The number restored can never exceed the character’s full normal total of hit points. This application of the skill can be used successfully on a character only once per day.
Revive Dazed, Stunned, or Unconscious Character (DC 15): With a first aid kit, the character can remove the dazed, stunned, or unconscious condition from a character. This check is an attack action.
A successful check removes the dazed, stunned, or unconscious condition from an affected character. The character can’t revive an unconscious character who is at –1 hit points or lower without first stabilizing the character.
Stabilize Dying Character (DC 15): With a medical kit, a character can tend to a character who is dying. As an attack action, a successful Treat Injury check stabilizes another character. The stabilized character regains no hit points, but he or she stops losing them. The character must have a medical kit to stabilize a dying character.
Surgery (DC 20): With a surgery kit, a character can conduct field surgery. This application of the Treat Injury skill carries a –4 penalty, which can be negated with the Surgery feat. Surgery requires 1d4 hours; if the patient is at negative hit points, add an additional hour for every point below 0 the patient has fallen.
Surgery restores 1d6 hit points for every character level of the patient (up to the patient’s full normal total of hit points) with a successful skill check. Surgery can only be used successfully on a character once in a 24-hour period.
A character who undergoes surgery is fatigued for 24 hours, minus 2 hours for every point above the DC the surgeon achieves. The period of fatigue can never be reduced below 6 hours in this fashion.
Treat Disease (DC 15): A character can tend to a character infected with a treatable disease. Every time the diseased character makes a saving throw against disease effects (after the initial contamination), the treating character first makes a Treat Injury check to help the diseased character fend off secondary damage. This activity takes 10 minutes. If the treating character’s check succeeds, the treating character provides a bonus on the diseased character’s saving throw equal to his or her ranks in this skill.
Treat Poison (DC 15): A character can tend to a poisoned character. When a poisoned character makes a saving throw against a poison’s secondary effect, the treating character first makes a Treat Injury check as an attack action. If the treating character’s check succeeds, the character provides a bonus on the poisoned character’s saving throw equal to his or her ranks in this skill.
Try Again?: Yes, for restoring hit points, reviving dazed, stunned, or unconscious characters, stabilizing dying characters, and surgery. No, for all other uses of the skill.
Special: The Surgery feat gives a character the extra training he or she needs to use Treat Injury to help a wounded character by means of an operation.
A character can take 10 when making a Treat Injury check. A character can take 20 only when restoring hit points or attempting to revive dazed, stunned, or unconscious characters.
Long-term care, restoring hit points, treating disease, treating poison, or stabilizing a dying character requires a medical kit. Reviving a dazed, stunned, or unconscious character requires either a first aid kit or a medical kit. Surgery requires a surgery kit. If the character does not have the appropriate kit, he or she takes a –4 penalty on the check.
A character can use the Treat Injury skill on his or herself only to restore hit points, treat disease, or treat poison. The character takes a –5 penalty on your check any time he or she treats his or herself.
A character with the Medical Expert feat gets a +2 bonus on all Treat Injury checks.
Time: Treat Injury checks take different amounts of time based on the task at hand, as described above. [/sblock]
That would give you a skill more useful at low levels or by classes without healing magic without being too overpowered. Any cleric would still need to go through his stock of healing in combat situations, but it will cut back downtime a bit and help deal with poisons/disease a little easier.
