Paolo Zanatta

Preliminary evidence for reduced preoperative cerebral blood flow velocity as a risk factor for cognitive decline three months after cardiac surgery: an extension study

This extension study investigated the association between preoperative cerebral blood flow (CBF) velocity and postoperative cognitive decline (POCD) at a three-month follow-up in patients who underwent cardiac surgery. Continuous transcranial Doppler ultrasound on both middle cerebral arteries (MCAs) was used preoperatively in 31 right-handed cardiac surgery patients at rest. Each patient performed a neuropsychological evaluation to assess cognitive performance before surgery, at discharge and at three-month follow-up. Patients with POCD at the three-month follow-up had a marginally significantly lower preoperative CBF velocity in the left MCA than patients without POCD. Moreover, the group with POCD had a significantly lower CBF velocity in the left than in the right MCA, whereas no difference between the left and right CBF velocity was found in the group without POCD. These preliminary findings suggest that reduced preoperative CBF velocity in the left MCA may represent an independent risk factor for cognitive decline in patients three months after surgery.

Microembolic signals and strategy to prevent gas embolism during extracorporeal membrane oxygenation

BackgroundExtracorporeal membrane oxygenation (ECMO) supplies systemic blood perfusion and gas exchange in patients with cardiopulmonary failure. The current literature lacks of papers reporting the possible risks of microembolism among the complications of this treatment.In this study we present our preliminary experience on brain blood flow velocity and emboli detection through the transcranial Doppler monitoring during ECMO.MethodsSix patients suffering of heart failure, four after cardiac surgery and two after cardiopulmonary resuscitation were treated with ECMO and submitted to transcranial doppler monitoring to accomplish the neurophysiological evaluation for coma.Four patients had a full extracorporeal flow supply while in the remaining two patients the support was maintained 50% in respect to normal demand.All patients had a bilateral transcranial brain blood flow monitoring for 15 minutes during the first clinical evaluation.ResultsMicroembolic signals were detected only in patients with the full extracorporeal blood flow supply due to air embolism.ConclusionsWe established that the microembolic load depends on gas embolism from the central venous lines and on the level of blood flow assistance.The gas microemboli that enter in the blood circulation and in the extracorporeal circuits are not removed by the membrane oxygenator filter.Maximum care is required in drugs and fluid infusion of this kind of patients as a possible source of microemboli. This harmful phenomenon may be overcome adding an air filter device to the intravenous catheters.

Multimodal Brain Monitoring Reduces Major Neurologic Complications in Cardiac Surgery

OBJECTIVE Although adverse neurologic outcomes are common complications of cardiac surgery, intraoperative brain monitoring has not received adequate attention. The aim of the present study was to evaluate the effectiveness of multimodal brain monitoring in the prevention of major brain injury and reducing the duration of mechanical ventilation, intensive care unit, and postoperative hospital stays after cardiac surgery. DESIGN A retrospective, observational, controlled study. SETTING A single-center regional hospital. PARTICIPANTS One thousand seven hundred twenty-one patients who had undergone cardiac surgery with cardiopulmonary bypass from July 2007 to July 2010. One hundred sixty-six patients with multimodal brain monitoring and a control group without brain monitoring (N = 1,555) were compared retrospectively. INTERVENTIONS Multimodal brain monitoring was performed for 166 patients, consisting of intraoperative recordings of somatosensory-evoked potentials, electroencephalography, and transcranial Doppler. MEASUREMENTS AND MAIN RESULTS The incidence of major neurologic complications and the duration of mechanical ventilation, intensive care unit, and postoperative hospital stays were considered. Patients with brain monitoring had a significantly lower incidence of perioperative major neurologic complications (0%) than those without monitoring (4.06%, p = 0.01) and required significantly shorter periods of mechanical ventilation (p = 0.001) and intensive care unit stays (p = 0.01) than controls. The length of postoperative hospital stays did not differ significantly between the 2 groups (p = 0.57). CONCLUSIONS This preliminary study suggests that multimodal brain monitoring can reduce the incidence of neurologic complications as well as hospital costs associated with post-cardiac surgery patient care. Furthermore, intraoperative brain monitoring provides useful information about brain functioning, blood flow velocity, and metabolism, which may guide the anesthesiologist during surgery.

FULL RECOVERY AFTER PROLONGED CARDIAC ARREST AND RESUSCITATION WITH MECHANICAL CHEST COMPRESSION DEVICE DURING HELICOPTER TRANSPORTATION AND PERCUTANEOUS CORONARY INTERVENTION

BACKGROUND Despite early cardiopulmonary resuscitation (CPR) by bystanders and early advanced cardiac life support (ACLS) maneuvers, some patients present to the emergency department with persistent cardiac arrest caused by a coronary artery occlusion. Although emergency percutaneous intervention (PCI) has been shown to be effective in improving survival, transporting patients in cardiac arrest to the hospital is not considered to be effective, due to the poor quality of CPR in the ambulance. In the case reported here, a mechanical chest compression device was used while transporting the patient by helicopter emergency medical services (HEMS). CASE REPORT A mechanical chest compression device was used to deliver chest compressions to a 53-year-old man in cardiac arrest. This device permitted the transfer of the patient by HEMS helicopter to the catheterization laboratory facility for a PCI. Return of spontaneous circulation was achieved 115 min after cardiac arrest and the patient survived without any neurological deficit. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The mechanical chest compression device has permitted safe and effective CPR during helicopter transportation. Although this is only a single case, it may present a new perspective for the treatment of prehospital cardiac arrest that is refractory to ACLS therapies.

Pain-related somatosensory evoked potentials and functional brain magnetic resonance in the evaluation of neurologic recovery after cardiac arrest: a case study of three patients

This case series investigates whether painful electrical stimulation increases the early prognostic value of both somatosensory-evoked potentials and functional magnetic resonance imaging in comatose patients after cardiac arrest. Three single cases with hypoxic-ischemic encephalopathy were considered. A neurophysiological evaluation with an electroencephalogram and somatosensory-evoked potentials during increased electrical stimulation in both median nerves was performed within five days of cardiac arrest. Each patient also underwent a functional magnetic resonance imaging evaluation with the same neurophysiological protocol one month after cardiac arrest. One patient, who completely recovered, showed a middle latency component at a high intensity of stimulation and the activation of all brain areas involved in cerebral pain processing. One patient in a minimally conscious state only showed the cortical somatosensory response and the activation of the primary somatosensory cortex. The last patient, who was in a vegetative state, did not show primary somatosensory evoked potentials; only the activation of subcortical brain areas occurred. These preliminary findings suggest that the pain-related somatosensory evoked potentials performed to increase the prognosis of comatose patients after cardiac arrest are associated with regional brain activity showed by functional magnetic resonance imaging during median nerves electrical stimulation. More importantly, this cases report also suggests that somatosensory evoked potentials and functional magnetic resonance imaging during painful electrical stimulation may be sensitive and complementary methods to predict the neurological outcome in the acute phase of coma. Thus, pain-related somatosensory-evoked potentials may be a reliable and a cost-effective tool for planning the early diagnostic evaluation of comatose patients.

Preexisting depressive symptoms are associated with long-term cognitive decline in patients after cardiac surgery.

OBJECTIVE To examine whether preoperative psychological dysfunctions rather than intraoperative factors may differentially predict short- and long-term postoperative cognitive decline (POCD) in patients after cardiac surgery. METHOD Forty-two patients completed a psychological evaluation, including the Trail Making Test Part A and B (TMT-A/B), the memory with 10/30-s interference, the phonemic verbal fluency and the Center for Epidemiological Studies of Depression (CES-D) scale for cognitive functions and depressive symptoms, respectively, before surgery, at discharge and at 18-month follow-up. RESULTS Ten (24%) and 11 (26%) patients showed POCD at discharge and at 18-month follow-up, respectively. The duration of cardiopulmonary bypass significantly predicted short-term POCD [odds ratio (OR)=1.04, P<.05], whereas preoperative psychological factors were unrelated to cognitive decline at discharge. Conversely, long-term cognitive decline after cardiac surgery was significantly predicted by preoperative scores in the CES-D (OR=1.26, P<.03) but not by intraoperative variables (all Ps >.23). CONCLUSIONS Our findings showed that preexisting depressive symptoms rather than perioperative risk factors are associated with cognitive decline 18 months after cardiac surgery. This study suggests that a preoperative psychological evaluation of depressive symptoms is essential to anticipate which patients are likely to show long-term cognitive decline after cardiac surgery.

Dynamic monitors of brain function: a new target in neurointensive care unit.

IntroductionSomatosensory evoked potential (SEP) recordings and continuous electroencephalography (EEG) are important tools with which to predict Glasgow Outcome Scale (GOS) scores. Their combined use may potentially allow for early detection of neurological impairment and more effective treatment of clinical deterioration.MethodsWe followed up 68 selected comatose patients between 2007 and 2009 who had been admitted to the Neurosurgical Intensive Care Unit of Treviso Hospital after being diagnosed with subarachnoid haemorrhage (51 cases) or intracerebral haemorrhage (17 cases). Quantitative brain function monitoring was carried out using a remote EEG-SEP recording system connected to a small amplification head box with 28 channels and a multimodal stimulator (NEMO; EBNeuro, Italy NeMus 2; EBNeuro S.p.A., Via P. Fanfani 97/A - 50127 Firenze, Italy). For statistical analysis, we fit a binary logistic regression model to estimate the effect of brain function monitoring on the probability of GOS scores equal to 1. We also designed a proportional odds model for GOS scores, depending on amplitude and changes in both SEPs and EEG as well as on the joint effect of other related variables. Both families of models, logistic regression analysis and proportional odds ratios, were fit by using a maximum likelihood test and the partial effect of each variable was assessed by using a likelihood ratio test.ResultsUsing the logistic regression model, we observed that progressive deterioration on the basis of EEG was associated with an increased risk of dying by almost 24% compared to patients whose condition did not worsen according to EEG. SEP decreases were also significant; for patients with worsening SEPs, the odds of dying increased to approximately 32%. In the proportional odds model, only modifications of Modified Glasgow Coma Scale scores and SEPs during hospitalisation statistically significantly predicted GOS scores. Patients whose SEPs worsened during the last time interval had an approximately 17 times greater probability of a poor GOS score compared to the other patients.ConclusionsThe combined use of SEPs and continuous EEG monitoring is a unique example of dynamic brain monitoring. The temporal variation of these two parameters evaluated by continuous monitoring can establish whether the treatments used for patients receiving neurocritical care are properly tailored to the neurological changes induced by the lesions responsible for secondary damage.

The role of asymmetry and the nature of microembolization in cognitive decline after heart valve surgery: a pilot study

Our objective was to determine the role of asymmetry and the nature of microembolization on postoperative cognitive decline in patients who had undergone heart valve surgery. Continuous transcranial Doppler ultrasound was intraoperatively used for both middle cerebral arteries in 13 right-handed heart valve surgery patients to detect microembolization. The Trail Making Test A and B, Memory with 10/30 s interference, the Digit Span Test and Phonemic Fluency were performed preoperatively, at discharge and three months after surgery. Our data suggest that early and late postoperative psychomotor and executive functions may be sensitive to microemboli in the left, but not in the right middle cerebral artery. Moreover, solid and gaseous microemboli are both similarly associated with early postoperative cognitive decline while, surprisingly, late postoperative cognitive decline is more likely to be associated with gaseous than solid microemboli.

Change in behavioral functional capacity is associated with preexisting cognitive function rather than with cognitive decline in patients 1 year after cardiac surgery

OBJECTIVE The objective was to examine whether preexisting cognitive function rather than cognitive decline associated with intraoperative procedures may predict change in behavioral functional capacity in patients 1 year after cardiac surgery. METHOD Forty-five patients completed a cognitive evaluation, including the Trail Making Test part B (TMT-B) for attention and psychomotor speed, the Memory with 10-s interference for working memory, the Digit Span test for short-term memory and the Instrumental Activities of Daily Living (IADLs) questionnaire for behavioral functional capacity, before surgery and 1 year after cardiac surgery. RESULTS Sixteen patients (36%) exhibited cognitive decline after cardiac surgery. Preoperative scores on TMT-B significantly predicted change in behavioral functional capacity as measured by IADLs (beta = 0.371, P < .05), whereas the postoperative cognitive decline and intraoperative variables were unrelated to residualized change scores in IADLs (all Ps > .08). CONCLUSIONS Preexisting cognitive dysfunctions as assessed by TMT-B can be a marker of preoperative brain dysfunction, which, in turn, in addition to brain damage caused by cardiac surgery procedures, may further predispose patients to poor behavioral functional capacity and outcome 1 year after surgery. Impaired cognitive functions before surgery should be considered when evaluating the effects of cardiac surgery procedures on long-term behavioral functional status of patients.

Biomedical and psychological risk in cardiac surgery: is EuroSCORE a more comprehensive risk measure than Stroke Index?

OBJECTIVE Several composite risk score indices, the most common being the Stroke Index and the European System for Cardiac Operative Risk Evaluation (EuroSCORE), have been developed to predict perioperative events such as cerebrovascular accidents or death. The main aim of the present study was to compare the preoperative associations between the Stroke Index or the EuroSCORE with anxiety, depression, memory, attention, and executive functions scores in patients undergoing cardiac surgery. METHODS Ninety-one patients were required to perform a preoperative psychological evaluation. Trail Making Test A and B (TMT A/B), Memory with 10 and 30s interference, Digit Span Test, Phonemic Fluency, State and Trait Anxiety Inventory (STAI Y1/Y2), and Center for Epidemiological Study of Depression Scale (CES-D) were administered. The Stroke Index and the EuroSCORE were also considered for each patient. Correlations between the Stroke Index or the EuroSCORE, mood, and neuropsychological scores were performed. RESULTS Seventy-seven patients completed the psychological evaluation. The Stroke Index was significantly correlated with TMT A (ρ=0.40, p=0.001), TMT B (ρ=0.38, p=0.001), Memory with 10s (ρ=-0.34, p=0.003) and 30s (ρ=-0.40, p=0.001) interference, and Phonemic Fluency (ρ=-0.29, p=0.01), but not with Digit Span Test (ρ=-0.18, p=0.13), STAI Y1 (ρ=0.08, p=0.44), STAI Y2 (ρ=0.06, p=0.56), and CES-D (ρ=0.11, p=0.31) scores. The EuroSCORE was significantly correlated not only with TMT A (ρ=0.49, p=0.001), TMT B (ρ=0.42, p=0.001), Memory with 10s (ρ=-0.23, p=0.04) and 30s (ρ=-0.35, p=0.002) interference, Phonemic Fluency (ρ=-0.28, p=0.01), and Digit Span Test (ρ=-0.28, p=0.01) but also with STAI Y1 (ρ=0.27, p=0.02), STAI Y2 (ρ=0.23, p=0.04), and CES-D (ρ=0.26, p=0.02). CONCLUSIONS While both the Stroke Index and the EuroSCORE account for the relationship between biomedical and cognitive risk factors in predicting perioperative risk, only the EuroSCORE also accounts for affective dysfunctions, which, in turn, have been proved to represent risk factors for perioperative adverse events. Therefore, compared with the Stroke Index, the EuroSCORE can be considered a more complete risk index in predicting perioperative risk. Data also suggest that a comprehensive preoperative evaluation of biomedical, mood, and cognitive performances might provide a more accurate mirror of the actual risk in patients undergoing cardiac surgery.