Abstract
Objective. Osteogenesis imperfecta is a connective tissue disorder that results from the inability to produce normal collagen. Eight types are described; type II is considered the lethal variant. Because of abnormal collagen production, these patients possess many anatomic and functional abnormalities. In addition to the obvious brittle bones, osteogenesis imperfecta patients may also possess respiratory, cardiac, spinal, endocrine, and hematologic abnormalities. These numerous derangements can lead to a challenging perioperative course. Case report. This report describes a case of a 27-year-old woman, G1P0 with history of type III osteogenesis imperfecta presenting at 31+ weeks with preterm premature rupture of membranes, lower extremity edema, and constipation. Because of progressive labor and cephalopelvic disproportion, an urgent cesarean section was performed under general anesthesia. Intraoperative coagulopathy was noted. After hemostasis was achieved, a colonic mass below the splenic flexure that measured 20 × 10 cm was revealed. General surgery was consulted intraoperatively, and a rectosigmoid resection was performed for a presumed colonic pseudo-obstruction. Patient tolerated the procedure well and was extubated at the completion of the case. The patient was discharged home on postoperative day 5. Clinical challenges. (a) Preoperative assessment of an osteogenesis imperfecta patient, (b) determination of anesthetic type, (c) management of hemorrhage/cardiovascular instability, and (d) management of hyperthermia. Conclusions. This case report illustrates that, with proper knowledge of this disease state, osteogenesis imperfecta patients can undergo a safe anesthetic during a potentially challenging combined cesarean section/colonic resection.
Case Report
History
A 27-year-old woman, G1P0 with history of type III osteogenesis imperfecta presented at 31+ weeks with preterm premature rupture of membranes, lower extremity edema, and constipation. The patient was contracting regularly, and chorioamnionitis was suspected. Antibiotics were subsequently initiated. Because of the patient’s cephalopelvic disproportion, a delivery plan consisting of a cesarean section was already in place. The premature rupture of membranes and regular contractions unresponsive to fluid therapy/tocolytics prompted the obstetricians to decide on an urgent cesarean section.
The patient possessed a history of numerous lower extremity fractures with subsequent surgical repair. She denied any other significant history. As well, she denied any previous mandibular issues/fractures. On physical exam, the patient weighed 36 kg and was 130 cm in height. The patient was able to flex and extend her neck in a limited fashion with a Mallampati class II airway. Her mandibular protrusion test was normal. Patient had poor dentition. Her back exam revealed fairly small interspaces and severe kyphoscoliosis. A general anesthetic was decided on because of the abnormal spinal anatomy, normal airway exam, and potential platelet dysfunction. The patient was brought to the operating room with 2 peripheral 18 gauge intravenous catheters. She was premedicated with famotidine, metaclopramide, and sodium citrate. A type and cross had been sent to the blood bank.
Surgery
The patient was placed supine on the operating room table. Although the patient possessed a normal airway exam, alternative airway devices in the form of a fiber-optic bronchoscope, video laryngoscope (glidescope), and intubating laryngeal mask airway were made available. The surgeons prepped and draped the patient in sterile fashion. A rapid sequence induction was performed with propofol and rocuronium. Cricoid pressure was applied. The patient was intubated uneventfully using direct laryngoscopy, and a 6.0 endotracheal tube was placed. Patient positioning was difficult because of her small and fragile stature. The arms were placed on the armboards in a flexed fashion, and the head and neck were kept in a neutral position. After confirmation of end tidal carbon dioxide, the obstetricians performed an expeditious cesarean delivery. The neonate, although breathing spontaneously, did appear to have a femur fracture and was taken to the neonatal intensive care unit. While attempting to repair the uterus, the obstetricians noted a colonic mass below the splenic flexure that measured 20 × 10 cm (Figures 1 and 2). General surgery was consulted intraoperatively and decided that a sigmoid colon resection with primary anastomosis was indicated. During the bowel resection, uterine atony was noted with subsequent uterine bleeding. Methergine and Hemabate were administered intramuscularly with mild improvement in uterine tone. Patient continued to hemorrhage losing a total of 1500 mL. An arterial line was attempted on both radial arteries but was repeatedly unsuccessful because of difficult patient anatomy. Venous samples were drawn to measure patient’s hemoglobin and coagulation status. A thromboelastogram was also sent to determine patient’s platelet function. The body temperature, measured by an esophageal temperature probe, was noted to be elevated at 38.7°C but stable. General surgery completed their sigmoid resection and the abdomen was closed. The patient was extubated uneventfully and brought to the recovery room.
Uterus and distended colon
Gross pathology: Resected colon
Postoperative Course
The patient received 2 units of packed red blood cells and 1 unit of fresh frozen plasma for a postoperative hemoglobin of 21% and a postoperative international normalized ratio of 1.5. The patient was provided with patient controlled analgesia and transitioned to oral pain medication. She resumed a normal diet on postoperative day 3 and was discharged home on postoperative day 5. No maternal orthopedic or dental injuries were noted. Her 6-week clinic follow-up was uneventful. The neonate spent 5 weeks in the neonatal intensive care unit and was discharged home with a diagnosis of osteogenesis imperfecta.
Discussion
Osteogenesis imperfecta is typically an autosomal dominant disease that occurs in approximately 1 out of 20 000 to 1 out of 60 000 live births. Eight types are described. Type II is the lethal variant. Type I, being the mildest variant, is what most parturients possess. Type III, which our patient possessed, is considered the progressive deforming variety that may first present with fractures and mild bone deformities at birth. It has a prevalence of 1 to 2/100 000. Fertility is usually preserved, and therefore these patients may present for delivery.1,4 Delivery is usually via a cesarean section because of pelvic deformities/fractures, cephalopelvic disproportion, and increased incidence of abnormal fetal presentation. Because of abnormal collagen synthesis, these patients typically present with orthopedic maladies. 2 These include osteoporosis, frequent fractures, joint and tendon laxity, cervical spine disease, small bowed limbs, a large head, and a short neck. Nonorthopedic organ involvement can include platelet dysfunction with an increased tendency to bleed, aortic and mitral valve dysfunction, hyperthyroidism, and temperature elevation. Malignant hyperthermia susceptibility secondary to osteogenesis imperfecta has never been consistently proven by muscle contracture or genetic testing.
Clinical Challenges
Preoperative assessment of an osteogenesis imperfecta patient
The initial workup of these patients should always include a thorough cardiac and pulmonary exam. An echocardiogram should be ordered to rule out valvular disease as aortic and mitral dysfunctions have been noted. If significant thoracic kyphosis is present, pulmonary function should be assessed. An airway exam should detail mandibular and cervical spine function/fragility. If excessive blood loss is expected, a thromboelastogram may be helpful in detecting preoperative qualitative platelet dysfunction. The presence of ultrasound may be useful in assessing neuraxial anatomy as well as assisting in vascular access.
Determination of general versus neuraxial anesthesia
Both uneventful general and neuraxial anesthetics are described for the obstetric osteogenesis imperfecta population. 5 This patient possessed significant lumbar scoliosis and narrow interspaces. As well, the qualitative function of the platelets was unknown. Because of these reasons, in addition to a normal airway exam, we elected for a general anesthetic. Although the airway exam was normal, rescue airway devices were made available. We attempted a very gentile direct laryngoscopy to as to avoid any mandibular trauma. Patient positioning was expectedly difficult, but the intubation was uneventful and atraumatic. When providing a general anesthetic for a patient with osteogenesis imperfecta, it is imperative to have multiple airway devices available as the airway can be difficult and fragile.
Management of hemorrhage/cardiovascular instability
Difficulty with hemostasis was noted during initiation of the bowel resection. We suspected that this was secondary to either uterine atony or platelet dysfunction. During this time, the patient also became hypotensive. We treated the atony with uterotonics (oxytocin and methylergonovine) and the hypotension with intravenous crystalloids and vasoconstrictors. We attempted to obtain a thromobelastogram to better study platelet function. Placement of a radial arterial line proved very difficult secondary to patient positioning. Hemorrhage with potential difficult vascular access should always be expected in these patients. Because of inability to obtain an arterial catheter, serial venous blood gases were drawn. In the future, when managing an osteogenesis imperfecta patient, it might be prudent to place an arterial line preoperatively or have an ultrasound present to assist in its placement.
Management of hyperthermia
Hyperthermia in osteogenesis imperfecta patients, resulting from central nervous dysfunction or excessive metabolism in bone, has been reported. 3 Our patient was also noted to be mildly hyperthermic to 39.0°C. This physiologic derangement was expected. We did not jump to a conclusion of malignant hyperthermia as no tachycardia or increase in end tidal carbon dioxide was noted. We instituted some mild cooling measures (setting the Bair Hugger [Arizant Healthcare Inc, Eden Prairie, MN] to ambient temperature) and the patient tolerated the anesthetic quite well suffering no adverse events.
Conclusions
Management of a gravid osteogenesis imperfecta patient during a complex surgery can present many anesthetic challenges. However, a detailed knowledge of the orthopedic, cardiovascular, pulmonary, and hematologic pathophysiology in these patients allows such a case to occur with minimal patient risk.
Footnotes
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
The author(s) received no financial support for the research, authorship, and/or publication of this article.