Anesthetic management in a patient with osteogenesis imperfecta for rush nail removal in femur.

Osteogenesis imperfecta (OI) is a rare genetically inherited syndrome involving connective tissues, resulting in anatomic and physiologic abnormalities, which results in any form of anesthesia, a challenging task. We hereby report a case of OI type I presented with distinctively blue sclera, hearing loss, kyphoscoliosis, and mild pulmonary restrictive disease who underwent rush nail removal in the femur.

INTRODUCTION

Osteogenesis imperfecta (OI), also known as brittle bone disease, is an inherited disease of connective tissue that affects bone, sclera, and inner ear, caused by the mutations of the collagen type I - COLIA 1 and COLIA 2 genes.[1]

According to SILLENCE classification, disease has been classified into four types.[2]

Type I (most common form) is inherited as an autosomal dominant fashion and is characterized by blue sclera, fragile bones, hyperextensible joints, progressive hearing loss, and dentinogenesis imperfecta. Type II is lethal either in utero or in the perinatal period. Type III and type IV both are inherited as an autosomal dominant fashion. In type III, patient usually dies in childhood or adolescence as consequence of cardiopulmonary complications; in type IV, patient has skeletal deformities without ocular, audiological, and dental abnormalities.[2]

The defect in skeletal growth is a result of lack of normal ossification of endochondral bone resulting in increased fragility of bones, hypermobile limbs, and kyphoscoliosis. In such disorder, anesthesiologists are challenged by difficult airway, short neck, risk of odontoaxial dislocation, cervical vertebra, mandible, and teeth fractures during laryngoscopy and intubation. These patients may also have cardiac valvular lesions, cor pulmonale, neurologic abnormalities, hyperhidrosis, cleft palate, metabolic abnormalities, malignant hyperthermia, obstructive uropathy following renal and ureteric stones platelet dysfunction.[1]

We report a case of anesthetic management of known case of OI type I who underwent a rush nail removal of femur.

CASE REPORT

A 15-year-old female presented in preanesthetic checkup clinic for rush nail removal of femur. She was a known case of OI type I and history of recurrent fractures for which she had been operated three times uneventfully under general anesthesia. There was no history of OI in the family.

On general examination, she was short statured with a height of 103 cm, weighing 49 kg, blue sclera, fragile bones, progressive hearing loss, kyphoscoliosis. Her blood pressure was 130/80 mmHg, and heart rate was 80 beats/min. There was no pallor, icterus, cyanosis, clubbing, lymphadenopathy, or pedal edema. Respiratory system revealed barrel-shaped chest with bilateral equal air entry, and cardiovascular system revealed normal heart sounds. Electrocardiogram (ECG), liver function test, renal function test, and coagulation profile were normal. Chest X-ray was normal except mediastinal widening; X-ray of the spine revealed dorsolumbar kyphoscoliosis to the left. Pulmonary function test was suggestive of mildly restrictive disease. Airway assessment showed acceptable flexion and extension at neck with adequate mouth opening and normal dentition, Mallampatti Class III. The patient was accepted for surgery as American Society of Anesthesiologists Grade III; in view odontoaxial dislocation and normal coagulation profile, we decided to proceed with a spinal anesthetic technique. Thorough operating room preparation was completed including difficult airway equipment, and measures made ready to deal with hyperthermias if any.

The patient was positioned very carefully on the operation table, and pressure points were padded adequately. An 18-gauge intravenous (i.v.) cannula was inserted on the dorsum of the right hand. Monitors including ECG, sphygmomanometer, and SpO2 were placed on the patient.

Her baseline blood pressure was 128/80 mmHg, heart rate was 90 beats/min, and O2 saturation on room air was 98%. An i.v. preload of 500 ml Ringer's lactate was administered. Despite the kyphoscoliosis, no difficulty was experienced in finding the subarachnoid space, and spinal anesthesia was given in the sitting position in the space L3–L4 space with 25-gauge Quincke needle with 2.5 ml of bupivacaine heavy 0.5%. The motor block was up to T 10 level. The operation lasted for 1 h and 45 min. There was no significant variation in the vitals, and the recovery was uneventful.

DISCUSSION

OI is a rare autosomal dominant inherited disease of connective tissue that affects bone, sclera, and inner ear. It affects 6–7 of 100,000 people and occurs in 1:20,000 births.[3]

Anesthetic management of OI is influenced by diversity of presentation, namely, coexisting orthopedic deformities, fragile bone prone for fractures at the time of positioning, platelet dysfunction, cardiovascular abnormalities such as mitral valve prolapse, tendency to develop malignant hyperthermia, anticipated difficult intubation because of abnormal cervical spine mobility, fragile teeth, odontoaxial dislocation, and risk of mandibular and facial fractures.[4]

There have been several case reports managing such cases under general anesthesia. Karabiyik et al. recommended total i.v. anesthesia along with intubating laryngeal mask airway (LMA)[4] while Malade et al. used balanced anesthesia in a case OI with gross deformity of the pelvis for abdominal hysterectomy.[5] Although Sahin et al. observed a significant degree of movement between the first and second cervical vertebra during direct laryngoscopy and with use of the intubating LMA.[6]

Epidural anesthesia has been reported in the patients with OI, and the use of spinal block is infrequent due to the difficulty in predicting the spread of local anesthetics. In our case, anatomic deformity was of higher degree; even then, we preferred spinal anesthesia so as to avoid the need of tracheal intubation. Moreover, kyphoscoliosis with pectus carinatum affects vital capacity along with chest compliance, resulting in ventilation-perfusion mismatch which eventually leads in arterial hypoxemia. Succinylcholine increases the risk of malignant hyperthermia; fasciculations can lead to fractures, and inhalational agents such as halothane also poses risk for malignant hyperthermia. Although general consensus is that hyperthermia in such cases is due to hypermetabolic state, it is not of the malignant type.

At least 50% of these patients also have increased levels of serum thyroxine levels. Regional anesthesia facilitates early detection of thyroid storm.

Automated blood pressure cuffs may be hazardous as overinflation may result in fracture, so either invasive blood pressure or manual sphygmomanometer should be used. Pressure points should be well padded. Thorough preoperative workup including patient coagulation profile and cardiorespiratory workup including electrocardiography, echocardiography, and pulmonary function tests is mandatory.

CONCLUSION

Patients with OI pose a significant challenge to anesthesiologist owing to difficult airway and associated multiple comorbidities; hence, in our opinion, meticulous workup of the patient with preferred regional anesthetic technique wherever permissible will have the favorable outcome of anesthesia in patients and appears to be a safe technique in the hand of a perfect vigilant anesthetist.

Blue sclera of the patient

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.