Medical Image of the Week: Pneumocephalus

Figure 1. Coronal CT Scan Image (Brain Lab Protocol) showing air in continuity with the frontal sinuses where there is no bone between the frontal sinus and the brain.

A 53-year-old woman underwent left craniotomy at an outside hospital after a trauma related to a motor vehicle accident. She was recovering well from her surgery. Two months later she started having headache and noticed progressive difficulty with word finding. She also reported periodic rhinorrhea upon further questioning. She presented to the emergency room at an outside hospital where a CT head was done. She was subsequently transferred to our ICU for higher level of care. Her CT Head revealed pneumocephalus involving the left frontal lobe along with regional mass effect leading to left to right shift of the anterior interhemispheric fissure. A dedicated brain lab protocol showed air in continuity with the frontal sinuses with a bone defect between the frontal sinus and the brain. She was evaluated by ENT and Neurosurgery services. She was placed on 100% oxygen via non-rebreather mask, frequent neuro-checks and a redo of the left frontal craniotomy for repair of the skull base defect was performed.

Administration of postsurgical supplemental oxygen through a non-rebreather mask has shown to significantly increase the absorption rate of postcraniotomy pneumocephalus as compared with breathing room air (1). In a prospective study of thirteen patients with postoperative pneumocephalus that was estimated to be > 30 ml were alternately assigned to breathe 100% oxygen using a nonrebreather mask (treatment group) or to breathe room air (control group) for 24 hours. There was a significant difference (p = 0.009) between the mean rate of pneumocephalus volume reduction in the treatment (65%) and control groups (31%) per 24 hours.

Tauseef Afaq Siddiqi MD, Enas M. Al Zaghal MD, and Sairam Parthasarathy MD

Division of Pulmonary, Allergy, Critical Care and Sleep Medicine

The University of Arizona

Tucson, AZ

Reference

1. Gore PA, Maan H, Chang S, Pitt AM, Spetzler RF, Nakaji P. Normobaric oxygen therapy strategies in the treatment of postcraniotomy pneumocephalus. J Neurosurg. 2008;108(5):926-9. [CrossRef] [PubMed] 

Reference as: Siddiqi TA, Zaghal EM, Parthasarathy S. Medical image of the week: pneumocepahlus. Southwest J Pulm Crit Care. 2014;9(1):57-8. doi: http://dx.doi.org/10.13175/swjpcc095-14 PDF

Medical Image Of The Week: Septic Pulmonary Emboli Misdiagnosed As Metastatic Disease

Figure 1. Representative thoracic CT axial images showing multiple pulmonary nodules (red arrows).

A 54-year-old previously healthy man presented with acute onset of left-sided, sharp pleuritic chest pain and dry cough. He denied having fever, hemoptysis, shortness of breath, or unintentional weight loss. Review of system was positive for bright blood per rectum for the last year. He had a root canal procedure done 3 weeks prior to presentation. His is a 30 pack-year smoker, drinks alcohol occasionally, but denied any IV drug use.

On admission, he was afebrile and hemodynamically stable. Clinical examination was positive for fecal occult blood test. CBC revealed WBC of 12,800/mm³ and his hemoglobin was11.9 g/dL. Thoracic CT scan with contrast was negative for pulmonary embolism, but showed multiple bilateral pulmonary nodules suspicious for malignancy (Figure 1). The left upper lobe showed a subpleural 2.4 x 1.5 cm rounded opacity and emphysematous changes. CT of the abdomen and pelvis showed folds in the stomach but was otherwise unremarkable.

Esophagogastroduodenoscopy was negative. Colonoscopy showed non-bleeding internal hemorrhoids. He underwent percutaneous CT guided lung biopsy. Pathology report showed distended alveoli filled with polymorphonuclear leukocytes mixed with fibrin consistent with septic emboli and no evidence of malignancy.  Special stains for organisms were negative. Blood cultures were negative, Trans-esophageal echocardiograph was normal. Mandibular film done was negative for dental abscess. HIV serology, Quantiferon gold, ß-d glucan, Aspergillus, and mycobacterial culture of sputum were negative. During his hospital stay he developed a fever and his WBC count increased. He was empirically started on broad spectrum antibiotics and he clinically improved significantly.

Septic pulmonary embolus (SPE) is a serious and uncommon condition that poses a diagnostic challenge and carries a high mortality (1,2). Presenting symptoms are often non-specific. Blood cultures may be negative initially. Similarly, chest radiography is not helpful to establish a diagnosis. CT is more useful, usually showing multiple peripheral nodular opacities. SPE can be suspected by the presence of potential source of underlying infection, febrile illness and multiple pulmonary nodules.

Dima Dandachi MD and Sathish Krishnan MD

Department of Internal Medicine

Saint Francis Hospital

Evanston, IL

References

1. Ye R, Zhao L, Wang C, Wu X, Yan H. Clinical characteristics of septic pulmonary embolism in adults: a systematic review. Respir Med 2014;108(1):1-8. [CrossRef] [PubMed]
2. Shiota Y, Taniguchi A, Yuzurio S, Horita N, Hosokawa S, Watanabe Y, Tohmori H, Ono T; Okayama Respiratory Disease Study Group. Septic pulmonary embolism induced by dental infection. Acta Med Okayama. 2013;67(4):253-8. [PubMed] 

Reference as: Dandachi D, Krishnan S. Medical image of the week: septic pulmonary emboli misdiagnosed as metastatic disease. Southwest J Pulm Crit Care. 2014;9(1):38-9. doi: http://dx.doi.org/10.13175/swjpcc083-14 PDF