Efficacy and Safety of a Nasopharyngeal Catheter for Selective Brain Cooling in Patients with Traumatic Brain Injury: A Prospective, Non-randomized Pilot Study.

BACKGROUND: The efficacy objective was to determine whether a novel nasopharyngeal catheter could be used to cool the human brain after traumatic brain injury, and the safety objective was to assess the local and systemic effects of this therapeutic strategy. METHODS: This was a prospective, non-randomized, interventional clinical trial that involved five patients with severe traumatic brain injury. The intervention consisted of inducing and maintaining selective brain cooling for 24 h by positioning a catheter in the nasopharynx and circulating cold water inside the catheter in a closed-loop arrangement. Core temperature was maintained at ≥ 35 °C using counter-warming. RESULTS: In all study participants, a brain temperature reduction of ≥ 2 °C was achieved. The mean brain temperature reduction from baseline was 2.5 ± 0.9 °C (P = .04, 95% confidence interval). The mean systemic temperature was 37.3 ± 1.1 °C at baseline and 36.0 ± 0.8 °C during the intervention. The mean difference between the brain temperature and the systemic temperature during intervention was - 1.2 ± 0.8 °C (P = .04). The intervention was well tolerated with no significant changes observed in the hemodynamic parameters. No relevant variations in intracranial pressure and transcranial Doppler were observed. The laboratory results underwent no major changes, aside from the K+ levels and blood counts. The K+ levels significantly varied (P = .04); however, the variation was within the normal range. Only one patient experienced an event of mild localized and superficial nasal discoloration, which was re-evaluated on the seventh day and indicated complete recovery. CONCLUSION: The results suggest that our noninvasive method for selective brain cooling, using a novel nasopharyngeal catheter, was effective and safe for use in humans.

Inducing Brain Cooling Without Core Temperature Reduction in Pigs Using a Novel Nasopharyngeal Method: An Effectiveness and Safety Study.

BACKGROUND: Acute brain lesions constitute an alarming public health concern. Neuroprotective therapies have been implemented to stabilize, prevent, or reduce brain lesions, thus improving neurological outcomes and survival rates. Hypothermia is the most effective approach, mainly attributed to the reduction in cellular metabolic activity. Whole-body cooling is currently implemented by healthcare professionals; however, adverse events are frequent, limiting the potential benefits of therapeutic hypothermia. Therefore, selective methods have been developed to reduce adverse events while delivering neuroprotection. Nasopharyngeal approaches are the safest and most effective methods currently considered. Our primary objective was to determine the effects of a novel nasopharyngeal catheter on the brain temperature of pigs. METHODS: In this prospective, non-randomized, interventional experimental trial, 10 crossbred pigs underwent nasopharyngeal cooling for 60 min followed by 15 min of rewarming. Nasopharyngeal catheters were inserted into the left nostril and properly positioned at the nasopharyngeal cavity. RESULTS: Nasopharyngeal cooling was associated with a decrease in brain temperature, which was more significant in the left cerebral hemisphere (p = 0.01). There was a reduction of 1.47 ± 0.86 °C in the first 5 min (p < 0.001), 2.45 ± 1.03 °C within 10 min (p < 0.001), and 4.45 ± 1.36 °C after 1 h (p < 0.001). The brain-core gradient was 4.57 ± 0.87 °C (p < 0.001). Rectal, esophageal, and pulmonary artery temperatures and brain and systemic hemodynamic parameters, remained stable during the procedure. Following brain cooling, values of oxygen partial pressure in brain tissue significantly decreased. No mucosal lesions were detected during nasal, pharyngeal, or oral inspection after nasopharyngeal catheter removal. CONCLUSIONS: In this study, a novel nasopharyngeal cooling catheter effectively induced and maintained exclusive brain cooling when combined with effective counter-warming methods. Exclusive brain cooling was safe with no device-related local or systemic complications and may be desired in selected patient populations.

Novo método de hipotermia encefálica exclusiva através de resfriamento nasofaríngeo: modelo experimental em suínos / New method of exclusive brain hypothermia by means of nasopharyngeal cooling: swine experimental study

INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas...

INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly...

Hipotermia no tratamento de hipertensão intracraniana refratária em pacientes com HSA grave, casos associados a vasoespasmo secundário / Hypothermia in the treatment of refractory intracranial hypertension in patients with severe SAH, cases associated with secondary vasospasms

A hemorragia subaracnóidea (HAS) é uma doença grave na qual 10% dos pacientes podem apresentar morte súbita antes mesmode chegar ao hospital. Os pacientes apresentam um risco elevado de complicações secundárias, incluindo o vasoespasmo . Paravasoespasmo o refratário e, essencialmente, para o controle de PIC, a hipotermia pode ser utilizada de forma terapêutica.Nosso objetivo foi avaliar a influência da hipotermia terapêutica nas taxas de mortalidade de pacientes com HSA grave ecom pressão intracraniana elevada, apesar de melhor tratamento clínico implementado previamente. As temperaturas foramreduzidas utilizando colchão térmico para uma temperatura alvo de 33 -35o C.Cinco pacientes foram incluídos. Dois pacientes foram admitidos com um Hunt- Hess de 2, dois com Hunt Hess de 3 e um comHunt Hess de 4. O tempo médio de hipotermia terapêutica foi de 7,2 dias. Dois pacientes sobreviveram com uma escala de Rankinde 0, e três faleceram.Em nosso estudo observacional foi observada uma taxa de mortalidade de 180 dias de 40% , que aumentou para 60% emanálise de seis meses. Estudos recentes descrevem uma taxa de mortalidade de 90% em pacientes com HSA com Hipertensãointracraniana refratária. Acreditamos que a hipotermia pode seja o melhor método para ser utilizado na presente situação clínica.

Apnéia do sono associada a obesidade: alguma influência na formação dos aneurismas cerebrais? / May sleep apnea associated with obesity play a role in brain aneurysm grouth?

Os autores selecionaram um grupo de pacientes com apnéia do sono e aneurismas cerebrais e procuraram correlacionar com casos de sobrepeso e obesidade, encontrando 80% de pacientes com obesidade do sexo feminino, com idades entre49 e 72 anos (média de 60,6 anos), todas submetidas a gastroplastia prévia, e tendo sido submetidas a repetidos regimes para emagrecer , com 60% de aneurismas rotos, todos Hunt-Hess entre III e V e Fisher 4 .. Aqueles com sobrepeso, idadeentre 53 e 70 anos ( média 60,5 anos), 50% tabagistas, 75%com aneurismas rotos, com gradação Hunt-Hess 3.3 em média,e Fisher de 3.3 em média. Concluir sobre a correlação é muito incipiente e mais estudos devem ser feitos neste sentido.

The authors have selected a group of patients with sleep apnea and brain aneurysms and sought to correlate with cases of overweight and obesity. They have found a high incidence of bleeding among those patients in both groups of obesity, most of them at computed tomography with Fisher score of III to IV,in patients with ruptured aneurysms (60% of rupture in severe obesity and 75% in overweight), and clinical status of Fisher I Vin obese patients and 3.3 in over weighed patients. Beyond any doubts, further studies should be accomplished to establish a strong correlation between associated obesity and sleep apnea and the patophysiology of brain aneurysms.