Definition Pneumorrhachis is the presence of air within the spinal canal (either in the intra- or extradural space). It is a rare phenomenon and is often asymptomatic. This condition was first reported in 1977 by Gordon et al. who used the term “pneumomyelogram” to describe air around the dura mater spinalis and has since been described by various terms in the literature (such as intraspinal pneumocele, spinal…
Definition Autonomic disturbances are disorders that affect the autonomic neurons of either or both the sympathetic and the parasympathetic nervous systems. Since the autonomic nervous system supplies almost every organ in the body, autonomic diseases influence localized organ function as well as integrated processes that control vital functions in the body such as arterial blood pressure and body temperature. The signs and symptoms present a wide…
Edema refers to abnormal, excessive accumulation of fluid in the cells, tissues, or body cavities. Brain edema results from excess accumulation of water in the extracellular and/or intracellular compartments of the brain. The brain is protected by a closed, rigid cranial cavity that contains brain tissue, cerebrospinal fluid (CSF), and intravascular blood. Any increase in either of its components is compensated by reduction or displacement of…
Definition Seizure activities are not only difficult to diagnose intraoperative in an anesthetized patient; they are also less recognized clinically, as compared to postoperative seizures in the intensive care unit. Seizure activity may be evident only in cases of incomplete muscle paralysis or use of electrocorticography (ECoG) in the intraoperative period. Postoperative seizures are, however, a well-recognized entity and defined as seizures with a short onset…
Definition Pneumocephalus is defined as an asymptomatic intracranial collection of air, commonly occurring after craniotomy or cranial burr hole. In a retrospective study, the incidence of intracranial air collection varied from 73% in park-bench position, 57% in prone position, and 100% in sitting position. Clinical data on the retrospective review of CT scans indicate that all patients have pneumocephalus in the first 2 days after a…
Definition Normal perfusion pressure breakthrough (NPPB) can be defined as the occurrence of multifocal areas of hemorrhage associated with unexplained cerebral edema after the resection of high-flow arteriovenous malformations (AVMs). Various theories have been proposed to explain the hemodynamic basis for this phenomenon. In 1978, Spetzler and colleagues first introduced the theory of NPPB. They suggested that hypoperfusion of the brain parenchyma surrounding an AVM (caused…
Definition Hydrocephalus (derived from Greek words hydros meaning water and cephalus meaning head) is defined as the excessive accumulation of cerebrospinal fluid (CSF) in the ventricular system and cisterns of the brain, leading to an increase in intracranial pressure (ICP) and its sequelae. Considering the hydrodynamics of the CSF, Rekate defined hydrocephalus as an active distension of the ventricular system of the brain resulting from inadequate…
Definition Emergence from general anesthesia is defined as the return of neuromuscular conduction, airway protective reflexes, and appropriate level of consciousness following discontinuation of anesthetic agents at the end of the surgery or intervention. Failure to regain the expected level of consciousness within 20–30 min of cessation of anesthetic agent administration is termed as delayed emergence. Time to emergence is variable and depends upon various patient…
Case Synopsis A 73-year-old woman with known severe mitral regurgitation and a permanent pacemaker is admitted to the surgical intensive care unit with urosepsis and refractory hypotension. Because of her lack of hemodynamic response to fluid boluses, a pulmonary artery catheter (PAC) is placed through her right internal jugular vein and advanced to 53 cm. The recorded pulmonary artery (PA) pressure is 90/30 mm Hg. The…
Overview Brain herniation is the displacement of brain tissue through the rigid dural folds (i.e., falx and tentorium) or skull openings (e.g., foramen magnum). Although patients with chronic brain herniation associated with developmental defects, such as Arnold–Chiari malformation, may remain asymptomatic for many years, acute brain herniation following neurosurgery is a catastrophic event that results in mechanical and vascular damage of the brain. In many circumstances,…
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Case Synopsis It is the first day of operation of the hospital’s new outpatient surgery wing. The anesthesiologist reports to work looking forward to a day of easy cases consisting of healthy American Society of Anesthesiologists class I outpatients. During the first case, however, a tiny chirp is heard, accompanied by an advisory stating that the oxygen (O 2 ) supply is low. Several seconds later,…
Case Synopsis A 76-year-old man is brought to the operating room emergently for open repair of a right ileac artery injury. The patient is placed on an under-body blanket that is connected to a properly functioning forced-air warming system, and the unit is turned on to the maximum setting (43°C). Postoperatively, the patient is noted to have partial- and full-thickness burns to the posteromedial aspect of…
Case Synopsis A 100-kg, 68-year-old man is anesthetized and intubated. Bilateral breath sounds are verified. The ventilator is turned on and set to a tidal volume of 600 mL, respiratory rate of 10, and inspiratory-expiratory ratio of 1:2. Two minutes later, the lowering tone of the pulse oximeter alerts the anesthesiologist, who notices an absence of chest wall movement. The ventilator appears to be cycling normally,…
Case Synopsis A 75-year-old man with metastatic non–small cell carcinoma of the lung is scheduled for bronchoscopic tumor ablation using laser, under general anesthesia. He has a chronic nonproductive cough, and a computed tomography scan reveals tumor encroachment on the right bronchus. Acknowledgment The author wishes to thank Dr. Pattricia Klarr for her contribution to the previous edition of this chapter. Problem Analysis Definition Improved technology,…
Case Synopsis A 35-year-old man weighing 90 kg undergoes mandibular fracture fixation. He receives total intravenous anesthesia with propofol and remifentanil infusion, oxygen, and air for 4 hours. Twenty minutes before the end of surgery the patient has a heart rate of 130 beats per minute and a blood pressure of 170/100 mm Hg. At the conclusion of the operation, he wakes up restless and combative…
Case Synopsis An 18-year-old man has open long bone fractures and severe traumatic brain injury due to a motor vehicle accident. His Glasgow Coma Scale score is 6, and a computed tomography scan of the head reveals diffuse cerebral edema. An intraventricular monitor reveals a pressure of 30 mm Hg. Treatment for increased intracranial pressure is initiated, and the patient is transferred to the operating room…
Case Synopsis Anesthesia induction has just been completed on a healthy 20-year-old man undergoing inguinal herniorrhaphy. Gas flows are set to 1 L/min of oxygen (O 2 ) and 2 L/min of nitrous oxide (N 2 O). The O 2 saturation begins to fall as the O 2 analyzer alarms ( Fig. 110.1 ). Actuating the O 2 flush valve resolves the problem temporarily. Problem Analysis…
Case Synopsis A 35-year-old man is brought to the operating room for an emergent awake tracheostomy after a gunshot wound to the face with facial and neck expanding hematomas. Chlorhexidine gluconate was used as antiseptic for the procedure, and the patient was draped with surgical towels while receiving 100% oxygen for preoxygenation. Acknowledgment The author wishes to thank Dr. Paul E. Kazanjian and Dr. Anthony R.…
Case Synopses Macroshock A 50-year-old man in good general health is undergoing laparoscopic cholecystectomy under general anesthesia. In the middle of the procedure, the anesthesiologist feels a tingle, and the patient develops ventricular fibrillation. Immediate resuscitation and defibrillation restore normal sinus rhythm. The case continues uneventfully after a faulty monitor is removed from service. Microshock In an adjacent room, a 60-year-old man with a temporary pacemaker…