From the Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan and Department of Anesthesiology, Washington University, St. Louis, Missouri.
Accepted for publication March 17, 2014.
The authors declare no conflicts of interest.
Reprints will not be available from the authors.
Address correspondence to George A. Mashour, MD, PhD, 1H247 Department of Anesthesiology, SPC-5048, 1500 E. Medical Center Dr., Ann Arbor, MI 48109-5048. Address e-mail to firstname.lastname@example.org.
“Expressionless, mute, and staring, their faces recalled the photographs in popular pictorial magazines of the blank and stunned victims of civil disasters, prompting us to employ the term ‘catastrophe reaction’ for the condition we had observed.”1
The frozen faces described by Meyer and Blacher1 in their landmark 1961 case series were not of shell-shocked soldiers returning from the Vietnam War, but rather surgical patients who had experienced awake paralysis or intraoperative awareness with explicit recall (AWR). The symptom complex of this “catastrophe reaction,” which included recurrent nightmares and profound anxiety, came to be known in 1980 as posttraumatic stress disorder (PTSD).2 It is well known that PTSD can be an adverse outcome of AWR and has been associated with up to 70% of AWR events (Table 1).3–10 What remains unknown, however, is the natural history of psychological distress attributable to AWR, which could include both PTSD and a subsyndromal complex of PTSD symptoms. One barrier to our understanding stems from the fact that the longest reported median time from prospectively studied AWR events to psychiatric evaluation is approximately 5 years (Table 1).9 It is therefore unclear what the long-term outcomes are of PTSD and related psychological symptoms after AWR. In this issue of Anesthesia & Analgesia, Laukkala et al.10 advance the field by describing a psychiatric assessment of AWR patients with a median follow-up time of approximately 17 years.
In brief, the authors followed patients who experienced AWR during 4 prospectively conducted trials (published from 1996 to 2002).4,11–13 Although 26 patients were determined to have experienced AWR in these studies, only 9 were available for subsequent evaluation. As such, like other studies in this field, a very small number of patients was available for assessment. For each patient with AWR, a control patient without AWR was matched on the basis of sex, age group, time of operation, and type of surgery (cardiac versus noncardiac). The 18 patients in the cohort (9 with AWR and 9 controls) were interviewed by a clinical psychologist trained in the Structured Clinical Interview for Axis 1 Disorders based on the Diagnostic and Statistical Manual of Mental Disorders-IV (the SCID-1 instrument); patients also completed a variety of questionnaires assessing psychosocial factors and psychiatric disease. It is important to note that the range of time between the AWR event and psychiatric evaluation was 13.2 to 18.6 years. This is >3-fold longer than comparable studies such as that by Leslie et al.,9 who evaluated patients with AWR and controls between 4.3 and 5.7 years after surgery. The study by Laukkala et al.10 therefore provides a new perspective on long-term psychological trajectories after AWR. The results were surprising: none of the patients with AWR met criteria for PTSD and, at the time of follow-up interview, none regarded their AWR experience as a traumatic event. Furthermore, there was no increased incidence of other psychiatric disorders in AWR patients compared with that of controls.
What is the significance of these findings and how do we reconcile them with past studies demonstrating a troubling incidence of PTSD in surgical patients experiencing AWR? First, we should avoid the conclusion that AWR does not have the potential to be a traumatic event simply because it was not associated with PTSD in this long-term analysis. It is firmly established that PTSD is a consequence of AWR and that it can persist for decades after surgery; prevention of AWR therefore remains of paramount importance. In fact, in the study by Osterman et al.6, 9 of 16 or 56% of patients experiencing AWR met diagnostic criteria for PTSD at a mean of 17.9 years after surgery compared with no diagnoses of PTSD in the controls. Why the difference? Although the precise answer is unclear, Osterman et al.6 studied a population of AWR patients who were recruited through advertising and referral, as opposed to a group of prospectively studied AWR patients with a known denominator. There is a risk of selection bias from an advertised study of PTSD and AWR, because volunteers may potentially have a higher chance of screening positive for the disorder. However, another possibility for the discrepancy is that the patients in the study of Laukkala et al.10 experienced less trauma than those in the study of Osterman et al.6, which is supported by the AWR event descriptions in the 2 investigations. In other words, less initial trauma would likely lead to less posttraumatic stress.
We as a field should respond to the findings of Laukkala et al.10 with a mixture of cautious optimism and renewed commitment to the prevention and treatment of PTSD after AWR. The cautious optimism relates to the possibility that, even assuming an initial stress response and subsequent development of PTSD, a surgical patient experiencing AWR may not suffer psychiatric or psychosocial consequences in the long term. However, there are significant caveats to keep in mind. First, simply because 0 of 9 patients did not have PTSD after AWR in this small cohort does not mean that there is precisely a 0% incidence of PTSD after AWR. The 95% confidence intervals of a 0% incidence in this study are 0% to 37%, the upper limit of which is not entirely inconsistent with past studies of PTSD after AWR. Furthermore, it is important to note that we lack critical data regarding the psychological trajectory of these patients (Fig. 1). It is well recognized with other traumatic events that there can be heterogeneity in psychiatric symptomatology,14 which is likely attributable to the premorbid psychological substrate, the inciting event itself, and the treatment of psychological symptoms in the aftermath. Examples of psychological trajectories following a trauma include (1) resilience or resistance, (2) delayed development, (3) recovery, and (4) chronicity. While the findings of Laukkala et al.10 provide information on chronicity in the small cohort studied, they do not reveal whether this lack of persistent PTSD is attributable to initial resilience or subsequent recovery (Fig. 1). Thus, although it is encouraging that this particular group of patients did not suffer from PTSD at the time of the interview, we need more information as to whether this reflects a less severe AWR experience, initial resilience, the natural history of the disease or the benefits of therapy.
The renewed commitment relates to efforts in anesthesiology and neuroscience to advance our understanding of the neural correlates of consciousness and anesthesia, which will help establish a foundation for the primary prevention of AWR. It is critical to emphasize that the data reported by Laukkala et al.10 do not mean that AWR is a complication without consequence. The field also needs to move toward an improved understanding of the risk factors for adverse psychological outcomes of AWR (across multiple anesthetic techniques)15 or high-risk surgery itself, as well as the validation of practical screening tools to identify those who are at highest risk in the postoperative period. The consistently reported occurrence of PTSD after major surgery and critical care, even in the absence of AWR,9,16 should prompt consideration of risk stratification for poor psychological outcomes in the postoperative period. Vulnerable patients can then be screened and, when appropriate, undergo early referral for psychiatric care and treatment with the current pharmacologic and nonpharmacologic therapies available for PTSD. It is known that early interventions can accelerate recovery from PTSD.
In conclusion, Laukkala et al.10 have conducted the longest follow-up study of PTSD in a defined cohort of AWR patients.10 They could not identify PTSD in 9 AWR patients studied at a median time of 17.2 years after surgery, in contrast to the most recent study reporting a 71% incidence at approximately 5 years after AWR.9 However, it is unclear whether the patients in this study went the path of resilience or recovery after their AWR event. One interpretation is to hope for the best but prepare for the worst. We hope that patients will not develop persistent PTSD after AWR, but we must prepare for the worst by increasing vigilance for AWR itself as well as postoperative PTSD and related symptomatology. Both this hope and preparation hinge on (1) understanding the preoperative, intraoperative, and postoperative risk factors for PTSD (including AWR), (2) screening those at highest risk, and (3) initiating early referral and treatment to maximize the chances of a healthy psychological trajectory in the long run.
Name: George A. Mashour, MD, PhD.
Contribution: The author helped write the manuscript.
Attestation: The author approved the final manuscript.
Name: Michael S. Avidan, MBBCh.
Contribution: The author helped write the manuscript.
Attestation: The author approved the final manuscript.
This manuscript was handled by: Sorin J. Brull, MD, FCARCSI (Hon).
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