First ICP measurements136,191,192 resulted from the adaptation of the intravascular Camino sensor (Camino Laboratories, San Diego, California) originally proposed by Lekholm and Lindström.40,45 Camino model 110-4B was considered to be accurate and reliable for ICP monitoring, presenting high-quality readings under laboratory and clinical conditions, a good correlation with SG sensors and fluid-filled systems, less drift and improved waveform resolution, insensitivity to hydrostatic artifacts and no flushing or infusion requirements.101,102,104,112,193,194 On the other hand, they also underwent extensive scrutiny leading to identification of several drawbacks and questioning their routine use, particularly in clinical practice. Transducer failures (e.g., breakage, cable kinking, probe dislocation, abnormal readings, etc.) may range from 10% to 25%.107 In the study of Yablon et al.,102 12% of sensors failures were caused by breakage of its components. Moreover, contamination of the probes is frequent and long-term monitoring seems to be associated with higher rates of infection.106 Yet clinically significant infections were considered to be rare.106 To minimize infections and zero drift of the transducer the manufacturer recommends placement of a new system under sterile conditions if monitoring is continued for more than five days.99 Several studies have addressed the drift characteristics of the transducer either in laboratory104 or clinical practice.101,106,107 Zero drift is an important feature because this type of transducers cannot be re-zeroed after implantation, meaning that cumulative significant errors may occur in long-term monitoring.101,106 Electrical calibration of external monitors is possible, but it cannot correct for inherent zero drift of the catheter once it is implanted.107 Manufacturers’ specifications for model 110-4B indicate a maximum zero drift during the first 24 h from 0 to and less than on subsequent days.99 Thus a continuous five-day monitoring can introduce a maximum error of 6 mmHg. This is not satisfactory because normal values for ICP usually range from 7 to 15 mmHg in adults and from 3 to 7 mmHg in children.109 Furthermore, values exceeding 20 mmHg require immediate treatment.195 Laboratory tests have indicated the transducer complied with manufacturers’ zero drift specifications, while results from clinical practice have suggested zero drift can be greater than reference values. As an example, Crutchfield et al.101 found a larger maximum daily drift of , a lesser average daily drift of and an average drift over a five-day period of . Münch et al.105 reported an average daily drift within reference values but after being removed from the patient it was for 50% of the probes. This value was normalized to the number of days of monitoring and decreased to only 6%.105 Martinez-Manas et al.106 reported only six of 56 implanted probes exhibited no zero drift, while the other readings ranged from a minimum of and a maximum of . After comparing their results with manufacturer’s specifications, they conclude that 61% of the probes performed according to the expected values. It is interesting to note that no correlation was found between zero drift and the duration of monitoring.106,107 Sensitivity to temperature remains a problem. A maximum of 3 mmHg over a temperature range of 22°C to 38°C is reported by the manufacturer.99 However, in the study of Czosnyka et al.104 temperature drift was leading to a maximum of 4.8 mmHg for the same temperature range.