WATSON, Justice.[fn1] [fn1] Pursuant to Rule IV, Part 2, § 3, Hall, J. was not on panel which heard and decided this case. See the footnote in State v. Barras, 615 So.2d 285 (La. 1993).
When death results from medical malpractice after an accidental injury, does satisfaction of a judgment against the accident tortfeasors bar litigation and recovery against the medical malpractice tortfeasors?
FACTS
Murphy J. Steptoe died from medical malpractice following September 6, 1985, automobile accident injuries. A wrongful death and survival suit was brought by his widow and twelve children against the automobile accident tortfeasors: the Town of Amite; its police officer employee, Julius Quinn; and its insurer, Great Global Assurance Company. After trial in June of 1986, Murphy Steptoe was found to be thirty-five percent at fault in causing the accident.
In August of 1986, the medical malpractice defendants: Lallie Kemp Regional Medical Center; New Orleans Charity Hospital; and the Louisiana Department of Health and Human Resources (DHHR), were added to the initial suit. Suit was brought against the medical malpractice defendants before the September 11, 1986, final judgment against the accident defendants. A $356,736.25 judgment (reduced by thirty-five percent from $548,825) against the City of Amite, Julius Quinn and Great Global Assurance Company was fully paid: satisfactions of judgment were filed in August of 1988.
The medical malpractice defendants filed peremptory exceptions of no right and no cause of action, claiming that satisfaction of the judgment against the original tortfeasors released their solidary liability. The trial court denied the exceptions, noting that solidarity had not been tried. After trial against the medical malpractice defendants, the trial court found that Murphy Steptoe had an accidental, untreated C-7 neck fracture but died of cardiac arrhythmia caused by medical malpractice. The trial court awarded a $643,297 judgment against the medical malpractice defendants on December 9, 1991.
The court of appeal reversed, sustaining defendants' exception of no right of action and dismissing the suit. Steptoe v. Lallie Kemp Regional Hosp., 618 So.2d 1008 (La.App. 1st Cir. 1993). A writ was granted to review the judgment. 623 So.2d 1288 (La. 1993).
MEDICAL MALPRACTICE LIABILITY
The trial court concluded that Murphy Steptoe died from a preventable cardiac arrhythmia caused by negligent medical treatment. His chance of surviving his accidental injuries was lost because of medical malpractice. Hastings v. Baton Rouge Gen. Hosp., 498 So.2d 713 (La. 1986); Martin v. East Jefferson General Hosp., 582 So.2d 1272 (La. 1991).
A tortfeasor is liable for related medical treatment injuries suffered by a tort victim. Weber v. Charity Hosp. of Louisiana, 475 So.2d 1047 (La. 1985); Lambert v. United States Fidelity Guaranty Co., 629 So.2d 328 (La. 1993). See Joiner v. Diamond M Drilling Co., 688 F.2d 256 (5th Cir. 1982). There is an ease of association between the original injury and the negligent treatment which creates solidary liability between the tortfeasor and those guilty of medical malpractice. LSA-C.C. art. 2324 (prior to its 1987 amendment); Younger v. Marshall Industries, 618 So.2d 866 (La. 1993); Lasha v. Olin Corp., 625 So.2d 1002 (La. 1993). The tortious medical treatment aggravated the accidental injury, and the malpractice defendants are liable for the full extent of the aggravation.
CAUSE OF ACTION ANALYSIS
A cause of action is based on an act which gives the right to invoke judicial interference. Trahan v. Liberty Mutual Insurance Company, 314 So.2d 350 (La. 1975). Plaintiffs' initial cause of action was based on negligent operation of a vehicle. A second cause of action manifested itself during discovery and trial, which was based on medical malpractice in treating the automobile accident injuries. There were separate and distinct acts of negligence. The automobile accident tortfeasors caused injury, and the medical malpractice defendants caused death. Although Steptoe's death was one occurrence, it was produced by more than one cause.
LSA-R.S. 13:4231(1) now provides:
Except as otherwise provided by law, a valid and final judgment is conclusive between the same parties, except on appeal or other direct review, to the following extent:
(1) If the judgment is in favor of the plaintiff, all causes of action existing at the time of final judgment arising out of the transaction or occurrence that is the subject matter of the litigation are extinguished and merged in the judgment.
The statute was amended in 1990 to make a substantive change in the law: a judgment bar to all causes of actions arising out of the same occurrence. Also see the amendment to LSA-C.C.P. art. 425. The amendments only apply to civil actions filed after January 1, 1991, and do not affect this suit.
LSA-C.C. art. 1795 provides, in pertinent part: "Unless the obligation is extinguished, an obligee may institute action against any of his solidary obligors even after institution of action against another solidary obligor." Plaintiffs were entitled to assert their separate actions against the separate groups of defendants unless barred by prescription or res judicata.
PRESCRIPTION
The cause of action against the medical malpractice defendants is not subject to a plea of prescription. Prescription was interrupted against the medical malpractice defendants when those defendants were found to have solidary liability. LSA-C.C. art. 2324 (prior to its 1987 amendment); LSA-C.C. art. 1797; LSA-C.C. art. 1799; Picone v. Lyons, 601 So.2d 1375 (La. 1992).
RES JUDICATA
The action is not subject to a plea of res judicata. Identity of the parties is required for res judicata. Safeco Ins. Co. of America v. Palermo, 436 So.2d 536 (La. 1983). The second proceeding lacked identity of subject matter, as well as identity of parties. Dornak v. Lafayette General Hospital, 399 So.2d 168 (La. 1981). Although collateral estoppel or issue preclusion is not a valid Louisiana defense, fault of the malpractice defendants was not raised or determined in the first proceeding.
SATISFACTION OF JUDGMENT
A valid final judgment is conclusive between the same parties. LSA-R.S. 13:4231. The final judgment here determined the merits of the claim against the accident tortfeasors. LSA-C.C.P. art. 1841. Issues not raised by the pleadings and not involved in the decision are not concluded by a judgment. Mitchell v. Bertolla, 340 So.2d 287 (La. 1976). The medical malpractice defendants' fault in causing Murphy Steptoe's death was not considered at the first trial and was not precluded by the original judgment. Safeco Ins. Co. of America v. Palermo, 436 So.2d 536 (La. 1983).
Plaintiffs did not intend to abandon their pending claims against the medical malpractice defendants when the satisfactions of judgment were executed in favor of the accident tortfeasors. Weber v. Charity Hosp. of Louisiana, 475 So.2d 1047 (La. 1985).
Defendants contend that the performance rendered by the accident defendants releases them from liability toward plaintiffs, relying on Civil Code Article 1794:
An obligation is solidary for the obligors when each obligor is liable for the whole performance. A performance rendered by one of the solidary obligors relieves the others of liability toward the obligee.
The original judgment was against only the accident defendants. When that judgment was satisfied, any liability of the medical malpractice defendants had not been determined or quantified. They argue that a solidary obligation existed as a matter of law, citing Narcise v. Illinois Cent. R. Co., 427 So.2d 1192 (La. 1983). Narcise held that two defendants liable on different grounds could be liable in solido but pointed out the necessity of weighing and apportioning fault. When the first judgment was paid, the medical malpractice defendants only had potential liability. Younger v. Marshall Industries, 618 So.2d 866 (La. 1993). The alleged fault of the medical malpractice defendants had not been determined or quantified, and they were not solidary obligors at the time of payment. Taylor v. United States Fidelity Guaranty Ins. Co., ___ So.2d ___ (La. 1993).
The satisfactions of judgment given the accident tortfeasors did not bar plaintiffs from litigating their damages against the medical malpractice defendants. LSA-C.C. art. 1802; Doyle v. State Farm (Mut.) Ins. Co., 414 So.2d 763 (La. 1982); Ugulano v. Allstate Ins. Co., 367 So.2d 6 (La. 1978). See Milicevich v. Sacramento Medical Center, 155 Cal.App.3d 997, 202 Cal.Rptr. 484 (1984).
DOUBLE RECOVERY
Defendants contend that plaintiffs have been paid the total damages due for Murphy Steptoe's wrongful death. However, plaintiffs were not paid their full damages because 35 percent was deducted for Steptoe's comparative fault in causing the automobile accident. Murphy Steptoe's fault in causing the automobile accident did not alter the standard of care owed by those treating his injuries. The medical malpractice defendants have full responsibility for their independent negligence.
COMPARATIVE FAULT
The trial court concluded that the health care providers' fault was an intervening and superseding cause of Steptoe's wrongful death. This conclusion may be factually correct: Murphy Steptoe might have survived his injuries if he had received appropriate medical treatment. However, the trial court's decision that the accident tortfeasors' initial fault was exonerated by the negligent medical treatment is legally erroneous. Weber v. Charity Hosp. of Louisiana, 475 So.2d 1047 (La. 1985). Legal causation is decided under a duty-risk analysis. The duty to refrain from negligent automobile operation includes the risk that an accident victim's medical treatment may cause further damage. Lambert v. United States Fidelity Guaranty Co., 629 So.2d 328 (La. 1993). The concept of intervening and superseding cause does not exonerate an initial tortfeasor when the victim's medical treatment prevents the victim's survival. The medical malpractice defendants are also liable for the malpractice consequences. Thus, the two groups now have solidary liability for the death.
The solidary liability of the accident tortfeasors and the medical malpractice defendants does not determine their rights in relation to each other. Williams v. Sewerage Water Bd. of N.O., 611 So.2d 1383 (La. 1993); Egros v. Pempton, 606 So.2d 780 (La. 1992); Hoefly v. Government Employees Ins. Co., 418 So.2d 575 (La. 1982).
In the first action against the automobile defendants, that trier of fact determined, on the evidence adduced, the degree of fault of the automobile defendants (65 percent) and the amount of damages caused by these defendants ($548,825). Because the automobile defendants did not file a third party demand against the medical defendants or request apportionment of fault, the judgment in the first action did not decide the medical defendants' degree of fault or the damages attributable to those defendants.
In the second action against the medical defendants, another trier of fact determined, on other evidence, the degree of fault of the medical defendants (100 percent) and the amount of damages caused by these defendants ($643,297). While this procedure was unusual, the second action was not barred by res judicata or collateral estoppel as those doctrines were applied in Louisiana at that time. The second action was necessary to determine the liquidated amount of that obligation, at least as between the medical defendants and plaintiff, and the degree of fault on the part of these defendants in causing that amount of damages. The second trier of fact was at liberty to determine the degree of fault of the medical defendants and the amount of damages caused by them, without regard to any of the findings of the trier of fact in the first action. In this respect the payment by the automobile defendants was no different than if they had paid that amount in compromise of their obligation, leaving the amount of the obligation and the degree of fault of the medical defendants to be determined by a subsequent trier of fact.
The medical defendants were deprived of their contribution rights by plaintiffs' acceptance of partial performance from the automobile defendants. The medical defendants could have protected themselves in the present action by pleading and proving that causative fault for the damages was attributable to the automobile defendants. Upon such proof, the medical defendants would have been entitled to a proportionate reduction of the damages. LSA-C.C. art. 1804; Harvey v. Travelers Ins. Co., 163 So.2d 915 (La.App. 3d Cir. 1964); Dill v. Department of Transp. and Dev., 545 So.2d 994 (La. 1989); Taylor v. United States Fidelity Guaranty Ins. Co., ___ So.2d ___ (La. 1993). Since the medical defendants failed to prove any fault on the part of the automobile defendants in causing plaintiffs' damages (or any fault on the part of the tort victim), they are not entitled to any reduction in the 100 percent damages determined by the trier of fact to be attributable to their fault.
CONCLUSION
The court of appeal erred in sustaining the exception of no right of action and dismissing plaintiffs' suit. The judgment of the court of appeal is reversed. The judgment of the trial court, awarding plaintiffs judgment against the medical malpractice defendants, is reinstated.
COURT OF APPEAL JUDGMENT REVERSED; TRIAL COURT JUDGMENT REINSTATED.