Terri G. Monk

Predictors of Cognitive Dysfunction after Major Noncardiac Surgery

Background:The authors designed a prospective longitudinal study to investigate the hypothesis that advancing age is a risk factor for postoperative cognitive dysfunction (POCD) after major noncardiac surgery and the impact of POCD on mortality in the first year after surgery. Methods:One thousand sixty-four patients aged 18 yr or older completed neuropsychological tests before surgery, at hospital discharge, and 3 months after surgery. Patients were categorized as young (18–39 yr), middle-aged (40–59 yr), or elderly (60 yr or older). At 1 yr after surgery, patients were contacted to determine their survival status. Results:At hospital discharge, POCD was present in 117 (36.6%) young, 112 (30.4%) middle-aged, and 138 (41.4%) elderly patients. There was a significant difference between all age groups and the age-matched control subjects (P < 0.001). At 3 months after surgery, POCD was present in 16 (5.7%) young, 19 (5.6%) middle-aged, and 39 (12.7%) elderly patients. At this time point, the prevalence of cognitive dysfunction was similar between age-matched controls and young and middle-aged patients but significantly higher in elderly patients compared to elderly control subjects (P < 0.001). The independent risk factors for POCD at 3 months after surgery were increasing age, lower educational level, a history of previous cerebral vascular accident with no residual impairment, and POCD at hospital discharge. Patients with POCD at hospital discharge were more likely to die in the first 3 months after surgery (P = 0.02). Likewise, patients who had POCD at both hospital discharge and 3 months after surgery were more likely to die in the first year after surgery (P = 0.02). Conclusions:Cognitive dysfunction is common in adult patients of all ages at hospital discharge after major noncardiac surgery, but only the elderly (aged 60 yr or older) are at significant risk for long-term cognitive problems. Patients with POCD are at an increased risk of death in the first year after surgery.

Anesthetic management and one-year mortality after noncardiac surgery

Little is known about the effect of anesthetic management on long-term outcomes. We designed a prospective observational study of adult patients undergoing major noncardiac surgery with general anesthesia to determine if mortality in the first year after surgery is associated with demographic, preoperative clinical, surgical, or intraoperative variables. One-year mortality was 5.5% in all patients (n = 1064) and 10.3% in patients ≥65 yr old (n = 243). Multivariate Cox Proportional Hazards modeling identified three variables as significant independent predictors of mortality: patient comorbidity (relative risk, 16.116; P < 0.0001), cumulative deep hypnotic time (Bispectral Index® <45) (relative risk = 1.244/h; P = 0.0121) and intraoperative systolic hypotension (relative risk = 1.036/min; P = 0.0125). Death during the first year after surgery is primarily associated with the natural history of preexisting conditions. However, cumulative deep hypnotic time and intraoperative hypotension were also significant, independent predictors of increased mortality. These associations suggest that intraoperative anesthetic management may affect outcomes over longer time periods than previously appreciated.

Detection, evaluation, and management of preoperative anaemia in the elective orthopaedic surgical patient: NATA guidelines

Previously undiagnosed anaemia is common in elective orthopaedic surgical patients and is associated with increased likelihood of blood transfusion and increased perioperative morbidity and mortality. A standardized approach for the detection, evaluation, and management of anaemia in this setting has been identified as an unmet medical need. A multidisciplinary panel of physicians was convened by the Network for Advancement of Transfusion Alternatives (NATA) with the aim of developing practice guidelines for the detection, evaluation, and management of preoperative anaemia in elective orthopaedic surgery. A systematic literature review and critical evaluation of the evidence was performed, and recommendations were formulated according to the method proposed by the Grades of Recommendation Assessment, Development and Evaluation (GRADE) Working Group. We recommend that elective orthopaedic surgical patients have a haemoglobin (Hb) level determination 28 days before the scheduled surgical procedure if possible (Grade 1C). We suggest that the patients target Hb before elective surgery be within the normal range, according to the World Health Organization criteria (Grade 2C). We recommend further laboratory testing to evaluate anaemia for nutritional deficiencies, chronic renal insufficiency, and/or chronic inflammatory disease (Grade 1C). We recommend that nutritional deficiencies be treated (Grade 1C). We suggest that erythropoiesis-stimulating agents be used for anaemic patients in whom nutritional deficiencies have been ruled out, corrected, or both (Grade 2A). Anaemia should be viewed as a serious and treatable medical condition, rather than simply an abnormal laboratory value. Implementation of anaemia management in the elective orthopaedic surgery setting will improve patient outcomes.

Central nervous system injury associated with cardiac surgery

Millions of individuals with coronary artery or valvular heart disease have been given a new chance at life by heart surgery, but the potential for neurological injury is an Achilles heel. Technological advancements and innovations in surgical and anaesthetic technique have allowed us to offer surgical treatment to patients at the extremes of age and infirmity-the group at greatest risk for neurological injury. Neurocognitive dysfunction is a complication of cardiac surgery that can restrict the improved quality of life that patients usually experience after heart surgery. With a broader understanding of the frequency and effects of neurological injury from cardiac surgery and its implications for patients in both the short term and the long term, we should be able to give personalised treatments and thus preserve both their quantity and quality of life. We describe these issues and the controversies that merit continued investigation.

Perioperative myocardial ischemic episodes are related to hematocrit level in patients undergoing radical prostatectomy

BACKGROUND: The anemia associated with perioperative blood conservation has raised concerns regarding the safety of these strategies in patients with ischemic cardiovascular disease. Therefore the relationship between hematocrit level and myocardial ischemic episodes in a group of elderly patients undergoing elective noncardiac surgery was studied.

A standardized method for calculating blood loss

BACKGROUND: The estimation of blood loss for a surgical procedure is both poorly reproducible and typically underestimated. Therefore, comparison of surgical transfusion outcomes such as blood loss and amount of blood transfused from one institution to another, or from one surgeon to another, is difficult. Recently, mathematical modeling has contributed to our understanding of transfusion strategies. STUDY DESIGN AND METHODS: A mathematical model of blood loss for a surgical hospitalization was developed on the basis of recently described mathematical principles for blood loss and hemodilution. The model was designed so that the calculation of blood loss would be based on easily measured factors such as the patients blood volume, the number and type of red cell units transfused, the initial hematocrit, the discharge hematocrit, the transfusion trigger, the volume of intraoperatively salvaged blood transfused, and the amount of hemodilution performed. The calculated blood loss was then compared with the intraoperative blood loss actually estimated by the anesthesiologist in 250 consecutive patients who underwent radical retropubic prostatectomy. RESULTS: The mathematical equations were placed in a computer model to allow rapid calculation of a particular patients blood loss. Figures were derived from the computer modelling to facilitate rapid manual calculation of the blood loss. There was a significant relation (p < 0.001) between the calculated blood loss for the hospitalization and the estimated intraoperative blood loss. However, the calculated blood loss was on average 2.1 times the intraoperative blood loss estimated by the anesthesiologist. CONCLUSION: The use of such mathematical modeling to rapidly estimate a patients blood loss has the potential to allow ready, objective comparisons between sites and even surgeons. It also allows for a more judicial and informed decision as to what (if any) blood should be available or what blood‐conservation techniques should be employed for a specific patient.

Type and Severity of Cognitive Decline in Older Adults after Noncardiac Surgery

Background:The authors investigated type and severity of cognitive decline in older adults immediately and 3 months after noncardiac surgery. Changes in instrumental activities of daily living were examined relative to type of cognitive decline. Methods:Of the initial 417 older adults enrolled in the study, 337 surgery patients and 60 controls completed baseline, discharge, and/or 3-month postoperative cognitive and instrumental activities of daily living measures. Reliable change methods were used to examine three types of cognitive decline: memory, executive function, and combined executive function/memory. SD cutoffs were used to grade severity of change as mild, moderate or severe. Results:At discharge, 186 (56%) patients experienced cognitive decline, with an equal distribution in type and severity. At 3 months after surgery, 231 patients (75.1%) experienced no cognitive decline, 42 (13.6%) showed only memory decline, 26 (8.4%) showed only executive function decline, and 9 (2.9%) showed decline in both executive and memory domains. Of those with cognitive decline, 36 (46.8%) had mild, 25 (32.5%) had moderate, and 16 (20.8%) had severe decline. The combined group had more severe impairment. Executive function or combined (memory and executive) deficits involved greater levels of functional (i.e., instrumental activities of daily living) impairment. The combined group was less educated than the unimpaired and memory groups. Conclusion:Postsurgical cognitive presentation varies with time of testing. At 3 months after surgery, more older adults experienced memory decline, but only those with executive or combined cognitive decline had functional limitations. The findings have relevance for patients and caregivers. Future research should examine how perioperative factors influence neuronal systems.

Propofol infusion during regional anesthesia: sedative, amnestic, and anxiolytic properties.

We examined the plasma concentrations and resultant clinical effects produced by four different propofol bolus infusion regimens in 98 healthy males undergoing elective urologic procedures under regional anesthesia. Patients were randomly assigned to one of four propofol dosage groups. In Groups 1-4, loading doses of propofol equal to 0.2, 0.4, 0.5, or 0.7 mg/kg intravenously, respectively, were followed by fixed-rate propofol infusions of 0.5, 1, 2, or 4 mg.kg-1.h-1, respectively, during the regional block procedure. Sedation (sleepiness) was assessed independently by the patient and a blinded observer using 100-mm visual analog scales. Intraoperative amnesia was assessed using picture recall. Sedation scores increased in a dose-dependent fashion (13 +/- 19, 21 +/- 19, 45 +/- 28, and 73 +/- 26 mm at 30 min in Groups 1-4, respectively). Within a given dosage group, sedation scores were stable during the maintenance infusion period. Mean plasma propofol concentrations increased with higher propofol infusion rates (0.16 +/- 0.3, 0.18 +/- 0.1, 0.47 +/- 0.2, and 1.1 +/- 0.8 microgram/mL at 30 min in Groups 1-4, respectively). However, significant variability was observed among individual patient sedation scores and plasma propofol concentrations. Anxiety scores decreased in all four propofol infusion groups during the maintenance period. Hemodynamic variables and hemoglobin oxygen saturation values were similar in all four treatment groups. Recovery from propofols central effects was rapid after discontinuation of the propofol infusion, and the incidence of side effects was low. Recall of intraoperative events was more commonly observed in the lower-dosage groups (86%, 96%, 58%, and 13% of patients in Groups 1-4, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

a Prospective Randomized Comparison of Three Blood Conservation Strategies for Radical Prostatectomy

BACKGROUND Preoperative autologous blood donation is a standard of care for elective surgical procedures requiring transfusion. The authors evaluated the efficacy of alternative blood-conservation strategies including preoperative recombinant human erythropoietin (rHuEPO) therapy and acute normovolemic hemodilution (ANH) in radical retropubic prostatectomy patients. METHODS Seventy-nine patients were prospectively randomized to preoperative autologous donation (3 U autologous blood); rHuEPO plus ANH (preoperative subcutaneous administration of 600 U/kg rHuEPO at 21 and 14 days before surgery and 300 U/kg on day of surgery followed by ANH in the operating room); or ANH (blinded, placebo injections per the rHuEPO regimen listed previously). Transfusion outcomes, perioperative hematocrit levels, postoperative outcomes, and blood-conservation costs were compared among the three groups. RESULTS Baseline hematocrit levels were similar in all groups (43%+/-2%). On the day of surgery hematocrit decreased to 34% +/-4% in the preoperative autologous donation group (P < 0.001), increased to 47%+/-2% in the rHuEPO plus ANH group (P < 0.001), and remained unchanged at 43%+/-2% in the ANH group. Allogeneic blood exposure was similar in all groups. The rHuEPO plus ANH group had significantly higher hematocrit levels compared with the other groups throughout the hospitalization (P < 0.001). Average transfusion costs were significantly lower for ANH (

The Extraperitoneal Approach and Subcutaneous Emphysema are Associated with Greater Absorption of Carbon Dioxide During Laparoscopic Renal Surgery

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