Atypical Pupil Reactions in Brain Dead Patients.

BACKGROUND: During routine diagnosis of brain death, changes in pupil diameter in response to the stimulation of peripheral nerves are sometimes observed. For example, pupillary dilation after diagnosed brain death is described in the literature as the ciliospinal reflex. However, pupil constriction creates diagnostic doubts. OBJECTIVE: The pupillometric analysis of pupil response to stimulation of the cervicothoracic spinal cord in patients with diagnosed brain death. METHODS: Instrumental tests to confirm the arrest of cerebral circulation were performed in 30 adult subjects (mean age 53.5 years, range 26-75 years) with diagnosed brain death. In addition, a pupillometer was used to measure the change in pupil diameter in response to neck flexion. INTERVENTION: Flexion of the neck and measuring the response in change of the pupil with the use of the pupillometer. RESULTS: The change in the pupil was observed in the examined group of patients. Difference in pupil size ≥ 0.2 mm was observed in 14 cases (46%). In five cases (17%), pupil constriction was found (from 0.2 to 0.7 mm). Measurement error was +/- 0.1 mm. CONCLUSIONS: Both pupillary constriction and dilatation may occur due to a ciliospinal reflex in patients with brain death. This phenomenon needs further research in order to establish its pathophysiology.

Comparison of Two Apnea Test Methods, Oxygen Insufflation and Continuous Positive Airway Pressure During Diagnosis of Brain Death: Final Report.

INTRODUCTION: Deterioration of the pulmonary function after the apnea test (AT) conducted with the classic oxygen insufflation AT (I-AT) is often observed during the brain death (BD) diagnosis procedure. In the present study, two AT methods were compared before a method is recommended for the currently revised Polish BD criteria. METHODS: Classic I-AT and continuous positive airway pressure AT (CPAP-AT) were performed in 60 intensive care unit patients. I-AT was performed at the end of two series of clinical tests, and approximately 1-1.5 h later, after BD was confirmed, a different method, CPAP-AT with 100% FiO2 and CPAP value of 10 cm H2O provided by a ventilator in CPAP mode was performed. The patients in I-AT and CPAP-AT groups were further divided into two subgroups: non-hypoxemic (NH) with good lung function before AT (PaO2/FiO2 index ≥ 200 mmHg) and hypoxemic (H) with poor lung function (PaO2/FiO2 index < 200 mmHg). PaO2 and PaCO2 were recorded prior to I-AT and CPAP-AT at time-point one (T1), 5 min after each test at time-point two (T2), and after 10 min prior to the end of tests at time-point three (T3). The I-AT NH subgroup consisted of 50 patients, and CPAP-AT NH subgroup 43 patients. The I-AT H subgroup consisted of 10 patients, and the CPAP-AT H subgroup 17 patients. RESULTS: In the I-AT NH subgroup, a gradual decrease in PaO2/FiO2 was observed throughout the AT but not in the CPAP-AT NH subgroup. The PaO2/FiO2 ratio during the AT in the CPAP-AT H group was stable with a slight tendency to increase but not in the I-AT H group. During the first 5 min of the AT, the mean increase in CO2 was approximately 5 mmHg/min. Most patients in all groups met the AT criteria after 5 min of the test. CONCLUSIONS: The results from the study show that I-AT may compromise pulmonary function in some cases and is one of the reasons for the recommendation of a safer option, CPAP-AT, in the currently revised Polish BD criteria. During AT, the mean CO2 increase rate was 5 mmHg/min, which, in most patients, would allow the test to be completed after just 5 min.

Apnea testing using the oxygen insufflation method for diagnosis of brain death may compromise pulmonary function.

INTRODUCTION: The aim of our study was to compare the reliability and safety of the classical I-AT with the continuous positive airway pressure apnea test (CPAP-AT). MATERIAL AND METHODS: In the group of 48 patients (group O), an I-AT was performed at the end of BD diagnostic procedures, and approximately 1-1.5h later CPAP-AT with 100% FiO2 and CPAP of 10cm H2O, provided by ventilator in CPAP mode. After pre­oxygenation with 100% FiO2 for 10min, the PaO2/FiO2 ratio was recorded prior to I-AT at time-point one (T1) and prior to CPAP-AT at time-point two (T2). Group O was categorized into subgroup N-H (non-hypoxemic), consisting of 41 patients with good lung function, and subgroup H (hypoxemic) consisting of 7 patients with poor lung function. Within each subgroup PaO2/FiO2 at T1 and T2 were compared. RESULTS: In Group O, PaO2/FiO2 decreased from 321±128mmHg at T1 to 291±119mmHg at T2 (p=0.004). In subgroup N-H, PaO2/FiO2 declined from 355±103 to 321±100mmHg (p=0.008), and in subgroup H, PaO2/FiO2 remained almost unchanged. Additionally, in 4 patients from subgroup N-H, PaO2/FiO2 decreased below 200mmHg at T2. CONCLUSIONS: Our study indicates that I-AT may compromise pulmonary function and this may support the recommendation of safer CPAP-AT alternative.

Evolution of apnoea test in brain death diagnostics.

The concept of brain death (BD) was initially described in 1959 and subsequently became widely accepted in the majority of countries. Nevertheless, the diagnostic guidelines for BD markedly differ, especially regarding the apnoea test (AT), a crucial element of clinical BD confirmation. The current basic guidelines recommend preoxygenation rather than disconnection from the ventilator and insertion of an oxygen insufflation catheter into the endotracheal tube. Although a properly prepared and conducted AT is relatively safe, it has to be aborted in cases of serious disturbances, such as severe cardiac arrhythmia, cardiac arrest, hypotension, hypercarbia, desaturation and tension pneumothorax. These complications may be more frequent in patients with previously existing risk factors, such as poor oxygenation, severe acidosis, hypotension and cardiac rhythm disturbances. Airway injuries can occur if the insufflation catheter is placed too deep or catheter-related obstruction of the intubation tube occurs. It is widely accepted that AT should be performed as the very last BD diagnostic procedure due to its possible lethal consequences. Reports concerning the possible pitfalls of AT and confounding situations have inspired attempts to determine the most effective and safe method of AT. The use of CPAP with oxygen supplementation is becoming highly popular. CPAP can be generated in three manners: directly by the ventilator; through the use of a CPAP valve with a reservoir; and through the use of a highly traditional T-piece system with a reservoir bag connected to distal tubing immersed in water.

Neurophysiological foundations of sleep, arousal, awareness and consciousness phenomena. Part 1.

The paper presents a state of the art review of the anatomical and physiological foundations of awareness, consciousness, arousal and sleep phenomena and provides current definitions. We describe 20(th) century discoveries that were milestones in the understanding of central nervous system function. Structures that are specifically involved in the quantitative and qualitative aspects of awareness are characterised here. We also describe the relationships between particular groups of neurons, their positive and negative feedback loops, and the neurotransmitters engaged in states of arousal and sleep.

Neurophysiological foundations of sleep, arousal, awareness and consciousness phenomena. Part 2.

Second section of the paper contains description of hypothalamic centres involved in regulation of circadian rhythms. Connections between these neurons and activating reticular system are described. Transition from arousal to sleep, promoted by substances called somnogens, is discussed. Lastly, function of suprachiasmatic nucleus as circadian oscillator is presented.

Hemothorax as a complication of subclavian vein cannulation with haemodialysis catheter - case report.

We present the case of a 39 year-old male patient admitted to ICU with symptoms of acute metabolic acidosis. He was investigated for the presence of methanol and glycol. Conservative treatment was initially started, followed by haemodialysis. During insertion of a temporary haemodialysis catheter in a location of Haapaniemi and Slatis, the patient was conscious but restless; therefore sedation was required to continue the procedure. After three hours of haemodialysis, the patient's general condition suddenly deteriorated. Hypovolemic shock and acute respiratory distress led to hypothesis of right haemothorax, which was rapidly confirmed by angio-CT examination. Trachea was intubated, drainage of right pleura was performed and aggressive fluid treatment begun. The patient was admitted to the operating theatre, and thoracotomy with reconstruction of damaged right venous angle was carried out. After the operation, the patient was transferred to ICU. He was mechanically ventilated and remained haemodynamically unstable. Although fluids and blood-made concentrates were transfused and catecholamines continuously administered, his clinical condition deteriorated and finally the patient died. We found two independent causes of this fatality: hypovolemic shock and acute extrinsic metabolic acidosis. However, this paper focuses on the problem of the iatrogenic complication, which was haemothorax. In the literature there are described examples of such cases. Authors emphasise the most traumatic moment of cannulation as being insertion of the guidewire and dilator to perform a tunnel for the catheter. Puncture by needle and localisation of the central vein results in fewer complications. Furthermore, we strongly recommend monitoring patients after central veins cannulation. All sudden deteriorations in clinical condition should be followed by meticulous diagnosis for the presence of this life-threatening complication.

[Myocardial infarction and shock associated with thyrotoxicosis]. / Przelom tyreotoksyczny powiklany zawalem miesnia sercowego i wstrzasem.

BACKGROUND: A thyroid storm--a sudden, life-threatening exacerbation of thyrotoxicosis--can lead to multiple organ failure due to hyperactivity of the sympathetic nervous system. Symptoms may include fever, tachycardia, cardiovascular collapse, myocardial infarction, hepatic failure, cerebral infarction, delirium, coma, and rhabdomyolysis. Various therapies have been proposed for the management of thyrotoxicosis. They include: reduction of sympathetic outflow (beta-blockers); decreased production and release of thyroid hormone (thiamazole, propylthiouracyl, or iodine solution); and peripheral conversion of T4 to T3 (beta-blockers and steroids). CASE REPORT: We present a case report of an atypical thyroid storm accompanied by multiple organ failure including coma, myocardial infarction, shock, respiratory failure and liver dysfunction. A 51-year-old female was admitted to the emergency department because of multiple organ failure. On admission the patient was unconscious, hypotensive, acidotic and hyperkalemic. Her core temperature was 37.6 degrees C, and she had an LVEF of 30%. Thyroid function tests showed thyrotoxicosis: the fT3 concentration was 17.3 pmol L(-1) (ref. range 2.3-6.3), fT4 50.4 pmol L(-1) (ref. range 10.3-24.4), and TSH 0.009 microU mL(-1) (ref. range 0.4-4.0). SGOT and SGPT concentrations were also increased. The electrocardiogram showed an elevated ST in leads II, III, aVF, and V2 to V5. Troponin I concentration was 5.1 ng mL(-1) (ref. range < 0.05). An emergency coronary angiogram revealed normal perfusion. Treatment was started with vigorous inotropic support(dopamine, dobutamine and norepinephrine, followed by intraaortic balloon counterpulsation. She also received thiamazole, beta-blockers, iodine solution, glucocorticoids and diuretics. On the 8th day, a subtotal thyroidectomy was performed. The patient was weaned from mechanical ventilation after 14 days and recovered without any neurological deficit. CONCLUSION: The described case showed that a thyroid storm can present as multiple organ failure, requiring intraaortic balloon counterpulsation for the management of catecholamine-resistant shock.

[Haemodialysis during resuscitation from hyperkalemic cardiac arrest]. / Skuteczne zastosowanie hemodializy podczas zatrzymania krazenia wywolanego hiperpotasemia.

BACKGROUND: Severe hyperkalaemia may be life-threatening, especially in patients with renal failure who are unable to excrete potassium. Various therapies including intravenous sodium bicarbonate, insulin/glucose infusion as well as several beta-2 agonists have been proposed for management of hyperkalaemia. However, if the potassium concentration increases rapidly and the situation becomes critical, haemodialysis may be used. External cardiac compressions can provide adequate blood flow. CASE REPORT: We report a case of a 53-year-old male drunk, multiple trauma patient who was admitted after falling from the tree 40 h earlier. Patients was tetraplegic and anuric. His serum potassium concentration was 8.5 mmol L(-1). Shortly after admittance he arrested and standard CPR was commenced. Because of hyperkalaemia veno-venous haemodialysis was initiated via the internal jugular vein. Blood flow was adequate. After 40 min of resuscitation serum potassium decreased to 5.44 mmol L(-1) and spontaneous sinus rhythm returned. Patient regained consciousness and could move his limbs. After another four dialysis he recovered completely. CONCLUSION: Haemodialysis should be considered as a rescue method during hyperkalaemic cardiac arrest if standard CPR and treatment of hyperkalaemia is not effective, even if there is no spontaneous circulation present.

[Iatrogenic tracheal rupture, tension pneumotorax and cardiac arrest]. / Jatrogenny uraz tchawicy powiklany obustronna odma prezna i zatrzymaniem krazenia.

BACKGROUND: Tracheobronchial rupture is a life-threatening complication that may occur during and/or after intubation and tracheostomy. In the majority of described cases, the posterior membranous part of the trachea was affected. CASE REPORT: A 35-year-old woman was admitted to the ICU because of viral meningo-encephalitis with subsequenttetraplegia and respiratory failure. Five days after admission she underwent surgical tracheotomy.The immediate postoperative period was complicated by accidental misplacement of the tracheal tube with hypoxia and bradycardia. The patient was intubated with difficulty and an endotracheal tube was inserted over a bougie guidewire. An ENT surgeon re-inserted the tracheal tube, but two hours later bilateral pneumothorax with subcutaneous emphysema occurred, and the patient was re-intubated. This was followed by a cardiac arrest. CPR was commenced and thoracic drains were inserted, resulting in a return of spontaneous circulation. Bronchoscopy revealed a 1 cm laceration of the anterior tracheal wall. The patient was ventilated for another 50 days and eventually recovered without neurologic deficit. CONCLUSIONS: Tracheal rupture is a rare complication of tracheostomy, and it is difficult to determine the exact mechanism of injury in the case described. In any case of sudden deterioration of a newly tracheotomized patient, pneumothorax should be suspected. Immediate intubation and bronchoscopy are recommended.