Regulation of hypnosis in Propofol anesthesia administration based on non-linear control strategy / Controle da hipnose na administração de propofol com base na estratégia de controle não linear

Abstract Continuous adjustment of Propofol in manual delivery of anesthesia for conducting a surgical procedure overburdens the workload of an anesthetist who is working in a multi-tasking scenario. Going beyond manual administration and Target Controlled Infusion, closed-loop control of Propofol infusion has the potential to offer several benefits in terms of handling perturbations and reducing the effect of inter-patient variability. This paper proposes a closed-loop automated drug administration approach to control Depth Of Hypnosis in anesthesia. In contrast with most of the existing research on anesthesia control which makes use of linear control strategies or their improved variants, the novelty of the present research lies in applying robust control strategy i.e. Sliding Mode Control to accurately control drug infusion. Based on the derived patient's model, the designed controller uses measurements from EEG to regulate DOH on Bispectral Index by controlling infusion rate of Propofol. The performance of the controller is investigated and characterized with real dataset of 8 patients undergoing surgery. Results of this in silico study indicate that for all the patients, with 0% overshoot observed, the steady state error lies in between ±5. Clinically, this implies that in all the cases, without any overdose, the controller maintains the desired DOH level for smooth conduction of surgical procedures.

Resumo O ajuste contínuo de propofol na administração manual de anestesia para um procedimento cirúrgico onera a carga de trabalho de anestesistas que trabalham em ambiente multitarefa. Indo além da administração manual e da infusão alvo-controlada (IAC), o controle de circuito fechado da infusão de propofol tem o potencial de oferecer vários benefícios em termos de manejo das perturbações e reduzir o efeito da variabilidade interpaciente. Este artigo propõe uma abordagem para a administração automatizada de drogas em circuito fechado para controlar a profundidade da hipnose (PDH) em anestesia. Em contraste com a maioria das pesquisas existentes sobre o controle da anestesia que usam estratégias de controle linear ou de suas variantes melhoradas, a novidade da presente pesquisa reside na aplicação de uma estratégia de controle consistente; isto é, o Controle por Modos Deslizantes (CMD) para controlar com precisão a infusão da droga. Com base no modelo derivado do paciente, o controlador projetado usa as medições do EEG para regular a PDH no Bispectral Index (BIS), controla a taxa de infusão de propofol. O desempenho do controlador é investigado e caracterizado com um conjunto de dados reais de oito pacientes submetidos à cirurgia. Os resultados deste estudo in silico indicam que, para todos os pacientes, com 0% de excesso observado, o erro de estado estacionário fica entre ± 5. Clinicamente, isso implica que em todos os casos, sem qualquer sobredosagem, o controlador mantém o nível desejado de PDH para a condução tranquila dos procedimentos cirúrgicos.

Surgical evacuation extradural hematoma under local anesthesia

Extradural hematoma as a result of traumatic injury is a serious neurological emergency that required immediate intervention. The standard protocol is to identify the condition at earliest and provide quick surgical evacuation of the hematoma. The situation tends to be fatally deteriorating and marks a high mortality rate and worse health outcomes. We have presented a case of extradural hematoma in this study where the surgery had a delay due to the unavailability of general anesthesia. However, the falling Glasgow Coma Scale scores encouraged the surgeons to induce the surgical procedure with the employment of local anesthesia. The intervention turned out to be successful and produced the possibility of using local anesthesia as an alternative in case of critical emergency situations in order to save a life

Acute sub dural hematoma with extra dural hematoma evacuation in ventricular septal defect patient using conventional craniotomy under local anesthesia following peer regimen

Background: extradural hematoma [EDH], and acute subdural hematoma [ASDH] are common pathologies encountered in neurosurgical emergencies following traumatic injuries usually secondary to road traffic accident, assault and fall. Both extradural hematoma and acute subdural hematoma have dreadful effects on patient's health if not managed properly and timely and even lead to death. The standard treatment for such problems is conventional large craniotomy under general anesthesia to prevent fatal outcomes

Method: we have presented a case of ASDH with EDH in a patient having history of large ventricular septal defect and due to large ventricular septal defect patient had delay in getting fitness and alongside patient had fallen Glasgow Coma Scale [GCS] which encouraged surgeon to perform the surgery under local anesthesia by following Peer Regimen

Results: the outcome of case turned fruitful and providing possibility of Local anesthesia [Peer Regimen] as an alternate in case of critical emergency to save life of patient

Conclusion: acute Subdural hematoma with either concomitant ventricular septal defect or alone can evacuated safely under local anesthesia using Peer regimen. Further studies should be carried to know the more benefits of procedure and potential hazards of procedure and to improve outcome from this lethal type of brain injury

Pattern of complications and presenting features in patients implanted ventriculoperitoneal shunt due to hydrocephalus

OBJECTIVE: This study is conducted to document the major complications and presenting features of ventriculoperitoneal shunt

STUDY DESIGN: Prospective observational

SETTING: Department of Neurosurgery Isra University Hospital Hyderabad over a period of two years from January 2009 to December 2011

METHODOLOGY: 40 Children of either gender under the age of 12 years presented with signs and symptoms of shunt malfunction, that passed either for communicating or noncommunicating hydrocephalus, were enrolled. All patients after the admission underwent a complete clinical assessment including a detailed history and examination with particular emphasis on neurological examination. On the basis of clinical findings and investigations a final diagnosis was made and treatment in individual cases was planned accordingly. Data was analyzed by using the statistical package of social sciences [SPSS] version 16. Descriptive statistics were presented as frequency and percentages

RESULTS: Among total of 40 patients, majority were males [52.5%]. Most of the patients were under the age of one year [52.5%] and majority developed complication in the first 3 months after VP shunt insertion [35%]. Poor feeding [50%], nausea and vomiting [45%], Bulging fontanallae [45%], and dilated scalp veins [40%] were the most common presenting complaints observed. Most common complication of VP shunt was obstruction of shunt [52.5%]

CONCLUSION: A shunt implantation should be considered as a major operation, carried out by a senior neurosurgeon experienced in shunt insertion, with maximum vigilance to prevent infection and mechanical complications

Surgical outcomes of lumber discectomy in patients with and without degenerative spinal lesions

Objective: To compare the outcomes of conventional open lumbar discectomy on lumbar prolapsed intervertebral disc in relation to the presence or absence of degenerative spinal lesions

Study Design: Observational descriptive study

Patients and Methods: A total of 60 patients were included in the study having prolapsed intervertebral disc, divided into two groups. In group A, 30 patients having simple prolapsed intervertebral disc with radiculopathy with or without neurological deficit, while in group B 30 patients having prolapsed intervertebral disc and degenerative spinal lesion diagnosed on radiographs. MRI was main tool of investigation/ diagnosis in both groups. Surgical procedure hemilaminectomy and discectomy was done at the involved interspace on the appropriate side

Results: In group A, 19 patients were male and 11 patients were female while in group B, 22 patients were male and 8 patients were female. Twenty-seven patients [90%] in group A show good to excellent relief i.e. they are either completely pain free [23 patients] or had residual minor pain [4 patients], while 10% of patients shows little or no improvement. In group B, 76.6% of patients shows good to excellent improvement i.e. they are either completely pain free [19 patients] or had residual minor pain [4 patients], while only 7 patients remained either same or shows little improvement [p=0.29]