Eliane de Araújo Cintra

Vasopressin serum levels in patients with severe brain lesions and in brain-dead patients

INTRODUCTION Patients with severe brain lesions (SBL) and brain-dead patients (BD) frequently present with vasopressin (AVP) secretion disorders. OBJECTIVE To evaluate AVP serum levels in SBL and BD patients. DESIGN Prospective, open label, observational trial. SETTING A general teaching hospital. METHOD Three groups of adult subjects (age> 18y) of both sexes were included in this study: control group: 29 healthy volunteers; SBL group: 17 patients with Glasgow Coma Scale (GCS)< 8; and BD group: 11 brain-dead patients. Samples of venous blood were collected in the morning at rest from healthy volunteers and at 8 hourly intervals over a period of 24h from SBL and BD patients for AVP determinations. Concomitantly, some clinical and laboratorial variables were also recorded. RESULTS AVP serum levels (pg/ml) were [mean (SD); median]: control [2.2(1.1); 2.0]; SBL [5.7(6.3); 2.9]; and BD [2.6(1.0); 2.8]. AVP serum levels varied greatly in SBL patients, but without statistically significant difference in relation to the other groups (p=0.06). Hypotension (p=0.02), hypernatremia (p=0.0001), serum hyperosmolarity (p=0.0001) and urinary hypoosmolarity (p=0.003) were outstanding in BD patients when compared with SBL. CONCLUSIONS The AVP serum levels did not demonstrate significant statistical difference between the groups, only showing a greater variability in SBL patients (manifested as serum spike levels). Hypernatremia and hyperosmolarity were present in BD patients, indicating a failure of the hypothalamic-pituitary system in AVP production and release.

Hemometabolismo cerebral : variações na fase aguda do coma traumatico

OBJECTIVE: to evaluate the interrelationships between cerebral and systemic hemometabolic alterations in patients with severe traumatic brain injury managed according to a standardized therapeutic protocol. DESIGN: prospective, interventional study in patients with traumatic coma. SETTING: a general Intensive Care Unit in a teaching hospital. PATIENTS AND METHODS: twenty-seven patients (21M e 6F), aging 14¾58 years, with severe acute brain trauma, presenting with three to eight points on the Glasgow Coma Scale, were prospectively evaluated according to a cumulative protocol for the management of acute intracranial hypertension, where intracranial pressure (ICP) and cerebral extraction of oxygen (CEO2) were routinely measured. Hemometabolic interrelationships involving mean arterial pressure (MAP), ICP, arterial carbon dioxide tension (PaCO2), CEO2, cerebral perfusion pressure (CPP) and systemic extraction of oxygen (SEO2) were analyzed. INTERVENTIONS: routine therapeutic procedures. RESULTS: no correlation was found between CEO2 and CPP (r = -0.07; p = 0.41). There was a significant negative correlation between PaCO2 and CEO2 (r = -0.24; p = 0.005) and a positive correlation between SEO2 and CEO2 (r = 0.24; p = 0.01). The mortality rate in this group of patients was 25.9% (7/27). Conclusion: 1) CPP and CEO2 are unrelated; 2) CEO2 and PaCO2 are closely related; 3) during optimized hyperventilation, CEO2 and SEO2 are coupled.

Plasmatic vasopressin in patients undergoing conventional infra-renal abdominal aorta aneurysm repair.

OBJECTIVES To evaluate plasmatic arginine vasopressin (AVP) levels in patients undergoing scheduled conventional abdominal aortic aneurysm (AAA) repair. METHODS Plasmatic AVP concentrations were measured by radioimmunoassay in 22 non-consecutive adult patients undergoing infra-renal AAA repair. They were under combined general and epidural anesthesia at the following time frames: 1--pre-operative (T0); 2--2h (T1) and 6h (T2) after the surgical procedure; 3--in the morning at the first (T3), second (T4) and third (T5) post-operative days. Some clinical and laboratory variables were also recorded. RESULTS The mean age of patients was 68 ± 10 years; 17 were males. Plasmatic AVP (mean ± SD; pg/mL) was within the normal range at T0 (1.4 ± 0.7; baseline), increasing significantly at T1 (62.6 ± 62.9; P<0.001) and at T2 (31.5 ± 49.7; P<0.001), with a progressive fall, returning to basal levels at T5 (2.1 ± 3.8; P = NS). Positive and statistically significant correlations were found between AVP and glycemia, serum lactate and white blood cells counts, but not with systemic arterial pressure or plasma osmolarity during the postoperative period. CONCLUSIONS Considering that no correlations were found between AVP levels and hemodynamic or plasmatic osmolarity variations in AAA repair, it seems that stress response is mainly secondary to noxious stimulation mediated by the autonomic nervous system that is not completely blocked by anesthetics.Objectives: To evaluate plasmatic arginine vasopressin (AVP) levels in patients undergoing scheduled conventional abdominal aortic aneurysm (AAA) repair. Methods: Plasmatic AVP concentrations were measured by radioimmunoassay in 22 non-consecutive adult patients undergoing infra-renal AAA repair. They were under combined general and epidural anesthesia at the following time frames: 1 - pre-operative (T0); 2 - 2h (T1) and 6h (T2) after the surgical procedure; 3 - in the morning at the first (T3), second (T4) and third (T5) post-operative days. Some clinical and laboratory variables were also recorded. Results: The mean age of patients was 68±10 years; 17 were males. Plasmatic AVP (mean±SD; pg/mL) was within the normal range at T0 (1.4±0.7; baseline), increasing significantly at T1 (62.6±62.9; P<0.001) and at T2 (31.5±49.7; P<0.001), with a progressive fall, returning to basal levels at T5 (2.1±3.8; P=NS). Positive and statistically significant correlations were found between AVP and glycemia, serum lactate and white blood cells counts, but not with systemic arterial pressure or plasma osmolarity during the postoperative period. Conclusions: Considering that no correlations were found between AVP levels and hemodynamic or plasmatic osmolarity variations in AAA repair, it seems that stress

Vasopressin serum levels and disorders of sodium and water balance in patients with severe brain injury

BACKGROUND Disorders of water and sodium balance are frequently seen in patients with severe brain injury (SBI), and may worsen their prognosis. PURPOSE To evaluate vasopressin (AVP) serum levels and sodium and water balance disorders during the first week post-injury in patients with SBI. METHOD Thirty-six adult patients with SBI (admission Glasgow Coma Scale score < or= 8) and an estimated time of injury <or= 72 hours were prospectively studied. Clinical and laboratory data were recorded and AVP was measured in venous blood samples collected on the 1st, 2nd, 3rd and 5th days following inclusion. RESULTS AVP serum levels remained within the normal range in SBI patients (either traumatic or non-traumatic), although tended to be greater in non-survivor than in survivor patients (p=0.025 at 3rd day). In-hospital mortality was 43% (15/36), and serum sodium and plasma osmolality variabilities were greater in non-survivor than in survivor patients during the observation period (p<0.001). CONCLUSION AVP serum levels remained within the normal range values in these SBI patients, but those who died have shown higher incidence of abnormal sodium and water balance during the first week post-injury.

Glasgow outcome scale at hospital discharge as a prognostic index in patients with severe traumatic brain injury

OBJECTIVE Evaluate the Glasgow outcome scale (GOS) at discharge (GOS-HD) as a prognostic indicator in patients with traumatic brain injury (TBI). METHOD Retrospective data were collected of 45 patients, with Glasgow coma scale <8, age 25±10 years, 36 men, from medical records. Later, at home visit, two measures were scored: GOS-HD (according to information from family members) and GOS LATE (12 months after TBI). RESULTS At discharge, the ERG showed: vegetative state (VS) in 2 (4%), severe disability (SD) in 27 (60%), moderate disability (MD) in 15 (33%) and good recovery (GR) in 1 (2%). After 12 months: death in 5 (11%), VS in 1 (2%), SD in 7 (16%), MD in 9 (20%) and GR in 23 (51%). Variables associated with poor outcome were: worse GOS-HD (p=0.03), neurosurgical procedures (p=0.008) and the kind of brain injury (p=0.009). CONCLUSION The GOS-HD was indicator of prognosis in patients with severe TBI.

Vasopressina e morte encefálica

Brain death results in the breakdown of effective central regulatory mechanisms of cardiocirculatory stability, even in patients with artificial mechanical ventilation, correction of electrolytic and acid-basic disorders and maximal conventional pharmacological support of the circulation. Recent evidences have shown that the fall of vasopressin levels in the blood circulation significantly influences the cardiocirculatory stability of patients with brain death, and its exogenous administration is defended by many authors for the management of multiorgan donor patients. In this brief review we analyse and discuss some experimental and clinical relevant studies about the role of vasopressin in the control of cardiocirculatory stability in brain death, and its potential usefulness in the management of multiorgan donor. We conclude that the role of vasopressin in the pathophysiology of brain death and its usefulness as a pharmacological agent in the management of multiorgan donor are not well elucidated, deserving further investigations.

Fator natriurético atrial: ele é o responsável pela hiponatremia e natriurese em neurocirurgia?

Objective: To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods: The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results: Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion: Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.Objective To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.