By O. Barrack. College of Mount Saint Vincent.
In this situation the airway should remain secured until the edema resolves (usually in 2–3 days) buy 10 mg zocor otc quetiapine cholesterol levels. Fiberoptic endos- copy is a less stressful procedure and is better tolerated order zocor 10 mg with mastercard cholesterol free diet chart. When endoscopy reveals clear space around the larynx, and especially if laryngeal structures can be identi- fied as well as space between the endotracheal tube and glottic rim, extubation or change of the endotracheal tube can be considered. Effects on Renal Function The kidneys are vulnerable to injury in patients with serious burn injury. Ischemic injury may occur during the resuscitation phase because of hypovolemia and burn shock, especially if there is a delay in resuscitation. Peripheral edema may be so severe that compartment syndrome develops in extremities. Rhabdomyolysis may result in release of myoglobin when perfusion is restored by escharotomy. Myoglobin is toxic to kidneys and myoglobinuria should be treated with mannitol diuresis and alkalin- ization of the urine with bicarbonate. It is important to monitor urine color during resuscitation to check for development of myoglobinuria. For patients who have survived the resuscitation phase with renal function intact, overwhelming infection and sepsis also pose a threat to the kidneys. In these cases every effort must be made to preserve renal perfusion and oxygen delivery. In the preoperative evaluation it is important to review laboratory values to check renal function. PHARMACOLOGICAL CONSIDERATIONS Physiological and metabolic changes resulting from large burn injuries and their medical treatment may dramatically alter patients’ responses to drugs. Responses are altered by pharmacokinetic as well as pharmacodynamic determinants. At the very least, consid- eration of altered response may require deviation from usual dosages in order to avoid toxicity or decreased efficacy. At the other extreme, potentially lethal ef- fects of succinylcholine contraindicate the use of this drug for a limited period following large burn injuries. The complex nature of pathophysiological changes, interpatient variation in nature and extent of burns, as well as the dynamic nature of these changes during resuscitation and recovery make it difficult to formulate precise dosage guidelines for burn patients. Effective drug therapy in burn patients requires careful monitoring of effects and titration of dosage to the desired response. Anesthesia 117 The two phases of cardiovascular response to thermal injury affect pharma- cokinetic parameters in different ways. During the resuscitation phase, loss of fluid from the vascular space causes decreased cardiac output and perfusion of tissues including kidney and liver where much drug elimination takes place. Decreased cardiac output will accelerate the rate of alveolar accumulation of inhalation agents and can result in exaggerated hypotension during induction of general anesthesia. Volume resuscitation during this phase dilutes plasma proteins and expands the extravascular space especially, but not exclusively, around the burn injury itself. These changes tend to increase sensitivity and prolong the action of many drugs during the first 1–2 days postinjury. From 2 to 3 days after burn injury, a hypermetabolic and hyperdynamic circulatory phase is established that has different effects on pharmacokinetic vari- ables and drug responses compared with the resuscitation phase. During this phase increased body temperature, oxygen consumption, and cardiac output are associated with increased perfusion of liver and kidney and increased activity of some drug-metabolizing enzymes. During this phase clearance of some drugs is increased to the point that increased dosages are required. This can affect drug response because many anesthetic drugs are highly protein-bound. For highly protein-bound drugs, drug action and elimination are often related to the unbound fraction of the drug available for receptor interaction, glomerular filtration, or enzymatic metabolism.
In contrast with fibrous liferates in the medulla of bone and also attacks the corti- dyplasia cheap 20mg zocor fast delivery cholesterol levels normal range mmol/l, there is a probable risk of tumor propagation buy zocor 40mg cheap cholesterol check up fasting. Histologically the polyostotic and monostotic forms are identical ( Chapter 4. The condi- The Maffucci syndrome is a condition with unilaterally tion involves mosaic change in the genetic sturcture with occurring enchondromas (as in Ollier disease), combined differing degrees of penetrance. The manifestation of the The disease was described by Maffucci in 1881. Both sexes inherited, because if all cells are affected by the genetic are equally affected. The hemangiomas are already present at birth and The following are distinguished: occur principally at subcutaneous level, enabling a diag- monostotic form ( Chapter 4. A recent investigation has polyostotic form, provided evidence to indicate the presence of numerous McCune-Albright syndrome (polyostotic fibrous dys- nerve fibers and the secretion of large quantities of mito- plasia, pigmentations of the skin, hormonal disorders genic neurotransmitters in the vicinity of the hemangio- with precocious puberty). These neurotransmitters play a role in the pathogen- esis of the disease. The enchondromas in Maffucci While the various forms of fibrous dysplasia are rare, the syndrome, and thus the orthopaedic problems as well, are monostotic type in particular often involves no clinical signs similar to those in Ollier disease, as is the risk of their ma- and symptoms. As a result, a relatively large number of cases lignant degeneration, for which a figure of 23% has been remain unreported. By contrast, the risk of degeneration of the in Great Britain has been calculated for the polyostotic form hemangiomas or hemangioendotheliomas is very low. Females are slightly more frequently affected (Polyostotic) fibrous dysplasia, Albright syndrome than males. The McCune-Albright syndrome is extremely rare (less than 5% of all cases of fibrous dysplasia). The congenital developmental disorder progresses slowly These lesions increase in size as the patient grows. The as the child grows and normally comes to a halt on condition can affect a single or multiple bones and, very completion of growth. The condition is usually diagnosed rarely, is associated with endocrine abnormalities such as during the first decade, although often not until the sec- precocious puberty, premature physeal closure and hy- ond decade. When associated with hormonal disorders but most commonly affect the proximal metaphysis of the condition is known as Albright syndrome. Several lesions can also occur dystrophia fibrosa, osteitis fibrosa disseminata, Mc- simultaneously in one bone. The condition progresses Cune-Albright syndrome, Jaffé-Lichtenstein disease asymptomatically unless a pathological fracture occurs or bowing is outwardly visible (⊡ Fig. Historical background Bowing particularly affects the proximal femur, where the Polyostotic fibrous dysplasia was first described by Lich- soft bone can bend into the shape of a »shepherd’s crook« tenstein in 1938. Clinically relevant leg length discrepancies merged the polyostotic and monostotic forms under can also occur. The osteolytic areas, the cortex is thin and bulges out, usually individual lesions are generally asymptomatic and do the whole bone is widened and the basic structure shows a not require treatment. Only if symptoms, fractures or ground glass opacity in the osteolytic zones. This ground pronounced bowing occurs are therapeutic measures in- glass pattern is attributable to the formation of new bone. A suitable Osteolytic and sclerotic components appear next to each solution for stabilization is an intramedullary load-bear- other. The cortical bone is eroded and the bone is wid- ing implant in the area of the femoral neck, or so-called ened as a result of new periosteal bone formation. Mi- »Y nail« or Gamma-nail (also known as a »Zickel nail«) crofractures also occur and can lead to painful episodes. In children with open epiphyseal plates tively signal-rich in both the T1- and T2-weighted images, the new telescopic Gamma-nail can be used (⊡ Fig, 4. In the McCune-Albright syndrome the polyostotic fi- If doubt exists, the diagnosis must be confirmed by bi- brous dysplasia is accompanied by abnormal skin pigmen- opsy before such a radical measures is undertaken. Since tations that resemble the café-au-lait spots in neurofibro- fracture and osteotomy healing is not usually impaired, matosis.
Hemiplegics generally are afﬂicted by equinus of the hindfoot and occasionally equinovarus or equinovalgus zocor 20mg low price cholesterol tea. Most recently botulinum toxin and tone reducing medications have been found effective in reducing tone in spasticity and can be helpful in delaying surgical treatment order zocor 40mg on line cholesterol medication fatigue. The effects are not permanent and the overall average time of effectiveness of botulinum toxin is roughly eighteen months. Diplegics are more severely involved and usually have hindfoot equinovarus or equinovalgus, knee ﬂexion deformity or contracture, hip ﬂexion, adduction and internal rotation deformity, and occasionally hip subluxation and dislocation. In the hemiplegic, the upper extremity 125 Myelomeningocele commonly will have pronation and ﬂexion at the wrist, digital ﬂexion, and “thumb-in-palm” ﬂexion deformity. It is important that the pediatric orthopedic surgeon be an integral part of the overall team management of patients with cerebral palsy, particularly of the spastic type. It is recommended that appropriate orthopedic referral is obtained once the diagnosis is ﬁrmly established, particularly in spastic cerebral palsy. Myelomeningocele (myelodysplasia) Myelomeningocele is characterized by a failure of fusion between the developing vertebral body arches with subsequent dysplasia of the spinal cord and membranes. Experimentally, myelomeningocele can be produced by preventing closure of the neural tube, or by causing a rupture of the tube once it has already closed. There is a substantial incidence of appearance of the defect in subsequent offspring. Two recent advances, namely prenatal ultrasound to deﬁne the fetal spine and serum analysis to determine the presence of levels of alphafetoprotein, have facilitated antenatal diagnosis. Currently folic acid supplemental treatment is recommended in women of child-bearing age and early in pregnancy and has dramatically helped in reducing the incidence. As with cerebral palsy, the multisystem involvement of a child with myelomeningocele necessitates a medical and allied health team to optimize habilitation. The neural defect results in muscle paresis and paralysis, and the muscle imbalance leads to bone and joint deformity. Many youngsters will require surgical intervention at the soft tissue and bony level to facilitate standing or walking. Orthopedic involvement should be obtained early to assist in the management of deformities relative to neuromuscular imbalance. Scoliosis of Miscellaneous disorders 126 signiﬁcant magnitude is commonly seen. Higher neurologic levels (T12, L1) usually render the patient wheelchair bound, where skin problems (decubitus), osteopenia, and scoliosis dominate. The most important prognostic factor related to the ability to walk is the neurologic level. In lower levels, compatible with some form of ambulation (independent or assisted ambulation), soft tissue contractures, and osseous deformity may require surgical attention. Hip dislocation has not been deﬁnitively shown to be a signiﬁcant deterrent to ambulation, particularly if bilateral. Orthotics are utilized in most patients, with patients functioning at the lower lumbar and upper sacral levels requiring the simplest and least bracing. The presence of knee extension usually implies that only short leg bracing, at the most, will be necessary. As a consequence of osteopenia (neurologic and disuse), fractures are common and decubitus ulcers can occur secondary to insensate tissue. Loss of continued ambulation in later years seems directly linked to excessive body weight. Inasmuch as nearly all myelomeningocele patients will require periodic orthopedic, neurosurgical and urologic care as they grow, early referral is suggested from the primary care standpoint. Optimally the primary care physician should be the central coordinator of the health care team. Sprengel’s deformity Congenital elevation of the scapula, or Sprengel’s deformity, is a condition in which the scapula rests at a level much higher in the superior posterior thorax than normal. Its elevated position is believed to be the result of an error in development. The scapula, after forming in the ﬁfth post-conception week, gradually descends from its original location opposite the ﬁfth cervical vertebra to its adult position.
Treatment is well within the domain of the primary care physician zocor 40 mg free shipping high cholesterol foods bacon, with orthopedic referral reserved for those cases failing conservative regimens discount 20 mg zocor with mastercard high cholesterol medication grapefruit. Adolescence and puberty 100 Calcaneal apophysitis (Sever’s disease) Calcaneal apophysitis is the most common cause of heel pain in adolescents and teenagers. Although previously thought to be an osteochondritis, it is clearly a mechanical pain syndrome more closely related to a tendinitis with a self-limited benign prognosis. As the calcaneal apophysis begins to progressively ossify at the time of adolescence, it commonly arises from more than one center of ossiﬁcation and presents as a very dense radiographic pattern not unlike that seen in other osteochondritic processes (Figure 5. Lateral radiograph of the foot demonstrating normal irregular increased density seen on the radiograph, it ossiﬁcation and sclerosis within the calcaneal apophysis. The classicsite of discomfortonmedial lateral compression of the heel in calcaneal apophysitis. The youngsters in this age group will complain of pain in their heel, particularly with mechanical activities. The most characteristic distinguishing feature on physical examination is exquisite pain produced on medial and lateral compression of the heel at the site where the calcaneal apophysis attaches to the main body of the calcaneus (Figure 5. This pain is not on plantar pressure, or posterior or retrocalcaneal pressure, but on medial and lateral compression. The symptoms resolve once the calcaneal apophysis amalgamates with the main body of the calcaneus. A simple in-shoe orthotic, consisting of a soft material covered by leather that will slightly raise the heel and cushion the impact of weight bearing, will generally result in pain relief within six weeks to three months. The elevated pad also tends to relax the gastroc-soleus complex and releases tension on the calcaneal apophysis. The author’s personal preference is for a sponge-ﬁlled, leather-covered compressible heel pad that compresses down to ﬁve-eighths of an inch and is transferable into alternative shoe wear. In less than 10 percent of cases, a short leg plantar ﬂexion cast, worn for three to four weeks, may be necessary. Properly recognized, this condition can often be managed by primary care physicians. In roughly two percent of all adults the accessory navicular persists as a complete and separate ossicle unattached to the ossiﬁed navicular and embedded in the substance of the posterior tibial tendon. The etiology of the syndrome seen in adolescence and puberty is directly related to a chronic posterior tibial tendinitis occurring in association with an accessory navicular (Figures 5. Not uncommonly a very prominent medial “cornuate-shaped” navicular may produce similar posterior tibial (b) tendinitis in the absence of any ossiﬁed Figure 5. The pain is clearly mechanical in nature and generally resolves with rest. On examination, a medial prominence is encountered at the site of the proximal medial portion of the navicular, with tenderness commonly seen along the posterior tibial tendon as it reaches its insertion onto the navicular. When pressure is applied to the plantar-medial portion of the bony prominence, exquisite pain is elicited, mimicking the patient’s symptoms (Figure 5. Adolescence and puberty 102 It was originally thought that the discomfort occurred because of a marked pronovalgus (ﬂatfoot) deformity accompanying the accessory navicular. The pain was thought to arise from chronic pressure due to ﬂattening of the longitudinal arch in the presence of a weak posterior tibial tendon. This explanation is untenable in light of the fact that the majority of patients with this condition do not have signiﬁcant pronovalgus feet. It is likely that fewer than half of the patients with this accessory ossicle have sufﬁcient pain to seek medical attention. Treatment initially should be conservative in nature and consist of a sponge-ﬁlled long arch orthotic that can be transferred from shoe to shoe in conjunction with anti-inﬂammatories and physiotherapy modalities. Although cortisone injections have been utilized, they are not commonly Figure 5. The location of point tenderness in posterior tibial tendinitis successful, are extremely painful, and carry a associated with an accessory navicular bone.