THE FAILURE TO TIMELY DIAGNOSE CAUDA EQUINA SYNDROME (CES) IN THE EMERGENCY ROOM AND ITS RELATED CON
INTRODUCTION
A 25-year-old otherwise healthy male lifts a heavy piece of machinery while at work and immediately suffers low back and bilateral leg pain. The company physician places him on bed rest for one week. At the end of the week, the injured worker continues to experience both severe back and leg pain. He presents to his local emergency room with complaints of back and leg pain with no neurological findings except for a positive straight leg raise. He is discharged home only to return the next day with urinary incontinence and a weak foot. An emergent MRI scan reveals a large ruptured disk at the L3-L4 level. Surgery is performed immediately but the man has permanent bladder problems. He files suit against the emergency room for failure to diagnose his cauda equina syndrome (CES). What result?
A 50-year-old male with diabetes, hypercholesterolemia, hypertension, and chronic low back pain presents to the emergency room with an increase in his low back pain as well as a several week history of urinary incontinence. The patient’s neurological examination is essentially normal except for absent ankle reflexes. The ER physician obtains plain lumbar X-rays that show moderate degenerative changes. The patient is discharged home with follow-up to his local physician. Several days later the same patient presents to a different emergency room with acute urinary retention. An emergent MRI reveals a large ruptured disk at the L4-L5 level. The patient undergoes emergency surgery, has permanent bladder dysfunction, and subsequently files suit against the first emergency room for failure to diagnose a cauda equina syndrome. What result?
A 40-year-old otherwise healthy male presents to his local emergency room after work with a several day history of severe back and right leg pain. His neurological examination reveals a weak (4/5) extensor hallucis longus on the right. Plain radiographs are normal, and the patient is discharged home with pain medications. The following morning, the same patient presents to the emergency room with increasing pain, increasing weakness, and difficulty voiding. Neurological examination is essentially unchanged from the previous evening, but the patient is unable to void without catheterization. The ER physician waits twelve hours to call an orthopedist who waits until the next morning to obtain an MRI scan. The scan reveals a ruptured disk at the L3-L4 level. The patient undergoes surgery that afternoon but is left with permanent bladder dysfunction. The patient brings suit against the ER for failure to diagnose and treat his cauda equina syndrome in a timely manner. What result?
The above scenarios illustrate routine encounters in the emergency department between patients and physicians involving the failure to diagnose and the failure to treat cauda equina syndrome. In the first example, no medical negligence occurred inasmuch as the patient did not have cauda equina syndrome upon his first visit to the emergency room. The next day, when the patient did have urinary symptoms, the management of the patient comported with the applicable standard of care.
In the second example, no medical negligence occurred for essentially the same reasons. The patient did not have acute cauda equina syndrome upon presentation to the first emergency room and as such received treatment that comported with the applicable standard of care. In the third example, the medical negligence should be obvious with regard to both the emergency room’s treatment as well as the orthopedist’s treatment of the patient. Acute cauda equina syndrome is a neurological emergency and investigative procedures as well as treatment should be instituted as soon as possible. Both the emergency room physician’s delay in consultation as well as the orthopedist’s delay in ordering an MRI scan and performing surgery breached the applicable standard of care.
The most common causes of emergency room malpractice arise from misdiagnosis, the failure to diagnose, and the lack of consultation with appropriate specialists. Most failure-to-diagnose cases include the failure to diagnose appendicitis, myocardial infarction, meningitis, ectopic pregnancy, and fractures.1 While not among those entities most commonly misdiagnosed in the emergency room, cauda equina syndrome is accompanied by a common emergency room complaint – low back and leg pain – and if not properly diagnosed and treated, the condition carries high rates of morbidity including permanent weakness, sensory loss, and bladder/bowel dysfunction.2,3 As a result, a patient who presents to the emergency room with signs and symptoms compatible with cauda equina syndrome must be approached in a thorough, careful, and timely manner to exclude the possibility of acute cauda equina syndrome and its attendant need for emergency imaging and surgery.
OVERVIEW
Cauda equina syndrome (CES) is a severe neurological disorder that appears to have been first described by Mixter and Barr in 1934.4 The disorder can be caused by any entity exerting pressure upon the cauda equina including hematomas, tumors, infections, or fractures. More importantly, however, between two and six percent of lumbar disk herniations result in cauda equina syndrome.5-10 As a consequence, if a patient is encountered in the emergency room suffering from cauda equina syndrome, most likely the cauda equina compression is secondary to a disk herniation and not a tumor, hematoma, or other entity (See Table 1).
Although some authors have grouped patients with differing degrees of urinary dysfunction into separate categories11,12, most authors define cauda equina syndrome as a neurological disorder characterized by the clinical features of low back pain, bilateral or unilateral leg pain (radiculopathy), saddle anesthesia, motor weakness, sensory deficit, and bladder or bowel incontinence (See Table 2).5-10 Significantly, the syndrome may progress to paraplegia and/or permanent bladder or bowel incontinence.5,6
The majority of lumbar disc herniations can be managed conservatively with surgery used only as a last resort for patients who experience increasing neurological deficits or who experience no clinical improvement following appropriate conservative measures. Cauda equina syndrome, on the other hand, is generally treated as a true surgical emergency. As Ahn notes, “It (CES) is thought to be the primary absolute indication for the acute surgical treatment of lumbar disc herniation.” 5 A published comment following Shapiro’s article notes: “The reader should not be left with the impression that it is acceptable to wait up to 48 hours before surgery. The sooner the cauda equina is decompressed after the onset of symptoms the more likely it is that the patient will not be left with residual neurological deficits.” 6
Although patients with cauda equina syndrome may present to their family practitioners or even specialists such as neurosurgeons or orthopedists, a far greater number present to the emergency department for initial evaluation and treatment. As mentioned previously, many patients present to the emergency department with a primary complaint of low back pain or radiculopathy and only upon taking a history from and performing a physical upon the patient, does the true nature of their complaints become apparent. As a result, the emergency department and related personnel are frequently involved in the initial evaluation and treatment of a patient with cauda equina syndrome, and as such, may trigger events that lead to medico-legal difficulties. Generally, certain acts or omissions by the emergency department staff can lead to medico-legal difficulties. Such acts or omissions include failure of the nursing staff to document and communicate a patient’s symptoms, signs or progression thereof; failure of a physician to obtain an accurate, thorough history accompanied by a complete physical and neurological examination including a rectal examination; failure of the physician to recognize cauda equina syndrome; failure to obtain emergency imaging, consultation, or referral once a patient is diagnosed with cauda equina syndrome; failure to discuss the need for prompt return if bladder or bowel problems arise once the patient is discharged; and finally, discharging a patient without ruling out the presence of cauda equina syndrome.6,8,9 In the emergency room setting, the most important aspect of cauda equina syndrome is the need for early diagnosis and early referral leading to surgical treatment within forty-eight hours of the onset of symptoms. 6,8,9 This brief article will, hopefully, enhance the readers’ understanding of CES and its medico-legal implications. The following cases will illustrate instances of cauda equina syndrome that generated medico-legal consequences and will present pointers and pitfalls with respect to the diagnosis and treatment of cauda equina syndrome in patients encountered in the emergency department.
Gustavo Landin and Patricia Landin v. Roland Zachow, P.A., Thomas Strawmyer, M.D. and Concentra Health Services, Inc. d/b/a Concentra Medical Center:13
In Landin v. Zachow et. al., the plaintiff and his wife brought a medical negligence suit based upon an alleged failure to diagnose the plaintiff’s progressive cauda equina syndrome. The defendants included the physician assistant, the supervising physician, and the hospital.
In 1998, Mr. Gustavo Landin was employed as a steel factory worker. On January 6, 1998 Mr. Landin sustained a significant on-the-job back injury that resulted in severe low back pain and bilateral, radiating, leg pain. Mr. Landin was sent to Concentra Medical Center for evaluation, work-up, and treatment.
Upon arrival at Concentra Medical Center, Mr. Landin was seen and evaluated by Roland Zachow, a physician assistant under the supervision of Thomas Strawmyer, M.D. Upon presentation, Mr. Landin complained of severe lower back pain as well as bilateral, lower extremity radiating pain. When requested to provide a urine sample, Mr. Landin was unable to do so. Neither Zachow nor Strawmyer performed any further testing upon or diagnostic evaluations of Mr. Landin.
Mr. Landin was subsequently assigned the diagnosis of lower back strain and discharged to home. The medical records noted that an L5-SI injury had been ruled out, although the procedure by which it had been so was not specified. Mr. Landin was given a prescription for physical therapy and pain medication but received no instruction or warnings with regard to any bladder problems.
The following morning, Mr. Landin returned to Concentra Medical Center with continued severe pain radiating down both legs, perineal numbness, and bladder distension with incontinence. Mr. Landin underwent immediate bladder catheterization resulting in removal of 1400 ccs of urine; normal bladder capacity is 200 – 400 ccs. A neurosurgeon was immediately consulted, diagnosed Mr. Landin with cauda equina syndrome and performed emergency surgery.
Following surgery, Mr. Landin was left with permanent bladder dysfunction, permanent sexual dysfunction, and the need for enemas to stimulate bowel movements. During the course of the suit, Mr. Landin’s neurosurgical expert testified that the delay in diagnosing his cauda equina syndrome resulted in his permanent bladder, bowel, and sexual dysfunction. The case settled for a confidential amount prior to trial.
DISCUSSION
The Landin case illustrates several important points with regard to the failure to diagnose cauda equina syndrome in an acute setting. The first principle involves a patient who presents with severe low back pain and bilateral lower extremity radiculopathy accompanied by bladder dysfunction. Although cauda equina syndrome following a traumatic event is somewhat uncommon, as has been noted previously, its hallmarks are severe low back pain, bilateral sciatica, and urinary dysfunction.5-10,14 Shapiro notes that in 70% of patients presenting with cauda equina syndrome bilateral sciatica heralded the impending cauda equina compression while the other 30% of patients presented with the fully developed syndrome.6-8 In addition, he noted that urinary retention always preceded urinary incontinence and that “it is important to recognize these patients and to not treat them conservatively.” 8 Such a failure would or could be classified under the failure to diagnose cauda equina syndrome or the failure to recognize the syndrome even in the face of positive clinical signs and symptoms.
In Mr. Landin’s case, both the physician assistant and supervising physician failed to diagnose cauda equina syndrome as well as failed to recognize and investigate the syndrome. Mr. Landin presented with severe lower back pain and bilateral sciatica/radiculopathy accompanied by an inability to urinate (urinary retention). His presentation fits with the clinical syndrome of cauda equina syndrome, and he should have been diagnosed, investigated with appropriate radiographic studies (MRI), and treated for such in a timely manner. By failing to do so, both the physician assistant and physician breached the applicable standard of care in their treatment of Mr. Landin.
Another issue presented in the Landin case involves the follow-up instructions with regard to bladder or bowel symptoms provided to a patient with severe back pain and sciatica who is discharged and treated conservatively. As has been previously noted, cauda equina syndrome can progress to complete bladder dysfunction, but cauda equina syndrome, a true neurological emergency, does not exist until bladder dysfunction is noted in a patient.5-10 In fact, most authors define the onset of cauda equina syndrome by the onset of bladder or bowel dysfunction.5-10, 15 More importantly, as Shapiro notes, more than 85% of patients develop the signs and symptoms of cauda equina syndrome over a period of a few hours. As a result, it is incumbent upon health care personnel who discharge patients with severe back and leg pain to instruct them in the proper procedure for emergency follow-up if bladder or bowel symptoms occur. In a patient with severe back and leg pain, conservative therapy can be appropriate. In a patient who develops bladder dysfunction and is thus classified as suffering from cauda equina syndrome, emergent diagnosis and treatment is indicated. Such a requirement comports with Kostuik’s premise with regard to the medico-legal difficulties encountered in the emergency department vis-à-vis cauda equina syndrome.6-9
In Mr. Landin’s case, no healthcare worker provided follow-up instructions to Mr. Landin with regard to bladder dysfunction and the need for urgent return or follow-up care. By failing to emphasis the possibility of bladder dysfunction and the need for emergent follow-up, all of Mr. Landin’s health care providers breached the applicable standard of care. More simply, however, the physician assistant and physician who discharged a patient with bladder retention in association with the severe back pain and bilateral sciatica breached the applicable standard of care.
Sullivan v. Johnson16
In Sullivan v. Johnson, the female plaintiff filed a medical malpractice suit based upon a failure to timely diagnose a cauda equina syndrome when she presented to an emergency room with complaints of back pain and a “numb crotch.” She alleged that the delay in diagnosis resulted in her permanent bladder and bowel dysfunction. The defendant named in the suit was the emergency room physician who allegedly failed to diagnose the plaintiff’s cauda equina syndrome.
In 1990, Ms. Sullivan was a 35-year-old female who presented to her local emergency room with the chief complaint of low back pain and a “numb crotch.” The emergency room physician, Dr. Johnson, adamantly denied that Ms. Sullivan complained of a “numb crotch” during her initial visit. Ms. Sullivan was seen and evaluated during her initial visit. She was subsequently discharged to home for conservative treatment with appropriate discharge instructions.
After approximately six hours, Ms. Sullivan experienced a feeling of bladder fullness but was unable to void, in other words – urinary retention. Ms. Sullivan immediately phoned her local emergency room, and spoke with Dr. Johnson who advised her to return immediately to the emergency room. Ms. Sullivan did as she was instructed.
During her second visit to the emergency room, Ms. Sullivan was diagnosed as suffering from cauda equina syndrome. She underwent emergency surgery for decompression of her cauda equina. Ms. Sullivan suffered permanent bladder and bowel dysfunction with urinary difficulty and the need for mechanical bowel stimulation.
During the course of the trial, Ms. Sullivan’s emergency room expert testified that Dr. Johnson breached the applicable standard of care by failing to diagnose cauda equina syndrome during the first emergency room encounter. Both the plaintiff’s treating orthopedist and ER expert testified that her permanent bladder and bowel dysfunction resulted from the delay in diagnosis. On the other hand, Dr. Johnson testified that the plaintiff never complained of a “numb crotch.” Moreover, his neurosurgical expert testified that Dr. Johnson did not breach the standard of care and could not make the diagnosis of cauda equina syndrome based solely on low back pain. Additionally, he testified that diagnosis and treatment at the time of the plaintiff’s first ER visit would not have changed the outcome. The jury found for the defendant.
DISCUSSION
The Sullivan case illustrates several points with regard to the emergency room treatment of a patient with possible cauda equina syndrome. The first point deals with the diagnosis of cauda equina syndrome. As has been noted previously, cauda equina syndrome does not exist until bladder or bowel dysfunction is evident. The diagnosis of cauda equina syndrome is not appropriate until bladder or bowel dysfunction exists in a patient.2,3,5-9 In addition, the first manifestation of bladder dysfunction in a patient with cauda equina syndrome is generally urinary retention.6,8 The urinary retention subsequently progresses to urinary incontinence with continued pressure on the cauda equina.6-8 Although bladder dysfunction can progress fairly rapidly over several hours in a patient with potential cauda equina syndrome, cauda equina syndrome cannot be diagnosed in a patient whose only complaints are back pain and a “numb crotch” and who lacks any associated bladder dysfunction.
Ms. Sullivan presented to the emergency room with an undisputed chief complaint of back pain and possibly a “numb crotch.” At no point did she complain of or exhibit any bladder dysfunction. Ms. Sullivan was discharged with a normal bladder. Based upon her complaints and absence of bladder dysfunction, Ms. Sullivan could not be diagnosed with cauda equina syndrome during her first ER visit inasmuch as her symptoms did not constitute the clinical entity of cauda equina syndrome. Ms. Sullivan did not develop the earliest bladder dysfunction manifested by patients with cauda equina syndrome – bladder retention – until six hours after her initial visit. Moreover, when she telephoned for instructions with regard to her new symptoms, Dr. Johnson recognized the emergent nature of her condition and advised her appropriately. Once she arrived at the emergency room, her new cauda equina syndrome was treated appropriately. The jury correctly found for the defendant.
The second point illustrated by the Sullivan case begins to touch upon the timing of treatment for cauda equina syndrome as it relates to permanent sequelae. This issue will be developed more thoroughly in a later case but suffice it to say that the earlier diagnosis and treatment for cauda equina syndrome, the better. That being said, during the early period of cauda equina research, investigation, and articles, most researchers recommended that surgical decompression be carried out within six hours of the onset of acute urinary symptoms in patients with cauda equina syndrome.7 Over the years, as more investigation has been accomplished vis-à-vis the cauda equina syndrome, the six hour window has been increased to between twenty-four and forty-eight hours. As a result, most researchers and clinicians believe that a good outcome can be achieved in a patient operated upon within twenty-four to forty-eight hours of onset of their cauda equina syndrome while significantly poorer outcomes are associated with surgical intervention after forty-eight hours.2, 3, 5-10
In the Sullivan case, Ms. Sullivan presented within six hours of her first visit to the emergency room with the first onset of urinary retention. She subsequently underwent emergent diagnostic evaluation and emergency surgery. Although the case does not specify the number of hours, her surgery was clearly within twenty-four hours of her first urinary symptoms, and in fact, was within twenty-four hours of her first presentation to the emergency room. As such, Ms. Sullivan’s treatment falls within the accepted time period for emergency surgical decompression. Moreover, based upon the current literature, a diagnosis and possible treatment six hours earlier would not have had a measurable effect upon her outcome. The defendant’s neurosurgical expert was correct in testifying that earlier treatment at the time of her first emergency room visit would not have altered her ultimate outcome. On both the issues of liability and causation, the Sullivan jury was correct from a medical standpoint.
William Moore v. Little Falls Hospital; Victor Osinaga, M.D., O.M. Wadhera, M.D.; and Richard Chemielewski, M.D.17
In Moore v. Little Falls Hospital et. al., the plaintiff brought a medical negligence suit based upon the alleged failure to diagnose cauda equina syndrome, failure to make a timely referral, and failure to perform appropriate diagnostic tests. As a result of these failures, the plaintiff alleged that he had suffered permanent sensory loss as well as permanent bladder and bowel dysfunction. The defendants included the two emergency room physicians as well as the hospital that staffed and operated the emergency room.
In Moore, Mr. William Moore was a 29-year-old male who, on August 18, 1993, injured his lower back lifting a heavy object while at work. This injury resulted in lower back pain. On October 6, 1993, as a result of his lower back pain, Mr. Moore was evaluated in the emergency room by Dr. Osinaga. Dr. Osinaga obtained a history and performed a physical examination upon Mr. Moore. In addition, Dr. Osinaga obtained plain lumbar radiographs in Mr. Moore’s evaluation. The x-rays were read as normal. Dr. Osinaga diagnosed Mr. Moore with low back syndrome and discharged him back to work.
On October 10, 1993, Mr. Moore collapsed while on the job as a result of back pain and was returned to the same emergency room where he was evaluated by Dr. Chemielewski. At this second visit, Mr. Moore complained of right lower extremity sciatica as well as the continuing lower back pain. Dr. Chemielewski examined Mr. Moore, diagnosed him with low back strain accompanied by right sciatica, and discharged him to home on conservative treatment. The conservative treatment included bedrest, work abstention, and medications.
On October 18, 1993, Mr. Moore again presented to the emergency room with complaints of low back pain and lower extremity numbness. He was seen, examined, and released by Dr. Wadhera. On October 20, 1993, Mr. Moore was referred to a neurosurgeon following new complaints of bladder dysfunction. The neurosurgeon diagnosed Mr. Moore as having cauda equina syndrome and performed emergency surgery upon him. Following surgery, Mr. Moore suffered permanent bladder, bowel, and sexual dysfunction as well as sensory dysfunction.
During the trial, Mr. Moore claimed that he complained of bladder and bowel symptoms over the course of his emergency room treatment. The medical records and notes contained no documentation of any of these complaints. Moreover, during the early course of his treatment, Mr. Moore continued working. The jury returned a verdict for the defense.
DISCUSSION
The Moore case illustrates many similar points as the previous cases with regard to the emergency room treatment of a patient with possible cauda equina syndrome. The Moore case also illustrates several nuances with regard to evaluating a patient with back and leg pain in the emergency room. As has been noted previously, cauda equina syndrome can only be diagnosed in a patient with bladder symptoms. The patient may present with a myriad of symptoms but such symptoms must include bladder complaints (See Table 2).2,3,5-9 A diagnosis of cauda equina syndrome cannot be based upon a patient’s complaints of back pain alone or even back pain in combination with lower extremity pain. In addition, a diagnosis of cauda equina syndrome cannot be made based only upon findings in a patient of weakness or numbness. All those signs and symptoms may be present in a patient with cauda equina syndrome but without bladder symptoms, such signs and symptoms are not sufficient, in and of themselves, to establish the diagnosis of cauda equina syndrome. In addition, as noted previously, the majority of patients with back pain, radiculopathy, or even ruptured disks can be treated conservatively with bedrest, medications, physical therapy, and other related treatments.5,6 In fact, cauda equina syndrome is the only true indication for emergency surgery in a patient with a herniated disk.6,8,9
In the Moore case, Mr. Moore presented multiple times to the same emergency room over the course of several weeks with back and leg pain resulting from an accident occurring months prior to his ER visit. During each of his visits, Mr. Moore complained of back pain, leg pain, and leg numbness but never complained of any bladder or bowel dysfunction. Mr. Moore was evaluated and examined by three different physicians, none of whom documented any complaints of bladder or bowel dysfunction. As a result, Mr. Moore did not suffer from cauda equina syndrome during any of his emergency room evaluations. Moreover, Mr. Moore was treated with the appropriate conservative therapy upon his discharge from the emergency room. This appropriate conservative therapy included bedrest, work abstinence, and medications; all modalities used to treat back and leg pain caused by a ruptured disk. Overall, at no point did the emergency room physicians breach the applicable standard of care with regard to their diagnosis and treatment of Mr. Moore.
The Moore case also illustrates the importance of obtaining a detailed history from the patient and documenting any signs, symptoms or complaints voiced by the patient. As noted previously, cauda equina syndrome is a diagnosis based primarily upon bladder dysfunction accompanied by other related complaints. As such, an ER physician must take a detailed history particularly with regard to any bladder complaints voiced by the patient.6,8,9 Such a history, and accompanying physical examination, must be well documented so as to establish the true diagnosis for the patient.6,8,9
In Mr. Moore’s case, Mr. Moore claimed that he complained of bladder dysfunction during his visits to the emergency room. No documentation for these complaints existed in the medical records, and more significantly, three separate emergency room physicians who obtained a detailed history from Mr. Moore noted no bladder complaints. In fact, Mr. Moore returned to work following his first visit and worked at least four days following his initial emergency room visit. As a result, his alleged complaints of bladder dysfunction were not validated by his physical actions and were largely unsubstantiated. Such unfounded allegations by a plaintiff demonstrate unequivocally the need for a thorough history and careful documentation of the complaints and findings in patients evaluated in the emergency room. In this case the jury believed the defendant physicians and returned a verdict that comported with the medical realities of Mr. Moore’s situation.
Anonymous 47-Year-Old Female v. Anonymous Chiropractor and Anonymous Emergency Room Group18
In Anonymous v. Anonymous, the female plaintiff brought a medical negligence suit based upon a chiropractor’s alleged negligent back manipulation that resulted in an acute herniated disk. In addition, her suit alleged a failure to diagnose her cauda equina syndrome in the emergency room, and a failure to treat her cauda equina syndrome in a timely manner causing her to suffer permanent bladder, bowel, and neurological dysfunction. The defendants named in the suit included the chiropractor who performed the alleged negligent back manipulation as well as the emergency room physician and emergency room group.
In Anonymous v. Anonymous, the female plaintiff suffered chronic lower back pain with a multiple year history of lumbar pain. As a result of her back pain and paucity of treatment options, she presented to the defendant chiropractor for therapeutic manipulations. The defendant chiropractor performed several lumbar manipulations that resulted in the patient developing severe back pain, an inability to urinate, and perineal numbness.
Following the chiropractic manipulation and immediately following the above complaints, the female plaintiff presented to the emergency room that was staffed by the defendant emergency room group and their physician. In the emergency room, the plaintiff was evaluated by the emergency room physician, found to have bladder dysfunction, diagnosed with urinary retention, and discharged home with no definitive follow-up or instructions.
Approximately fourteen hours later, the female plaintiff returned to the emergency room and was evaluated by a different emergency room physician. The physician immediately diagnosed her with acute cauda equina syndrome and performed the appropriate emergent diagnostic evaluations. The plaintiff underwent emergency surgery. Following her surgery, however, the plaintiff experienced permanent bowel and bladder incontinence as well as permanent perineal numbness.
Multiple neurosurgeons and emergency room experts were willing to opine as to the breaches of the standard of care vis-à-vis the emergency room physician and group. In addition, the experts were willing to opine that the delay in treatment was the direct cause of the plaintiff’s subsequent bladder, bowel, and neurological dysfunction. The case did not go to trial but settled for 2.975 million dollars, of which 2.5 million dollars was contributed by the emergency room group.
DISCUSSION
The case of Anonymous v. Anonymous illustrates several points that have already been discussed previously including the need for diagnosing cauda equina syndrome in a timely manner, the need for and rationale behind investigation of urinary retention, and the need for appropriate follow-up and discharge instructions in certain patients with back pain. The most important point developed in Anonymous v. Anonymous, however, is the timing of emergency surgery and its effect upon the ultimate outcome of the patient. The following discussion presents current thinking with regard to the timing of surgery and its impact on patient outcomes.
Prior to approximately 1986 and the more recent studies detailing cauda equina syndrome, most authorities recommended that surgical treatment be undertaken within six hours after onset of an acute cauda equina syndrome.7 Recently, however, most authors advocate that patients with acute cauda equina syndrome undergo surgical treatment as early as possibly but no later than forty-eight (48) hours after the onset of symptoms.2,3,5,6,8 In fact, most studies demonstrate that patients who undergo surgery more than 48 hours after onset of symptoms have a much poorer outcome than those patients who do undergo surgery within 48 hours (See Table 3).2,3,4,5,8 In both Jennett and Robinson’s study, two studies published prior to 1970, no patient underwent surgery within 48 hours of onset of their cauda equina syndrome.19,20 As a result, in Jennett’s study, only 2 of 14 patients regained bladder and bowel control while in Robinson’s study, one half the patients continued with paralysis for more than two weeks.19,20
As more patients with cauda equina syndrome were studied, it became apparent that earlier surgeries lead to better outcomes. In a 1980 study, Nielsen reported that patients who underwent surgery within two days of onset of their cauda equina syndrome suffered fewer late bladder abnormalities than did those operated upon after two days.21 In a 1986 study, Hellstrom documented 13 of 17 patients who underwent surgery within 48 hours of onset of their cauda equina syndrome and who experienced good return of bladder function.22 Hellstrom’s study also demonstrated increased sexual potency after earlier surgery.22 In 1986, Kostuik et. al. detailed 31 patients with cauda equina syndrome of whom 10 could be diagnosed with acute cauda equina syndrome presenting with bladder dysfunction and other CES signs and symptoms.7 In those patients with acute cauda equina syndrome, the time to operation ranged from six (6) to forty-eight (48) hours with an average of 1.1 days.7 Kostuik noted: “Detailed analysis of the results was not possible in this retrospective chart review.”7 The study, however, did note that post-operative motor results were considered good in the acute group who received surgery within 48 hours.7
Later studies, with detailed analyses, have clearly shown a benefit to early surgery, especially if surgery is performed within 48 hours of onset of acute cauda equina syndrome symptoms. In 1993, Shapiro reported 14 patients who presented with acute cauda equina syndrome as a result of a ruptured lumbar disk.6 In Shapiro’s study, all patients with urinary incontinence who underwent surgery within 48 hours regained continence and unassisted ambulation.6 Only two of six patients with incontinence who underwent surgery after 48 hours of onset of symptoms, however, regained bladder control.6 After his analysis, Shapiro noted: “Every effort should be made to operate within 24-48 hours of onset. Additionally, we now counsel all patients with less severe problems from disc disease to report any problems with bilateral weakness and/or incontinence emergently, so there is no delay in treatment. Early diagnosis and treatment does improve outcome from this uncommon lesion.” 6
In a follow-up study, Shapiro studied 44 patients with acute cauda equina syndrome in detail, analyzed the results of surgery performed within 48 hours of symptom onset, analyzed the results of surgery performed after 48 hours of symptom onset, and compared the two results.8 In Shapiro’s study, 20 patients underwent surgery within 48 hours of symptom onset, and of those 20 patients, 18 patients (90%) underwent surgery within 24 hours of symptom onset. In the remaining 24 patients, surgery was performed more than 48 hours after symptom onset. The causes of delay involved misdiagnosis by a primary care or emergency room physician, failure to obtain a diagnostic study, or delay of surgical treatment to a more convenient time vis-à-vis the surgeon. In the majority of cases where an inappropriate delay occurred, the treatment or lack thereof centered around a weekend or holiday.
Based upon a Χ2 analysis, Shapiro determined that a delay in surgery was associated with a significantly greater chance for permanent motor weakness (P = 0.006), urologic dysfunction (P = 0.008), chronic severe pain (P = 0.025) and sexual dysfunction (P = 0.006). These results were demonstrated in the group of patients that received surgical therapy more than 48 hours after onset of symptoms. As a result, Shapiro noted that: “The data strongly support the management of cauda equina syndrome from lumbar disc herniation as a diagnostic and surgical emergency” and that “Obviously, nighttime, weekends, and holidays are not an excuse for neglecting an emergent approach.”8
As further support for emergent surgery, in 2000, Ahn, Kostuik, and other authors performed a meta-analysis of surgical outcomes of cauda equina syndrome as a result of lumbar disk herniation.5 They analyzed outcomes in 322 patients with regard to the timing of surgical intervention following onset of cauda equina symptoms (based upon and defined as onset of urinary dysfunction).5 The patients were divided into several groups based upon time to surgery; the groups included those with a time to surgery of less than 24 hours, time to surgery of 24-48 hours, time to surgery of 2-10 days, time to surgery of 11 days to 1 month, and time to surgery of more than 1 month. For their analysis, Ahn et. al. used logistic regression with regard to associated outcomes and time to surgery. Based upon such analysis, Ahn and Kostuik determined that there was a significant advantage to surgery performed within 48 hours of onset of symptoms as opposed to surgery performed after 48 hours of onset of symptoms. They, however, found no difference between patients treated within 24 hours as compared to those treated between 24 and 48 hours from onset of symptoms. In addition, they found no difference in outcome between the three groups treated more than 48 hours after onset of symptoms. In their conclusion, Ahn and Kostuik noted: “there was a significant advantage to treating patients within 48 hours as opposed to later than 48 hours, with improved outcomes in resolution of sensory deficit, motor deficit, urinary function, and rectal function.” 5
In the case of Anonymous v. Anonymous, the female plaintiff was diagnosed with cauda equina syndrome fourteen hours (14 hours) after her initial presentation to the emergency room. She subsequently underwent emergency surgery within 24 hours of her initial presentation to the emergency room and easily within 48 hours of her initial injury and urinary dysfunction. Her experts, including Dr. Shapiro, whose articles are detailed above, agreed to testify that had she been diagnosed and treated in a timely manner, her injuries would not have been as severe. Unfortunately, based upon the studies reviewed above, as well as Gleave’s study11 (a study that demonstrates no difference in early versus late surgery based upon different diagnostic criteria for cauda equina syndrome), the plaintiff’s injuries would have been the same whether she was treated at her initial visit or within twenty-four hours as she was.
Based upon the above studies, the difference in outcome is manifest at 48 hours. Patients who have surgery before 48 hours of presentation do better than those with surgical therapy after 48 hours. Although most authors agree that the earlier the surgery the better, no statistically significant studies have demonstrated the superiority of surgery at 6 hours, 12 hours, 14 hours, or even 24 hours. Most authors indicate that earlier surgery is advisable, and in fact, mandatory, if possible, based upon hoped for outcomes.
In the case of the Anonymous plaintiff, no statistically significant outcome differences are available. In other words, based upon the above studies, the plaintiff in Anonymous would have had the same outcome if she had been treated emergently at her initial presentation versus the treatment she actually received – surgery within twenty-four hours of her initial presentation. The case settled based, not upon concrete medical data, but the plaintiff’s initial faulty diagnosis and the possibility that the plaintiff may have had a better outcome if she had been operated upon 14 hours earlier.
SUMMARY
Cauda equina syndrome is a neurological entity caused by pressure upon the cauda equina generally due to a ruptured lumbar intervertebral disc. Other etiologies of cauda equina syndrome include tumor, infection or hematoma, but they are much less common than a ruptured disk. Cauda equina syndrome is characterized by low back pain, bilateral or unilateral lumbar radiculopathy, motor and sensory deficits as well as bladder or bowel dysfunction. Most authors define cauda equina syndrome only when bladder dysfunction is present in the patient. In other words, cauda equina syndrome does not exist and cannot be diagnosed in the absence of bladder dysfunction. With regard to treatment, most ruptured lumbar disks can be treated conservatively, either successfully or on an interim basis until surgery becomes necessary.
Cauda equina syndrome, on the other hand, is a true surgical emergency and is the only true absolute indication for surgical treatment of a patient with a ruptured lumbar disk. In fact, most authors recommend surgery as soon as possible with studies indicating much poorer results if the surgery takes place 48 hours or more following the onset of symptoms.
With regard to the medico-legal implications of cauda equina syndrome, Shapiro notes: “Serious legal implications about emergency room and doctor office management of this problem exists.” To avoid these “serious legal implications” practitioners must continue to view cauda equina syndrome as a true surgical emergency that requires both emergent diagnostic and treatment actions. Any patient with urinary dysfunction must be studied on an emergent basis particularly if the patient has suffered an acute change coupled with other discogenic symptoms. The ER physician must be aware of the condition and must have the skills to diagnose the entity and order an MRI to evaluate the cauda equina and lumbar spine. Moreover, the ER physician must recognize that cauda equina syndrome is a surgical emergency requiring immediate referral to or consultation with a qualified spine surgeon. The patient cannot be allowed to linger without studies or consultation. This caveat is especially true with regard to evenings, weekends or holidays. A patient with acute cauda equina syndrome cannot be treated as a routine back pain patient and to do so exposes the ER physician to serious medico-legal consequences.