Affidavit of Kalman Blumberg, MD Regarding Yolanda Jensen & Causation

PERSONALLY APPEARS before the undersigned authority, duly authorized to administer oaths, comes Kalman Blumberg, MD, who after first being duly sworn, states as follows:

Introduction

1.             Plaintiff’s counsel has asked me to provide an affidavit addressing the causation question in this case — partially in response to arguments raised by the Defense well after my deposition.

2.             In considering these arguments, I have revisited the issues and reviewed medical literature I did not review in preparation for my deposition.

3.             To create this affidavit, Plaintiff’s counsel consulted with me about my views on and then drafted an affidavit based on our discussion.

4.             Plaintiff’s counsel sent the draft to me in Microsoft Word format. I reviewed it and edited it to make sure it correctly states my views.

5.             This affidavit follows the format chosen by Plaintiff’s counsel. Beyond reviewing the draft to make sure it correctly states my views, I have not completely edited the sentence structure, wording, style, etc. I provided some but not all of the specific words. Regardless of the origin of any specific language, though, I have approved and adopted the language.

6.             I understand that Plaintiff’s counsel has discussed the same issues with three medical experts including myself. I understand that all three of us have essentially the same substantive view. That is not surprising, given the simplicity of the issues here. Additionally, I understand that Plaintiff’s counsel created the initial draft of the affidavit for all three experts, so I would expect the structure and wording of all three to be similar. Again, however, I have finalized and signed this affidavit only after reviewing it carefully to make sure it correctly states my views. In this respect, this affidavit is akin to publications in many fields, in which a document is attributed to multiple authors who sign onto it and adopt it as their own statements, although they may have varying and limited responsibility for drafting the text. Such publications abound in scientific fields, including medicine.

7.             Indeed, as to the core substantive points here, even some of the Defense witnesses seem to agree. Thus:

Defendant Ki-Hon Lin, Orthopedic Surgeon

Defense Expert Dr. Karl Schultz, Neurosurgeon

Qualifications

8.             My qualifications have previously been provided to Defense counsel. Briefly, however, I am an orthopedic spine surgeon and have significant clinical experience with patients suffering spinal cord compression — including cancer patients with metastatic tumors in the spine — which threaten to (or do) cause neurologic deficits.

Key Facts

9.             The following facts are drawn from Yolanda Jensen’s medical records from Tanner Medical Center and Emory University Hospital.

10.          Yolanda was admitted to Tanner Medical Center on May 7, 2017. (TMCb 162.) She was not transferred to Emory University Hospital until May 13 — six days later. (TMCb 182.)

11.          Upon admission, Yolanda had a tumor invading her spinal canal at the T11 level. The tumor took up approximately 70% of the spinal canal — limiting the space for the spinal cord. (TMCb 301.)

12.          This tumor posed an obvious danger of permanent harm from spinal cord compression, if the tumor was not removed in time to prevent deficits.

13.          However, on admission Yolanda suffered no neurologic deficits from spinal cord compression. As Dr. Ki-Hon Lin wrote the next morning (May 8, at 0835 hrs), Yolanda was “neurologically intact.” (TMCb 190-93.)

14.          Given the obvious danger of severe, permanent harm, Yolanda should have been transferred for surgery to remove the tumor before it caused permanent neurologic harm.

15.          But the providers at Tanner delayed for six days.

16.          During those six days, Yolanda deteriorated:

·      May 8

o   morning: Dr. Ki-Hon Lin notes that Yolanda “is neurologically intact.” (TMCb 190-93.)

o   May 8, evening: Dr. Randall Pierce notes that Yolanda is experiencing “a little numbness/tingling occasionally in legs, mainly right, but no strength or gait issues, no bowel or bladder issues.” (TMCb 194.)

·      May 9

o   morning: Nurse Practitioner Kelly Thompson (supervised by Dr. Nalini Narayan) notes that Yolanda is experiencing “bilateral lower extremity leg spasm.” (TMCb 203-07.)

o   evening:

§  Dr. Pierce notes that Yolanda has “increased numbness and tingling in the legs that has her worried.” (TMCb 208.)

§  A nurse notes that Yolanda “is not able to ambulate on her own and needs assistance every time she uses the restroom.” (TMCb 417.)

·      May 10

o   morning:

§  A nurse notes that “Pt admitted to getting out of the bed and crawling on the floor to get back in the chair.” (TMCb 317.)

§  Yolanda now has an indwelling urinary catheter for possible neurogenic bladder. NP Thompson (supervised by Dr. Vaughn Clagette) notes, “We will continue her Foley secondary to possible neurogenic bladder from core compression.” (TMCb 211-15.)

o   afternoon: Dr. Pierce notes, “When I saw her this morning she states she could not walk, but her motor testing was still quite intact in the lower extremities. It appears to be more just an issue of feeling very weak. … Sensation abnormal (slight numbness right leg intermittently, having somewhat similar symptoms on the left leg.” (TMCb 216.)

·      May 11

o   morning: NP Thompson (supervised by Dr. Narayan) notes, “Remains with Foley catheter for possible neurogenic bladder from spinal cord compression.” (TMCb 219-23.)

·      May 12

o   mid-day:

§  NP Thompson (supervised by Dr. Narayan) notes that Yolanda now has back spasms and bowel constipation: “Back spasms and pain continued to be a problem. … Main complaint today is that of constipation and poor oral intake.” (TMCb 228-33.)

§  A nurse notes that Yolanda “stated that she has been unable to walk because of hip pain.” (TMCb 418.)

§  Dr. Pierce notes, “Pain is still a problem quickly with any movement. I believe she is triggering spasms much of the time.” (TMCb 234-37.)

·      May 13

o   mid-day:

§  Dr. Pierce notes, “She is complaining of more weakness in her right leg and generally more dense numbness and tingling. … Sensation abnormal (she has more evidence of foot drop on the right with more consistent numbness and tingling sensation throughout both lower extremity’s which seems to be worse). … I am concerned she is having some evolution of symptoms, so we are still early in her course.” (TMCb 244.)

§  Only two hours after Dr. Pierce’s note — after Yolanda is transferred to Emory University Hospital — orthopedic surgeon Dr. Sangwook Yoon examines Yolanda and notes, “Patient has profound right leg paralysis and left leg weakness.” (EUHb 125.)

17.          In short: When Yolanda came into Tanner on May 7, she was neurologically intact. When they transferred her on May 13, she was suffering severe neurologic deficits, including neurogenic bladder and paraparesis.

18.          The providers at Tanner could have transferred Yolanda for surgery before any significant neurologic deficits developed in the first place.

Causation Question 1: Prevention of Deficits

19.          The first question here is whether surgical removal of the tumor would have stopped the progression of neurologic deficits — either preventing a given deficit from developing in the first place, or preventing a deficit from becoming more severe.

20.          The answer is Yes.

The Principle

21.          The basic principle is simple: If you remove the cause before the effect develops, then you prevent the effect.

22.          Generally, if spinal cord compression is relieved before major deficits develop, then those deficits will not develop.

23.          If Yolanda had been transferred for surgery before paraparesis developed, it is highly likely that she would never have suffered paraparesis.

24.          Similarly, Yolanda reported in her 2018 deposition that she suffered chronic neuropathic pain and spasms that her physicians attributed to the spinal cord compression. If Yolanda had been transferred for surgery before those neuropathies developed, it is highly likely she would never have suffered them.

Empirical Confirmation

25.          Again, the general principle is that if spinal cord compression is relieved before it causes major neurologic deficits, those deficits are unlikely to develop later.

26.          Among physicians dealing with spinal cord compression, this principle is well known and arises from broad, general clinical experience (as opposed to isolated anecdotes). There is a body of medical literature that supports the principle, but even if no such literature existed, the breadth of clinical experience would provide a sound basis for the principle.[1]

27.          In any event, there is medical literature that confirms the principle here.

28.          The research confirms that patients are unlikely to deteriorate neurologically after surgery to remove a tumor compressing the spinal cord.

29.          I have searched for medical literature relevant to the issues here, and so did Plaintiff’s counsel. This affidavit does not attempt a comprehensive list of relevant literature. The articles mentioned below are only examples of the available literature. Plaintiff’s counsel found these examples and drafted the affidavit citing them. They suffice both to exemplify the literature and to support the causation point in this case:

·      Harrington, Kevin D. “Anterior decompression and stabilization of the spine as a treatment for vertebral collapse and spinal cord compression from metastatic malignancy.” Clinical Orthopaedics and Related Research 233 (1988): 177-197.

This early article reports on 77 patients treated surgically over a 10-year period. Only one patient deteriorated neurologically after surgery — apparently because of additional tumor not identified before surgery. (See page 189, 191.)

·      Chaichana, Kaisorn L., Graeme F. Woodworth, Daniel M. Sciubba, et al. “Predictors of ambulatory function after decompressive surgery for metastatic epidural spinal cord compression.” Neurosurgery 62, no. 3 (2008): 683-692.

This article (with Plaintiff’s expert Dr. Sciubba as a co-author) reports that of the patients who received surgery before they lost the ability to walk, 89% maintained that ability. And the 11% who later lost the ability to walk did so because of “disease progression” — that is, progression of their cancer, not as a time-delayed result of cord compression.

The article cites seven prior studies that showed similar findings.

·      Fürstenberg, C. H., B. Wiedenhöfer, H. J. Gerner, and C. Putz. “The effect of early surgical treatment on recovery in patients with metastatic compression of the spinal cord.” The Journal of bone and joint surgery. British volume 91, no. 2 (2009): 240-244.

This study found that after symptoms developed, for patients given surgery within 48 hours of the symptoms developing, 38% of patients improved and 62% of patients stayed the same — with none deteriorating. When surgery was delayed for more than 48 hours after symptoms began, then existing symptoms did get worse in 21% of the delayed-surgery patients.

30.          These articles do not exhaust the relevant medical literature. They merely exemplify it.

*   *   *

31.          The medical literature confirms the well-known, generally accepted principle that after surgery relieves spinal cord compression, neurologic deficits attributable to cord compression are unlikely to develop or become more severe after surgery.

32.          In other words, the six-day delay in transferring Yolanda Jensen to a spine-surgery-capable hospital likely caused the paraparesis and related deficits Yolanda suffered until her death.

Causation Question 2: Reversal or Improvement of Deficits

33.          Obviously it is better to prevent a deficit from arising in the first place, than to try to reverse the deficit after it arises. However, a second potential question here is whether surgery within 48 hours of the development of a given neurologic deficit would have enabled Yolanda to improve — to recover some of the function that had been lost before the surgery.

34.          Taking account of both the literature and Yolanda’s later recovery of bladder function and her limited, partial recovery of ambulation, it is more likely than not that surgery within 48 hours of the onset of any given deficit would have led to improvement of the existing deficits — in particular, impaired ability to walk.

35.          The Chaichana et al article discussed above (co-authored by Plaintiff’s expert Dr. Sciubba) discusses the likelihood of patients recovering the ability to walk after surgery. The study found that overall — regardless of the timing of surgery — 52% of patients who had lost the ability to walk before surgery regained it after surgery. (See page 686, Table 2.)

36.          Furthermore, the study found that patients who had surgery within 48 hours of symptom onset were nearly three times more likely to regain the ability to walk than patients who had a more delayed surgery. (See page 686.)

37.          The study authors summarized this result as follows (at pages 689-90):

38.          As that study noted, “Surgery for MESCC [Metastatic epidural spinal cord compression] has led to recovery rates that range between 40 and 60% in several series [] which is consistent with this study.”

39.          In addition to the general information from the literature, we have information specific to Yolanda, from her December 2018 deposition. Yolanda testified that by that time (Dec 2018), her bladder and bowel function were normal. (Yolanda Jensen 2018 deposition, page 131.)

4         Q.     In regard to your bowel and your

5  bladder now, are you able to go to the bathroom

 6  independently now?

 7         A.     Yes.

 8         Q.     And your bowel and bladder seem to

 9  be doing well and working appropriately?

10         A.     Yes.

40.          Yolanda also testified that through physical therapy she had regained some minor ability to walk — although a very limited amount. (Yolanda Jensen 2018 deposition, pages 47-49.)

10                In your written responses it states

11  that since May 7th, 2017, you have been bed bound

12  and unable to stand on your own power. 

13                Is that accurate?

14         A.     That’s accurate.

15         Q.     So, sitting here today, you are not

16  able to stand up on your own?

17         A.     I can stand up.

18         Q.     Do you have to use -- utilize any

19  assistance in standing?

20         A.     Just my arms and the table.

21         Q.     And I’m talking about right now,

22  once standing, are you able to take any steps?

23         A.     No.

24         Q.     And that would be unassisted or with

25  the use of crutches or a walker, et cetera; you

                                                               48

1  can’t do either?

2         A.     If someone is with me with a walker,

3  I can take a step or two.  But then I have to sit

4  down or they have to follow me with the chair.

5         Q.     Do you have to sit down because of

6  pain or --

7         A.     Yes.

8         Q.     -- stamina or both?

9         A.     Both.

10         Q.     Okay.  And is that something that

11  your walking ability -- is that something that

12  seems to be improving?

13         A.     No.

14         Q.     How long has it been at its current

15  status that you can stand and take a very few steps

16  assisted, but then sit back down?

17         A.     About seven months.

18         Q.     So let’s call that mid 2018.  Then

19  there was a change. 

20                What was your walking ability like

21  before that time?  Let’s call it the first part of

22  2018. 

23         A.     I couldn’t walk.

24         Q.     So from May, 2017, until mid 2018

25  you could not walk at all?

                                                               49

1         A.     No.

2         Q.     Okay.  The improvement that you had

3  in mid 2018 -- to your understanding, is that from

4  physical and occupational therapy?

5         A.     Yes.

41.          Based on the general statistics across patients, as well as the information specific to Yolanda Jensen, it is more likely than not that if Yolanda had been transferred in order to receive surgery within 48 hours of the development of leg paraparesis or paralysis, then her paraparesis or paralysis would have been reversed or improved after surgery.

42.          All neurologic deficits from spinal cord compression arise from injury to nerve fibers.

43.          Therefore, the potential for improvement in ability to walk likely applies to other neurologic deficits, too.

44.          More likely than not, therefore, if Yolanda had been transferred in order to receive surgery within 48 hours of the development of any particular neurologic deficit, then that particular deficit would have been reversed or improved after surgery.

Question 3: Timing of Beneficial Surgery

45.          Our ability to pinpoint the progression of Yolanda’s deficits — and the timeline of beneficial surgery — is limited by the information available in the Tanner medical records. After the morning of May 8, no physician at Tanner documented an adequate neurologic exam. That limits our knowledge of Yolanda’s neurologic status at any given time.

46.          Additionally, there is an apparent conflict between Dr. Pierce’s May 13, 1123 hrs note (documenting mere leg weakness) and Dr. Yoon’s exam only two hours later (documenting profound paralysis of the right leg). While it is possible that Yolanda’s condition became suddenly and dramatically worse in those two hours, that is unlikely. So the apparent conflict between Dr. Pierce’s note and Dr. Yoon’s note limits one’s ability to rely confidently on Dr. Pierce’s notes.

47.          However, from the records it is still clear that after the various deficits began to develop, the providers at Tanner had multiple opportunities to transfer Yolanda at various points before the deficits became severe.

48.          From the information in the records, we can conclude as follows, more likely than not. My conclusions here revise and expand on my limited testimony on the issue of timing at my deposition. The revisions are based on revisiting the records and considering the literature on improvement of deficits when surgery is performed within 48 hours of symptom onset.

·      May 8

o   As of this date, Yolanda had only limited numbness and tingling in her legs. (See Dr. Pierce’s note at TMCb 194.)

o   If Yolanda had been transferred for surgery on May 8, that likely would have prevented leg paraparesis or paralysis, the associated spasms and pain, and neurogenic bladder or bowel.

·      May 9

o   This day saw the addition of leg spasms and impairment of Yolanda’s ability to walk. It appears she could still walk with assistance, though: “She is not able to ambulate on her own and needs assistance every time she uses the restroom.” Yolanda may have begun suffering weakness in one or both legs. (See Dr. Pierce’s note at TMCb 208 and nursing note at TMCb 417.)

o   If Yolanda had been transferred for surgery on May 9, any leg paraparesis likely would not have progressed, and likely would have been improved or reversed after surgery (along with the associated spasms and pain). Additionally, a transfer likely would have prevented neurogenic bladder or bowel.

·      May 10

o   This day saw evidence of further weakening of Yolanda’s legs: “Pt admitted to getting out of the bed and crawling on the floor to get back in the chair.” (TMCb 317.) Dr. Pierce’s note from the same day, however, says “When I saw her this morning she states she could not walk, but her motor testing was still quite intact in the lower extremities. It appears to be more just an issue of feeling very weak.” (TMCb 216.) The two notes appear to conflict, but if Dr. Pierce’s statement is true, then Yolanda had not yet approached paralysis in either leg. Likely, weakness in her legs was progressing but was not yet severe.

o   Additionally, as of this day, Yolanda was given a Foley catheter for presumed neurogenic bladder.

o   Assuming the accuracy of Dr. Pierce’s note: If Yolanda had been transferred for surgery on May 10, then her leg paraparesis likely would not have progressed. Further, since only about 24 hours had passed since paraparesis began, it likely would have been improved or reversed after surgery (along with the associated spasms and pain). Additionally, it is highly likely that neurogenic bladder would have been reversed or improved (since it was reversed later anyhow, despite the actual, lengthy delay of surgery).

·      May 11

o   The records from this day do not indicate worsening of Yolanda’s neurologic deficits.

o   Again assuming the accuracy of Dr. Pierce’s May 10 note: If Yolanda had been transferred for surgery on May 11, then her leg paraparesis likely would not have progressed. Further, since only about 48 hours had passed since paraparesis began, it likely would have been improved or reversed after surgery (along with the associated spasms and pain). Additionally, it is highly likely that neurogenic bladder would have been reversed or improved (since it was reversed later anyhow, despite the actual, lengthy delay of surgery).

·      May 12

o   Again on this day there is tension between the nursing notes and Dr. Pierce’s notes. The nursing notes say, “She stated that she has been unable to walk because of hip pain.” (TMCb 418.) Dr. Pierce’s note does not comment on inability to walk. (TMCb 234-37.)

o   However, Dr. Pierce’s note adds an indication of bowel dysfunction: “Main complaint today is that of constipation and poor oral intake.” (TMCb 234-37.)

o   Again assuming the accuracy of Dr. Pierce’s notes: If Yolanda had been transferred for surgery on May 12, then her leg paraparesis likely would not have progressed.

o   However, as of May 11, because it had been more than 48 hours since paraparesis began, we cannot say it is more likely than not that a transfer for surgery on this day would have reversed or improved the paraparesis. It may have, and Yolanda’s chances of improvement on May 11 were certainly better than two days later, but we cannot say transfer would have reversed or improved the deficits more likely than not.

49.          These conclusions about timing are contingent on the accuracy of the medical records — Dr. Pierce’s especially — as produced in this lawsuit.

Question 4: Practicality

50.          A final question here is whether Yolanda would actually have been able to be transferred for the surgery earlier. The answer is Yes.

51.          I understand the Defense suggests Yolanda would not have been given the surgery she needed any earlier than she got it — either because no accessible hospital would have been able to provide it, or because no spine surgeon would have agreed to perform it.

52.          Both suggestions are fanciful.

53.          Yolanda was near Atlanta, and received the surgery at Emory University Hospital.

54.          Atlanta has several spine-surgery capable hospitals. Other such hospitals were available in the larger region. Based on my knowledge and experience, it is all but certain that a hospital was available that would have been able to provide the surgery Yolanda needed — starting as early as May 7 when Yolanda was admitted to Tanner, and continuing thereafter.

55.          That inference is supported by the fact that there was apparently no difficulty at all in arranging a transfer to Emory for the surgery, once Yolanda’s providers at Tanner chose to seek a transfer.

56.          Indeed, once the providers at Tanner decided to pursue a transfer, the transfer happened almost immediately. Dr. Pierce entered his May 13 progress note at 1123 hrs. Barely two hours later, Yolanda was at Emory University Hospital, and at 1336 hrs Dr. Yoon performed a physical exam of Yolanda.

57.          The near-immediate transfer confirms what I know from my own experience: A transfer in Yolanda’s circumstances would be highly likely to occur quickly at any time during her May 7 admission at Tanner — if only her providers had sought a transfer.

58.          Similarly, the fact that Emory’s Dr. Yoon agreed to perform the surgery suffices to show the likelihood that any competent and diligent spine surgeon would have agreed to perform the surgery before paraparesis developed, just as Emory’s Dr. Yoon did after paraparesis developed.

59.          More broadly, though, it is universally understood that surgery should be done before neurologic deficits develop, rather than afterward. That conclusion is reflected throughout the medical literature, including in the Chaichana et al article cited above (and in the court decision discussed below). This elementary principle is reflected in well-accepted adages in medicine (e.g., “time is function”) as well as in human affairs generally (e.g., “an ounce of prevention is worth a pound of cure”). Because of that basic principle, it is highly likely that a spine surgeon would have agreed to a surgical resection of the tumor in Yolanda’s spine before (as well as after) paraparesis developed.

Defense Arguments

60.          Plaintiff’s counsel has informed me of arguments made by Defense counsel.

Comparing a 6-Day Delay to a 4-Hour or 24-Hour Delay

61.          I understand the Defense cites a legal decision (McDowell v. Brown) in which the court found it inadequate to rely solely on an “earlier treatment is better” principle in concluding that a four-hour or 24-hour delay in surgery for an epidural spinal abscess caused harm.

62.          I am not a lawyer, so I obviously do not discuss the legal aspects of that or any court decision. I address only the medical issues in the decision.

63.          A six-day delay is different from a 4-hour, a 24-hour, or even a 48-hour delay.

64.          I understand that the court in McDowell appeared to accept that a 48-hour delay would likely cause harm. Plaintiff’s counsel informs me that the court wrote as follows:

We also agree with the district court’s conclusion that Dr. Merinkangas’s contention that McDowell’s injury could have been prevented had he entered surgery four hours earlier failed the Daubert analysis. Dr. Merinkangas could not identify any empirical data, survey, study, or literature to support his theory, save the study in SPINAL CORD COMPRESSION, which dealt with a delay of 48 hours, which is more than twice the delay here. Notwithstanding his lack of support, Dr. Merinkangas further opined that had McDowell been treated 24 hours earlier, then he would have no resulting paralysis. Taking either of Dr. Merinkangas’s propositions (a four-hour delay or twenty-four delay), there is no support addressing anything less than a 48-hour delay. There is a considerable gap between a 24-hour to a 48-hour delay, and even more so with a 4-hour delay. This runs afoul of Allison’sadmonition that a theory should not “leap” from an accepted scientific premise to an unsupported one. 184 F.3d at 1314. Furthermore, an expert opinion is inadmissible when the only connection between the conclusion and the existing data is the expert’s own assertions, as we have here.

— McDowell v. Brown, 392 F.3d 1283, 1300 (11th Cir. 2004)

65.          Here, of course, as noted above, medical literature exists showing that a delay of 48 hours is likely to cause harm. And again, the delay in Yolanda’s case exceeded 48 hours.

66.          Furthermore, one critical point in Yolanda’s case is the opportunity to transfer Yolanda for surgery before neurologic deficits developed in the first place. Plaintiff’s counsel informs me that the court in McDowell did not discuss that issue. That issue, too, is a material difference that distinguishes Yolanda’s case from the McDowell case.

Yolanda’s Later, Partial Recovery

67.          The Defense notes that at my deposition I was unaware of the extent to which Yolanda had recovered after suffering paraparesis. That is true but largely irrelevant to the causation issue I am addressing here.

68.          Obviously, for example, if Yolanda had not suffered paraparesis in the first place, she would not have had to recover from it (which apparently she never did, to any significant extent). The point here is that if Yolanda’s medical providers at Tanner had acted appropriately, Yolanda would not have suffered paraparesis at all.

69.          To the extent Yolanda’s later, limited recovery is relevant, it is only because it strengthens the likelihood that even after deficits developed surgery within 48 hours of symptom onset would have reversed or at least improved deficits that existed at the time of surgery.

Conclusion

70.          If Yolanda Jensen had been transferred for surgery before developing paraparesis or other major neurologic deficits, it is highly likely that such deficits would never have developed.

71.          If Yolanda had been transferred for surgery during the development of any particular neurologic deficit, it is highly likely that such deficits would, at worst, have remained fixed at the level of severity they were at before the surgery.

72.          Finally, if Yolanda had been transferred for surgery within 48 hours of any particular deficit developing, it is likely that the respective deficit would have improved after surgery.

73.          By causing a delay in Yolanda’s transfer for surgery, her providers at Tanner caused Yolanda harm.

                                                                                    Kalman Blumberg, MD

SWORN TO AND SUBSCRIBED before me

_________________, 2023

____________________________________

NOTARY PUBLIC

My Commission Expires:

[1] Many, if not most, medical principles rest on common clinical experience even in the absence of peer-reviewed literature reporting on empirical studies. Thus, to take simple, obvious examples: a gunshot to the head is likely to kill the subject; a fall from a great height is likely to kill the subject; surgical wounds closed after surgery are less likely to develop infections than surgical wounds left open; complex fractures are more likely to heal well if reset and fixed in place than if not; a patient suffering peritonitis from a bowel leak is more likely to survive if the bowel leak is repaired than if not; etc. These and a great many other medical principles are reliable and well-founded despite never having been specifically researched. They are not uncertain enough to justify the effort of researching them, and practical and ethical constraints prevent researching them. It would be both difficult and unethical, for example, to enlist participants in a study designed to research the medical consequences of leaving surgical wounds open after surgery. In medicine as in the rest of life, specific research is not always necessary in order to draw conclusions reliably.